BGVP YSP04 Metal 10.2mm Dynamic Unit In-ear Earphone Hifi Headphone with Mic Titanium Crystal Coating Composite Unit Headset (Silver with mic)


Headphoneus Supremus
Pros: Stellar build quality - Unique design
Cons: Redundant accessories - Overwhelmingly boosted, textureless bass

Today we’re taking a brief look at the YSP04 from BGVP. The brilliance of the naming schemes for products from this company continues to escape me…

The YSP04 features a 10.2mm nano-titanium crystal composite diaphragm which is mounted transversely within CNC machined metal housings out of which extend a 32 strand, double shielded OFC copper cable. Sounds impressive doesn’t it? Does it all come together to produce a good sounding earphone worthy of your hard-earn dollar? Well, sort of.


The YSP04 was purchased at a discounted rate for the purposes of review. The thoughts within are my own and do not represent BGVP, Penon, or any other entity. There has been no financial incentive put forth for writing this.

At the time of this review the YSP04 could be picked up for 19.50 USD:


For at home use the YSP04 was powered by a TEAC HA-501 desktop amp or straight out of my Asus FX53V laptop. For portable use it was paired with an LG G5, HiFi E.T. MA8, Walnut V2s or Shanling M1, all of which brought it up to listening volume without any effort. I enjoyed running it through the Walnut F1 which lowered the absurd mid-bass quantity.

Personal Preferences:

I listen primarily to various EDM sub-genres (liquid drum and bass, breakbeat, drumstep, etc.), hip hop, and classic rock. While I enjoy a variety of signatures in my headphones I generally lean towards slightly warm with elevated treble and sub-bass, an even and natural mid-range response, with reduced mid-bass. The HiFiMan RE800, MacaW GT600s, and thinksound On2 offer examples of signatures I enjoy.


Sensitivity: ≥110dB

Frequency Response: 13-23000Hz

Drivers: 10.2mm titanium crystal composite diaphragm dynamic driver

Impedance: 18Ω

Maximum power: 15mW

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Packaging and Accessories:

One thing BGVP does quite well is offer up their headphones in a nice package, and support it with a strong accessory kit. The YSP04 is a good example of this arriving in a small case about the size of a watch box. The exterior sleeve which can be easily removed features the BGVP logo on the front and a sticker on the back with the YSP04’s specifications.

Sliding off the sleeve and lifting the lid reveals the earphones displayed in a foam cutout, much as you would expect had BGVP been selling you a watch instead. Lifting out the foam insert reveals the cable neatly wrapped, and a pile of accessories;

  • felt-lined carrying bag
  • black silicone tips (s/m/l)
  • green silicone tips (s/m/l)
  • orange silicone tips (s/m/l/)
While I appreciate that BGVP gives you a ton of spare tips, they’re all pretty much the same tip but in different colors. This means that if one set doesn’t fit your ears well, none of them will. Some variety in tip style is sorely needed in order to provide legitimate value to the quantity and give you options in getting the best possible seal. As is, they might as well have dropped to sets and included something else.

Build, Comfort, and Isolation:

Another area BGVP seems to excel in is build, something you immediately sense upon first picking up the YSP04. The feeling of quality puts much more expensive products to shame when you see how carefully machined and well-put together this earphone is. There’s no glue squeezing out between the component parts and nothing sits at an odd angle or with gaps here and there. The L and R indicators are printed and look very sharp, as does the YSP04 branding on the inside by one of two pin holes vents.

The excellent materials and build continues to the cable which is a standout among budget offerings. The sheath is very dense and durable with strong anti-tangle properties, no stickiness, and no bounciness. It does retain some memory meaning the original bends from when you first unpack the product stick around for a while, but that’s about the only real negative. Strain relief at the ear pieces and 45 degree angles jack is excellent, and the inclusion of a chin cinch is always welcome, even if movement is limited by the inline mic. Speaking of the mic, the module is a common one found on a few other products but it’s well built. The button clicks purposefully with a clear, tactile response and the mic sounds good on calls.

