At the time this review was written, the Fidue A91 Sirius hybrid in-ear monitor was listed for sale on Hifiheadphones and Penon Audio's website. Here are links to their listings of the product:
http://www.hifiheadphones.co.uk/fidue-sirius-a91-hybrid-drivers-iem-earphones-with-replaceable-cable.html
http://penonaudio.com/Fidue-Sirius-A91
Introduction
I’m a Fidue fanboy. I’ll be the first to admit this.
My admiration of the company started with an opportunity to review the A83 hybrid in-ear monitor. To this day they are an incredible sounding earphone. The A83 was Fidue’s flagship for almost two years prior to the release of the Sirius. After enjoying the A83 for over a year, I also purchased the A73 and A65. The A73 immediately became a personal favorite. I reviewed both the A73 and A65 as well. All three earphones are great for their asking price and to this day are all still very relevant.
When I heard Fidue was releasing a new flagship named Sirius, I was immediately fascinated. I knew they were something I would want to experience. I contacted Fidue and expressed interest in covering them. I was fortunate enough to receive a sample. I have had the pleasure of listening to them for the last few weeks and am ready to share my experience with Fidue's new flagship in-ear monitor. I hope my review captures the essence of this incredible earphone, and gives you the information you need to know when considering them as your next high end earphone purchase.
Disclaimer
I was given an opportunity to review the A91 Sirius in exchange for my unbiased opinion and review. I am in no way affiliated with Fidue. I would like to take this time to personally thank them for the opportunity.
My Background
I AM NOT a numbers and graphs audiophile or sound engineer. Personal audio enthusiast? Absolutely! Headphone junkie? Possibly…
There’s something about quality DAPs, DACs, Amplifiers and Earphones that intrigues me. I want to hear any earphone that looks promising, in hopes that I can share my impressions with enthusiasts and help them find the audio product they’re looking for. My Head-Fi profile has a list of audio products ranked from favorite to least favorite. For me, this hobby is more about getting great price to performance ratio from a product, and having a variety of different gear to mix and match. With personal audio gear, we tend to pay a lot of money for minor upgrades. One thing I’ve learned over the last few years is that just because a headphone has a higher price tag, it doesn’t mean that it has superior build and sound quality.
I’m always looking for great audio at a great price. I’m after headphones and IEMs that give me the “WOW” factor. I can appreciate different builds and sound signatures as long as they are solidly built, with ergonomics and sound that is pleasing to my ears. It’s my pleasure to share my experiences with audio products and make recommendations based on gear I have owned and used.
REVIEW
The Sirius comes in premium box that is wrapped in a cardboard sleeve. The sleeve is black with green and white accents. The front of the box features the brand and product name, along with key features of the product in fine print.
The back of the box displays specifications in three different languages, and some artistic verbiage about where the Sirius name comes from. For those who don’t know, Sirius is the brightest star in our galaxy.
Removing the sleeve reveals the premium synthetic black leather coated box which flips open to show the earphone housings and silicone tip selection.
*Please click on the pictures for a larger image
The housing and tips are set in a removable foam and synthetic leather inlay. The underside of the foam inlay holds two adapters for the Sirius cable. They’re a 3.5 mm TRRS four pole balanced cable, and 3.5 mm TRS three pole cable adapter for standard (unbalanced) music sources. Removing the top layer gives access to a quality assurance card, owner's manual and a premium metal canister which holds the Sirius cable which is terminated in a 2.5 mm TRRS four pole balanced jack. Also included in the canister is a quarter inch adapter, airline adapter, cleaning tool and MMCX removal tool.
