[510198]

 

[2leftears]

Folks,

I have returned to this thread (and head-fi) after a few years of absence! I'm working part-time now and have more spare time for these luxuries

I have renovated quite a few HD540 and HD250 over the last three years, and it may be useful to share some tips re. replacement of foam, felt, cushions and head-band.

First, I stopped trying to find foam discs of the correct diameter & thickness for all the replacements required both outside of and inside of the drivers. Too much hassle and too expensive (plus some are odd-shaped). In the end I looked around for suitable bulk sheets of foam, after all Sennheiser will also cut these things out of large rolls of foam they source from somewhere.

Then I found this foam on Amazon:

PC Computer Fan Dust Proof Filter Foam Sheet

or:

https://www.amazon.co.uk/gp/product/B01F8YZIMW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It is marketed as computer fan dust proof filter foam and comes in 100cm x 100cm square sheets of black foam, so you can cut out as many big, small & odd-shaped pieces of foam as you need. I held this foam up against all the different pieces of original foam in the HD540 & HD250. Honestly, to me it looks and feels the same. Same thickness (about 2.5 to 3mm), same density, same colour, same "sponginess" etc. So far (3 years and counting) this foam has worked extremely well in all the places where I needed to replace the foam in the HD540 / HD250 headphones: external covers over the drivers for HD540 & HD250, internal grill covers on HD540 (a cloth/foam sandwich, cloth can be re-used after washing), internal driver covers for HD250 (a felt/foam sandwich, felt can be re-used after peeling of old foam).

For any felt replacements I use a pack of large un-treated felt cleaning cloths I picked up from the local hardware store (Robert Dyas). It comes in assorted garish colours, but fortunately also contains some neutral blue-greyish ones. Again, this felt feels very similar to the original stuff in the Sennheisers, feels like the same acoustic density, same thickness. Being mineral felt it does tend to dull hobby knives quickly when cutting: have some spare blades ready.

For replacement of the flexible pleather part of the head-band (some are very deteriorated) I cut the same shapes out of both a piece of 0.5mm thick black polystyrene modelling sheet (incl. the location tabs) and a piece of cloth-backed black pleather furniture upholstery (excl, the location tabs), and stick the two together using double sided floor tape designed for use on vinyl flooring (you need tape resistant to migration of the plasticisers used in pleather & vinyl furniture upholstery, something I learnt from working with pleather and vinyl in camera repairs whilst trying to avoid contact glues which are very messy).

Replacement cushions I get from China. I spent ages trying to find ones that have an acoustically acceptable density of memory foam and thickness of pleather (as I have gotten older I find I now need easy-clean pleather, velours cushions have become problematic for reasons of hygiene.) These cushions so far have had the least impact on sound compared to the originals and I find them to work equally well on the HD540 and HD250. For me they are preferable to the pleather cushions Sennheiser still has available for the HD430, which also fit the HD540 and HD250. The orinal seller on eBay I can no longer find, but they seem to have changed shop-front and these appear to be exactly the same (albeit that they have now doubled the price, I used to get them for £4 per pair and fortunately have quite a stock!):

Replacement Ear Pad Cushions

Most other ones I have tried have too high a density of memory foam which emphasises the bass far too much. To be honest, memory foam seems unavoidable these days but for these older Sennheisers in general it is not such a good foam to use. IMO the original open-cell polyurethane foam is acoustically better for these old cans.

Both eBay and Amazon links are usually short-lived, so I can't guarantee they'll still work a few weeks from now!

 

[sennsay]

Folks,

I have returned to this thread (and head-fi) after a few years of absence! I'm working part-time now and have more spare time for these luxuries

I have renovated quite a few HD540 and HD250 over the last three years, and it may be useful to share some tips re. replacement of foam, felt, cushions and head-band.

First, I stopped trying to find foam discs of the correct diameter & thickness for all the replacements required both outside of and inside of the drivers. Too much hassle and too expensive (plus some are odd-shaped). In the end I looked around for suitable bulk sheets of foam, after all Sennheiser will also cut these things out of large rolls of foam they source from somewhere.