Despite the odd shape and sharp angles, the YSP04 is not an uncomfortable earphone. This is likely due in part to the light weight and stubby nozzle that protrudes straight out of the housing. At least for me, it ensures the earpiece doesn’t touch my ear at all, and sort of floats in place. If it didn’t do this, I could see the angles touching and causing hotspots which is something I suspect others users may experience..

When it comes to isolation I found the YSP04 well below average for a metal-shelled single dynamic, blocking out very little sound. When using this earphone outside, turning the volume up considerably more than I liked was a necessity to combat external noises like cars and voices. The sounds of my keyboard clacking while typing away was clearly audible too, even with music playing.

Overall the YSP04 is beautifully constructed with a unique design. Ergonomically it’s pretty decent, but isolation is well below average. It’s a fine earphone to use in quieter areas, especially since it doesn’t bleed a lot of noise, but it definitely won’t cut it for commuting.

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The YSP04 is characterized by a very warm, v-shaped signature skewed heavily towards the low end, backed by an expansive soundstage uncommon in this budget earphone.

The YSP04’s treble has a smooth, easy going presentation that is completely free of harshness or sibilance. It’s not particularly sparkly, though it has just enough emphasis to keep it from being dull. Despite not being overly prominent, it still gives a good sensation of space. Detail levels are okay at best with micro details being smoothed over. This is a good presentation for long term listening, not critical listening.

The mid-range is naturally toned with lots of warmth befitting female vocals greatly. Unfortunately, the mid-range is heavily recessed. That combined with a monster of a mid-bass hump means the lower mids are subject to heavy bleed and end up sounding veiled and overshadowed more often than not. It’s pretty disappointing as otherwise the mid-range is quite pleasant.

Bass on the YSP04 is a party piece. It’s big and bold, very much devoid of any form of technical prowess. The mid-bass hump is massive and combined with a reasonably sluggish response means it is a very boomy, one-note kind of presentation. Sub-bass extension is actually quite good, it’s just hard to hear or feel over that mid-bass lump. Texture is lacking too which further emphasizes that one-note feel. This is one of those cases where the presentation is simply too smooth.

To go along with that big bass is a big sound stage. These two qualities go together pretty well actually with basslines reverberating outwards away from your head as they diminish. It reminds me of when I uses to work as an Usher Supervisor at Paramount Canada’s Wonderland during their Kingswood Festivals, standing in front of the massive 8 driver loundspeakers while trying to keep idiots from climbing on the stage. Layering, imaging, and separation are all pretty average. In all honestly these qualities are better than they should be given how silky smooth the YSP04 makes everything.

Overall the YSP04 is just okay at best. If that mid-bass hump was toned down, a lot, it would make for a very pleasant listen. However, as is the bass overwhelms and overpowers the rest of the signature and diminishes all texture and detail under some one-note thumping. I was really hoping for more from these given how great they look and beautifully they’re built.

Select Comparisons:

BGVP BKYT MRY6 (~15.00 USD): The MRY6 and YSP04 make for an interesting comparison. From a physical standpoint I find the MRY6 vastly inferior. Sure, they’re just as well built and have a look that is just as unique, but from the perspective of ergonomics they’re just wrong. The broad housings and stubby nozzles mean none of the included tips actually fir the earphone properly, and if turning to third party tips your options are severely limited due to the nozzle length. Once you find something that works they’re about as comfortable as the YSP04. You’re given 9 pairs of tips though, none of which fit. That’s just wrong. The MRY6 is a nightmare ergonomically compared to the YSP04 if using it in it’s stock format.

In terms of sound, the YSP04 and MRY6 share their bass-heavy signatures with the MRY6 getting a number of tweaks that make it superior. It tones down the mid-bass hump (it’s still huge), dials in a bit more treble, brings forward the mids which means there is less bleed, and improves clarity top to bottom. Texturing is improved as well, and the already impressive sound stage is even larger. They’re very similar and I prefer the YSP04’s mid-range tonality, but the tweaks made to the MRY6 mean it the superior sonic performer.