Specifications and Accessories
Specifications
Drivers: Single Exclusive Super Bass 10mm Dynamic Driver / Four Custom-Made Balanced Armature Drivers
Frequency Range: 4Hz - 45kHz
Impedance: 20Ω
Sensitivity: 113dB
Max Input Power: 30mW
Distortion: <1%
Plugs: 2.5mm/3.5mm Balanced and 3.5mm stereo, Rhodium plated
Main Cable: 1.3m
Conversion cables: 0.18m
Accessories
1X Pair FIDUE SIRIUS A91 Reference Class 5-Way Hybrid In Ear Monitor
4X Silicone eartips (XS/S/M/L)
1X Cleaning tool / disassembling tool
1X Comply foam tips (M)
1X Flight adaptor
1X ¼ inch stereo jack adaptor
1X Luxury aluminium carrying case
Every component of the Sirius package is premium with a slight exception being the tips. The black silicone tips are relatively standard in terms of materials used. The single pair of medium T-500 comply foams is nice, but several sizes would have been more ideal. I would have liked to see a more premium and larger assortment of tips come with the Sirius. It would be a negative experience for someone to purchase these and come to find out that they can’t find a tip that creates a consistent seal. Fortunately for me, I have lots of aftermarket tips to try with these earphones.
Housings
The build quality and aesthetic of the Sirius housings are stunning. They’re a cleverly constructed gunmetal gray aluminum shell. It’s relatively lightweight for its size, and is larger than your average in-ear monitor. The Fidue inspired layering is formed on the outside of the housing, similar to designs with the A83 and A73. The Fidue brand logo is printed on the outside. The inside of the Sirius housing has a few driver venting holes and L/R channel markers.
Nozzles on the Sirius are slightly wider and and shorter than the average in-ear monitor. There is no lip on the nozzle. These factors will make tip rolling a bit more of a challenge than average, although not incredibly difficult. For the most part it's a matter of applying some extra effort to get the tip’s bore to stretch over the wider nozzle.
The cable connects via MMCX plugs and jacks. There is also machined threads outside of the connectors which allows two very clever screw on fittings to hold the cable’s MMCX connections securely in place (More on this in a bit).
Cable, Y-Split, Cable Jack, Strain Reliefs
A very premium kevlar coated eight core silver plated stock cable comes in the package. The cable has very little spring and virtually no memory. It’s a little bit on the thicker side for a in-ear monitor cable and is noticeably heavier than average. The stock jack terminates in a 2.5 mm TRRS balanced jack. Two adapters come with Sirius. One adapter is for normal 3.5 mm jacks, and another for 3.5 mm TRRS balanced connections. Application wise, there is no need to purchase an aftermarket cable for most portable sources. Whether you have a standard or balanced output, the Sirius has it covered thanks to its clever cable and adapters. Owners of Astell & Kern, Onkyo, Hifiman and other portables with balanced output will be able to maximize the sound output and quality without having to shell out cash beyond the Sirius asking price. Although it is added (and unwelcomed) bulk, it does its job and works well.
Strain reliefs are heavy duty rubber and are well done. I have no concerns about cable shortages. The Y-split and straight style cable jacks and adapters are jacketed in metal and are very rugged. There’s nothing about the cable that looks like it's going to break any time soon. If there’s one thing that I would question about the Sirius cable, it’s the kevlar/cloth material used to cover the cabling. Although it hasn’t happened yet, I assume months or years of daily use could eventually cause the cable jacketing to fray.
The MMCX connection on each channel is excellent. Over the last year MMCX has become more and more popular, and also more and more scrutinized by audio enthusiasts. Over time, MMCX adapters can loosen and cause intermittent or total signal loss as a result of strain and daily abuse loosening the connection. Fidue has addressed this by adding a locking mechanism. After snapping the MMCX jacks into the housing, a metal ring twists into place around the connection, securing it in place and making it just as strong as a wired connection.
Functionality
The Sirius is all about maximizing the listening experience rather than being a cell phone companion. There is no microphone or remote that comes in the package. However, you can purchase an aftermarket cable with this feature if need be. If I had to guess, Fidue will probably release a phone cable with their exclusive MMCX locking mechanism in the future.
Ergonomics, Fit and Microphonics, Isolation
Although larger than the average in-ear monitor, I was able to get a fantastic fit. The bulkier size of the housing helped to fill the concha of my ear, and provide a secure and comfortable fit. The shallower fit could be an issue for some but I had no problem with this. Tip rolling, and finding a longer bore tip will extend the nozzle and remedy things if this is an issue for you. I wasn’t able to get a good seal with the stock tips, and foam tips seemed to impact the soundstage and made the sound too smooth for my preference. I was able to get a good seal with large Spiral Dot tips. One thing to note, the Sirius doesn’t create a vacuum like seal in my ears similar to many other in-ear monitors. Because of this isolation is average at best.
