How to improve the sound of Senn's HD-25 II?

To improve details you can change steel cable with hd600/650 cable, cheap, reversible, 5min job. Soundstage is narrow due to great isolation of hd 25 1 all you can do is find an amp with crossfeed  or some kind of software for ipod.

I own these 'phones and put a HD600 cable on them but cables change nothing in my personal experience (and scientifically I might add). If you haven't got the one with velour pads I recommend replacing the cheapy plasticky ones with velour and that does add a bit more width between the drivers and your ears which passively increases soundstage just a little bit.

These headphones are realistically targeted at DJs who need to monitor electronic music and as such I tend to use them for these genres, although I find them quite nice with metal too.

Overall, the HD25s are fantastic in the bass section, so not sure why you'd want 'warmer' bass. They are already very good in the lower frequencies. Soundstage wise there's not much you can do unfortunately.

Many people say the Denon D7000s have great bass along with great soundstage though - you may want to give those a listen (quite expensive however).

You have to check this thread,

http://www.head-fi.org/forum/thread/96334/senn-hd25-1-mods

It has some info that could help... 

Don't bother with replacement cable if you are using the HD-25 outdoor in subway or similar noisy environment as you won't be able to hear the slight difference OFC cables made. The steel cable is durable and perfect for outdoor use. If you turn the driver cups upside down (i.e. cables hanging down) to use the HD650 cables, and use the headphone outdoor, sooner or later the the cable sockets will get loosen and make the sound even worse than using the stock steel cables.

The stock cable sounds absolutely fine, except for its poor EMF isolation. The stock cable would induce EM noise just by crossing an AC power line.

I have bought some Star Quad cables and will DIY a replacement cable soon just for the reason of better noise isolation . I will keep the "cable up" configuration 

There will be improvements, difference between my clip and my mixer are clear. More sound authority , bass is tighter and more punchy , like they are bouncing on my head 

But eventual amp should be in budget class since hd 25 1 needs a little push to sound real good. Total Airhead is decent amp and it has crossfeed...

I never thought of HD25 1-II personally as being not warm; in every setup I've put them in, I'd say they're right about at the threshold of warmness that I can tolerate.  The bass and low mids, which contributes to warmness, IMO, is forward and plentiful.  I use it mostly straight out of my iphone 3G and I find it to be warm yet very detailed and forward.  If you do feel the need for more bass, there are lot of cheap options for that, such as Fiio E3 and such.

The velour pads will take away bit of the upper mid/low treble harshness of the HD25 and also tighten/control the bass a little more.  I personally just use the vinyl pads as I use them strictly as my outdoor cans and vinyl pads are more harsh weather friendly and also isolate better.  But sound wise, the velour pads do sound more "correct".

Not much you can do with soundstage unless you get an amp for it... but even then, it's not quite enough to notice... it'll be a very minimal difference.

With something like HD25... it's not something I'd worry about too much.  I don't see it as something that needs a great amp at all.  Fiio is not a refined amp at all and I personally see it as a simple bass boost, but if you are looking for more warmth/bass, it'll do that.

I don't have much experience with Cowon's Jet Effects, but that might have some of the effects you're looking for if you're willing to switch players

Quote:

Originally Posted by rubba 

Well the FiiO E5 looks very interesting ... I thing I'm gonna purchase one together with the velour pads.

I guess this is the best deal for me to upgrade the sound a bit and it will also ease my mind in search for the best sound a guess!

I love my hd25 for it's true sound, it's isolation, sturdiness ...

 

Well, the Fiio e5 is not bad, you will have some improvement on sound. I got mine 2 weeks ago and you get some improvement on the bass when using the bass boost.