Kinera BD005 (~25.00 USD): The BD005 is a nice budget hybrid that for the most part seems to have flown under the radar. If tasked with choosing between it and the YSP04, Kinera would be my choice.

The earpieces on BGVP’s offers are superior given the use of CNC machined metal and a unique design. The BD005 uses a generic plastic housing used by numerous other companies. I found both equally comfortable, preferring the Kinera’s more stable over-ear fit. Their cables use an identical sheath with the BD005 getting the win there due to the use of MMCX to make them detachable. Gotta give props to BGVP for including a chin cinch though; something the BD005 could use.

In terms of sound, the BD005 is a huge step up to my ears. It’s v-shaped signature has a better balance between bass, mid-range and treble without the low end stealing the show and masking everything else. It is notably more detailed and textured with more punch and definition to it’s bass presentation.

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Final Thoughts:

BGVP nailed a number of aspects with the YSP04, but soared past the mark on the most important one; sound. It’s a fantastic looking product made from quality materials that are put together well, and the accessory kit is extensive though redundant. It’s also priced very well for what you get.

That said, while it’s treble and mid-range presentations are entirely pleasant, it is all hindered by an abundance of overemphasized mid-bass that drowns out everything else. It also doesn’t help that the YSP04’s signature is so smoothed over that this massive bass ends up one-note and lacking punch.

I am sure that there will be many out there that purchase these and enjoy the heck out of them, but in the grand scheme of things their sound is merely acceptable in the most basic sense of the word. At least they’re great to look at and well built, so you’ll surely get your money’s worth out of them in the long run.

Thanks for reading!

– B9Scrambler

***** ***** ***** ***** *****

Some Test Tunes:

Aesop Rock – The Impossible Kid (Album)

Hail Mary Mallon – Are You Going to Eat That? (Album)

King Crimson – Lark’s Tongues in Aspic (Album)

King Crimson – Starless and Bible Black (Track)

Supertramp – Crime of the Century (Album)

Infected Mushroom – Legend of the Black Shawarma (Album)

Gorillaz – Plastic Beach (Album)

Massive Attack – Mezzanine (Album)

Fleetwood Mac – Rumors (Album)

Run the Jewels – Run the Jewels (Album)

The Prodigy – The Day is My Enemy (Album)

Tobacco – screw*d Up Friends (Album)

Felt – Felt 2 (A Tribute to Lisa Bonet) (Album)

Michael Jackson – Thriller (Album)

The Crystal Method – Grace (feat. LeAnn Rimes) (Track)

Jidenna – Long Live the Chief (Track)

Skrillex – Ragga Bomb (Track)

Big Grams – Run for Your Life (Track)

Funkadelic – Maggot Brain (Track)

Aesop Rock – Fishtales (Track)


Headphoneus Supremus
Pros: Great build quality and cable. Unique and interesting design
Cons: Dominating bass

BGVP has been around for a while and as far as I know they used to be known as Sidy, or at least released several earphones/earbuds under that name. So, with that very informative little nugget of information let's get into it. Today I'm looking at the BGVP YSP04, a single dynamic earphone utilizing 10.2 mm titanium composite drivers and tuned for those who like bass. Lots of it.


This sample was provided for the purpose of an honest review. All observations and opinions here are my own, based on my experience with the product.

The BGVP YSP04 is currently priced at $29.90 and is available from Penon Audio.

Packaging and accessories

The YSP04 arrives in a simple black box that is wrapped in a black sleeve. The sleeve is plain except for the BGVP logo on the front. The box itself is adorned with the same logo and is likewise bare except for some specifications on the back.

Inside the box you're presented with the earphones in a foam cutout. Underneath are the accessories which include:
  • 9x pairs of silicone ear-tips
  • Carrying pouch
  • Shirt clip
  • YSP04 earphone
It's a very basic package but this is one of the methods manufacturers can employ in order to bring consumers high quality products at lower prices and I for one appreciate this as most of the time boxes just end up in the trash or repurposed anyway.

