Sendy Audio Apollo
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TLDR -
This is a headphone with superb all-day comfort and an attractive design suitable for lovers of a rich, V-shaped sound with zero midrange intensity.
Introduction –
Sendy Audio is a sub-brand of Sivga, yet ironically may be better known in the international market. This is for their highly successful Aiva planar magnetic headphone, which quickly won over the hearts of critics and consumers alike, cementing a solid reputation for the relatively new company. The brand has since released a good selection of headphones with varying tunings and targets. The Phoenix was a warm yet relatively well-balanced dynamic driver model at a low price point and the recently released Peacock was their all-out attempt at making a flagship planar magnetic headphone. The new Apollo lies somewhere in-between. It assumes the quad-former driver tech pioneered by the flagship and brings the price point down to mid-fi levels making it far more accessible for most buyers. It targets a rich, engaging sound and high efficiency, representing the next chapter in Sendy’s headphone designs.
The Apollo is available for $499 USD. You can read all about it on Sendy Audio’s website here!
Disclaimer –
I would like to thank Collin from Sivga/Sendy Audio very much for his quick communication and for reaching out to organise a review of the Apollo. All words are my own and there is no monetary incentive for a positive review. Despite receiving the headphones free of cost, I will attempt to be as objective as possible in my evaluation.
Specifications –
Behind the Design –
QUAD-FORMER Driver
Image provided by Sendy Audio
First seen on the flagship Peacock, the Apollo also uses a derivative of the company’s quad-former technology. This encompasses a modified planar magnetic driver. This starts with a double-sided magnet design but is further expanded upon with double-sided dual voice coils, meaning there are 4 on each driver. The company reasons this provides improved efficiency in addition to more uniform force distribution over the diaphragm surface resulting in lower distortion.
Premium Housings
The Apollo is made from rosewood that has been carved using CNC, sanded, polished, painted and dyed for an immaculate finish. Furthermore, it sports tough steel grills forming a low resonance, high-damping acoustic environment for the 68mm planar driver. The company spent 3 years developing this design and driver to work in tandem to provide their desired sound.
Unboxing –
Overall, the unboxing experience is highly similar to Phoenix which sets the tone for much of my following impressions. The Apollo comes in a hard box with simple print on the front and back. Opening the lid reveals a nice moulded carrying case within a foam inlet as seen on the Phoenix. Inside are the headphones alongside a hessian pouch containing the cable and a 4.4mm to 3.5mm adaptor – a nice touch. It’s a considerate unboxing that has everything required to get the user started. I am especially a fan of the carrying case for its modest dimensions and snug fit with the headphone. In addition, as the sliders simply move the strap within the metal spring, the headphones fit into the case no matter what position they are set to.
Design –
Glancing the Apollo and you’ll see a clear family resemblance to the Phoenix and flagship Peacock. All employ a very similar base chassis with round grills, articulating hangers and a low-profile suspension headband. The Apollo has a unique flared design that, alongside CNC milled cherrywood earcups, gives it heaps of personality. I am personally a fan of matte/raw wood finishes, though arguably the lacquering here does provide better contrast to its matte features otherwise. It also provides some contrast to the Phoenix which has an inverted texture palette. As a result, the faceplates tend to draw focus with their gradient-inducing curve framed by moody satin black. It’s an attractive headphone with reasonable dimensions that will appeal to those that find most full-size open-back headphones intimidating.
Below are dual 3.5mm mono connectors similar to what you’d see on Hifiman and Meze’s 99 headphones. They exit at an angle to prevent the cable from contacting the wearer’s shoulders during listening. The stock cable impresses with its quality representing a huge step up from the Phoenix’s. It’s a 4-wire braided unit with 6N OCC conductors and a two-tone smoke/clear jacket that complements the housings beautifully. The jacket is soft with minimal memory or microphonic noise transmission making it a pleasure to live with day-to-day. This is aided by knurled metal connectors that are easy to handle and decent strain relief at each termination. I appreciate that the company decided to terminate the cable in balanced 4.4mm as you can always use a single-ended adaptor to convert a balanced cable but not vice versa.
Fit & Comfort –
Given the abundant similarities between Sendy/Sivga’s line-up, I feel these products should contextualise my experience here. To elucidate, I did not have a fantastic ergonomic experience on the Phoenix as I found its small, shallow pads to form hotspots over time. The same cannot be said for the Apollo which thankfully, represents a total transformation in terms of wearing comfort despite the visual similarities. The headband offers a similar experience to before being low-profile yet comfortably conforming to the head. Though the padding is light, the soft goatskin strap combined with the relatively light 395g total weight of the headphones means hotspots on the top of the head shouldn’t be an issue. Compared to the Phoenix, you have a slightly larger range of adjustment too, though I did find myself maxing out the slider so these may not be the best choice for those with a large or tall head. As always, let your experience with other headphones dictate your judgement here.
The earpads are the main improvement, that said, benefitting from substantial enlargement in all dimensions. Their tapered design means the company was able to give them a huge surface area and internal dimension without overly enlarging the headphone shells themselves. With super soft memory foam stuffing, the pads conform beautifully to individual head shape and spread the clamp force wonderfully. Their large aperture and depth meant my ears didn’t contact the drivers at all, providing perfect long term comfort. Perhaps the only area of complaint here is that they have a faux leather complexion which may not wear as well as authentic leather. They also aren’t especially breathable but are easily replaced as they are secured only by a twist lock. Isolation is minimal as expected for an open-back design meaning these are best reserved for home listening.
Sound –
Tonality –
The Apollo has an interesting frequency response and is reminiscent of older Audeze models with a dark, laid-back character through the midrange. Combined with broadly elevated bass and treble ranges, this provides a clearly V-shaped signature. Where it differentiates itself is with regards to its warmer tonality invoked by a hump in the mid to upper-bass region. This gives the Apollo a thick and somewhat roomy character. The top-end is similarly broadly elevated which reintroduces an ample level of clarity and openness, especially in the context of its otherwise thicker and more laid-back presentation. Altogether, it is refreshing to see an unabashed truly V-shaped headphone these days as this style of tuning has fallen out of popularity. The Apollo also does so on a solid planar magnetic platform that helps to keep things focused and controlled.
Bass –
The low-end immediately comes to the fore sitting just in front of the treble and clearly ahead of the midrange. It provides a robust foundation for the headphone’s thick, warm character. It doesn’t awe with huge pressure and dynamics due to a progressive sub-bass roll-off but delivers impressive drive and mid-bass impact in return. This means that though the headphones extend well into the perceptual, this isn’t a quality that stands out during listening. Rather, it is the plump, thick mid and upper-bass and the large, full note structure they create in turn. It isn’t an exceedingly bloated or fuzzy presentation due to the nature of its note presentation in addition to the wideband emphasis that doesn’t overly bias any particular frequency range. However, the headphone does sound somewhat tubby which simply cannot be avoided with this style of tuning.
Another quality to note is the lower-contrast nature of its transitions. The Apollo doesn’t employ the sizable upper-bass/lower-mid dip that other bass-orientated headphones usually do, and in turn, the midrange is more obviously coloured. I do find the driver to be well-controlled and offer both an assertive attack and agile decay, however, the note presentation is not quite in sufficient measure to completely clean up the presentation. Still, while this doesn’t make it into an especially fast sounding headphone due to the sheer level of fullness on display, the Apollo is far from a poorly defined or ill-separated headphone as a result. Mid-bass texture deserves special mention, and they are responsive enough to keep up with faster tracks too. While one should keep expectations in order regarding separation, the Apollo is certainly a headphone that will appeal to those wanting an especially rich and textured low-end.