Microphonics are basically non-existent thanks to their over-ear fit. If you do experience microphonics, a chin/neck slider will help snug the cable in place and prevent the cable from rubbing against surfaces above the Y-split. I usually look for a chin/neck slider in an earphone to secure the over-ear fit, but the weight of the Sirius cable creates enough of a tug that I didn’t necessarily need to use it for the most part. Gravity holds the cable securely over my ears.
When using the Sirius for long listening sessions, the cable would create a small amount of irritation from the kevlar jacketing rubbing against the tops of my ears. I was able to easily remedy this by using a pair of aftermarket ear guides. To be honest I’m splitting hairs here. I don’t use ear guides for the most part because the discomfort is so minimal and only happens when listening to the Sirius for hours while on the go.
Sound Review
I did my demo with my usual gear. I used an LG-V10 for smartphone use, and either my Shanling H3 or iBasso DX80 DAP/Bushmaster D14 DAC/Amp for high fidelity portable use. For desktop use, I used my Toshiba Satellite Laptop in combination with a ifi micro iDSD playing at 32/192 kHz. I tested them with several other sources as well. I used Google Music in its highest download quality (320 KBPS), and also streamed FLAC via Tidal streaming service. I also used purchased and downloaded tracks in MP3, FLAC, WAV and DSD. I make sure that any gear I test has sufficient playtime before writing a review.
I used my usual same songs for testing gear:
“Limit to your love” by James Blake (bass speed, punch, response)
“Doin’ it Right” by Daft Punk (sub bass)
“Get lucky” by Daft Punk (bass to midrange transition resolution, male vocals)
“Madness” by Muse (soundstage, separation)
“Some nights” by Fun (soundstage and male vocals)
“The soundmaker” by Rodrigo y Gabriela (texture and imaging)
“Bassically” by Tei Shi (bass to midrange resolution, female vocals)
“Skinny Love” performed by Birdie (female vocals, acoustic playback)
“One” by Ed Sheeran (male vocals, acoustic playback)
“Outlands” from the Tron Legacy Soundtrack (symphonic presentation, imaging)
“Sultans of swing” by Dire Straits (detail, separation, balance)
“And Justic for All” by Metallica (driver distortion, treble response, rock playback)
“Ten thousand fists” by Disturbed (driver distortion, treble response, rock playback)
Note: Other tracks were used, but the listed songs were primarily used to assess and break down the gear’s response.
Source Selection
Sirius comes in at a comfortable twenty Ohms. One thing I really appreciated was how well they worked with just about any portable and low powered source I had. I consider this to be a decisive advantage over many of the very sensitive top of the line multi-armature and hybrid earphones which can cause noise floor issues depending on what source they are used with. The Sirius sounded good with my smartphone, DX-80, micro iDSD, and just about every other portable source I tried them with.
The unique tuning of the Sirius didn’t necessarily discriminate low bitrate music files or poor recordings. They are slightly forgiving and won’t make your MP3s sound bad. They will upscale well and are pushed to their full potential when using them with your best files and source with a balanced output.
Sound Signature
*This graph was provided directly from Fidue
The A83, A73 and A71 were all at least to some extent bass forward, so I was expecting the A91 Sirius to follow suit. This wasn’t the case. The A91 Sirius bass is adequate in terms of quantity and quality, but it isn’t the most forward frequency in the mix, nor is it the star of the show this time around. The tuning will work with all genres, but won’t render the same bass forward response that many consumer oriented earphones do. The Fidue team has taken a more mature and high end approach to the tuning of their new flagship. The Sirius sound is very balanced and leans slightly towards a midrange forward sound and overall smooth presentation. The key word is SOUNDSTAGE (which I will touch on later).
