[nwavesailor]

Well, there are a few things to consider. First, Hifiman wanted these headphones to come in at a certain price point, $300. That means there going to have to make some sacrifices versus a more expensive headphone. Second, different people have different preferences. Other pads may not be BETTER than the stock pads, but they may give certain people the specific sound they want more than the stock pad. Third, the grills were designed with cloth covers to keep out dust. Hifiman themselves have suggested removing those if you want a change in sound, but it's with the caveat that you're removing a certain level of protection. Some people go further and replace the entire grill.

The nice thing about most of these mods is that they're cheap and easy to reverse. You're not drilling holes anywhere or rewiring anything. The amount of change possible will vary from person to person, based on what they're able to perceive (and perhaps, yes, want to perceive). If you don't want to mod the 400S at all, no problem. They're great headphones out of the box. But I don't think we can wave the changes of the mods away simply by claiming confirmation bias. And it doesn't mean Hifiman didn't deliver the best headphone they could, it just means there are certain compromises that had to be made to hit the target price, and certain design decisions that may not suit each individual.

Merrick is spot on! Multiples in audio, with dealers in the mix, need to be 5-7 X production cost. At $300 retail, you need to look at every dime and dollar of parts and labor cost to make it pencil out.
 
You can buy the HE400S OEM Velpads for $15-$16 shipped retail where the FocusPads cost $39 shipped. Ship the 400S w/ Focus Pads and the retail is no longer the $300 sweet spot target hp. I agree that these hp are great right out of the box.
 
The pads are not expensive if you want to do a little experimentation. The grill mod is cheap and 100% reversible. If it an audio 'expectation' with little or no merit, simple, revert to the stock configuration!

 

[MarcelE]

You're right, the changes are done easily and are reversible. So you can try out things.
And it's not that I think it can't change the sound for the better, but almost 99% of the changes I read are
positive. I get a sort of Ikea feeling with that - I changed/made something and am proud of it and
it somehow gives a good feeling.
I must honestly say I never changed anything in my hifi/headphones so I could be completely wrong.

The only thing I would change (with my HE400, not the s) is the headband, after 3 hours or so I feel it
a little bit (having no hair on top doesn't help either haha), so I change it a little and can go on for another
few hours.

 

[DangerClose]

 
Merrick is spot on! Multiples in audio, with dealers in the mix, need to be 5-7 X production cost. At $300 retail, you need to look at every dime and dollar of parts and labor cost to make it pencil out.
 

 
That sounds like a tight squeeze at first, but then I think about all the headphones that cost 10x less than $300.

 

[nwavesailor]

  You're right, the changes are done easily and are reversible. So you can try out things.
And it's not that I think it can't change the sound for the better, but almost 99% of the changes I read are
positive. I get a sort of Ikea feeling with that - I changed/made something and am proud of it and
it somehow gives a good feeling.
I must honestly say I never changed anything in my hifi/headphones so I could be completely wrong.

The only thing I would change (with my HE400, not the s) is the headband, after 3 hours or so I feel it
a little bit (having no hair on top doesn't help either haha), so I change it a little and can go on for another
few hours.

Yep............. When we are told to expect X or Y, we can or think we indeed do 'hear' that.
 
I did the mesh mod and found it to be a subtle change. The FocusPad A swap was more obvious, but not day and night. I prefer Focus Pad A feel and fit better than the Velpads. If it wasn't (IMO) a PITA to line up the 4 notches in the pads for removal / replacement I would do a bit more A/B between the OEM Velpads and Focus A pads.
 
Still waiting for the Brainwavz to arrive on a VERY slow boat from Hong Kong!

 

[Astrogoth]

My friendly postman brought the Brainwavz today. Took the plastic rings off the stock pads as I saw no need to keep them around. Easy removal. Put the rings on the Brain pads. A bit tricky but not hard to do. For the people who said the rings were too small, they are not, keep playing with it and it will come to you eventually.
If your pads with the stock rings refuse to stay locked in place keep playing with them and you will get it. I did.
 
The sound: Yes the Brain pads do bring out the bass some. The bass they introduce is on the low end but not quite sub bass sounding. As stated by others this is NOT a life changing mod. It brings out some bass but not a basket full and not enough for a "Bass Head" to love. For me it's exactly the right amount. Almost.
 
So what? With the wire mesh mod and the Brainwavz together you get clearer, clearer highs and more present bass in about the same amounts. That leaves the mids wanting more than ever. Listening to songs I know well I kept thinking that something was missing. Presence. People. Mids.
 
The end: I see no way to improve the mid band on these cans. The two standard mods are still a good idea and do improve the sound quite a bit. Doing that exposes the lack of mids but it is still an improvement, Oh well. I still plan to replace my mesh screens with copper or plastic when I can find some the right thickness and weave. That should improve the highs a hair more and then I shall declare the job done.