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Build, comfort and isolation

Right away you'll notice the YSP04 is very well built considering its low price. They're crafted from a lightweight, gunmetal colored metal in an unusual and striking teardrop-shaped design. There's a truncated cone attached to the side that holds the cable connector, has a small bass port and also denotes the Left and Right sides. On the inner side of the housing the model number is printed in black text. Overall the build quality is exceptional.

I noticed that the nozzles are very short but they have a good lip on the end which holds tips securely and because the nozzles sit at the tapered end of the housing you can still get a good insertion depth.

The YSP04's cable is also excellent with its black and silver coloring and clear outer tubing. Starting at the top there are some decent strain reliefs attached to the housing. Down the right side is a metal in-line remote with microphone. Even the button is metal and feels solid with a nice tactile click. The Y-split is also metal and just above it is a hard rubber chin slider. The cable terminates in an angled, gold-plated plug which again has good strain relief. Even when wearing them cable down there is very little microphonics present.

Comfort is surprisingly good despite the unusual shape and these IEMs can be worn over-ear or cable down. Even though the housings have a flat back with a straight edge I found the YSP04 to be right up there with the most comfortable of IEMs.

Isolation is above average (assuming you have a good seal) with the "teardrop" filling in the ear's conch and providing a natural barrier to the outside world. These are definitely suitable for noisy environments.

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Sources used for testing
Acoustic Research AR-M20
Music Bee > Topping DX7 > YSP04

The YSP04 is easy to drive and doesn't require amplification but hooking up to a good source improves separation and layering. Having said that though it still sounds fine coming straight out of my Galaxy Note 5.

This is where things get a bit tricky for me. At times I feel the YSP04 sounds great and others pretty underwhelming. It depends a lot on what kind of music you're playing. I'll start by saying that the YSP04 has a very bass heavy sound. However it's still surprising that this earphone is also capable of revealing quite a lot of detail and good tonality. With its L-shaped signature there's lots of emphasis on mid and sub-bass which carries over well into the lower midrange but quickly clears up once you get to the middle midrange. I found that it responds very well to some EQ and with a bit of tweaking can sound much more balanced and quite nice.

Bass is definitely the star of the show here and is pretty huge. It's not boomy or loose but rather thick with good impact. Despite its slow attack and long decay it does manage to keep pace reasonably well during complex segments. Sub-bass gets a great rumble going on and is capable of shaking skulls but the metal housing and quality dynamic driver keep things in check, avoiding any distortion or looseness.

Midrange is fairly recessed particularly in the upper mids. Male vocals get plenty of love, coming through thick and rich but retaining good tonality regardless. Female vocals don't fare quite as well as they tend to get swallowed up by the low end. What is impressive here is the separation and detail that still manages to come through the thickness of the low end.

Treble is polite on the YSP04 but it does have good extension and timbre. On bass light tracks you'll appreciate its nimbleness and lightness but most of the time you're attention will be drawn to the low frequencies.

Soundstage is decent but depends a lot on the music you're listening to. Bass heavy tracks feel a little confined but in acoustic music the YSP04 is able to spread itself out a lot more. Imaging is not bad but it's not great either falling somewhere in between.



Brainwavz Jive ($28 USD)
The Jive has long been (in my opinion) the undisputed king of budget IEM build quality and while the YSP04 comes very close it can't quite match the exquisite craftsmanship of this offering from Brainwavz. Another area where the Jive is unmatched is in the accessory bundle which included the fantastic semi-hard carry case.

In terms of sound the Jive has a really clean and clear sound and a relatively linear bass in stark contrast to the massive mid-bass hump and colored lower midrange of the BGVP. While the Jive will leave bassheads feeling deeply dissatisfied it's much better suited for those who prefer a more balanced approach.