Sirius sounds like a top of the line full sized headphone to my ears. The Sirius makes vocals and midrange instruments the star of the show, regardless of whatever genre you use them with. Their perceptually and slightly forward midrange presence combined with a tremendous level of quality, detail and texture in this range makes these earphones both unique and exceptional. Add a tremendously detailed, extended and smooth treble response, Sirius has a sound signature that is incredibly engaging and easy on the ears. This is done without sacrificing detail or extension on either end of the sound spectrum.
Another great feature about the Sirius sound is that I can enjoy them at any volume without feeling like I’m losing any sound quality. The Sirius sounds just as good to me at lower volumes as it does when I crank it up.
Bass
In terms of forwardness, I’m not going to say the bass of Sirius is polite, but it is the next step up from it. Bass of the A91 is responsive without being incredibly punchy. Extension and tone are world class. Sirius has dynamics that purists will appreciate. Bassheads might be wishing for more boost with these, but those who want a more natural and realistic bass response will appreciate this tuning.
In terms of sub bass, they aren’t rolled off at all to my ears. The Sirius extends to the limit of my hearing and hits every note easily. The balance and transition from the lowest of bass notes to midbass is pretty flawless. Midbass is decent and in nice balance with surrounding frequencies. The A91 midbass is on the softer side in terms of its attack and decay. Even still, things like midbass bleed don’t even need to be mentioned with Sirius.
When reviewing an earphone for review, I figuratively try to split hairs and find anything others could perceive as flaws. If there’s one minor caveat about the Fidue bass is that I wish it was a tiny bit tighter and punchier. With the A91 there’s a little bit more rumble than punch. Other than that it’s excellent.
Summarized, the bass of the A91 isn’t the star of the show, but it isn’t necessarily lacking in any way either. It has weight to it, it's extended and very adequate, but it isn't the prettiest girl at the dance. We're about to meet her in the next criteria.
Midrange
This is where I find the Sirius to be magical. The keywords are balanced and beautiful. As compared to many other pairs of earphones, the Sirius midrange is perceptually slightly more forward than average to my ears, but without any perceived spike or drop. Midrange sounds, especially vocals will pop and take center stage in a magical way. The midrange is just a touch on the warmer side of neutral, and doesn’t render ANY sounds unnaturally to my ears. The dynamics, timbre and detail are insane for an in-ear monitor.
Fidue’s midrange is rich and dynamic without being artificial. Male and female vocals are great, and harmony is fabulous. When reviewing, I usually look for complex music passages to cause the earphone to lose its level of resolution, but with the Sirius I look forward to hearing complex layering of sounds. The Sirius handles it like a boss, and plays with a world class level of separation.
If you are a fan of acoustic music and live recordings, these are something I strongly suggest you check out. You won’t hear midrange as alive and vibrant as this very often from an in-ear monitor. Like I said before, the Sirius will sound good with just about any genre, but play something that calls for spectacular midrange and you will hit a sweet spot with them.
At the time of writing this review, I can’t think of an in-ear monitor that does midrange much better. I’m being “SIRIUS” when I say that (Sorry, I had to use that at least once in this review). There’s nothing I could identify as a fault. Maybe someone coming from a much colder sounding midrange would find them to be a bit colored.
Treble
Treble is detailed, extended and smooth at the same time. A lot of times earphones trying to achieve a “balanced” or “natural” sound will have some funky level of extension that is hard on my ears at louder volumes. Fidue has taken that edge off of upper frequencies without losing the natural and balanced feel. I can hear sibilant sounds without them being harsh. Some people might desire a little more sparkle, buy I really enjoy how the higher frequencies are presented on the Sirius. These are a fatigue free listening experience thanks the the smooth and detailed treble response. It’s refreshing to hear an earphone that doesn’t have any perceptual roll off while avoiding harsh spikes.
Soundstage and Imaging
What I’m about to say might leave some scratching their heads. I own a lot of earphones, but the best earphones I’ve heard in terms of soundstage is a properly driven Havi B3 Pro1. Yes, it’s a fifty dollar earphone, but hearing is believing. If you own the Havi B3 Pro1 you probably know what I’m talking about. When driven with the proper source, The Havi soundstage is world class.
