This is a review of Westone W40 in-ear headphones from their new W-series. Westone W40 As much I enjoy reviewing and sharing my experience of headphones in different price categories, nothing puts a bigger smile on my face when I dive into sound with multi-driver IEMs (in-ear monitors). If you just want to listen to a melody or vocals, and you consider that all headphones sound the same, you can probably skip this review. For others who want to experience the real sound, you will know and appreciate a meaning of three-way crossover which separates bass, mids, and treble to drive 4 separate balanced armature drivers packed inside of miniature in-ear device that takes your breath away when you rediscover details of a sound you never thought existed before. Westone has been around for 50+ years working and perfecting this technology. They are among a handful of audio manufacturers who are well known for their top quality and design, and also being able to produce a premium line of multi-driver affordable headphones. This year they are introducing a new series of W10, W20, and W40 with a lot of design and sound improvements. The model numbering of their headphones corresponds to a number of drivers used in a design (W10 - singe driver, W20 - dual driver, W40 - quad driver), and for my review I was provided with W40 quad driver unit. Lets take a closer look to see what I have found. Starting with a package box, right away the outside sleeve sets a tone of a premium product. Filled with a lot of info about W-Series design as well as details about this specific W40 model, you get a very clear picture of the product even before opening the box. After sliding the sleeve off, and opening the magnetic flap of soft touch box - you are presented with a display of W40 IEMs and included accessories. What is amazing, no matter if you are getting single driver with less expensive W10 or quad driver top of the line W40 - it will come with the same set of accessories and a similar looking design. Looking into accessories, the first thing that will stand out from a crowd is a heavy duty bright orange Monitor Vault - a specially design storage hard shell case for W-series which is air and moisture proof, has a hard plastic shell exterior and soft foam lining, and even an air seal valve. This is something you can take along with you on any adventure, even if you are planing to climb a mountain or go kayaking! Furthermore, you get a set of 5 pairs of True-Fit foam tips and 5 pairs of STAR silicone tips, all color coded so you don't have to through a pile of mix'n'match tips. You also get a wax removal tool, 2 sets of removable cables, and 3 sets of exchangeable faceplates and hex driver to remove these. One thing is to talk about customizable full size over-ear headphones where you can exchange and replace different plates, but these are tiny earbuds that have a capability of faceplate customization!!! Furthermore, you have 2 sets of cables, one is a braided audio only cable and the other one MFI cable with in-line remote and mix. Designed for iDevices, the multifunction button works perfectly with Android phones for play/pause/call, playback control, and to start Google Now. Phone calls were loud and clear, and I had no issues controlling my Note 2 with a remote. Both cables are highly flexible which is important because W-series can only be worn with wire over your ear. Epic cable design has a sliding tension tab which enhances over-ear fitment but bringing cables closer, and I was actually surprised how well it worked considering its a braided/twisted cable. Another very important point about these cables is their replaceable nature and using a new universal connector that works interchangeable between different Westone models as well as other brands. Having a replaceable cable is very important when you are investing so much money into high quality headphones where broken cable is the most common point of failure. At the other end of the cable, you have 90-degree 3.5mm gold plated connector which a decent cable strain relief and perfect sizing to work with most of the phone cases. Earpieces itself are very lightweight, low profile, and comfortable to fit inside of your earlobe. Its a very clever design considering amount of technology they have to fit inside of such a small device and still make it low profile so it doesn't stick out. Of course, all this technology packed inside of a such small package leads to one big question - so how does it sound? When it comes to such a complex design, you can no longer use a judgment of the cost vs sound quality. Considering a number of other in-ear headphones I have reviewed, I can tell you with certainty that even in this premium price range it all comes down to a company and how they envisioned interpretation of the sound - thus a sound signature of different headphones. While in the past I have reviewed quad-armature driver design of UE900, those were more analytical upfront IEMs. Westone W40 have a warm and smooth sound with an enhanced bass response. I would even dare to say it has somewhat of a "fun" signature with slightly recessed mids, more detailed extended bass with a nice quantity, and tamed treble for a more comfortable extended listening experience. Without a doubt the sound is very detailed and you will enjoy analyzing every part of your favorite tune while rediscovering new elements you haven't noticed before, but the sound will not be crispy clear but rather warm and lush. The soundstage is average in width. Also, because of this warm sound signature, W40 is not as forgiven when you listen to low quality mp3s or audio streaming which will sound dull. I would definitely recommend at least 320kbps or FLAC. With it's 31 ohm impedance, I had no problem driving it directly from Note 2 as well as my laptop. I also tested it with E18, and with an exception of some improvement in dynamics at high gain setting, no other significant changes were heard. These headphones are definitely perfect for mobile use. In general, they have very durable and rugged design that will work great for outdoor use as well. Overall, I enjoyed W40 very much and was very pleased with its warm and smooth sound. The sound signature of these is very close to "fun" without too much of a dip in mids. Those who enjoy an extra bass, will be very pleased with their sound as well. For others who are looking for a more analytical neutral sound to analyze every detail - you might want to look into other multi-driver designs. Also, if you are on a budget but still want to experience a luxury of W-Series from Westone, you have an option of either single or dual driver W10 and W20 designs. Although some details in sound will be sacrificed going down in a number of drivers, these are still balanced armature drivers where Westone tunes each model for sound precision. I would definitely give them a listen!!! Here are the pictures.