Big thanks to InEar and Musicteck for providing a review sample in exchange for my honest opinion.
Manufacturer website:
http://www.inear-monitoring.eu/en/produkte/inear-universelles-monitoring/monitoring-stagediver.htm
Musicteck website (official InEar US distributor):
https://shop.musicteck.com/products/inear-stagediver-sd-4-standard-small, also available on Amazon.
Intro.
When I received my review pair of InEar StageDiver SD4s monitors, I thought they made a mistake and instead of universal StageDiver series sent me a custom one from LivePro series. I have reviewed multiple dozens of universal and custom IEMs, but never seen such a unique shell design which looks like something generated from a custom ear impression mold. Later I learned that SD shell was created from an overlap of over 500 different ear scans used to come up with one common shape for universal fit. I'm probably jumping ahead of myself with design impression and will definitely come back to it later in more details, but wanted to mention that StageDiver design got my attention from the first look!
While being familiar with so many different US and Asian IEM manufacturers, German InEar was never on my radar until I was asked by their official US distributor (Musicteck) if I’m interested to take their flagship StageDiver model for a test drive. I was pleased to learn that InEar takes care of all the development and production, uses the latest CAD tools, and implements advanced 3D manufacturing system. Also, they target different groups of audience with products designed for pro musicians, music enthusiast, broadcasting professionals, as well as making hearing protection and communication devices for those involved in outdoor construction and car racing.
The StageDiver SD4s model represents their flagship in-ear monitor quad BA driver design and will be the focus of my review. Just for clarification, the “s” suffix of the model name stands for “smaller” shell version which they also offer in a regular size under SD4 model name, identical in spec and performance but slightly bigger in size. Now, let’s take a closer look to find out about my experience with SD4s after spending 3 weeks of testing.
Unboxing and Accessories.
There was nothing special about the unboxing since the packaging itself consist only of Pelican 1010 micro case with a branded company sticker on top of the cover. In theory, you are not going to get a better protection than these common Pelican micro cases, and visiting InEar website can provide you with all the spec details. Sometime I still crave to see a fancy packaging box, though perhaps it’s just me reminiscing good old days of brick’n’mortar stores where I as able to visit a physical place and browse the isles while looking at the packaging to read about the product inside. But I have to be realistic, and it looks like InEar followed a robust protection case packaging route with more emphasis on a product inside.
Opening the case reveals a pair of SD4s with a surprise of a “custom” universal shell, a set of silicone single flange eartip pairs in XS/S/M/L size, gold plated 1/4” adapter, and 3 cleaning wipes (!!!). With an adapter, I usually consider it as fillers for IEMs since many people use earphones with portable sources, but I have a feeling it was included here intentionally since InEar puts an emphasis on professional use where musicians often deal with pro equipment and 6.35 jacks. Eartips cover different sizes, but for me personally I found an absolutely necessity to use Comply tips (T500 size). As much as I'm not a fan of fumbling with foam tips, I needed these badly to improve the seal in order to bring up the bass and to tame down upper frequencies. This fine tuned the sound to my personal liking.
With cleaning wipes, I’m puzzled. Perhaps the idea of universal shell suggests sharing and maintaining a proper hygiene, thus a necessity for wipes. Not quite sure about this one, but it was definitely something different which I haven’t seen with any other IEM or CIEM during unboxing. Overall, unboxing experience was very basic and the amount of accessories was limited by the space inside of Pelican protection case. Lack of packaging box is not a showstopper, but I would suggest to include at least a pair of T500 Comply tips – they do come in handy!
Cable.
The original stock cable that comes with SD4s is a typical generic OFC wire in a tight rubbery jacket, very pliable, and with hardly any microphonics. Though it's a generic cable, the 3.5mm gold plated 90deg plug stands out with a unique flat housing and a good strain relief. It was refreshing to see something different, and it fits all my DAPs without a problem, but I wish the collar of the plug would have been a little taller to accommodate thicker smartphone cases. It worked ok with mine, but left hardly any margin. I know, cable is replaceable and some don't even care about using TOTL IEMs with a smartphone, but I found a brighter SD4s signature to pair up well with warmer sound of my Note 4.
From the headphone plug you have 3 twisted wires going to a rubbery y-splitter with a good strain relief at each end. Having a dedicated y-splitter instead of a shrink-wrapped one always a plus, but here it also means combining ground wires going down to the plug. Does it make any difference versus 4 twisted wires with separate grounds? I didn't hear any sound changes while comparing to my other generic OFC cables with separate ground wires, but you never know if someone decides to re-terminate their cable with a balanced plug. Going up you have a clear tube chin-slider with just enough friction not to slide freely, and further up you have memory wire underneath of a soft flexible tube, both attached to standard 2-pin connectors marked with Red (right) dot and Blue (left) dot for easy id.