Mids –
I recall cringing at early audio reviews that bashed the midrange performance of a V-shaped headphone only on account of it being laid-back. In reality, you can have an excellent midrange even if it isn’t pushed into the listener’s face. In this instance, however, I do find myself agreeing with these sentiments as I do perceive the midrange as being the weakest aspect of the Apollo’s sound. That doesn’t necessarily make it a poor performer but does mean this won’t appeal to those valuing timbral accuracy and overall balance. The Apollo, as mentioned below, is a warm, roomy headphone with a rather laid-back midrange presentation. It essentially has a complete lack of head gain with a dip from 1-3kHz instead. While objectivist will light their torches, to me this isn’t blatantly incorrect but a matter of preference. For instance, fans of older Audeze headphones likely won’t find this too strange, likely enjoyable, and the voicing overall doesn’t strike as off even coming from other headphones. However, while the voicing isn’t overtly unnatural, they remain a highly coloured headphone relative to most competitors.
The tone is very warm, and this introduces a slight yet persistent stuffiness into their sound that is most noticeable on male vocals. In addition, the lower-midrange appears more present by comparison to its dipped centre and upper-midrange. This instigates its thick and roomy character and accordingly, separation, cleanliness and tonal accuracy are not the Apollo’s forte nor is small detail retrieval or layering. This does not mean it has no redeeming features. For instance, as treble ramps up after, vocal presence is adequate, and congestion and veil aren’t excessive as a result. Female vocals remain laid-back but have a far more transparent character than male vocals due to the quick ramp-up entering the treble. This also makes the Apolla a reasonably articulate headphone and, given its sizable warmth and body, this quality never manifests as thinness, rasp or sharpness, but permits an acceptable level of clarity and openness. While the Apollo is unorthodox in its methods, it may appeal to an audience wanting just that. This is a lush, full-bodied headphone with no pretence of balance or accuracy.
Highs –
By comparison to the midrange, the top-end is a breath of fresh air, impressing from both a tonal and technical point of view. It sits roughly on par with the bass and is impressively linear in its execution. Treble presence ramps up around 5kHz following the recessed upper-midrange and sustains evenly into the middle-treble region before a subtle lift in the upper treble. This gives it an even-handed, just slightly upper-harmonic biased voicing that manifests in the form of a slight “tizziness” and emphasis on shimmer. It has a keen note attack with good bite, crispness and definition in the lower treble that forms the foundation for a well-detailed, detail dense foreground. Instruments are just a touch thin but, otherwise, impress from a texture and body point of view. Accordingly, the timbre is quite natural, just slightly on the energetic side.
This contributes to an overall more engaging character that helps to round out the Apollo’s otherwise darker, thicker character. With an uptick of air and openness, the headphone upholds respectable if not outstanding headroom that does a lot to combat congestion. Extension performs at an average level in-class despite the headphone possessing a good amount of upper-treble on measurement. There isn’t a whole lot of information here meaning micro and background detail retrieval is about what you would expect from a midrange planar headphone. It serves more to enhance its energetic timbre and sense of vibrance in its foreground presentation. The Apollo’s top-end is in good execution and balance, being easy to enjoy and riding a tasteful line between engagement and accuracy.
Soundstage –
As extension is limited, the Apollo doesn’t provide a huge, out of the head experience here, but rather a more intimate and focused approach. The stage dimensions are fairly modest, expanding just beyond the head and, therefore, being one of the more intimate open-back headphones I’ve tested. However, its proportions are especially well-rounded. The imaging performance draws most focus. The Apollo offers an impressively keen sense of directionality – more impressive given the lack of huge brightness or treble peaks. This gives the headphone a very multi-dimensional quality, the round stage aiding this impression.
While layering is harmed by the lack of midrange foreground/background contrast, I still found this to be a very involving headphone that places the listener in the centre of the stage, a quality that some may enjoy. Separation unsurprisingly leaves to be desired. The bass and midrange are both thick and warm with minimal air/ether surrounding each element. Note definition is quite good so the headphone doesn’t suffer from smear but does suffer on complex passages when taken as a whole. Treble, however, tells a different story as it is able to pace and separate well.
Driveability –
With a 97dB sensitivity and low 16-ohm impedance, the Apollo is an efficient headphone that doesn’t require much voltage to reach high listening volumes. At the same time, you will want a good amplifier with high current output due to the lower impedance. This isn’t so much of an issue in the modern-day where such can be found freely and cheaply.
Output Impedance Sensitivity
To test the impedance curve, I used 20-Ohm adaptors to artificially simulate a higher output impedance up to a 40-Ohm rating. Besides a volume drop, I didn’t notice a huge change, perhaps the headphones became a touch brighter and less bass-focused, however, not to a large degree. In turn, I would surmise that the Apollo has a relatively flat impedance curve at the impedances you’d be likely to see from modern sources. Being a low-impedance design, OTL tube amplifiers are not recommended.
Driving Power
The Apollo isn’t too demanding of the amplifier, able to achieve a dynamic and textured sound even from a dongle. Switching between my desktop stack with THX789 and the Astell & Kern Dual DAC, I was hearing a similar overall tonality. The desktop stack naturally provided a harder-hitting sub-bass with a bit more depth and power, but the dongle wasn’t far behind. Above, the midrange and treble were similarly defined. The desktop stack sounded slightly more spacious and the overall note definition was a step up. However, the Apollo is overall one of the easiest headphones to drive of those I’ve tested.
Suggested Pair Ups
True to Sendy’s design goals, the Apollo is efficient and easy to drive which adds to the value proposition as buyers shouldn’t feel the need to invest substantially in a source for these headphones. It isn’t sensitive to output impedance and can be driver nicely from lower-powered sources. Due to its coloured nature, the Apollo benefits from clean and well-defined sources such as the Hidizs S9 Pro and crop of NFCA and THX-based amplifiers. This will help to maximise separation and counterbalance its warmer nature. While some may prefer to further enhance its richness with a warmer source, this wasn’t to my personal preferences.
Comparisons –
Sivga Phoenix ($255): The dynamic driver flagship from Sendy’s sister company Sivga. The Phoenix looks similar and also pursues a warmer tuning, albeit with more restraint. The Phoenix is actually the more balanced and tonally cleaner headphone. Both have a similar style of bass tuning with wideband emphasis and a thicker, warmer character. The Apollo is more upper bass focused giving it a tubbier quality. However, the note presentation is more controlled and faster on the Apollo giving it the more textured and visceral sound all the same. Above, the Apollo is noticeably more laid-back with the Phoenix having more head-gain and midrange clarity in general.
The Apollo sounds much more laid-back and darker in general but is also more articulate which helps to redeem clarity and openness to some extent. The Phoenix is more balanced and has bigger, clearer vocals while the Apollo is more coloured and contrasted. The Apollo has the superior treble presentation in all aspects. The Phoenix is a bit crisper around the lower treble, however, the Apollo is more linear and has a sharper transient response. This makes it sound both more balanced and more detailed by a good margin. Neither extend terrifically nor have the largest soundstage. The Apollo has noticeably sharper imaging while the more balanced Phoenix rewards with better separation.
Hifiman Sundara ($349): At their now reduced price, the Sundara is the headphone to beat in the midrange planar category. Of course, it is difficult to compare apples and oranges as the Sundara comes across as more of an all-rounder than the more coloured, niche Apollo. The Sundara has a small mid-bass bump for warmth that the Apollo takes to another level. In turn, it comes across as bassier, fuller but also tubbier. The Sundara has better separation and slightly more sub-bass that gives it a more dynamic and balanced character. The Apollo has more mid-bass texture and a keener attack and faster decay but also a fuller note structure that means gains in note definition can be difficult to appreciate. The midrange is far more present on the Sundara, delivering greater balance and clarity.
