Before I begin, I want to thank Justin at Headamp for loaning these out to me. If it weren't for Justin and Headamp, I don't think I would have become as interested in electrostatics as I am now. To drive the SR-407, I was also sent the Stax SRM-252S electrostatic amp (NOT the amp pictured above), which is also sold on Headamp for $495. The SR-407 is the very first electrostatic headphone I've demoed. I honestly did not know what to expect. Perhaps my assumption of 'stats in general was that they were mostly on the bright side with lots of air and detail, perhaps too analytical, sterile, and dry. I didn't read much into 'stats as they were a niche product in my eyes, being too situational, too expensive, and too picky with what you can use them with. They need their own specialized amps, unlike dynamic and planar magnetic headphones which work with most traditional devices. Electrostats just seemed too restrictive for my taste. I didn't like their looks (aside from the Sennheiser Orpheus, Stax Omega 007, and 009). I can honestly say that while they are indeed a bit restrictive, electrostatics are more than worth looking into.
Build Quality: The Stax SR-407's build quality isn't anything special. It has an extremely retro design, made of almost all brown plastic from what I can see. The cups are rectangular and aesthetically hideous to my eyes, but there is a charm to it's non-standard looks. The adjustment sliders are decent, and hold their place very well. I'd prefer a little more freedom in it's extension, but it fits me fine at full extension. The headband strap is absolutely the best part of the 407's build, the underside covered in extremely soft and comfortable suede-like material.
The earpads are made of brown pleather (I believe). There isn't a lot of surface contact area, so it's not horribly sweat inducing as other pleather-padded headphones. It could definitely stand to be thicker, though that may alter the amazing sound quality.
The cable is flat/ribbon-like and a very decent length. Seems to be tangle proof. It's a bit wide and strap like. I'm definitely a fan of this type of cable.
Comfort: The Stax-407 is passable in comfort. It's pretty lightweight, but the rectangular cup design will feel awkward at first. The 407 is lightweight. The pads don't have much contact with the skin, but it's pleather, and ultimately will induce sweat. As mentioned previously, the pads are a bit thin, and with a little force, you can feel the plastic housing so close to the skin.
The headband strap is soft, and perfectly forms to one's head shape. Quite possibly the most comfortable headband 'strap' I've ever felt. Literally no force felt on the top of my head. The clamping force is moderate. The 407 feels secure on my head. Not loose, not too tight.
Accessories: Bare essentials. Just the headphone.
Isolation/Leakage: It's an extremely open headphone, so don't expect any privacy in or out.
Sound: The sound? THE SOUND. If there was one word to describe the SR-407 (and I assume any 'stat worth their grain in salt), that word would be: EFFORTLESS. What I mean is that the 407 sounds like producing sound is the easiest thing to do in the world. It's almost problematic, because you can pump up the volume to louder than bearable levels, and it will happily sing with no perceivable distortion anywhere to be found. I found myself jamming out to music and realizing that it's a bit louder than I tend to listen to with other headphones. That's how clear, grain free, smooth, and effortless the sound quality is. This is indeed the first time I have felt that there is ZERO fault in the headphone if you ever hear distortions.
The 407 is a neutral sounding headphone. Quite linear, with lots of speed, texture, quick decay, air, and instrument separation in spades. There is basically NO harhness to be found despite it not being rolled off. I've heard smoother/darker headphones that can be harsh. I don't know how the 407 does it, but there just isn't any harshness to my ears, despite a bell like clarity. My only gripe I have with the sound signature is that it's slightly dry (coming off the velvety smooth, liquid, and full bodied LCD2), and mids while blended in perfectly well with the treble and bass, doesn't sound 'forward' so it doesn't bring immediate attention to itself. It's not the fullest sounding headphone either. More neutral than natural/organic, which is the planar magnetic's strength over electrostatics, from what I've read. Still, the 407 is not sterile or too analytical, keeping a great amount of musicality and enjoyment to it's sound.
On to the different aspects of sound.
Bass: I expected the bass to be weak and understated. While the sub bass is noticeably lacking in comparison to the LCD2, mid bass is tight, punchy and clearly present. I can listen to EDM or Hip Hop and jam with the 407. Not 'bassy' by any means, but the bass is nicely presented. It has more body and impact than the Q701, but not as much as the K702 Anniversary. I'd say it's basically neutral. However, if the source is bassy, these will surely please anyone not a pure basshead. It can be quite fun.
Mids: The mids are presented very, VERY cleanly, though they aren't forward or recessed. They are blended in with the bass and treble, not bringing a lot of attention to itself. If anything, it's not romanticized in any way. It's there, it's clean, and well balanced. Again, neutral. Does this mean that it's safe? Yes. Boring? Not at all. It sounds faithful to the source. Unlike something like the Sennheiser PC360 headset which is also well balanced, but lacking in energy. Energy is definitely not one thing the 407 is lacking.
Treble: The treble to me is the biggest strength in the 407. It's extremely clean sounding, yet completely grain free to my ears and no harshness. Even on sibilant tracks, I didn't feel any fatigue.This may sound like hyperbole, but this is definitely the best treble I've heard on any headphone. Sparkle and smoothness bundled in one, which isn't typically found on traditional headphones. No ringing, no harshness, no fatigue. You basically have to hear it for yourself to understand what I'm talking about.
Soundstage: My first taste of electrostatic soundstage. It's quite open and with plenty of space between sound cues, but it's a bit two dimensional and linear in comparison to the better dynamics and planar magnetics. So it has a very good soundstage size, but not the best depth. However, it still translates very well into gaming.
Positioning: The SR-407 performs very well for gaming in Dolby Headphone. The soundstage is a pretty decent size. Paired with the amazing clarity and slight dryness of the sound overall, sound cues come out very, very clearly. Soundstage depth isn't the best, but DH helps it out enough to make positional cues pretty strong.
Clarity: The 407 is easily one of the clearest headphones I have heard, if not the absolute clearest. Bass is quick, very textured, and tight. The mids are very well balanced and clean, though not forward in the same way the LCD2 and HD650's mids are. Treble, as mentioned earlier is the cleanest, most refined treble I've heard on any headphone to date. Smooth and sparkly at the same time, with zero grain, and no perceivable ringing to my ears. While other headphones like the K701 are emphasized for clarity, they can't compare to the overall refinement and effortlessness of the 407.
Amping: As stated, these demand an electrostatic amplifier. In terms of that, the SRM-252S is the cheapest 'desktop' 'stat amp in production, and to my ears drives the 407 just fine. I don't feel a lack of anything.
Value: Value is purely subjective, but I personally feel that for around $575 you get a headphone that stands toe to toe with the LCD2 (and exceeds it in certain areas like neutrality, and clarity). You do need to spend money on an electrostatic amp, the SRM-252S being nearly $500 itself. Considering the 407 is basically the same in sound as the more expensive SR-507 (with different pads and materials), which I've read as being on par with the HE-6 and HD800 (if not better) to certain people, this may be the best entry point into high-end audio for a price not in the realm of impossible.
Final Impressions: Call me an absolute believer of electrostatic headphones. So much refinement, clarity, and technical superiority over dynamics and arguably even planar magnetics. The Stax SR-407 makes a very compelling case for itself as the perfect starting point into electrostatic headphones (and possibly end). It's not perfect, with a slight dryness to the sound, wonky design, mediocre build quality, and okay comfort, but it's sound quality more than makes up for these shortcomings. For gaming, it's one of the better all-rounders on the guide, without question.
Final Scores...
