I've posted this already on another well-known headphone forum, here however I see DIY is more prominent.

I'm thinking about bying an used pair of ESP 950s and seriously modding them. I've considered making a totally DIY ESL headphone, but making the headband and enclosures for them is too much for my limited skills. Kosses though seem to be a fine ESL headphone as they are, and from pictures of their insides on Wikiphonia it seems that there are some mods easily possible.

1) Removing damping and maybe adding 'phase corrector' like on old Fostex T50 - a felt ring which suppresses high frequencies coming from outer parts of their drivers to even out phase and frequency responce.

2) Regluing drivers to remove possible squealing.

3) Maybe drilling some vent holes around driver to play with air loading on both directions - if needed. As Kosses are regarded as very tonally level, I suppose it's already alright.

4) Using laser CNC to cut a more open and more stiff stators to replace stock ones. Stocks seem to be not very stiff and having too little open area. Also I don't get the purpose of 'tubes' on their stators' holes. These can be replicated by thicked PC board, I believe.

5) Recabling them using DIY 'Verumecce' cable: http://www.diyaudio.com/forums/analog-line-level/194548-new-interconnect-design.html Additional opposite bias would be required though, but that is not a problem.

So, I'm asking more experienced people here, would these mods provide improvements? Maybe someone already tried something like that? Thanks!

What are you trying to achieve after the mods?

Wachara C.

Dont forget a heavy application of cocobolo bolos for a reduction of plasticine plurality.

Then you be rockin teh ganja mon!

I can't comment on the mods, but thank you for the link to the interconnect design. As one too cheap to buy silly expensive cables, I'm always interested in a new DIY wire recipe.

What are you trying to achieve after the mods?

Wachara C.

I'm mainly approaching that from a technical point of view, getting rid of some more or less obvious drawbacks.

They are said to be not as clear, revealing and detailed as top-level Staxes and Sennes, and I'm thinking that these mods may improve on that.

One more mod: 'deresonating' the diaphragm by making spacer opening's shape an irregular polygon. Theoretically, this should remove diaphragm standing wave resonances at high-mids and low-highs.

ok, so, by "said to be", are you suggesting these mods without having heard them?

ok, so, by "said to be", are you suggesting these mods without having heard them?

No, of course I'm not suggesting any one else do them. I'm asking the reverse, if anyone did something like that, or generally has insight into what mod would do what, I'd like to hear are the mods worth doing.

Everybody's preferences might not be the same. What you like might not be the same as what others like. I say you should try to listen to the ESP950s first and see if you want to do anything to change what you hear.

As for me, I like it better without any damping material on the drivers. That's with my own DIY drivers, of course.

Wachara C.

I have a pair of ESP-950s, bought them off Audiogon, the previous owner had put a Stax cable on them. He did a really nice job, it looks totally factory. There is some advantage to be gained from using the ESP-950's on the SRM-1/MK2 vs. the stock Koss amp. Bass is more solid and highs more refined. However, I find the overall sound less coherent than Stax- more colored, not as neutral. In some ways (bass impact, texture) I like the ESP-950 better than Lambda's I've got, but the Koss sound... well, just a little less neutral and not as coherent in the mids and highs. They are a good 'phone, don't get me wrong, and for $500~$600 worth the money.

Mine don't squeal.

I really wonder if drilling holes or adding / removing damping is going to make them sound better.