The Sirius and Havi have a somewhat similar soundstage in terms of width. Take the Havi and relax the treble just a bit (while keeping the extension). Now, give the the Havi considerably more soundstage depth. That is what the Sirius is. The A91 soundstage is massive to my ears, trumping most of my full size headphones.
Midrange takes the center of the stage, with supporting frequencies that have plenty of detail, balance and extension. I consider the A91 imaging to be elite.
Comparisons
Campfire Andromeda ($1000 USD on ALO Audio's website)
The Andromeda is the earphone most people have asked me to do a comparison with. They are number one on my list at the time of writing this review. Their five balanced armature and patented “resonator box” delivers incredible fidelity. They are one of the most complete sounding earphones I've heard.
Comparing the two, the Andromeda is the cleaner sounding of the two, while the Sirius takes a more musical approach. The Andromeda is slightly brighter, slightly more detailed and extended at upper frequencies. Bass on the Andromeda is slightly more forward and tighter. Midrange of the Sirius is warmer, making the Andromeda midrange seem colder in comparison. Sirius has a more engaging midrange, and sounds better at louder volumes. In terms of preferences, those who like musicality, soundstage and vocals will prefer the Sirius. Those who prefer detail and extension will prefer the Andromeda. I feel blessed to have heard both. They both deliver world class sound quality.
In terms of universal driveability, Sirius gets the edge. With more powerful portable sources I get a background hiss from the thirteen Ohm Andromeda. Even still, matching the Andromeda with the right source, the sound is pretty amazing.
Build quality and design goes to the Sirius. The MMCX cable and adapters is more solid and universally applicable than the Andromeda. The Sirius is a more comfortable and easy to wear earphone as well. I give a slight edge to the Andromeda for accessories. Their leather case is more pocket friendly and their tip selection is a bit better.
Unique Melody Miracle V2 Universal ($1000 USD on Musicteck’s website)
The Miracle is an incredibly balanced and transparent pair of earphones. I consider them to be a more extended multi driver upgrade from the ER4 in terms of neutrality. Unique Melody’s six driver earphone produces an incredibly linear sound to my ears.
Comparing the two, the Miracle V2 bass is tighter and punchier than the more musical dynamic driver bass of the A91. Midrange of the Sirius is more engaging, dynamic and all around more fun to listen to than the more technical approach of the Miracle V2. Fidue’s flagship has another dimension of musicality and energy to its midrange presentation. In terms of treble, the Miracle V2 has a more more forward and technically accurate treble response. Sibilance in recordings will sound more natural, but also slightly harsher (especially at louder volumes). If you like “true to the recording” type of sound the Miracle V2 will be the way to go. If you are going for all out musical enjoyment and fatigue free listening, go for the Sirius.
Build quality and design goes to the Sirius. The Miracle V2 cable is cheap in comparison. The metal housing of the Sirius are superior to the acrylic build of the V2. Advantage goes to the Miracle V2 for accessories. They offer a larger variety of high quality tips.
Conclusion
If I took the earphones I have that cost five hundred dollars or more and put them in the hands of someone who doesn’t follow this hobby the way most of us do, and asked them which earphone they think is the most expensive, I can almost guarantee that most people would guess that it’s the Fidue Sirius. The build quality is heavy duty and truly extraordinary.
The tuning takes midrange and soundstage to a level that isn’t often achieved from what I’ve heard in in-ear monitors. This goes for products that cost much more as well. The Fidue A91 is meant for the person who wants to maximize sound quality through their best portable or low powered desktop rig. If you want to take your listening experience to another level, and experience the midrange and vocals of your album collection all over again, I strongly suggest you try the Sirius.
When rating this product (and factoring in price), I have to take into account all criterias and average them out. I give the Sirius four and a half to five stars for build and design, four and a half to five stars for sound (depending on your preferences), and four stars for accessories (minus one star for lack of tip selection). All in all I give the Sirius four and a half stars. They are definitely worthy of their flagship status, and a top contender for the best universal in-ear monitors the world of high end earphones has to offer.
Thanks for reading and happy listening!