The Apollo is noticeably more relaxed, being much fuller, warmer and more coherent but also lacking the same vocal clarity. In a recurring theme, it is a more articulate headphone but this isn’t enough to compensate for its dipped tuning. The treble is a bit more even on the Apollo while the Sundara has a small bump in the lower treble for crispness. This gives it a thinner and more aggressive detail presentation. However, the Apollo despite not being as bright, does sound a bit more refined, providing greater fine detail retrieval and accuracy here. Both extend similarly and offer similar levels of headroom in turn. The Sundara has a slightly larger stage while the Apollo has a sharper sense of direction. The Sundara unsurprisingly has better separation due to its more balanced tuning.
Grado RS-1x ($750): A more price-appropriate comparison would be the RS-2x, however, I did not have this model on hand at the time of review. The RS-1x serves as a good Grado-representative due to its combination of warm low-end and bright, revealing nature above that contrast heavily to the Apollo. The Apollo is immediately bassier and more mid-recessed. The Apollo extends better and has thicker, bigger bass notes. The RS-1x is meanwhile faster and cleaner. Both have a similar level of definition but the RS-1x has a big separation advantage at the expense of dynamics. The midrange presentations represent foils to each other. The Grado is bright, revealing and endlessly clear and open.
It resolves the minutiae far better and also layers better. The Apollo is lusher and more relaxed. It has much higher coherence and less intensity. However, though articulate, it doesn’t glimpse the same definition of the Grado. Both headphones have an energetic top-end, the Grado more so. The Apollo is more focused and linear here while the Grado has an airier, more coloured nature. The Apollo has a sharper leading edge, delivering a bit more detail in the foreground while the Grado extends better and resolves more fine detail above. The Grado has a larger soundstage with much better separation and layering. Meanwhile, the Apollo has a sharper sense of direction from its more intimate stage.
Verdict –
The Apollo was a headphone that really took some thought to review as its heavily coloured nature makes fair evaluation a far more subjective endeavour. For instance, coming from other headphones like the Sundara, the Apollo sounds murky and ill-defined. Though vice versa, the Sundara may sound thin and intense. Listeners can acclimatize to many sound signatures over time and it is only after you have extensive experience with a variety of gear that you develop an “internal reference” of sorts. For me, that makes the Apollo a headphone with acceptable clarity and midrange performance but impressive bass texture and a very well-executed treble response. Whilst evidently not the choice for vocal-centric genres or those wanting the largest soundstage, the Apollo weaves together an interesting mix of qualities to provide an engaging listen all the same. It isn’t genre versatile and cannot be freely recommended to all but like all coloured headphones, surely offers special appeal to a select niche. This is a headphone with superb all-day comfort and an attractive design suitable for lovers of a rich, V-shaped sound with zero midrange intensity.
The Apollo is available from Sendy Audio (International) for $499 USD at the time of writing. I am not affiliated with Sendy Audio and receive no earnings from purchases made through these links.
Track List –
Billie Eilish – dont smile at me
Bob Seger – Night Moves
Courtney Barnett – Rae Street
Cream – Wheels of Fire
Dire Straits – Communique
Dirty Loops – Next To You
Eagles – Hotel California
Elton John – Honky Chateau
Fleetwood Mac – Rumours
H.E.R – I Used To Know Her
Jasen – BYE
John Mayer – Continuum
Kanye West – Ye
Missy Higgins – The Sound of White
Radiohead – OK Computer
TALA – ain’t leavin` without you
The Beatles – Abbey Road
The weeknd – After Hours
Vampire Weekend – Father of the Bride
This is a headphone with superb all-day comfort and an attractive design suitable for lovers of a rich, V-shaped sound with zero midrange intensity.
Introduction –
Sendy Audio is a sub-brand of Sivga, yet ironically may be better known in the international market. This is for their highly successful Aiva planar magnetic headphone, which quickly won over the hearts of critics and consumers alike, cementing a solid reputation for the relatively new company. The brand has since released a good selection of headphones with varying tunings and targets. The Phoenix was a warm yet relatively well-balanced dynamic driver model at a low price point and the recently released Peacock was their all-out attempt at making a flagship planar magnetic headphone. The new Apollo lies somewhere in-between. It assumes the quad-former driver tech pioneered by the flagship and brings the price point down to mid-fi levels making it far more accessible for most buyers. It targets a rich, engaging sound and high efficiency, representing the next chapter in Sendy’s headphone designs.
The Apollo is available for $499 USD. You can read all about it on Sendy Audio’s website here!
Disclaimer –
I would like to thank Collin from Sivga/Sendy Audio very much for his quick communication and for reaching out to organise a review of the Apollo. All words are my own and there is no monetary incentive for a positive review. Despite receiving the headphones free of cost, I will attempt to be as objective as possible in my evaluation.
Specifications –
- Driver: 68mm planar magnetic driver
- Impedance: 16 ohms
- Sensitivity: 95 dB
- Frequency Response: 20 Hz – 40 kHz
- Weight: 395g
Behind the Design –
QUAD-FORMER Driver
First seen on the flagship Peacock, the Apollo also uses a derivative of the company’s quad-former technology. This encompasses a modified planar magnetic driver. This starts with a double-sided magnet design but is further expanded upon with double-sided dual voice coils, meaning there are 4 on each driver. The company reasons this provides improved efficiency in addition to more uniform force distribution over the diaphragm surface resulting in lower distortion.
Premium Housings
The Apollo is made from rosewood that has been carved using CNC, sanded, polished, painted and dyed for an immaculate finish. Furthermore, it sports tough steel grills forming a low resonance, high-damping acoustic environment for the 68mm planar driver. The company spent 3 years developing this design and driver to work in tandem to provide their desired sound.
Unboxing –
Overall, the unboxing experience is highly similar to Phoenix which sets the tone for much of my following impressions. The Apollo comes in a hard box with simple print on the front and back. Opening the lid reveals a nice moulded carrying case within a foam inlet as seen on the Phoenix. Inside are the headphones alongside a hessian pouch containing the cable and a 4.4mm to 3.5mm adaptor – a nice touch. It’s a considerate unboxing that has everything required to get the user started. I am especially a fan of the carrying case for its modest dimensions and snug fit with the headphone. In addition, as the sliders simply move the strap within the metal spring, the headphones fit into the case no matter what position they are set to.
Design –
Glancing the Apollo and you’ll see a clear family resemblance to the Phoenix and flagship Peacock. All employ a very similar base chassis with round grills, articulating hangers and a low-profile suspension headband. The Apollo has a unique flared design that, alongside CNC milled cherrywood earcups, gives it heaps of personality. I am personally a fan of matte/raw wood finishes, though arguably the lacquering here does provide better contrast to its matte features otherwise. It also provides some contrast to the Phoenix which has an inverted texture palette. As a result, the faceplates tend to draw focus with their gradient-inducing curve framed by moody satin black. It’s an attractive headphone with reasonable dimensions that will appeal to those that find most full-size open-back headphones intimidating.
Below are dual 3.5mm mono connectors similar to what you’d see on Hifiman and Meze’s 99 headphones. They exit at an angle to prevent the cable from contacting the wearer’s shoulders during listening. The stock cable impresses with its quality representing a huge step up from the Phoenix’s. It’s a 4-wire braided unit with 6N OCC conductors and a two-tone smoke/clear jacket that complements the housings beautifully. The jacket is soft with minimal memory or microphonic noise transmission making it a pleasure to live with day-to-day. This is aided by knurled metal connectors that are easy to handle and decent strain relief at each termination. I appreciate that the company decided to terminate the cable in balanced 4.4mm as you can always use a single-ended adaptor to convert a balanced cable but not vice versa.
