This review covers the comparison of three different headphones.1. Max Rock Soft Silicone Headphones $9.99 Without a doubt, the best earbud I have yet used, however, as the R6 is a reference headphone, I am comparing against other reference headphones, hence the 4 stars.Standard disclaimer: I am an audio engineer by training and profession, currently making my living as an audiovisual technician. I am NOT a top producer with 40 years experience, and I do not hold a PhD in acoustics, but I can speak from some low level of authority on this particular topic.Spectrum: Advertised frequency response range is 10Hz to 19kHz, roughly correlated by my toe generator. Of course, notes are indistinguishable below around 20Hz; lower than that the oscillations just sound like a mechanical repetition, like a two stroke motor, but those oscillations drop off sharply in loudness below 10Hz, so there we are. On the upper end, I have to admit that I can't hear much above 18k despite having taken exceptionally good care of my ears, but the advertised figure seems accurate to me.The overall sound of these headphones, in regards to spectrum, is a bit dark, which to me is reminiscent of Sennheiser's characteristically dark tone in their reference cans, specifically the Hd 550 and 650 models. The darkness of the R6's tone is perhaps less pronounced than Sennheiser's, but can result in some murkiness while reproducing certain recordings.Most musical tastes will favor this tone, however, I find that, as with the Sennheisers, I have to turn the volume up uncomfortably loud in order to listen analytically in the 4 kHz to 8 kHz range. I will be sure to update this review if the high end opens up over the "break in" period, however for that matter I have never experienced a spectral change in headphones over time that I couldn't chalk up to just my brain adjusting to the headphones' tone.All of that being said, my favorite reference cans are my Grado 325i, which have a nice bright tone that some listeners find annoying. Different strokes.I find the bass response to be a touch exaggerated for a reference headphone, but not overbearing for everyday listening, which is pretty much perfect. I wouldn't change a thing on the low end.Incidentally, the seal formed between the oval tip and your ear canal is absolutely essential for good bass response. Take the time to try all of the tips included and find the ones that make the best airtight seal in your ears.Sound Stage: Comparisons start to break down on this front. The sound stage is more spacious in the R6 than any earbud I've compared it to (not very many, tbh), but it's still an earbud. You won't get the same wide open sound stage from these that open-backed headphones deliver. For this reason, I don't take the R6 really seriously as a reference headphone, but it also costs less than $100, which is a fraction of what you'd need to pay for good reference cans. The fact that you can even discuss the R6's performance as a reference places it in the running for headphones in the sub- $250 range if you ask me.Comfort: The all important question is, "Can I wear it for 3 hours without pain" and the news is surprisingly good. This is the first pair of rubber tips I've ever actually liked. Every other rubber-tipped earbud has left me disappointedly cramming old memory foam tips onto them to remedy the seal, or the isolation, or both. The oval tips on the R6 do perform as advertised in my particular ear canals, providing an airtight seal with minimal pressure and excellent noise isolation. That minimal pressure is the important point here, because what you need is an airtight seal for a long period of time without feeling like your ears are being resized to fit a baseball bat.The seal is so good, in fact, that I find I have to push the earbud in deep until the excess air in my ear canal pops out, then back it off to an equilibrium point. Otherwise it feels like my ears need to pop, as if I'm on an ascending plane or driving through a mountain range.Overall, this is an excellent pair of headphones, if a bit sub-par as a reference tool. Worth a listen for the audio engineer, headphone enthusiast, or music lover looking for a great pair of earbuds.Headphone are ok - sounds are clear and bright enough. They fit well after adjusting the buds. There's little if any discomfort...I still need to work out exactly the best way to push them into my ears. The anti-tangle cables are interesting if a little distracting since they do prevent tangling but they also resist any kind of wrapping. So unless you're fond of dangling cables from every pocket you need to pay a little more attention when putting them away.....but the "universal remote" isn't that good. I'd go as far as to say (for me at least with a Sony Walkman running Android) it was pretty useless.Firstly the remote lacks pretty much any kind of button or indication of any volume, pause or play functionality. The white on black card that fell out of the packaging and has 2 diagrams that would baffle the Sphinx is worse that useless. Even if I could decipher what the card was trying to tell me comparing the picture to the block of anonymous black plastic hanging from one earphone is a task designed to make the most ardent audiophile weep.No amount of pressing of that blob makes the slightest difference to anything...except my fingers: they ached - a lot!I'm not that fussed since I pounced to get these when the price collapsed below £50. the remote was a nice to have and I really would have liked to have it. I'd be extremely annoyed if I'd paid the original price and the remote blob had been as useless. As it is I'm annoyed but will know better next time.If you want a nice set of earphones, you could do worse than these at the lower price. If you want a pair of earphones with a built in remote - don't bother with these.These are very hard to get hold of now but if you can, they are a fantastic pair of earphones. I had a pair of over ear Klipsch Image One's so when my latest Denon's died (I thought the sound on them was excellent), I went for the R6i's. I've had Sony's and Sennheiser's before both of which were good, but couldn't find a like for like Denon - When I read the reviews on the Klipsch's I went to a local audio store, but they didn't have a demo pair of these but the lower spec S4's - They were excellent and better than the demo Sony's and Sennheisers. I took the punt on the R6i's without listening to them based on the sound of the S4's and how glad I was that I did. These are phenomenal. The range is excellent and whilst not the largest range, that is made up for in absolute quality. Hard Bass or High Trebles these can handle it all without losing quality even at Max Volume (primarily used with iPhone 6S). If you can get them, these are (in my opinion) the best sub-£100 earphones you can buyI bought these to replace the S4i earphones which I carelessly lost. I particularly like the Klipsch design for the actual buds, I find these more comfortable than many others. These are light and extremely well-made with a flat cable far less likely to tangle and a neat in-line control, which is higher up the cable than the previous models. Sound quality is excellent: for me they have the perfect balance to cope with a wide variety of music and spoken word.The included (soft, zipped) carrying case is just the job and so much more sensible than the tin case that came with with the older ones I had.All in all I'm delighted with them and pleased that I decided to spend the extra rather than simply replace the S4is.I have had to use an EQ to get the most out of these headphones as the bass still requires boosting for my liking.While the cables feel sturdy the rubber causes a significant amount of noise to transfer to your ears. The tiniest amount of contact with clothing is extremely audible so I will probably only be using these while seated. Still experimenting with the ear tips but they are comfortable.The case comes with the headphones is compact but as such it feels cheap and provides little to no protection. I will stick with the slightly bulkier third party hard case I already own.Overall a solid 4/5.I've owned a number of Klipsch S4i and S4i II's which fit my ears really well and sound great. So I was interested in how much better the R6i's would be. I was disappointed, not as bright with less punchy bass.I've also owned B&W C5's, Bose in ears, AKG 451 (on ear) and AKG Y50BT (over ear bluetooth wireless) and thought I'd try an these. The C5's sound great, but they're so uncomfortable (for me). For pure comfort I always reach for the AKG 451's.So I will be buying S4i's until I find that perfect balance between comfort, bass extension and clarity (and all for less then a re-mortage of the house)