[John Willett]

Quote:

Originally Posted by Beagle /img/forum/go_quote.gif Metal for a damping material?

Yes - damping is just the control of air movements by restricting the free flow; so this can be done just as well by a perforated metal sheet as a silk material - you just have to make sure the airflow is restricted equally by both if you change from one to the other.

 

[cansman]

Quote:

Originally Posted by John Willett /img/forum/go_quote.gif The original HD650 had acoustic silk damping, however this was difficult to fix reliably and identically every time. Therefore Sennheiser (several years ago) changed over to a perforated metal acoustic damping material. This was done so that every HD 650 would be more consistent with less variations than the flexible acoustic silk. This was done so they would all sound the same and not to change the sound in any way.

Some people hear the difference between the black acoustic silk and the silver metal versions, and some don't. The debate rages on. Is there a difference or not? Let me suggest that the answer is both YES and NO!

How can this be? Let me give you a plausible explanation. As John Willett mentioned in the above quote, Sennheiser had experienced difficulties in fixing reliably and identically the black acoustic silk. I believe part of the difficulty was due to the different climatic conditions that the phones ended up in which perhaps caused the tension in the acoustic silk version to sag and hence, the differing sound quality experienced by end-users. This resulted in the change-over to the current silver metal mesh version.

Evidence for this hypothesis is taken from sennheiser.com website Sennheiser Worldwide - High Quality Headphones, HD 650, Around Ear - Private Audio

"A specially developed damping element, made from fine acoustic metal mesh, ensures a precise damping over the entire diaphragm surface, highly constant in all climates."

If the damping of the older black acoustic silk version is not consistent, it is possible that this would have affected overall sound quality; hence, the boom in the bass and veiled sound experience.

However, not all black acoustic silk versions have this problem as I'm sure some were 'perfectly manufactured' within established tolerances. I am certain that these 'within spec' versions would sound identical to the silver metal ones. This might explain why some people say that there is no difference...in this instance, they are right to say this!

For myself, I had purchased the old acoustic silk version and it was boomy and veiled. Perhaps like others, I had ones which had reliability issues in regard to the proper attachment of the silk material. To my ears, the new silver version which I now currently use sounds significantly quicker and tighter. So perhaps we too are also right!

That is my response to the confusion that many have experienced! Unless there is a more plausible explanation, this is the best explanation I can think up so far.

What do you guys think of this explanation?

Cheers,
cansman

 

[pp312]

I think it's entirely plausible. I could hear no difference between the two versions.

 

[donunus]

cansman that post should be stickied somewhere

 

[Beagle]

Quote:

Originally Posted by John Willett /img/forum/go_quote.gif Yes - damping is just the control of air movements by restricting the free flow; so this can be done just as well by a perforated metal sheet as a silk material - you just have to make sure the airflow is restricted equally by both if you change from one to the other.

Fair enough. I just figured that silk would absorb some stray resonances or standing waves, whereas metal would reflect them.

Quote:

Originally Posted by cansman /img/forum/go_quote.gif Some people hear the difference between the black acoustic silk and the silver metal versions, and some don't. Sennheiser had experienced difficulties in fixing reliably and identically the black acoustic silk. I believe part of the difficulty was due to the different climatic conditions that the phones ended up in which perhaps caused the tension in the acoustic silk version to sag

I doubt this would happen. This "silk" is stretched tight and fused to the plastic.

Is there any difference between regular silk and acoustic silk? I went into a fabric shop today and asked for acoustic silk and the lady gave me a strange look and asked what I needed it for and I told her I was making a veil.

 

[khaos974]

Quote:

Originally Posted by donunus /img/forum/go_quote.gif So consistency was the reason for the change in design? hmm okay. I would think that the metal would be the reason for the brighter sound.

It's because metal looks bright and therefore one would get a brighter and unveiled sound signature, the silk has a smoother aspect, hence the smoother sound. It is the same phenomenon that affect HD600/650, the 600 is blueish black, while the 650 is grayish black, the more polite appearance gives it a more polite sound sig.

In case you did not notice, I was jesting above, but the sound signatures still match eerily with the appearance, don't they?