Fit & Comfort –
Given the abundant similarities between Sendy/Sivga’s line-up, I feel these products should contextualise my experience here. To elucidate, I did not have a fantastic ergonomic experience on the Phoenix as I found its small, shallow pads to form hotspots over time. The same cannot be said for the Apollo which thankfully, represents a total transformation in terms of wearing comfort despite the visual similarities. The headband offers a similar experience to before being low-profile yet comfortably conforming to the head. Though the padding is light, the soft goatskin strap combined with the relatively light 395g total weight of the headphones means hotspots on the top of the head shouldn’t be an issue. Compared to the Phoenix, you have a slightly larger range of adjustment too, though I did find myself maxing out the slider so these may not be the best choice for those with a large or tall head. As always, let your experience with other headphones dictate your judgement here.
The earpads are the main improvement, that said, benefitting from substantial enlargement in all dimensions. Their tapered design means the company was able to give them a huge surface area and internal dimension without overly enlarging the headphone shells themselves. With super soft memory foam stuffing, the pads conform beautifully to individual head shape and spread the clamp force wonderfully. Their large aperture and depth meant my ears didn’t contact the drivers at all, providing perfect long term comfort. Perhaps the only area of complaint here is that they have a faux leather complexion which may not wear as well as authentic leather. They also aren’t especially breathable but are easily replaced as they are secured only by a twist lock. Isolation is minimal as expected for an open-back design meaning these are best reserved for home listening.
Sound –
Tonality –
The Apollo has an interesting frequency response and is reminiscent of older Audeze models with a dark, laid-back character through the midrange. Combined with broadly elevated bass and treble ranges, this provides a clearly V-shaped signature. Where it differentiates itself is with regards to its warmer tonality invoked by a hump in the mid to upper-bass region. This gives the Apollo a thick and somewhat roomy character. The top-end is similarly broadly elevated which reintroduces an ample level of clarity and openness, especially in the context of its otherwise thicker and more laid-back presentation. Altogether, it is refreshing to see an unabashed truly V-shaped headphone these days as this style of tuning has fallen out of popularity. The Apollo also does so on a solid planar magnetic platform that helps to keep things focused and controlled.
Bass –
The low-end immediately comes to the fore sitting just in front of the treble and clearly ahead of the midrange. It provides a robust foundation for the headphone’s thick, warm character. It doesn’t awe with huge pressure and dynamics due to a progressive sub-bass roll-off but delivers impressive drive and mid-bass impact in return. This means that though the headphones extend well into the perceptual, this isn’t a quality that stands out during listening. Rather, it is the plump, thick mid and upper-bass and the large, full note structure they create in turn. It isn’t an exceedingly bloated or fuzzy presentation due to the nature of its note presentation in addition to the wideband emphasis that doesn’t overly bias any particular frequency range. However, the headphone does sound somewhat tubby which simply cannot be avoided with this style of tuning.
Another quality to note is the lower-contrast nature of its transitions. The Apollo doesn’t employ the sizable upper-bass/lower-mid dip that other bass-orientated headphones usually do, and in turn, the midrange is more obviously coloured. I do find the driver to be well-controlled and offer both an assertive attack and agile decay, however, the note presentation is not quite in sufficient measure to completely clean up the presentation. Still, while this doesn’t make it into an especially fast sounding headphone due to the sheer level of fullness on display, the Apollo is far from a poorly defined or ill-separated headphone as a result. Mid-bass texture deserves special mention, and they are responsive enough to keep up with faster tracks too. While one should keep expectations in order regarding separation, the Apollo is certainly a headphone that will appeal to those wanting an especially rich and textured low-end.
Mids –
I recall cringing at early audio reviews that bashed the midrange performance of a V-shaped headphone only on account of it being laid-back. In reality, you can have an excellent midrange even if it isn’t pushed into the listener’s face. In this instance, however, I do find myself agreeing with these sentiments as I do perceive the midrange as being the weakest aspect of the Apollo’s sound. That doesn’t necessarily make it a poor performer but does mean this won’t appeal to those valuing timbral accuracy and overall balance. The Apollo, as mentioned below, is a warm, roomy headphone with a rather laid-back midrange presentation. It essentially has a complete lack of head gain with a dip from 1-3kHz instead. While objectivist will light their torches, to me this isn’t blatantly incorrect but a matter of preference. For instance, fans of older Audeze headphones likely won’t find this too strange, likely enjoyable, and the voicing overall doesn’t strike as off even coming from other headphones. However, while the voicing isn’t overtly unnatural, they remain a highly coloured headphone relative to most competitors.
The tone is very warm, and this introduces a slight yet persistent stuffiness into their sound that is most noticeable on male vocals. In addition, the lower-midrange appears more present by comparison to its dipped centre and upper-midrange. This instigates its thick and roomy character and accordingly, separation, cleanliness and tonal accuracy are not the Apollo’s forte nor is small detail retrieval or layering. This does not mean it has no redeeming features. For instance, as treble ramps up after, vocal presence is adequate, and congestion and veil aren’t excessive as a result. Female vocals remain laid-back but have a far more transparent character than male vocals due to the quick ramp-up entering the treble. This also makes the Apolla a reasonably articulate headphone and, given its sizable warmth and body, this quality never manifests as thinness, rasp or sharpness, but permits an acceptable level of clarity and openness. While the Apollo is unorthodox in its methods, it may appeal to an audience wanting just that. This is a lush, full-bodied headphone with no pretence of balance or accuracy.
Highs –
By comparison to the midrange, the top-end is a breath of fresh air, impressing from both a tonal and technical point of view. It sits roughly on par with the bass and is impressively linear in its execution. Treble presence ramps up around 5kHz following the recessed upper-midrange and sustains evenly into the middle-treble region before a subtle lift in the upper treble. This gives it an even-handed, just slightly upper-harmonic biased voicing that manifests in the form of a slight “tizziness” and emphasis on shimmer. It has a keen note attack with good bite, crispness and definition in the lower treble that forms the foundation for a well-detailed, detail dense foreground. Instruments are just a touch thin but, otherwise, impress from a texture and body point of view. Accordingly, the timbre is quite natural, just slightly on the energetic side.
This contributes to an overall more engaging character that helps to round out the Apollo’s otherwise darker, thicker character. With an uptick of air and openness, the headphone upholds respectable if not outstanding headroom that does a lot to combat congestion. Extension performs at an average level in-class despite the headphone possessing a good amount of upper-treble on measurement. There isn’t a whole lot of information here meaning micro and background detail retrieval is about what you would expect from a midrange planar headphone. It serves more to enhance its energetic timbre and sense of vibrance in its foreground presentation. The Apollo’s top-end is in good execution and balance, being easy to enjoy and riding a tasteful line between engagement and accuracy.
Soundstage –
As extension is limited, the Apollo doesn’t provide a huge, out of the head experience here, but rather a more intimate and focused approach. The stage dimensions are fairly modest, expanding just beyond the head and, therefore, being one of the more intimate open-back headphones I’ve tested. However, its proportions are especially well-rounded. The imaging performance draws most focus. The Apollo offers an impressively keen sense of directionality – more impressive given the lack of huge brightness or treble peaks. This gives the headphone a very multi-dimensional quality, the round stage aiding this impression.
While layering is harmed by the lack of midrange foreground/background contrast, I still found this to be a very involving headphone that places the listener in the centre of the stage, a quality that some may enjoy. Separation unsurprisingly leaves to be desired. The bass and midrange are both thick and warm with minimal air/ether surrounding each element. Note definition is quite good so the headphone doesn’t suffer from smear but does suffer on complex passages when taken as a whole. Treble, however, tells a different story as it is able to pace and separate well.