Then I found this foam on Amazon:

PC Computer Fan Dust Proof Filter Foam Sheet

or:

https://www.amazon.co.uk/gp/product/B01F8YZIMW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It is marketed as computer fan dust proof filter foam and comes in 100cm x 100cm square sheets of black foam, so you can cut out as many big, small & odd-shaped pieces of foam as you need. I held this foam up against all the different pieces of original foam in the HD540 & HD250. Honestly, to me it looks and feels the same. Same thickness (about 2.5 to 3mm), same density, same colour, same "sponginess" etc. So far (3 years and counting) this foam has worked extremely well in all the places where I needed to replace the foam in the HD540 / HD250 headphones: external covers over the drivers for HD540 & HD250, internal grill covers on HD540 (a cloth/foam sandwich, cloth can be re-used after washing), internal driver covers for HD250 (a felt/foam sandwich, felt can be re-used after peeling of old foam).

For any felt replacements I use a pack of large un-treated felt cleaning cloths I picked up from the local hardware store (Robert Dyas). It comes in assorted garish colours, but fortunately also contains some neutral blue-greyish ones. Again, this felt feels very similar to the original stuff in the Sennheisers, feels like the same acoustic density, same thickness. Being mineral felt it does tend to dull hobby knives quickly when cutting: have some spare blades ready.

For replacement of the flexible pleather part of the head-band (some are very deteriorated) I cut the same shapes out of both a piece of 0.5mm thick black polystyrene modelling sheet (incl. the location tabs) and a piece of cloth-backed black pleather furniture upholstery (excl, the location tabs), and stick the two together using double sided floor tape designed for use on vinyl flooring (you need tape resistant to migration of the plasticisers used in pleather & vinyl furniture upholstery, something I learnt from working with pleather and vinyl in camera repairs whilst trying to avoid contact glues which are very messy).

Replacement cushions I get from China. I spent ages trying to find ones that have an acoustically acceptable density of memory foam and thickness of pleather (as I have gotten older I find I now need easy-clean pleather, velours cushions have become problematic for reasons of hygiene.) These cushions so far have had the least impact on sound compared to the originals and I find them to work equally well on the HD540 and HD250. For me they are preferable to the pleather cushions Sennheiser still has available for the HD430, which also fit the HD540 and HD250. The orinal seller on eBay I can no longer find, but they seem to have changed shop-front and these appear to be exactly the same (albeit that they have now doubled the price, I used to get them for £4 per pair and fortunately have quite a stock!):

Replacement Ear Pad Cushions

Most other ones I have tried have too high a density of memory foam which emphasises the bass far too much. To be honest, memory foam seems unavoidable these days but for these older Sennheisers in general it is not such a good foam to use. IMO the original open-cell polyurethane foam is acoustically better for these old cans.

Both eBay and Amazon links are usually short-lived, so I can't guarantee they'll still work a few weeks from now!

Thank you, nice work there. I too am not a fan of memory foam, having had quite negative experiences with both the HD540's and HD650/6xx. Agreed too with pleather on the HD430s, not good, velour/cloth is much nicer as these cans have little use for bass power anyway, so velour/cloth works much better and I might as well be much more comfortable wearing them My HD430s came from Germany (eBay) with pleather pads that are way too firm and the 'Ohrpolsters' I bought for the HD250s' are sitting in their box now unused. I will chase down some of that foam you've mentioned, save me having to buy 'wang' velour and well as the pleather pads just to get the right thickness of foam for the latter, which strangely come with half as thick again foams than the velour pads. I couldn't agree more with your last statement re memory foam v open cell poly.
I have a very occasional light 'buzz' in one of my HD250 capsules that I haven't resolved yet, figuring out how to find and dust that might have got in there and what to do about it. I've had to make my own inner foam combo to match the originals as much as possible, or the bass reflex air movement doesn't work correctly. Tricky.
Great info re the headbands, I have a set of Denon AH-D1000 that need doing sometime, my favourite testing cans when I'm repairing electronics. Thanks again, you are most welcome back.

 

[2leftears]

...
I have a very occasional light 'buzz' in one of my HD250 capsules that I haven't resolved yet, figuring out how to find and dust that might have got in there and what to do about it. I've had to make my own inner foam combo to match the originals as much as possible, or the bass reflex air movement doesn't work correctly. Tricky.
...

Hi sennsay,

From my experience I would not be surprised if that 'buzz' is caused by a hair that has managed to partially work its way through the felt dust guard protecting the driver and is now "tickling" the driver membrane from the outside. I have seen that a lot on these Sennheisers. Dust/hairs on the inside of the membrane are more tricky, but the hole in the magnet is fairly large to allow for the two bass reflect ports so one can get a very fine pair of tweezers down there if the dust is near the middle (with extreme care, that membrane and the silk dome cover are fragile!!). No such luck with the HD540, the hole down its magnet is much smaller.