 

[GrouchoMarx1933]

Up until now, I'd only used the 400S in balanced mode on my Geek Out V2 and Pono. Today I pulled out the stock cable for the first time and ran the cabs single-ended through my Vali 2 with the Geek Out as DAC.

This combination is simply magical. I couldn't stop listening! The Vali 2 really brings the 400S to life. Lots of rich detail and a smooth, warm, immensely enjoyable sound. I highly recommend this as an excellent mid-fi setup.

 

[pootyash]

Do the 400Ss need an amp/DAC?  I'm looking for something that can be driven well from my phone (HTC One M8) or laptop - without any extra accessories to deal with - but still sounds really good.  Got a Fidelio X2 recently but have been somewhat underwhelmed (some songs sound great, others muddy and congested).  Also tried the Sennheiser HD-598 but thought they sounded thin and lacking in bass.  Would these cans, or the 400is, be better without an amp?

 

[GrouchoMarx1933]

The 400S is more efficient than the 400i, so will work better without an amp. However, I've found you really need an amp to make them shine. That's just me.

 

[jon parker]

  Do the 400Ss need an amp/DAC?  I'm looking for something that can be driven well from my phone (HTC One M8) or laptop - without any extra accessories to deal with - but still sounds really good.  Got a Fidelio X2 recently but have been somewhat underwhelmed (some songs sound great, others muddy and congested).  Also tried the Sennheiser HD-598 but thought they sounded thin and lacking in bass.  Would these cans, or the 400is, be better without an amp?

 I dont know if you only want open back but I can heartedly reccomend looking to the closed back OPPO PM3 - closed back planer designed to be driven by anything.
If you get a chance to listen to a pair, please do. I had the 400S but am much happier with the Oppo's After 200 hours burn in the balance between the highs, mids, and lows is superb - the planer sound signature is still there, They are still are warm headphone but they sound really really good

 

[pootyash]

Thanks for the feedback.  I had really been looking mostly at open, over-ears, hoping to get the best imaging and soundstage possible.  Hadn't really considered the Oppo, although I see it's gotten great reviews.  How's its soundstage when compared with open-back cans?

 

[jon parker]

  Thanks for the feedback.  I had really been looking mostly at open, over-ears, hoping to get the best imaging and soundstage possible.  Hadn't really considered the Oppo, although I see it's gotten great reviews.  How's its soundstage when compared with open-back cans?

 
I find the soundstage question a tricky one for cans - I have found the 'sound width' to be wonderfully wide sometimes BUT it depends to some degree on whether or not you listen to the type of music that is mixed and mastered for that!?
 
Listening to some Billie Holiday there is a pretty big width, with different instruments clearly far to each side BUT not so far that its hard to listen to the music as a whole!
As one gets older I suspect the appreciation leans more to well balanced and well mixed / mastered than to noticable gains in certain areas?
 
Listening to Bill Fay on my HD600's and now on the Oppo's I dont think there is a big difference in sound stage...its more that the emphasise on different elements of the audio gives a different experience - the Oppo's are richer and more intimate but the HD600's are clearer with less intimacy so its kind of 6 of one and half a dozen of the other! o_0 -
Because the HD 600's sound a bit cleaner it may be that the soundstage 'appears' to be a bit wider but I think that may to some degree be an audible illusion!! 
 
+ different records work better with each headphone
 
That's why i  mentioned to have a listen to the Oppo if you can rather than just saying it would be 'better' - In this case, having owned both, I think its a matter of taste.
I listen to a lot of vinyl rips which sometimes can be a tad too warm with the Oppo's.
 
I didnt like the bass on the 400's - i found it  a bit lazy and 'immature' - similar to the Oppos out of the box . . . but now the Oppos sound very well behaved indeed
 
So yeah, impossible to say! - I do love that I can listen loudly on the Oppos and no-one can hear any audio leakage which is amazing! AND  the planer sound....heavenly  
Youre on to a good thing either way - Sorry I cant give more details about other open backs - maybe just buy your choice of headphone from somewhere that accepts returns! 
From experience though I have found a good 1-200 hours burn in can make a big difference with planer's
Good hunting

 

[jon parker]

Put it this way,  I previously called the the Oppo PM3 the Gentleman's Afternoon Audiophile Headphone so If you are wanting something that blow your mind with width I don't think you will find that here..although...

 

[nwavesailor]

  My friendly postman brought the Brainwavz today. Took the plastic rings off the stock pads as I saw no need to keep them around. Easy removal. Put the rings on the Brain pads. A bit tricky but not hard to do.
 
 
Like Astrogoth, my Brainwavz angled pads finally arrived today.............now I need to wait for the mounting rings to try these puppies out!

 

[yoyorast10]

Does this have the same sound signature as the he-500? Good mids?

 

[Aegruin]

  Does this have the same sound signature as the he-500? Good mids?

Well, no actually. He-500 has more powerful bass. Besides that, 400S has more smooth mids and better treble.