For those who are interested in the company history - VSONIC was found in 1980 as a Chinese own Japanese company. In '95, the company setup its China factory for R&D and manufacture of headphone in order to fulfill the Japanese market. In '05, they began to market their products toward the China market as well as the rest of the world. While VSONIC itself might not be a big brand in the consumer headphone world, their OEM/ODM clients and partners are some of the most well known in the world. In fact, the bio-cellulose diaphragm used in the R04 Pro are said to be licensed from Sony, which perhaps serves as a testimony to the company relationship with the Japanese's giant.
R02 Pro II
Driver: 11mm Dynamic
Rates impedance: 24 ohm
Sensitivity: 105dB / 1mW
Frequency Response: 12Hz to 25kHz
Distortion: ≤ 0.2% @ max sensitivity(20upa)
Channel Imbalance: ≤ 1dB (at 1000 Hz)
Rated Input Power: 10mW
Max Input Power: 30mW
Connector: 3.5mm gold-plated stereo mini plug
Cable: 1.3M with silver-plated OFC wires
Driver: 11mm Dynamic with multi-layers bio-cellulose diaphragm
Impedance: 24 ohm +/- 10%
Frequency Range: 10-24,000Hz
Distortion: ≤ 1%
Channel Imbalance: ≤ 5dB
Rated Input Power: 10mW
Maximum Input Power: 50mW
Connector: 3.5mm gold-plated stereo mini plug
Cable: 1.3M with 6N mono-crystal OFC wires
Packaging, Build Quality and Accessories
Both IEM come with thick paper box (like a gift box) where the IEM themselves hold by foam. For the kind of price they are asking, the packaging is decent and perhaps a class better than most Chinese made IEM, but nothing spectacular to speaker of. The brownish R04 Pro box with its velvet lining do a good job to accompany and showoff the (also brownish/black colored) R04 Pro. The deviation from the standard black / white color combo that most IEM have is a welcomed change.
When it comes to build quality, VSONIC certainly shows that they are no slouch. After all, they have been in the OEM/ODM business for quite a while now. However, there is a little historical complication on R02 Pro II that I believe we should clear it up before continuing the review.
The R02 series has been quite a long running and fairly successful model for VSONIC as both an independent product line as well as an OEM product. If I remember correctly, VSONIC is one of the first (if not the first) to use this type of earpiece design. Some of the similar IEM from well known Western brand are actually OEM'ed by VSONIC using the R02 design. In recent years however, there were unconfirmed news and troubling rumors regarding VSONIC and another company with similar branding - while I don't want to go into all the tall tales and speculations, the fact is there are similar product also named R02 being sold in the current market, as well as several different generations of R02 from VSONIC itself. The point is, the one being reviewed here is the latest R02 Pro II 'Silver Cable' edition (or sometime simply known as the 'silver' edition). It is probably the best sounding and best build of the VSONIC R02 series so far. Not only both transducers of R02 Pro II are matched; they also have their own serial number. Beside using silver plated cable which said to have better sound quality than the typical OFC cable, the cable sleeve is made out of some kind of very soft, tangle free, slightly translucent rubbery material, like a cross between the transparent cable from MEElectronics and the PPE cable from HifiMAN - and like the other two, this cable looks and functions great.
The strain reliefs on the cable are also adequate, though the Y-splitter is on the small size. Microphonics is fairly low. You can use the included shirt clip or wear the IEM over-the-ear to further reduce any cable noise. Isolation is slightly below average. Good for street but not enough when it is really noisy. Like other R02 type of IEM, it is quite comfortable to the ear. Accessories wise, there are a pair of bi-flanges, 3 pairs of different sized single flange eartips (S, M, L), a shirt clip and a soft pouch.
As far as build quality is concerned, R04 (also known as R04 Pro) is one step up from R02 Pro II. It also features the same translucent cable sleeve (though in brownish color instead of the grayish silver on R02 Pro II) with ultra pure mono-crystal OFC wires. The decision to go with OFC instead of silver plated cable seems to be that VSONIC thinks OFC has a better synergy with R04's transducer. The cable itself is physically thicker than that of R02 Pro II's so it is less flexible, but overall it retains most of the same characteristic.