Re. the bass reflex air movement, yes, it is fairly critical. That is the reason I decided to re-use the original felt inside those drivers, and just replaced the foam layer. It may surprise many to hear that the HD250 has (2) tiny bass reflex ports, as such it is not a truly "closed" headphone, but that is part of the reason it has such relatively good bass extension for a "closed" can.

Re. the memory foam, unfortunately that seems to be a bit of a rage now, probably motivated more by comfort and trying to get a good "seal", rather than acoustic benefits. Memory foam comes in a huge range of acoustic transparencies, densities and rates of bounce-back. Unfortunately I find most pads use too dense and acoustically too opaque a memory foam, more like the stuff memory-foam ear plugs are made of. Add a thicker heavy-weight pleather on top and the both then significantly change the resonance frequency and rate of damping of the apparent air volume contained between the ear and the driver, making the bass far too prominent and "boomy". The pads I settled on do have memory foam, but it is light-weight and of very high porosity and acoustically almost (not quite!) acts like the original open-cell foam Sennheiser used (it is a blue-green foam, but that probably doesn't mean much). Ideally the pleather should have been a bit thinner and acoustically more transparent also like the original Sennheiser pleather, but then that always was a more fragile pleather and we all know how that behaved as it got older...

 

[sennsay]

Hi sennsay,

From my experience I would not be surprised if that 'buzz' is caused by a hair that has managed to partially work its way through the felt dust guard protecting the driver and is now "tickling" the driver membrane from the outside. I have seen that a lot on these Sennheisers. Dust/hairs on the inside of the membrane are more tricky, but the hole in the magnet is fairly large to allow for the two bass reflect ports so one can get a very fine pair of tweezers down there if the dust is near the middle (with extreme care, that membrane and the silk dome cover are fragile!!). No such luck with the HD540, the hole down its magnet is much smaller.

Re. the bass reflex air movement, yes, it is fairly critical. That is the reason I decided to re-use the original felt inside those drivers, and just replaced the foam layer. It may surprise many to hear that the HD250 has (2) tiny bass reflex ports, as such it is not a truly "closed" headphone, but that is part of the reason it has such relatively good bass extension for a "closed" can.

Re. the memory foam, unfortunately that seems to be a bit of a rage now, probably motivated more by comfort and trying to get a good "seal", rather than acoustic benefits. Memory foam comes in a huge range of acoustic transparencies, densities and rates of bounce-back. Unfortunately I find most pads use too dense and acoustically too opaque a memory foam, more like the stuff memory-foam ear plugs are made of. Add a thicker heavy-weight pleather on top and the both then significantly change the resonance frequency and rate of damping of the apparent air volume contained between the ear and the driver, making the bass far too prominent and "boomy". The pads I settled on do have memory foam, but it is light-weight and of very high porosity and acoustically almost (not quite!) acts like the original open-cell foam Sennheiser used (it is a blue-green foam, but that probably doesn't mean much). Ideally the pleather should have been a bit thinner and acoustically more transparent also like the original Sennheiser pleather, but then that always was a more fragile pleather and we all know how that behaved as it got older...

... yes we do! But oh so comfortable! I have tried memory foam from two different sources, one of them shall remain un-named but is a very popular current brand, the other a Chinese source ... oh dear for both of them! Thanks for the info on the HD250, I shall go over it with a magnifying glass and see what I can find. I understand about the bass port issue, I had a pal who has dealt with a lot of these over many years and he suggested what he does to mimic the original dual layer system which is extremely hard to find now. It seemed to work fairly well, but I could never really enjoy the big bass shelf below the extremely linear mid/treble balance. It just seemed so out of balance. Here we have this amazing virtually flat mid/treble with a superbly focused soundstage, then it's as if someone has turned up an equaliser for the bass out of proportion to the rest of the frequency range. I ended up using the 'wang' velour pads to open out that excess and it's effective to a degree, but they are no HD540 Ref 1s with Mogami cable and 'wang' pleather pads!

 

[elquixote]

Loving these so far, specially on the Darkvoice

 

[T 1000]

Loving these so far, specially on the Darkvoice

How to compare the size of the sound stage in relation to HE 1000 v2

 

[wppk]

This is all I am finding on my 600 ohm.