Accutone Lyra ($39 USD)
The Lyra is one that escaped the attention that it deserves as it's a very competent budget earphone. The build quality is excellent, as is the cable but the YSP04 a better feeling, metal in-line remote. The Lyra also comes with a magnet sealing semi-hard carry case. It's much more balanced than the BGVP although it does have a boosted bass presence. The Lyra has a fantastic treble that's energetic and lively but never becomes strident or harsh but does leave the mids a bit recessed.

Similar to the Jive, bassheads will likely be left feeling underwhelmed with the Lyra and if it's bass you want the YSP04 brings it in spades.



While the YSP04 won't appeal to everyone, those who like a good extra dose of bass won't be disappointed. A standout characteristic is how it's able to allow the details to come through and the tonality to remain fairly good. It's testament to the fact that the titanium composite driver and housing materials are top quality. It comes across as an intentional tuning rather than poor implementation which is why I'm giving it a 4/5 rating even though it's not my preferred type of sound signature - objectivity and all that.

So it's very well built, does what it's tuned to do (bass) well, is comfortable and priced at around $30. If you're a budget basshead you'll most likely get a kick out of the BGVP YSP04.
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Reactions: B9Scrambler
Pros: All metal housings, Awesome cable, Great over the ear fit, Bass forward tuning will be enjoyed by many
Cons: Lingering bass will be too much for some, No foam tips included
At the time of the review, the BGVP YSP04 was was on sale on Easy Earphone’s Amazon and Aliexpress stores. Here is a link to their listings of the product:
The budget-fi world of earphones has some lesser known companies that offers some very cool products. One of them is BGVP (formerly known as Sidy).
BGVP manufactures some nice budget-fi earphones that offer solid price to performance ratios. They have released some very respectable models that I’ve really enjoyed. The BGVP house sound for the most part has been a bass forward yet still clear sound. This type of tuning can be found in a majority of their product line. This review will focus on their most recent release, the YSP04.
To go along with the YSP04 review, I purchased a pair of BGVP adapters that looked too interesting to not try. To go along with the YSP04 review I will be sharing my experience with this product.
I was given an opportunity to review the YSP04 in exchange for my honest opinion and review. I am in no way affiliated with BGVP. I would like to take this time to personally thank Easy Earphones 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, especially if they can be had for low prices. I will buy the $5 to $500 earphone that looks promising, in hopes that I will discover that one new gem that can compete with the big names in this industry. If you look at my Head-Fi profile you will see that I have purchased MANY different headphones and earphones, ranging from from dirt cheap to higher end products. For me, this hobby is more about getting great price to performance ratio from a product, and have a variety of different gears with varying builds and sound 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 ergonomic, and the sound is pleasing to the ear. It is my pleasure to share my experiences with audio products and make recommendations based gear I have owned and used.
The YSP04 comes in a black box the size of a large jewelry box. The BGVP logo is printed on a silver sleeve that prevents the box from flipping open.
The back of the sleeve shows specifications in Chinese and English.
Opening the box, I was greeted with a glimpse of the unique YSP04 housings in a piece of crafted foam. Underneath this foam lies the accessories.
Specifications and Accessories
Model Number: BGVP YSP04
Transducer Principle: Dynamic
Driver Diameter: Ø10.2mm
Impedance: 18ohm
Sensitivity: 110dB
Frequency Response: 13Hz-23000Hz
Maximum power:15mW
Plug:3.5mm Gold-plated
1x Pair of YSP04 earphones
1x Shirt clip
1x Velvet carrying pouch
3x Silicone gray/red tips (S,M,L)
3x Silicone red tips (S,M,L)
3x Silicone black tips (S,M,L)
The package is formidable, but the tip selection is somewhat redundant in terms of tips. I would have traded two sets of tips for a clamshell case and single pair of foam tips.
The housing of the YSP04 is one of the most uniquely shaped in-ear models I’ve ever seen. It’s an all metal construction designed to hold a side-firing 10.2 mm titanium composite driver. It is a flat teardrop shape with a second piece of metal that attaches to the housing and leave room for cable attachment. It has a dull brushed nickel finish that looks pretty high end. The YSP04 name is printed on the flat side of the housings. Left and right markers are displayed on the opposite side.
The YSP04 nozzle is pretty standard, and sets up to make tip rolling easy to do.
Cable, Y-Split, Cable Jack, Strain Reliefs
The YSP04 cable is very nicely constructed. It has black and silver innards that are jacketed in a clear rubber coating. The cable has a small amount of spring and memory, neither of which was a major issue or created any major issues when using them. The Y-split is constructed of a black metal jacketing and rubber inner portion, with a chin/neck slider that works well. It is made of the same material and sits flush with the Y-split when not in use. The cable jack is a sixty degree design with a gold plated plug and plastic housing. Strain reliefs are subtle but very adequate. If handled with care, I don’t see the YSP04 breaking any time soon.
My pair of YSP04 didn’t come with a microphone or remote. However there is a microphone and remote version that can be purchased.
Ergonomics, Fit and Microphonics, Isolation
