I have been throughly enjoying the excellent JVC HA S500 and needed to get the wife one (that's what we all use as an excuse right ?) so I ordered the JVC HA S400 (couldn't decided which color, ordered the Red and the Silver)
Links to DSnut's thread on the excellent HA S500: http://www.head-fi.org/t/621063/the-new-jvc-ha-s500-40mm-carbon-nanotubes/1080#post_8677801
Here's the 2 new addition to the HA S500.
The Red one caught my eyes, they reminded me of the Audio Technicas.
The Silver looks much better in person, the chrome ring lends a classy look to the headphone. (Wife choose the silver)
The S500 and the S400 both share the same cable and the headphone connecting bridge are the exact same plastic moldings.
Folded view of the HA S500. (Left) and HA S400 (Right)
Beside the larger 40mm drivers the extra cost of the S500 went into the plusher and better quality headband paddings. (To be fair, I can't feel the differences)
Outside view of the housings, they are the same size, the S500 has a one piece Gunmetal plated plastic cup (Mine's peeling as you can see here) the S400 has a mirror finish plastic cup surrounded by a painted or chromed ring.
Inside view of the housings, the pleather pads are the same, if you click and look at the larger image, it is difficult to tell the larger 40mm drivers from the smaller 30mm drivers.
Comparing cup to cup, they appear to have the same diameter.
Side by side view of the cups the S500 seems slightly thicker by a few mm.
I ended up with the less classy but more hip looking Red S400 (I certainly prefer the looks and finishing of the S400 over the S500) the piano mirror finish may attract finger prints easily but at least they won't peel or flake off like the S500.
As I've mentioned over at the S500 thread, I was shocked at how good the S400 sounded out of box, I will usually plug in headphones/iems out of box just to make sure both drivers are sounding and then leave them burning for a week.
Not so for the S400, I was like "Eh?" this sounds like it's been burn before, so I quickly took out the other pair to test and it too sounded the same. Needless to say, I ended up listening to a couple of albums with them.
I recall the S500 did not have a very coherent sound out of the box (Bloated bass, recessed mids and undefined highs) and only started to sound decent after about 50 hrs of burning, The S400 out of box sounded like it has 50 hrs of burning done.
The bass is there and with a nice deep sub bass extension, certainly not bloated, Mids are nicely balanced and not recessed, the highs are there but could do with a bit more defination. At this point, it wouldn't be fair to compare them to my fully burned in S500 but as it is, they are certainly not that far behind, sound signature between the 2 are indentical.
I am wondering how much change burning would have on the S400, if it is as much as the S500 then I think I would really love the S400. As it is currently, I am prefering the finishing and weight of the S400 over the S500, the S400 is so light that you'll soon forget there's a headphone sitting on your head, with the S500, I have to readjust the cups every now and then to ease the pressure of the pads sitting on top of my head.
Okay then, I will do an A/B of the S400 and S500 in a weeks time after the S400 have about 150hrs of burn to see which I prefer sonically, stay tuned.
Edited - 13 Sep 2012 - Imswjm's impression here:
Edited - 15 Sep 2012 - My A/B comparision between S500 and S400 (with 100hrs+ burn) here:
Edited - 24 Sep 2012 - My comparision between a 200hrs+ burn and Out of Box pairs:
Edited - 26 Sep 2012 - Imswjm's S400 pads recommendations:
Edited by Ghostfit - 12/8/12 at 12:56am