Hi there ! I have something to add to this very interesting post. Thanks for the picture ! but I have to add something that dosen't seem to be known on head fi ( or I haven't found it yet) . there must be three of these different impedances, at least, because I own three hd540 gold, which have different caracters written on this very place you mention. On one, I have EM 600, which obviously means 600 ohms. on the second, I have the same as you, ehg 00 ( for extra high grade ? ) but 00 doesn't say what is the impedance, and on the third, it is written 300. then 300 ohms. when I listen to the three and compare them, ther are defenitely very different. the 300 gives much more high mids and highs and less bass than the 600 and the 00 is half way between the two others and sounds flatter to my ears.

 

[sennsay]

Hi there ! I have something to add to this very interesting post. Thanks for the picture ! but I have to add something that dosen't seem to be known on head fi ( or I haven't found it yet) . there must be three of these different impedances, at least, because I own three hd540 gold, which have different caracters written on this very place you mention. On one, I have EM 600, which obviously means 600 ohms. on the second, I have the same as you, ehg 00 ( for extra high grade ? ) but 00 doesn't say what is the impedance, and on the third, it is written 300. then 300 ohms. when I listen to the three and compare them, ther are defenitely very different. the 300 gives much more high mids and highs and less bass than the 600 and the 00 is half way between the two others and sounds flatter to my ears.

Hi there, do you have access to a small digital multimeter? If so, it's very easy to find the impedance of your headphones, just by connecting the black wire from the meter to the ground pin on the main headphone jack (the one you plug in to your amp) and the red wire from the meter to either the left to right channel part of the jack - it doesn't matter, they should both read very similar. Just make sure the meter is set to OHMS and the 2K or 2000 ohms setting, whichever yours has. Easy done in seconds. Happy testing.

 

[elquixote]

Hi there ! I have something to add to this very interesting post. Thanks for the picture ! but I have to add something that dosen't seem to be known on head fi ( or I haven't found it yet) . there must be three of these different impedances, at least, because I own three hd540 gold, which have different caracters written on this very place you mention. On one, I have EM 600, which obviously means 600 ohms. on the second, I have the same as you, ehg 00 ( for extra high grade ? ) but 00 doesn't say what is the impedance, and on the third, it is written 300. then 300 ohms. when I listen to the three and compare them, ther are defenitely very different. the 300 gives much more high mids and highs and less bass than the 600 and the 00 is half way between the two others and sounds flatter to my ears.

What are the serial numbers for the different versions? Can you post pictures? I have only seen one that has nothing printed on it but says 600 ohm on the manual and is <10k serial, and others like mine that say 300ohms in the cup (serial 19,521)

 

[elquixote]

How to compare the size of the sound stage in relation to HE 1000 v2

its not as wide or as holographic sounding, feels scaled in from the he1k, vocals more intimate but def wider than something like 6xx 600 series. With the 1k it does feel like Fong described it, the best seat in the hall.

 

[lantian]

What are the serial numbers for the different versions? Can you post pictures? I have only seen one that has nothing printed on it but says 600 ohm on the manual and is <10k serial, and others like mine that say 300ohms in the cup (serial 19,521)

For the golds everything up till 10000 is 600ohm and everything afterwards(from 10000 to 20000) are 300ohm.

 

[wppk]

What are the serial numbers for the different versions? Can you post pictures? I have only seen one that has nothing printed on it but says 600 ohm on the manual and is <10k serial, and others like mine that say 300ohms in the cup (serial 19,521)

the 600 ohms is 010572. I don't have the others close to me.

 

[elquixote]

the 600 ohms is 010572. I don't have the others close to me.

i had heard of models over 10k that were 600ohms. There was one floating on eBay that was around 12k serial and had nothing printed on the cups.

 

[wppk]

Hi there, do you have access to a small digital multimeter? If so, it's very easy to find the impedance of your headphones, just by connecting the black wire from the meter to the ground pin on the main headphone jack (the one you plug in to your amp) and the red wire from the meter to either the left to right channel part of the jack - it doesn't matter, they should both read very similar. Just make sure the meter is set to OHMS and the 2K or 2000 ohms setting, whichever yours has. Easy done in seconds. Happy testing.

yap, I have one, I will try that but not right now, I cannot find time...