When I first looked at them I thought there was no way these would promote a great fit. I was wrong, the YSP04 is a great fitting pair of earphones. Wearing them cable down was in line with the average earphone in terms of fitment, with microphonics being average for a universal in-ear monitor. Wearing them over the ear, they were one of the best fitting earphones I’ve experienced. The cable is perfectly angled from the housing to go over the ear, and the chin/neck slider made these fit like a glove.
Sound Review
I did my demo with my usual gear. I used an LG-G3 with the latest firmware for portable and smartphone use, and either my Shanling H3 or iBasso DX80 DAP for high fidelity portable use. For desktop use I used my Toshiba Satellite Laptop in combination with a ifi micro iDSD playing at 32/192k Hz. I tested them with several other sources as well. I used Google Music in its highest download quality (320 KBPS) and I 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
At 18 ohms, the YSP04 is easy to drive. You can get away with using a smartphone with them, but they will benefit from higher fidelity sources and files. Their bass forward signature will be forgiving with poorly recorded music, but they have some nice clarity and upper midrange energy that will make the YSP04 upscale well. I enjoyed listening to them most with a dedicated audio player like my iBasso DX80.
Sound Signature
The YSP04 continues to carry the BGVP signature sound, being bass forward with a warm tilted midrange and a crisp finish, but they also bring an enhanced level of clarity and overall fidelity that can be appreciated by discerning listeners. YSP04 packs a 10.2 mm titanium composite dynamic driver that not only brings the BVGP thump, it’s complemented by some accuracy and detail that hi-fi enthusiasts can appreciate with this type of driver style.
BGVP ABC Cable Kit
As stated earlier in the review, I purchased some special BGVP adapters that were advertised to tweak the sound. The kit has three adapters that plug into your source and go between the source and earphone. One cool thing to note is that they are 4 pole plugs that allow you to use the mic/remote with the adapters.
NOTE: This kit IS NOT a part of the YSP04 earphone package. It is a separate BGVP item that I purchased and decided to mention in this review. Please refer to the link for them if you are interested in finding out more or purchasing them:
I’m not sure exactly what or how they tweak the sound by using three inches of cable and plugs, but I’m sure it has to do with impedance adaptation. I’m happy to say that the three cables that come in the kit does alter the sound and give users an opportunity to tweak the sound of whatever earphones they are using. I see this kit as an opportunity to change the sound signature of your earphones without having to buy another set, or allow you to tweak an earphone that you feel needs a bit of adjustment. Make sure to reference the link for this kit and read the listing description. Here is are measurements taken by my Vibro Veritas, showing you how each adapter works.
NOTE: Although I will be using this kit with the YSP04, I feel the kit worked better with the BGVP DM4. With these adapters I was able to get some really great sound out of them. To be completely honest, this kit will make for some fun times experimenting with each pair of earphones and headphones you have and help you rediscover earphones you might not listen to anymore.
Option A
Option A decreases bass and made the YSP04 sound much more linear, bringing out the higher frequencies. This was my preferred way of wearing them.
Option B
Option B provides a slight decrease in sub bass presence while increasing the lower midrange. The overall feel is a beefier and more forward midrange (especially lower midrange).
Option C
Option C doesn’t alter the frequency response very much, but seems to do something to alter the soundstage presence. Although I can’t put my finger on it by listening to it, it seems to be some kind of crossfeed or reverb effect. I actually like it quite a bit.
Now that these adapters are explained, I will continue the rest of the review WITHOUT them being used.
Bass is omnipresent with everything you play. Those looking for a lean or neutral bass presentation should purchase the ABC Cable kit (and use cable option A), or look somewhere else. Although the YSP04 bass is forward, it is responsive and carries nice tone. It is forward enough to say they’re bassy, but not bassy enough to say that it ruins the sound. Mid bass is forward without any sense of bleed into the midrange. Although the bass kind of lingers over the entire YSP04 sound, I don’t find it to be a deal breaker. Long story short, and just like almost all BGVP models, the YSP04 falls into the “basshead audiophile” category.
I really enjoy the YSP04 midrange. Although it is pretty sloped, its tuning is high resolution and sounds entertaining to my ears. The overall sound isn’t V-shaped to my ears, but rather the midrange is V-shaped in its own right. A forward lower midrange slopes downward and bottoms out at around 1-2K, then raises again at 3K, giving vocals a nice bite. Any more spike and they might be shouty, and any less and they might be muddy sounding.
Treble rolls off at sibilant ranges and picks back up around 9-10K. The overall feel is a sense of them being smooth and extended at the same time.
Soundstage and Imaging
The authoritative bass prevents me from being able to say the YSP04 has a huge soundstage. The same applies in terms of imaging. The soundstage is intimate and encompassed by some beefy bass.
BGVP (SIDY) DM4 ($70 to $90 USD on many sites)
The DM4 is a flagship product from BGVP, offering an incredible build and accessories package, as well as a similar bass forward tuning.
Comparing the two, they are more sidegrades to each other. They both have very similar bass response, with the DM4 midrange being more balanced, and treble being slightly less extended. The YSP04 tuning is a little more extended at upper frequencies and a little more detailed and dynamic.
Build quality is a draw. Both of them have the same magnificent cable and metal housings. I give the DM4 an advantage for accessories thanks to their clamshell case and slightly better tip selection.