Driveability –
With a 97dB sensitivity and low 16-ohm impedance, the Apollo is an efficient headphone that doesn’t require much voltage to reach high listening volumes. At the same time, you will want a good amplifier with high current output due to the lower impedance. This isn’t so much of an issue in the modern-day where such can be found freely and cheaply.
Output Impedance Sensitivity
To test the impedance curve, I used 20-Ohm adaptors to artificially simulate a higher output impedance up to a 40-Ohm rating. Besides a volume drop, I didn’t notice a huge change, perhaps the headphones became a touch brighter and less bass-focused, however, not to a large degree. In turn, I would surmise that the Apollo has a relatively flat impedance curve at the impedances you’d be likely to see from modern sources. Being a low-impedance design, OTL tube amplifiers are not recommended.
Driving Power
The Apollo isn’t too demanding of the amplifier, able to achieve a dynamic and textured sound even from a dongle. Switching between my desktop stack with THX789 and the Astell & Kern Dual DAC, I was hearing a similar overall tonality. The desktop stack naturally provided a harder-hitting sub-bass with a bit more depth and power, but the dongle wasn’t far behind. Above, the midrange and treble were similarly defined. The desktop stack sounded slightly more spacious and the overall note definition was a step up. However, the Apollo is overall one of the easiest headphones to drive of those I’ve tested.
Suggested Pair Ups
True to Sendy’s design goals, the Apollo is efficient and easy to drive which adds to the value proposition as buyers shouldn’t feel the need to invest substantially in a source for these headphones. It isn’t sensitive to output impedance and can be driver nicely from lower-powered sources. Due to its coloured nature, the Apollo benefits from clean and well-defined sources such as the Hidizs S9 Pro and crop of NFCA and THX-based amplifiers. This will help to maximise separation and counterbalance its warmer nature. While some may prefer to further enhance its richness with a warmer source, this wasn’t to my personal preferences.
Comparisons –
Sivga Phoenix ($255): The dynamic driver flagship from Sendy’s sister company Sivga. The Phoenix looks similar and also pursues a warmer tuning, albeit with more restraint. The Phoenix is actually the more balanced and tonally cleaner headphone. Both have a similar style of bass tuning with wideband emphasis and a thicker, warmer character. The Apollo is more upper bass focused giving it a tubbier quality. However, the note presentation is more controlled and faster on the Apollo giving it the more textured and visceral sound all the same. Above, the Apollo is noticeably more laid-back with the Phoenix having more head-gain and midrange clarity in general.
The Apollo sounds much more laid-back and darker in general but is also more articulate which helps to redeem clarity and openness to some extent. The Phoenix is more balanced and has bigger, clearer vocals while the Apollo is more coloured and contrasted. The Apollo has the superior treble presentation in all aspects. The Phoenix is a bit crisper around the lower treble, however, the Apollo is more linear and has a sharper transient response. This makes it sound both more balanced and more detailed by a good margin. Neither extend terrifically nor have the largest soundstage. The Apollo has noticeably sharper imaging while the more balanced Phoenix rewards with better separation.
Hifiman Sundara ($349): At their now reduced price, the Sundara is the headphone to beat in the midrange planar category. Of course, it is difficult to compare apples and oranges as the Sundara comes across as more of an all-rounder than the more coloured, niche Apollo. The Sundara has a small mid-bass bump for warmth that the Apollo takes to another level. In turn, it comes across as bassier, fuller but also tubbier. The Sundara has better separation and slightly more sub-bass that gives it a more dynamic and balanced character. The Apollo has more mid-bass texture and a keener attack and faster decay but also a fuller note structure that means gains in note definition can be difficult to appreciate. The midrange is far more present on the Sundara, delivering greater balance and clarity.
The Apollo is noticeably more relaxed, being much fuller, warmer and more coherent but also lacking the same vocal clarity. In a recurring theme, it is a more articulate headphone but this isn’t enough to compensate for its dipped tuning. The treble is a bit more even on the Apollo while the Sundara has a small bump in the lower treble for crispness. This gives it a thinner and more aggressive detail presentation. However, the Apollo despite not being as bright, does sound a bit more refined, providing greater fine detail retrieval and accuracy here. Both extend similarly and offer similar levels of headroom in turn. The Sundara has a slightly larger stage while the Apollo has a sharper sense of direction. The Sundara unsurprisingly has better separation due to its more balanced tuning.
Grado RS-1x ($750): A more price-appropriate comparison would be the RS-2x, however, I did not have this model on hand at the time of review. The RS-1x serves as a good Grado-representative due to its combination of warm low-end and bright, revealing nature above that contrast heavily to the Apollo. The Apollo is immediately bassier and more mid-recessed. The Apollo extends better and has thicker, bigger bass notes. The RS-1x is meanwhile faster and cleaner. Both have a similar level of definition but the RS-1x has a big separation advantage at the expense of dynamics. The midrange presentations represent foils to each other. The Grado is bright, revealing and endlessly clear and open.
It resolves the minutiae far better and also layers better. The Apollo is lusher and more relaxed. It has much higher coherence and less intensity. However, though articulate, it doesn’t glimpse the same definition of the Grado. Both headphones have an energetic top-end, the Grado more so. The Apollo is more focused and linear here while the Grado has an airier, more coloured nature. The Apollo has a sharper leading edge, delivering a bit more detail in the foreground while the Grado extends better and resolves more fine detail above. The Grado has a larger soundstage with much better separation and layering. Meanwhile, the Apollo has a sharper sense of direction from its more intimate stage.
Verdict –
The Apollo was a headphone that really took some thought to review as its heavily coloured nature makes fair evaluation a far more subjective endeavour. For instance, coming from other headphones like the Sundara, the Apollo sounds murky and ill-defined. Though vice versa, the Sundara may sound thin and intense. Listeners can acclimatize to many sound signatures over time and it is only after you have extensive experience with a variety of gear that you develop an “internal reference” of sorts. For me, that makes the Apollo a headphone with acceptable clarity and midrange performance but impressive bass texture and a very well-executed treble response. Whilst evidently not the choice for vocal-centric genres or those wanting the largest soundstage, the Apollo weaves together an interesting mix of qualities to provide an engaging listen all the same. It isn’t genre versatile and cannot be freely recommended to all but like all coloured headphones, surely offers special appeal to a select niche. This is a headphone with superb all-day comfort and an attractive design suitable for lovers of a rich, V-shaped sound with zero midrange intensity.
The Apollo is available from Sendy Audio (International) for $499 USD at the time of writing. I am not affiliated with Sendy Audio and receive no earnings from purchases made through these links.
Track List –
Billie Eilish – dont smile at me
Bob Seger – Night Moves
Courtney Barnett – Rae Street
Cream – Wheels of Fire
Dire Straits – Communique
Dirty Loops – Next To You
Eagles – Hotel California
Elton John – Honky Chateau
Fleetwood Mac – Rumours
H.E.R – I Used To Know Her
Jasen – BYE
John Mayer – Continuum
Kanye West – Ye
Missy Higgins – The Sound of White
Radiohead – OK Computer
TALA – ain’t leavin` without you
The Beatles – Abbey Road
The weeknd – After Hours
Vampire Weekend – Father of the Bride
Sendy Audio Apollo Headphones - Godlike Delight
Sendy Audio Apollo is a 500 USD headphone based on the QUAD-Former technology, basically a Planar magnetic driver with double magnets + double sided coils and double sides of coils. This means that it gets to be compared with Adam Audio Studio PRO SP-5 Headphones (550 USD), iBasso SR-2 Open Back Headphones (500 USD), Sennheiser HD660S (500 USD), Dan Clark Aeon Flow RT (500 USD) and Avantone Pro Planar Headphones (450 USD)
Introduction
Sendy Audio is a company that's the high-end sister of Sivga, and the company keeps most of their entry-level headphones under the Sivga name, while most of their better, high-end offers are branded under the Sendy Audio moniker. The company makes excellent work with headphones, and they generally offer high price / performance ratio, and they offer a good warranty for their products. I am yet to hear about anyone who had any problem with a Sendy Audio or Sivga product, so their record is squeaky clean.