With SD4s shells having recessed sockets, these connectors went right in without any problem, though you have to be careful since the socket is slightly angled and you have to be sure not to force it in. But as I mentioned before, this is a universal 2pin connector which should be compatible with aftermarket cables. The big question here, is there a benefit in upgrading SD4s cable? I will talk about SD4s sound signature later in the review, but per my own personal preference and taking into consideration a brighter and more revealing signature of these monitors - I didn't like the effect of pure silver or pure copper or SPC cables which made sound crisper and brighter. Stock OFC wires kept the sound smooth and non-fatigue. Your mileage may vary, but in my opinion there is no need to invest in any replacement cables to enjoy SD4s to their full potential.
Design.
I already mentioned in the intro of the review that a shape of SD4s was derived from overlapping of over 500 ear impressions to come up with one unique universal design. I found they fit to be very comfortable and the shell, which appears to be made from acrylic material, to be lightweight and slick. Actually, it was a bit too slick where you have to be careful when replacing the cable because the grip is rather slippery, and I would suggest doing it over a secure surface. There is no issue otherwise when cables are attached and the only way to wear SD4s is with a wire over your ears.
Though the shells have a black glossy piano finish, InEar offers an optional wooden faceplate veneer for an additional fee. I love the idea of IEM/CIEM customization, though in case of SD4s I'm not so sure any additional customization is even necessary, but it's always nice to have it as an option. Also, you have a choice of going either with a standard size shell or a smaller compact shell. For my review I choose a smaller shell and found the fit to be just perfect with an excellent isolation.
Even so they have universal fit, I still found myself putting them in my ears and taking them out with a typical clock-wise rotation, similar to how I handle CIEMs – just a force of habit. Due to a unique shape, the shells are not symmetric and there are plenty of clues to distinguish Left from Right sides. As I mentioned before, the recessed socket accepts 2pin connectors which have red/blue dots, the marking on the shell has company/model and a serial number with R/L suffix, and also the nozzle has a red/blue filters which is hard to miss.
The SD4s features removable/replaceable filters, not for a sound modification purpose but rather for keeping earwax away from the drivers. Even so SD4s has its 4 drivers partitioned in two-way system with two low drivers and two mid-high drivers, they go up to a single bore opening inside of the nozzle where sound is mixed going into your ear canal. And to protect earwax from getting inside of the nozzle, they have replaceable cerumen (earwax) filters which are sold in a set of 15 color-coded pairs at an additional cost of $29 (
here). The set comes with a really neat dispenser which also has old filters collector, and a special tool to remove and to replace these. Personally, I get very little earwax build up so these can last me a very long time, but it could be a different story for others. You do have to keep in mind the additional cost of buying replacement filters, but you do get 15 pairs which could last you awhile. Also, in a typical German engineering fashion, I found the filter replacement steps to be quite engaging. Furthermore, keep in mind that you can get TSX500 series Comply eartips which already have earwax filter built-in.
Filter replacement.
The fit.
Sound analysis.
I don’t preach about burn-in, but simply state that I believe in what I hear. Even with multi-BA driver monitors there could be a burn-in effect of solder joints and miscellaneous crossover/filter components. The reason I’m bringing this up, out of the box I really liked how SD4s paired up with Linum BaX cable and even suggested to Musicteck who carries cables in addition to earphones, to sell it as a bundle. 75 hours later after a burn in where I left SD4s playing alone, the BaX made sound too bright for my taste, and I went back to a stock OFC cable. Now, with stock cable and TSX500 Comply tips while being driven from my “reference” Lotoo PAW Gold source, I was ready to analyze the sound.
I hear SD4s to have a slightly V-shaped sound signature with a bright revealing tonality. These are designed for performing artist where you typically find CIEM shell for the best fit and isolation, yet SD4s is able to accommodate all that with their universal shell design. Often with V-shaped signature you will find a sound tuning where the mids are scooped out too much, but in case of SD4Ss I hear it more like a boost in mid-bass region and also enhanced upper mids and treble. Actually, treble is not just lifted up but also extended pretty far to reach some piercing airy highs.
In more details, sub-bass is present and quite extended, but the rumble quantity is at a moderate level, maybe closer to a neutral level. The star of the low end is a tight punchy mid-bass with an overall articulate bass performance, always under control and never spilling into lower mids. In some songs I felt like upper mids/treble overpowered low end a bit, but I was still able to distinguish a tight punchy bass that always cuts through the mix with a fast attack/speed. With a supplied silicone tips, even the largest size pair, bass was lacking in quantity until I switched to Comply which improved the seal and brought up the low end performance.
Lower mids are on a thinner side, not much contribution to the body of the sound but rather contribution to v-shaped signature due to having a slightly recessed perception. Contrary to that, upper mids are bright, very detailed, quite revealing, and with plenty of crunch. When it comes to vocals the focus is not on natural organic full body performance, but rather accuracy and details. Those who prefer lush warm natural vocals need to look elsewhere since SD4s is not about that, at least not to my ears. As a result my perception of vocals was a bit on a grainy side which became slightly fatigue over an extended listening period while using silicone tips. Again, I strongly recommend Comply (T500) eartips which do the magic of smoothing out a few harsh peaks.