 

[donunus]

hehehe wiseguy

 

[cansman]

Quote:

Originally Posted by Cankin /img/forum/go_quote.gif http://www.head-fi.org/forums/f4/old...0/#post6142720 Here are two pics I took, first one is old HD600 and second picture is new HD650

In response to Beagle, if you look at the photo of the acoustic silk version, it looks a little lumpy at some parts. But would these small lumps be big enough to change the acoustic properties? Perhaps, as Sennheiser calls the black silk acoustic silk which possibly implies that it affects the acoustic properties of the cans.

Of course, I am merely speculating as to the exact reasoning why the sound production between the old and new might differ. I could be entirely wrong as to the sagging theory. It could be humidity that caused the silk to perhaps soak up more moisture, and thus change the acoustic damping properties. Or something else all together!

Nevertheless, what is indisputable is the fact that Sennheiser changed the silk version to the new metal mesh, and as John Willett mentioned, "This was done so they would all sound the same and not to change the sound in any way". If he is correct, this implies that somehow variations in the old version did change the sound and the new version has brought the HD65Os to within spec parameters. As I mentioned previously, obviously not all older silk versions experienced this problem - only those that were not 'perfectly maufactured' within accepted tolerances.

Beagle, thanks for your input!

 

[Beagle]

Quote:

Originally Posted by cansman /img/forum/go_quote.gif Nevertheless, what is indisputable is the fact that Sennheiser changed the silk version to the new metal mesh, and as John Willett mentioned, "This was done so they would all sound the same and not to change the sound in any way". If he is correct, this implies that somehow variations in the old version did change the sound and the new version has brought the HD65Os to within spec parameters. As I mentioned previously, obviously not all older silk versions experienced this problem - only those that were not 'perfectly maufactured' within accepted tolerances.

Consistency is good. Every manufacturer strives for it. I definitely noticed a difference between my original HD650 and the (updated) one I got last year. The newer one was less warm in the bass and a bit more light shining through on the top end.

I think it would be akin to the material used for loudspeaker grills. There would definitely be a difference in sound if you had two types using different materials. I think that the material that sits in front of the drivers can have as much effect on the sound as the choice of pads does.

 

[SP Wild]

I believe there could be a raft of reasons Senheisser decided to change the materials. But none of these reasons combined would ever justify the change unless the change reduced manufacturing costs.

 

[Penpal]

I've listened to both the new 650s and old 650s and couldn't really hear the difference, could just be my ears though

 

[Audiowood]

I just bought HD650 and there is no veil whatsoever. Bought from Amazon recently. Serial start 134XXX. The treble is almost on par with A900X with A900X slightly more. Its definitely more than shure SE 535. Very smooth sounding & forgiving on bad records, huge clamping force .. have to stretch it hard to feel comfortable. Bass is less than A900X and A900, Ed8, LCD-3 .. still more than HD800 and probably on par with LCD-2. Nice I like it. I expect bass to exceed all my other phones or at least at top 3 but am surprise.. Its very natural though... no artificial bass etc.. Did I say I like it?
 
A legendary headphone in my opinion and one of the most discussed in the last decade..

 

[Gradofan2]

It makes no difference why the "new version" sounds better than the "old version" - but, they do sound much better!
 
Though, the "new version" will not "bounce" against your head/ears when they hit bass notes, the way the "old version" did - but - I'll give that up for the improved clarity and treble.  

 

[donaldduck2004]

so what's better the new version or the older one?
XD
 
I'm joking...I read all the thread and the conclusion seems to be "take the new if you can but if you already have the older one the veiled sound will maybe resolved in the newer version...it depends from alignment of the planets in the exact moment the silk has been sewn"
 
Am I just on 10% right?

 

[moriez]

The impact on the silk(?) from the most ideal alignment of the planets always has and will continue to be what breaks or makes the HD650's. That in contrary to what makes or breaks the HD600's: restuffing the headpad with organic sheep wool as soon as possible.
 
Edit: ah blast. Jumped out the shower for the sake completeness. Slightly off-topic but for the HD600 do get the highest grade wool quality that you can possibly find. No less than 87% or you'll just lose out never reaching full potential. Furthermore, the results of facing the North East with chin in a ~40 degree angle when putting on your HD650 brought a yet indefinable dimension to the music. Still experimenting and to finetune it's best to get either a compass or goniometer not below 3k really. When finishing the listening session I always face North West just because it makes most sense logically speaking.. if you know what I mean