LZ-Z03A ($30 to $35 USD on many sites)
The Z03A is a recent review, and an excellent sounding earphone.
Comparing the two, the Z03A is a leaner, brighter and crisper sounding earphone. The YSP04 is going to be preferred by those who want more bass, thicker midrange and less fatiguing treble.
I give the YSP04 an advantage in both build quality and accessories. They have a velvet pouch for transport, and have a superior cable that would usually be found on more expensive earphones.

I have been a fan of BGVP for some time now. I appreciate the “basshead audiophile” sound they bring. Although it’s not “flat” or “neutral”, it’s entertaining for sure. Although a bass forward signature isn’t always my preferred cup of tea, I appreciate that they continue to refine their “house sound." I still reach for BGVP earphones when I need to feed my primordial need for some bassy music.  
The YSP04 has basically taken a titanium driver and tuned it to their specifications. The metal housing and phenomenal over the ear fit get a big thumbs up. They have a high end build and are fun to listen to.
Treble heads and neutralists will loath the YSP04. People liking a bassy and musical sound with plenty of detail will applaud them. BVGP continues to provide a unique approach to earphones.
If the YSP04 sounds like something you might possibly enjoy, go for it. You won’t be disappointed.
Thanks for reading and happy listening!
I'm with 'Paulpark222'....I too, was curious to know more about the way they sound.
Nice review!
Very interesting design...Thanks for another great review...
Just got the ABC adapters. I think they would have been much more durable and practical in the form of adapter jacks (just like impedance adapter jacks). Too bad