It should be noted that I have absolutely no affiliation with Sendy Audio, I am not receiving any incentive for this review or to sweeten things out. I'd like to thank Sendy Audio for providing the sample for this review. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in Sendy Audio Apollo find their next music companion.
Packaging
First things first, let's get the packaging out of the way:
The package of the Sendy Audio Apollo is similar to that of the Sendy Audio Peacock, the Apollo also coming in a cardboard package, and with a really nice leather carrying case. The headphones come with a high-end balanced cable that's ended in a 4.4mm connector, and also come with a 4.4mm to 3.5mm adapter. I am happy to report that the package is awesome for their 500 USD price point. There's a hemp carrying bag inside the package, to hold the cable and its adapter.
Build Quality/Aesthetics/Fit/Comfort
The technology inside of Sendy Audio Apollo is interesting, as they come with a huge planar magnetic driver, 68mm in side. It also has that QUAD-Former technology that has double everything, double magnets, double sides of coils on the diaphragm, and double coils on each side of the diaphragm. We will find out in the sonic impressions if this means double the quality compared to competition, and what it sounds like.
The company spent 3 years experimenting with the technology and perfecting it until they constructed Apollo to finally launch. The design is named Apollo as the outer cups are made of a sunlight pattern and mesh, and have glossy rosewood wood in the construction as well. The design is not random, and the headphones have the whole design arranged around sounding as good as possible.
We have a goatskin leather headband that is extremely soft, and in fact Apollo is slightly more comfortable than even Peacock, and much more comfortable than Sennheiser HD660S. The earpads are extremely thick and extremely large, making Apollo the most comfortable headphone you can grab in the sub 1000 USD price range. The earpads have a really unique design, where they look like a bowl, basically creating a very targeted acoustic chamber for your ears, and they have L and R markings on the headphones, and the cups. Earpads are replaceable, and the whole headphone is serviceable, in case you break something.
The earcups swivel in every direction, having the same adjusting mechanism as Sivga Peacock, and being able to adjust to any head size and shape. It is good to see that the company learned, and after SV021, which some found not to adjust enough, the Apollo will easily fit any head size and shape. What's even better, the earpads are so thick and soft that there's no one who won't have an excellent comfort with them. The headphones are light, at 395 grams, and given the headband design and the earpads design, both being smooth, thick and soft, you will not feel Apollo on your head, regardless of what you're doing. The clamping force is medium too, so they do not have any hotspots or wear discomfort regardless of how long you're wearing them for.
The balanced cable included in the package is a 6N OCC cable, and it tends to transmit minor amounts of noise if you're walking with the headphones on your head, but you won't hear it if you're sitting at your desk. With a 95dB of Sensitivity, and a 16 OHM impedance, Apollo is fairly hard to drive and you're likely to be sitting at your desk while using them, unless you'll be using a high-end DAP like iBasso DX220, iBasso DX240, Astell & Kern SP2000T, and Lotoo PAW6000. For a comfortable listening level I hover around 100 / 150 on high gain with Astell & Kern SE180.
The Sendy Audio Apollo has low leakage levels, but they do leak, being fully open back. You can listen at quiet and medium levels without bothering anyone, but high listening levels will be audible to those around you. Passive noise isolation is low, but at medium listening levels, the music drowns out the sound of my keyboard and computer fans.
Sound Quality
The sound of Apollo is super relaxed, soft, generally linear natural, slightly thick, warm and musical, with excellent staging and dynamics, and a really natural tonality in the midrange. I have been using mostly Astell & Kern SE180 and Cyrus One Cast for driving Apollo, and it has been providing a really clean, and engaging sound. Apollo sounds excellent at all listening volumes; they are more natural and balanced at quieter volumes, and become more mid centric and forward, also more punchy and impactful at higher listening volumes.
Starting with the bass of Apollo, it is pretty warm, and has a natural towards slightly slow note decay that will help a lot with the bass sounding natural. Apollo is clean and fatigue-free, having a smooth texture for the bass, mids and treble, and they have a really good bass extension, as low as 20 Hz. The impact of their bass is soft, and rather than a strong hit like Sendy Audio Peacock provides, Apollo is soft, relaxing and nuanced, but won't vibrate on your head, rather leaving the bass to be nuanced. You could call it a very linear bass, like what Etymotic tends to provide with their IEMs, and it would work great for mixing and mastering, but it won't be ideal for EDM, and Electronic music, rather working best with Rock, Metal, Emo, Post Hardcore, Classical, Jazz, and Easy Listening music. The bass is slightly recessed behind the midrange, which is the central element of Apollo's sound.
Now that we reached the midrange, I am coming to the conclusion that Sendy Audio follows a house sound where they bring the midrange as the central element of their sound. The mids of Apollo are higher in amount than their bass and treble, but Apollo has the most beautified, musical smooth and enjoyable midrange I found in the ~500 USD price range. Both male and female voices are extremely smooth, slightly thick, and buttery in texture. This also applies to guitars, and it feels like when Sendy Audio designed Apollo had a Rosson RAD-0 on their table, and tried to take all of the positive elements on RAD-0's sound and apply those to a midrange centric headphone. The soundstage of Apollo is wide and holographic, but has a natural depth. Even screamo music, and harsh music sounds like pure heaven on Apollo, and it is the kind of headphone I would recommend for anyone who finds everything fatiguing, or for someone who really wants to hear what ultimate musicality sounds like. Piano notes are etched and have no harshness, nor sibilance or strong edges, Apollo being great and smoothing out harsh edges in music.
The treble of Apollo follows the same principle and they have one of the cleanest, smoothest and most fluid trebles I have heard in a headphone ever. At first, I thought they had a roll-off, but the treble extends naturally up to the highest octaves, just being extremely smooth and clean, and helping give Apollo excitement, despite their linear and smooth sound. The sound is perfect to relax to, and rock, metal, pop, jazz music never sounded smoother, more enjoyable and more musical. Voices are always soft and enjoyable, while the treble has an open tuning despite the smooth nature. You can call the sound of Apollo transparent, because it creates the sensation you're in an open field listening to music sung to you.
Apollo is absolutely perfect for all music styles, as long as you don't need a high amount of bass. I can totally live with and enjoy their treble, which has good energy and extension, but is smooth and playful, but the lower bass amounts tilt Apollo for being better at playing rock, metal, pop, jazz, downtempo, rather than electronic and EDM or Rap and Dubstep. Bands like Bring Me The Horizon are musical and enjoyable, something which happens rarely, and Katy Perry sounds smooth and has a really pleasing and smooth tonality in her voice, plus Atilla and Chugaboom both sound really enjoyable and fun, with no harshness or listening fatigue even at extreme volumes. Apollo hides mastering errors well, and turns everything to be pleasing regardless of how botched the job was in the original master. The sound generally has excellent details, and clarity for the presentation, but you rarely stop and think about the technical aspect, when you hear sounds so beautiful and music played so well.
Comparisons
Sendy Audio Apollo vs Dan Clark Aeon Flow (500 USD vs 500 USD) - Those two headphones are quite different, despite both having planar magnetic drivers, Aeon Flow being a closed back headphone, and Apollo being open back. The cable quality is slightly better on Apollo, and they come with a balanced cable and adapter. The comfort is better on Apollo, which has thicker, softer, deeper earpads, and a softer headband, with less clamping force. Both headphones are similarly hard to drive, and are total opposites in terms of signature, Aeon Flor RT having a recessed midrange, and a strong sub-bass, and treble, especially upper treble, with a sharp and technical sound, tons of details and less focus on the midrange. Apollo is exactly the other way around, having most of the focus on the midrange, a smooth, relaxed and musical sound with less focus on technicalities and a softer presentation.
