Sennheiser HD-438 modding

[solderdude]

I finished modding my newly bought Sennheiser HD438.
If you are interested in what I did just download the pdf below (5.5MB)
www.mediafire.com/?isq8dinp9h7147z

very interesting closed headphone once modded.

I know it is not a well known headphone as it is new.
Also not that interesting without mods (typical Senn signature) but actually is much better than expected and IMO highly underrated.

[cj]

Hi Frans,

So how would you describe the sound of these post-mod?

I've been after a decent set of closed back for low cost for some while (have superlux HD662B, slightly modded) and would appreciate the low down, possibly with comparisons?

Cheers,

Chris


BTW, they are available here in Spain at €48 incl. domestic postage.

[solderdude]

I will have to do a subjective comparison and should include HD650, modded HD681, DT990 and perhaps some other cans.

Problem is I haven't really compared it directly yet, only listened to it as I just received it a few days ago and modded it today + write the pdf.
No sonic fatigue and no obvious 'shortcomings' noticed yet but might after direct comparison.
The wife immediatly noticed the very comfortable fit !

Will still have to hear how it behaves amped.
Only used it directly out of a sansa Fuze, with 320k MP3. (yes I know, shame on me)
Fun thing is with my new amp I can make the mod more or less effective by dialing in a different output resistance, as this filter reacts strong to different output resistances it will be very 'tunable'.
That is because it is an attenuating series filter, unlike the filters used in the Superluxes.

I modded an HD669 a week ago.
Liked it when listened to that one exclusively, until I compared it directly to HD681 and others.
So.. sold that one... It was slightly similar to an HD662 but with other type headband.
Not sounding bad at all but it was not quite what I hoped it would do.
Got it second hand for only 30 Euro incl. shipping.
Prices range from 60 to 80 Euros new over here.

Will report when I did the direct comparison.

a thing I forgot to add... besides the low clamping force it still remains very solid on your head.
This might have something to do with it being very lightweight without feeling flimsy, nor did it appear to be built fragile to me.

[funk1969]

The HD438 is very likeable. Did you also do a recable?

[solderdude]

I answerred that one in the mentioned pdf... bottom line, page 2

a small hint can be derived from this thread also..
rockgrotto.proboards.com/index.cgi?board=general&action=display&thread=6789&page=5

I actually like the stock cable, it is thin, supple and low in microphonics, litze wiring (each conductor isolated) and detachable, yet doesn't fall out if yanked on it. It comes with 2 cables of different lenghts which I think is great and have not had it tangled yet.

[cj]

Hi Frans,

Have you had any more time with these yet?

I'm interested on how they pan out.

Chris

[solderdude]

In modded state it kind of compares to the modded SR850 but overall a tad 'better' on most points.
This comparison is done playing John Lindberg Trio.
keep in mind this comparison is NOT the STOCK version of the HD438 which has a different character.

Imagine an HD650... it is 'tilted' towards warm (lows lifted and highs gradually sloping downwards)
The modded HD438 is tilted towards the brighter side, missing the warmth and brighter a bit more like AKG HP's but without the slight lift they have in the highs.
I prefer the HD650 for some music over HD438 and with darker music the HD438
When swithing from HD650 the HD438 appears to be lacking lows and is brighter (more brittle)
When reverting from HD438 to HD650 the warmth and bigger bass is obvious and highs (top end/extension) appears missing.
In case one listens to both continuously both are a pleasant and non-fatiguing listen.
The bass appears not lacking after some time and voices are bright and it sounds detailed, not colored.
When listening to the HD650 for a longer period the bass appears less obvious and becomes more realistic and the highs do not appear to be missing but warmth is overall there.

The HD650 can play pretty loud without unacceptable distortion, the HD438 cannot play that loud.
At lower levels it stays good.

Doesn't appear to miss bass but lacks extension.
Isn't sibilant but is bright sounding maybe a bit thin in some music.
You can adjust the tilting with other output resistances, the lower the brighter the signature, the higher the more tilted to the warmer side.

[bmorris458]

Hi solderdude,
I've taken a look through the pdf, and would like to do a similar mod to my 428s. In the part of the enclosure that I can access, there is no chip like in the 438s, so can I do the same mod? If so, where would I splice in the RC filter? On the same wire of each transducer?
Thanks.