This is a Review of Linum BAX headphone replacement cable with mmcx connectors. http://www.linum.dk/technology/ . I would like to Thank Linum team for providing me with a review sample in exchange for my honest opinion. A wire is the only thing that stands between your music source and your headphones, and despite what some think - it's a major contributor to a sound shaping. Just think about it, audio is nothing but an analog signal traveling through a metal wire which going to affect this signal. You don't have to be a rocket scientist to realize that depending on different materials and their property (including resistance), the signal could change from a very subtle to a more noticeable level. It's true that some of these changes could be hardly perceptible and as a result people refer to replacement cables as a "snake oil". Others don't even give them a chance and rely on someone else's opinion. But I think the biggest problem is the level of expectation people have thinking by spending x-amount of money they're going to see a proportional sound improvement. If you are looking into a quality replacement cables, it's going to cost you upward of $100 and a lot more depending on material used. Often it does falls into a category of diminishing returns, but make no mistake - you will hear a difference with a different level of sound improvement. I just want everybody to have an open mind before you start reading this review. So without further ado, let me talk about "magic" of Linum BAX cables. I was always a believer in replacement cables, but not so much into anything that cost over $50 for a reason of "diminishing returns". As a result I settled for a number of budget silver-plated cables where I did notice a sound being brighter, crispier, and with improved soundstage perception. But when it comes to a sound, it's hard to judge the improvement without comparison, thus I was in search for something better than a "budget" cable. This search lead me to Linum cables, a brand of Estron A/S (Denmark). I read a lot about this cable on-line and from other people's impressions, but didn't want to draw a final conclusion without testing it myself. Considering my vast collection of mmcx based IEMs (Westone W40/Pro30/Pro50, as well as UE900s and A83), I decided to look into Linum BAX mmcx model. Beside mmcx, Linum offers this cable with T2 and 2pin connectors, and also it comes in different flavors of Vocal, Music, BAX, and Balanced wired. I can't judge about comparison between Vocal/Music/BAX, but I trust their measurements in the graph below (red - BAX, blue - Music, green - Vocal): As you can see, the delta of sound boost at low end and high end varies by as much as 3dB (probably driven by impedance difference where with BAX at 1.5 ohm resistance you get a smallest voltage drop), so you should take this into consideration when trying to determine which type of cable going to fit you better. Also, refer to a more detailed comparison found in here: http://www.linum.dk/product-overview/ . In my case, I went for the extreme with Linum BAX, and here is what I found. The cable didn't arrive in any fancy packaging with hyped up marketing slogans. It was packaged in a very modest ziplock bag with a card, but it was a higher quality antistatic bag that felt rather durable. Included was a postcard with a picture of guitarist (the same picture featured on the card insert) and writing "The most comfortable earphone cable you will ever wear - feather light and nearly invincible". OK, maybe it does sound like a marketing slogan, but as I found out later - it's not a hype. With an ultra-thin diameter of about 0.9mm, super light weight of about 2.7g, and a nearly skin-colored shade - the cable literally becomes invisible once you wear it wire-up. Also, I liked the included button with "I'm a cable believer" - I found it appropriate for my taste! Right off the back before you even get a chance to test its sound performance, you can already see a benefit from its physical appearance. Wire is very lightweight and soft, no need for an earhook to keep it tucked behind your ear. Plus a chin slider (choker) assists in keeping wires together once you slide it up. Another benefit of this chin slider, it has red/blue dots to ID the Right (red) and Left (blue) sides of the wire connection. But I do have to mention this wire is not easy to manage during storage since it becomes a bit messy, though untangling is very easy (a hint - keep a chin slider all the way up to the top during storage). There is also some memory effect, but it straightens out very quickly when you extend to use it. The build quality is phenomenal: you get an adequate strain relief around connectors, and surprisingly the minimal design of y-splitter and chin slider is perfect without strain relief. Though Linum advices you to avoid sharp bends, the cables looks like it can take some serious abuse. The cable is very strong and actually tested to withstand a pull force of up to 60N (equivalent of 13 lbs). The jacket of the cable is made of skin friendly and UV safe (no fade or discoloration under sunlight) TPA material. I also found no hint of microphonics. I'm quite familiar with a typical cheap silver plated wires where you can never find the actual spec. Contrary to that, Linum is clear about their cable being made out of 6 Litz conductors, each with 7 individual strands, and with each strand made out of a silver plated copper with enamel. Hard to believe so much is packed into this dual-twisted BAX cable considering it being super thin! As a matter of fact, now I see a perfect connection between the picture of guitarist on the postcard and the insert card - the cable is made for musicians and the wires are as thin as guitar strings! Cable details. So how does it sounds? I took a close listening using Cayin N6 as a source and comparing my mmcx based IEMs between their stock cables and Linum BAX cable. In every case there was an improvement with an exception of A83 which already comes with a high quality silver plated cable. But overall, the dynamics improved, the retrieval of details was better (a lot more clarity), and soundstage got airy and wider (that was a real surprise to me!). Here is in more details. UM Pro 50/30 Epic cable vs Linum BAX In Pro 50 with Linum vs Epic - sound became more dynamic and less congested, I found an improved retrieval of details, more bass slam, and wider and more airy soundstage. In Pro 30 with Linum vs Epic - sound became more dynamic and less congested, I found an improved retrieval of details, improved sub-bass details and mid-bass punch, and wider and more airy soundstage. W40 Epic cable vs Linum BAX In W40 with Linum vs Epic - I found an improved retrieval of details and a little brighter upper mids, wider and more airy soundstage, though it did loose a bit of smoothness where upper mids became a bit harsher. UE900s Braided cable vs Linum BAX In UE900s with Linum vs Braided - I found sound to be more detailed, wider and more airy soundstage, though it did loose a bit of smoothness where upper mids became a bit harsher. Fidue A83 Stock silver-plated vs Linum BAX In A83 with Linum vs Stock - the improvement was down to minimum, mostly in soundstage width and airiness. Overall, as you can see the results varied between different IEMs depending on their included stock cables. A83 result shouldn't be a surprise since Fidue included a very high quality stock cable, but Westone and UE stock OFC cables are obviously not at the top of their game and improvements were more noticeable. Another thing to keep in mind is the sound signature of IEMs. For me UM Pro 50 is a target for the improvement because of their darker signature, so Linum BAX was a perfect match with an excellent synergy. For other IEMs, Linum Music could have been a better choice to decrease the harshness of high frequency boost introduced by BAX. Perhaps, if your IEM already has a strong low frequency presence, BAX might be not the right choice either since it will amply the bass slam. The bottom line, you have choices when considering Linum cables and should figure out your sound priorities. One thing for sure, don't rush with a replacement cable right after you get a new pair of IEM. Go through a proper burn in and give it a few months of listening with a stock cable - get to know the sound signature of your headphones. You are not going to appreciate or to properly evaluate the replacement cable unless you baseline your stock cable sound. For me personally, I found Linum BAX to be a great replacement cable for UM Pro 50 and I would strongly recommend it for consideration. Coincidentally, UM Pro line is designed for professional musicians, just like the intent of Linum cables!