Sendy Audio Apollo vs iBasso SR-2 (500 USD vs 500 USD) - We have two very similar headphones here, with both SR-2 and Apollo following similar levels of comfort, similar sonic signatures, similar price points, and similar construction quality as well. The biggest differences are in the ear pad depth, where SR-2 has more shallow earpads, and harder earpads, and Apollo has softer, and deeper earpads. The overall sound is really similar, both being relaxed, natural, transparent and smooth. Both have similar levels of details, and both are mid-centric, with iBasso being slightly colder in tonality, and Apollo slightly warmer, and SR-2 having slightly more bass, and Apollo having a more smooth texture in the midrange.
Sendy Audio Apollo vs Sennheiser HD660S (500 USD vs 500 USD) - The construction quality and comfort of Apollo is on another level, or rather another planet, compared to HD660S, which is a fairly uncomfortable headphone with a ton of camping force and hard headband, hard earpads. The sound is far more natural on Apollo, and they are easier to drive properly. HD660S sounds more detailed and more technical, has more overall forwardness and impact, Apollo being much smoother, more relaxed, softer, more musical and easier to enjoy with a wider selection of music. HD660S has similar amounts of bass compared to Apollo, but Apollo generally sounds more transparent and has a slower note decay that makes them less harsh and less sharp than HD660S.
Sendy Audio Apollo vs Avantone Pro Planar (500 USD vs 450 USD) - The comfort is actually comparable here, but the shape and aesthetics of Pro Planar are quite industrial and insider-like, where APollo looks great for anyone, regardless of their attire and costume plan. Pro Planar has more bass, more thickness, and more depth to their sound, whereas Apollo is wider, has a more natural midrange, a more open treble, with more transparency. Apollo is more relaxed, lighter and softer. The dynamics are similar between them, but Apollo is harder to drive properly and scales more with the source.
Sendy Audio Apollo vs Adam Audio Studio Pro SP-5 (500 USD vs 550 USD) - The comfort and build quality is much better on Sendy Audio Apollo, and they have thicker, softer and larger earpads, larger cups, and a more comfortable headband, with a more even and lighter clamping force. The sound of Apollo is much softer, less bright, less harsh than SP-5. SP-5 sounds much more detailed, but also more harsh and bright, more digital and they reveal both more detail but also more ugly in music, with a wider soundstage, where Apollo is more mid-centric, smoother, more musical, and more relaxed. SP-5 needs a thick, warm and preferably rolled-off source to sound good, while Apollo will pair well with any source.
Value and Conclusion
At the end of today's review, the value of Apollo is excellent, and at 500 USD, they have excellent build quality, excellent comfort, an excellent cable, and an excellent sonic performance for their price.
The comfort of Apollo alone places it in Audiophile-Heaven's Hall Of Fame, and if you're looking for their natural, open and soft sound, with an extremely smooth and clean presentation, you're in luck, because they're the best you can get before you reach 1000 USD as a price point. In fact, Apollo replaces Sivga Audio P-2 in the hall of fame, having a similar sound, but much better comfort, better overall construction quality, and a softer, smoother, more musical sound.
At the end of today's written review, Sendy Audio Apollo is an excellent purchase, for both those who love to relax, and those who want to hear beautiful music, it has extremely good performance for the price, and a fully recommended purchase for those who enjoy a mid centric sound with a smooth and relaxed nature.
Sendy Audio Apollo is a 500 USD headphone based on the QUAD-Former technology, basically a Planar magnetic driver with double magnets + double sided coils and double sides of coils. This means that it gets to be compared with Adam Audio Studio PRO SP-5 Headphones (550 USD), iBasso SR-2 Open Back Headphones (500 USD), Sennheiser HD660S (500 USD), Dan Clark Aeon Flow RT (500 USD) and Avantone Pro Planar Headphones (450 USD)
Introduction
Sendy Audio is a company that's the high-end sister of Sivga, and the company keeps most of their entry-level headphones under the Sivga name, while most of their better, high-end offers are branded under the Sendy Audio moniker. The company makes excellent work with headphones, and they generally offer high price / performance ratio, and they offer a good warranty for their products. I am yet to hear about anyone who had any problem with a Sendy Audio or Sivga product, so their record is squeaky clean.
It should be noted that I have absolutely no affiliation with Sendy Audio, I am not receiving any incentive for this review or to sweeten things out. I'd like to thank Sendy Audio for providing the sample for this review. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in Sendy Audio Apollo find their next music companion.
Packaging
First things first, let's get the packaging out of the way:
The package of the Sendy Audio Apollo is similar to that of the Sendy Audio Peacock, the Apollo also coming in a cardboard package, and with a really nice leather carrying case. The headphones come with a high-end balanced cable that's ended in a 4.4mm connector, and also come with a 4.4mm to 3.5mm adapter. I am happy to report that the package is awesome for their 500 USD price point. There's a hemp carrying bag inside the package, to hold the cable and its adapter.
Build Quality/Aesthetics/Fit/Comfort
The technology inside of Sendy Audio Apollo is interesting, as they come with a huge planar magnetic driver, 68mm in side. It also has that QUAD-Former technology that has double everything, double magnets, double sides of coils on the diaphragm, and double coils on each side of the diaphragm. We will find out in the sonic impressions if this means double the quality compared to competition, and what it sounds like.
The company spent 3 years experimenting with the technology and perfecting it until they constructed Apollo to finally launch. The design is named Apollo as the outer cups are made of a sunlight pattern and mesh, and have glossy rosewood wood in the construction as well. The design is not random, and the headphones have the whole design arranged around sounding as good as possible.
We have a goatskin leather headband that is extremely soft, and in fact Apollo is slightly more comfortable than even Peacock, and much more comfortable than Sennheiser HD660S. The earpads are extremely thick and extremely large, making Apollo the most comfortable headphone you can grab in the sub 1000 USD price range. The earpads have a really unique design, where they look like a bowl, basically creating a very targeted acoustic chamber for your ears, and they have L and R markings on the headphones, and the cups. Earpads are replaceable, and the whole headphone is serviceable, in case you break something.
The earcups swivel in every direction, having the same adjusting mechanism as Sivga Peacock, and being able to adjust to any head size and shape. It is good to see that the company learned, and after SV021, which some found not to adjust enough, the Apollo will easily fit any head size and shape. What's even better, the earpads are so thick and soft that there's no one who won't have an excellent comfort with them. The headphones are light, at 395 grams, and given the headband design and the earpads design, both being smooth, thick and soft, you will not feel Apollo on your head, regardless of what you're doing. The clamping force is medium too, so they do not have any hotspots or wear discomfort regardless of how long you're wearing them for.
The balanced cable included in the package is a 6N OCC cable, and it tends to transmit minor amounts of noise if you're walking with the headphones on your head, but you won't hear it if you're sitting at your desk. With a 95dB of Sensitivity, and a 16 OHM impedance, Apollo is fairly hard to drive and you're likely to be sitting at your desk while using them, unless you'll be using a high-end DAP like iBasso DX220, iBasso DX240, Astell & Kern SP2000T, and Lotoo PAW6000. For a comfortable listening level I hover around 100 / 150 on high gain with Astell & Kern SE180.
The Sendy Audio Apollo has low leakage levels, but they do leak, being fully open back. You can listen at quiet and medium levels without bothering anyone, but high listening levels will be audible to those around you. Passive noise isolation is low, but at medium listening levels, the music drowns out the sound of my keyboard and computer fans.