The strain reliefs on R04 are also beefed up. They look great but a little too hard to actually relief any strain. It would be a serious concern but the good news is that the cable is good enough that it doesn't have weak point where it can get over bent. The other downside about the cable is, since it is less flexible as that of R02, it doesn't quite want to stay over-the-ear as it is designed to. A silicone ear guide will fix the problem easily but unfortunately VSONIC doesn't include them in the package. They are however considering to include the ear guide (as well as a case and some other accessories) in their future packaging, as they also have plan to release the R04 Pro to international market.
The earpieces are rectangular on the front, but no worry as it actually quite small and fit very well due to the rounded back. One of the main features of R04 Pro is its user adjustable nozzle angle for better fit and comfort. VSONIC claims that they invented the swingable nozzle, but I have seen similar deign on Microsonic Music's IEM before. Regardless of who was the first, the truth is most likely that they had came up with the idea on their own quite some time ago (note: R04 Pro was first announced back in early 2008, around the time Microsonics Music started to get into the IEM business. I personally doubt many know or still remember either of the both events). In any case, the swingable nozzle works fairly well on R04 Pro. It is tight enough that it won't swing wildly, so the nozzle angle remains fairly precise to where you left it. The stem of the nozzle is made out of aluminum which actually looks great.
Microphonics is fairly low on the R04 Pro since it is designed to be worn over-the-ear (and best with ear guide). Isolation is slightly over average. The fit is a little on the tight side, but I won't call it uncomfortable. The included eartips are fairly good, but I end up using cloned Sony Hybrid eartips as they give me better fit. Accessories are a bit slim. You only get 4 pair of 3 different sized single flange (S, M, M, L), a pair of foam tip and a pair of big bi-flanges. As mentioned before, there might be more accessories in the future packaging.
Beside the fact that R04 Pro could use more accessories, I think I am quite happy with both of them so far.
As part of my review procedure, both IEM have been given over 50 hours of burn-in before any serious audition. Generally speaking, dynamic transducer tends to benefit more (but not always) from burn-in. In R02 Pro II, I didn't notice any major change as the overall sound remains fairly 'intact' during the whole time. On the other hand, the bio-cellulose diaphragm on R04 is said to require a little 'loosen up', so I gave it just over 100 hours of burn-in to be sure that it is more or less in its stable stage. I did notice the rough edge on the treble from the initial listening was mostly smoothed after the burn-in.
The overall sound signature of R02 Pro II is warm, smooth, fairly musical with a better than average soundstage. Treble has decent extension, but in a fairly smooth fashion and lacks the top sparkle to show off fine detail or give better resolution. Mid is slightly full, but not enough to show texture or being sweet. Bass has good impact and body, though not at the deepest end. Soundstage is good from side to side (width), but not airy enough to show true depth. It might not have the best of anything, but the overall blend doesn't have any major flaw as well. In other words, R02 Pro II has a rather 'popular' sound signature.
The overall sound signature of R04 is very warm, quite musical, mid-centric with a good vocal performance. Treble extends far enough, but has some unwanted peaks on the lower end and roll off too early at the upper end, giving the feeling of veil with little rough edges. Mid is full, forward, sweet and well textured. Bass is slightly above neutral with decent impact, not quantitatively large in any sense but fairly good in quality and helps to accentuate the mid. Soundstage is only average but with better resolution than R02 Pro II.
While R02 Pro II has a mellower, easy going sound to suit different genres of music and taste, R04 strength in mid range makes it great for vocal but a poor choice for most instrumental music. The official price for R02 Pro II is around $30 in China, which is much more attractive than the $40+ price point commonly found on eBay (not to be mistaken with the cheaper and older R02 Pro). The official price for R04 is around $73 in China, and the good news is the only R04 seller on eBay is selling it at a reasonable $78. It is not hard to recommend both models even on the higher prices, but VSONIC ought to find a better way to distribute their products internationally without inflation. Let's cross our fingers that VSONIC could spend more effort on establish better distribution route on the near future with the updated R04 package (with better accessories) and certainly before the release of their true flagship, the R07. With rumors of R07 going to be almost $150 a pot, I can't imagine how much eBay seller will inflate the price.
You can read the quick sum up here.