Treble is bright and clear, nicely extended, full of crunch and airiness, and very crisp. I'm not gonna lie, with the original silicone tips a few of the test tracks got close to a threshold of my sibilance tolerance, but Comply T500 set of eartips got everything under control. Being so used to warmer and smoother sounds of headphones I have been reviewing lately, this was quite a revelation of details that jumped right in my face, and thanks to foam eartips I was actually able to enjoy a longer listening session. As a disclaimer, take this with a grain of salt since we all have a different threshold for high frequency tolerance.
Soundstage expansion was impressive in all 3 directions. While not exactly on a holographic level, the width/height/depth were all above the average without any exaggeration. Here, I can also see the effect of treble extension with extra airiness which contributed greatly to separation and layering of instruments and vocals. There is absolutely no congestion of sound and everything could be easily distinguished. I also found imaging to have a good placement of instruments and vocals, very accurate position where I can pin-point everything.
Last, but not least, InEar specs SD4s at 26dB of isolation which I’m not equipped to measure exactly but can definitely confirm – outside noise was attenuated significantly. Plus with Comply foam tips, were I actually prefer to use TSX500 that have a rounded comfortable shape, I felt the isolation to improve even further. Furthermore, with a lip around the tip of the SD4s nozzle, Comply tips always stayed on secure when taking SD4s in/out of my ears.
Comparison.
SD4s vs CFA Andromeda – Both have a very similar soundstage where depth/height are nearly the same, while Andro is a little wider. Andro sub-bass also a little higher in quantity and mid-bass has a slightly stronger impact, but the speed and the articulation of the low end is similar. SD4s lower mids are thinner and overall mids are a little recessed in comparison to a more balanced Andro signature. Also, SD4s upper mids/treble are more revealing and slightly brighter in comparison, but not as smooth or have the same natural body as Andro. SD4s treble extends further and has a little more airiness.
SD4s vs UM Maestro – the height of soundstage is similar, but SD4s has more width and more depth in comparison. Maestro has deeper sub-bass, while mid-bass is nearly identical with the same amount of punch and the same fast attack. Both have thinner lower mids, but SD4s is slightly more recessed in comparison. Upper mids in Maestro are a little smoother and have more body, making vocals sound more natural. Treble is very similar, bright and crisp with plenty of airiness, though SD4s has a slight edge in extension.
SD4s vs 64 Audio U6 – soundstage has the same depth and height, but SD4s is a little wider in comparison. U6 has a deeper sub-bass with more rumble, while mid-bass punch is nearly the same. U6 lower mids are thicker in comparison, and have more body. SD4s upper mids are more revealing and brighter, while U6 is smoother, warmer, and more organic in comparison. SD4s treble has a better extension, brighter, more crisp and with more airiness.
SD4s vs Sirius – soundstage has a similar depth and height, but Sirius is wider in comparison. Sirius sub-bass extends deeper and has more weight to it, while SD4s mid-bass has a faster punch and overall bass is tighter in comparison. Sirius lower mids are more balanced, warmer, and with more body, and Sirius upper mids are warmer and smoother and more organic in comparison to SD4s which is more revealing and brighter. SD4s treble extends further, more crisp and brighter, and has more airiness.
Pair up.
I suspect that due to its high 120dB sensitivity, there was some underlying hissing with most of the sources, but surprisingly it was mild and not too distracting. And with 22 ohm impedance it paired up well with all of my sources.
I found neutral-bright tuned sources to enhance the revealing nature of SD4s, though it can also make them sound a bit too bright. For example, it paired up great with LPG, Opus#1, X7 w/AM2, and N5 but could get a bit too bright with some of the tracks (based on my personal taste).
Contrary to that, going with warmer/neutral sources such as my Note 4, X3ii, and L5Pro made the sound more organic while still keeping it very revealing and detailed. Surprisingly, it also paired up great with my laptop which is my warmest source.
By far, the best pair up was with Micro iDSD where switching to ECO gain and High Sensitivity sub-gain reduction yielded the sound quality which actually became more balanced and even added some body. But the most important - the sound became more natural and organic.
Conclusion.
On their website InEar mentions the company works according to a principle of "for Musicians by Musicians". I don’t think I could have said it better myself. Stage musicians need monitors that are comfortable to wear, have great isolation, and have a clear and detailed sound tuned for performance. That’s exactly what you're getting with SD4s and their custom-like universal shell with a secure and comfortable over-ear wire fit, great sound isolation which can be enhanced with foam eartips, and a performance oriented sound tuned with a great low end impact and a clear detailed crisp highs. For an extended listening session where you are craving a smooth relaxed natural sound, these might not fit the bill exactly, but music enthusiasts who want to squeeze out more revealing details from their in-ear monitors will greatly appreciate SD4s tuning and will enjoy the comfort of their fit.