Sound Quality
The sound of Apollo is super relaxed, soft, generally linear natural, slightly thick, warm and musical, with excellent staging and dynamics, and a really natural tonality in the midrange. I have been using mostly Astell & Kern SE180 and Cyrus One Cast for driving Apollo, and it has been providing a really clean, and engaging sound. Apollo sounds excellent at all listening volumes; they are more natural and balanced at quieter volumes, and become more mid centric and forward, also more punchy and impactful at higher listening volumes.
Starting with the bass of Apollo, it is pretty warm, and has a natural towards slightly slow note decay that will help a lot with the bass sounding natural. Apollo is clean and fatigue-free, having a smooth texture for the bass, mids and treble, and they have a really good bass extension, as low as 20 Hz. The impact of their bass is soft, and rather than a strong hit like Sendy Audio Peacock provides, Apollo is soft, relaxing and nuanced, but won't vibrate on your head, rather leaving the bass to be nuanced. You could call it a very linear bass, like what Etymotic tends to provide with their IEMs, and it would work great for mixing and mastering, but it won't be ideal for EDM, and Electronic music, rather working best with Rock, Metal, Emo, Post Hardcore, Classical, Jazz, and Easy Listening music. The bass is slightly recessed behind the midrange, which is the central element of Apollo's sound.
Now that we reached the midrange, I am coming to the conclusion that Sendy Audio follows a house sound where they bring the midrange as the central element of their sound. The mids of Apollo are higher in amount than their bass and treble, but Apollo has the most beautified, musical smooth and enjoyable midrange I found in the ~500 USD price range. Both male and female voices are extremely smooth, slightly thick, and buttery in texture. This also applies to guitars, and it feels like when Sendy Audio designed Apollo had a Rosson RAD-0 on their table, and tried to take all of the positive elements on RAD-0's sound and apply those to a midrange centric headphone. The soundstage of Apollo is wide and holographic, but has a natural depth. Even screamo music, and harsh music sounds like pure heaven on Apollo, and it is the kind of headphone I would recommend for anyone who finds everything fatiguing, or for someone who really wants to hear what ultimate musicality sounds like. Piano notes are etched and have no harshness, nor sibilance or strong edges, Apollo being great and smoothing out harsh edges in music.
The treble of Apollo follows the same principle and they have one of the cleanest, smoothest and most fluid trebles I have heard in a headphone ever. At first, I thought they had a roll-off, but the treble extends naturally up to the highest octaves, just being extremely smooth and clean, and helping give Apollo excitement, despite their linear and smooth sound. The sound is perfect to relax to, and rock, metal, pop, jazz music never sounded smoother, more enjoyable and more musical. Voices are always soft and enjoyable, while the treble has an open tuning despite the smooth nature. You can call the sound of Apollo transparent, because it creates the sensation you're in an open field listening to music sung to you.
Apollo is absolutely perfect for all music styles, as long as you don't need a high amount of bass. I can totally live with and enjoy their treble, which has good energy and extension, but is smooth and playful, but the lower bass amounts tilt Apollo for being better at playing rock, metal, pop, jazz, downtempo, rather than electronic and EDM or Rap and Dubstep. Bands like Bring Me The Horizon are musical and enjoyable, something which happens rarely, and Katy Perry sounds smooth and has a really pleasing and smooth tonality in her voice, plus Atilla and Chugaboom both sound really enjoyable and fun, with no harshness or listening fatigue even at extreme volumes. Apollo hides mastering errors well, and turns everything to be pleasing regardless of how botched the job was in the original master. The sound generally has excellent details, and clarity for the presentation, but you rarely stop and think about the technical aspect, when you hear sounds so beautiful and music played so well.
Comparisons
Sendy Audio Apollo vs Dan Clark Aeon Flow (500 USD vs 500 USD) - Those two headphones are quite different, despite both having planar magnetic drivers, Aeon Flow being a closed back headphone, and Apollo being open back. The cable quality is slightly better on Apollo, and they come with a balanced cable and adapter. The comfort is better on Apollo, which has thicker, softer, deeper earpads, and a softer headband, with less clamping force. Both headphones are similarly hard to drive, and are total opposites in terms of signature, Aeon Flor RT having a recessed midrange, and a strong sub-bass, and treble, especially upper treble, with a sharp and technical sound, tons of details and less focus on the midrange. Apollo is exactly the other way around, having most of the focus on the midrange, a smooth, relaxed and musical sound with less focus on technicalities and a softer presentation.
Sendy Audio Apollo vs iBasso SR-2 (500 USD vs 500 USD) - We have two very similar headphones here, with both SR-2 and Apollo following similar levels of comfort, similar sonic signatures, similar price points, and similar construction quality as well. The biggest differences are in the ear pad depth, where SR-2 has more shallow earpads, and harder earpads, and Apollo has softer, and deeper earpads. The overall sound is really similar, both being relaxed, natural, transparent and smooth. Both have similar levels of details, and both are mid-centric, with iBasso being slightly colder in tonality, and Apollo slightly warmer, and SR-2 having slightly more bass, and Apollo having a more smooth texture in the midrange.
Sendy Audio Apollo vs Sennheiser HD660S (500 USD vs 500 USD) - The construction quality and comfort of Apollo is on another level, or rather another planet, compared to HD660S, which is a fairly uncomfortable headphone with a ton of camping force and hard headband, hard earpads. The sound is far more natural on Apollo, and they are easier to drive properly. HD660S sounds more detailed and more technical, has more overall forwardness and impact, Apollo being much smoother, more relaxed, softer, more musical and easier to enjoy with a wider selection of music. HD660S has similar amounts of bass compared to Apollo, but Apollo generally sounds more transparent and has a slower note decay that makes them less harsh and less sharp than HD660S.
Sendy Audio Apollo vs Avantone Pro Planar (500 USD vs 450 USD) - The comfort is actually comparable here, but the shape and aesthetics of Pro Planar are quite industrial and insider-like, where APollo looks great for anyone, regardless of their attire and costume plan. Pro Planar has more bass, more thickness, and more depth to their sound, whereas Apollo is wider, has a more natural midrange, a more open treble, with more transparency. Apollo is more relaxed, lighter and softer. The dynamics are similar between them, but Apollo is harder to drive properly and scales more with the source.
Sendy Audio Apollo vs Adam Audio Studio Pro SP-5 (500 USD vs 550 USD) - The comfort and build quality is much better on Sendy Audio Apollo, and they have thicker, softer and larger earpads, larger cups, and a more comfortable headband, with a more even and lighter clamping force. The sound of Apollo is much softer, less bright, less harsh than SP-5. SP-5 sounds much more detailed, but also more harsh and bright, more digital and they reveal both more detail but also more ugly in music, with a wider soundstage, where Apollo is more mid-centric, smoother, more musical, and more relaxed. SP-5 needs a thick, warm and preferably rolled-off source to sound good, while Apollo will pair well with any source.
Value and Conclusion
At the end of today's review, the value of Apollo is excellent, and at 500 USD, they have excellent build quality, excellent comfort, an excellent cable, and an excellent sonic performance for their price.
The comfort of Apollo alone places it in Audiophile-Heaven's Hall Of Fame, and if you're looking for their natural, open and soft sound, with an extremely smooth and clean presentation, you're in luck, because they're the best you can get before you reach 1000 USD as a price point. In fact, Apollo replaces Sivga Audio P-2 in the hall of fame, having a similar sound, but much better comfort, better overall construction quality, and a softer, smoother, more musical sound.
At the end of today's written review, Sendy Audio Apollo is an excellent purchase, for both those who love to relax, and those who want to hear beautiful music, it has extremely good performance for the price, and a fully recommended purchase for those who enjoy a mid centric sound with a smooth and relaxed nature.
