[acs236]

Hmmm.. Do you I want to go into a fabric store or Victoria's Secret? That's a close call.

Anyway, if anyone finds any material that seems to do the job especially well -- let's hear it!

 

[JaZZ]

acs236...

...I effectively see the problem, too: the pantyhose nylon gauze must be stretched by any kind of frame.

Lou...

...I'm glad that you enjoy the modification, as I do. If it's allright for you, you can leave the foam away without substitution and overly risk of damage, I suppose. But the sound would possibly benefit from a fine fabric cover: I'm perceiving better contour with the nylon gauze. The reason may be the reflections between driver and ear/headskin. With some sound absorbing material inbetween these continuous bidirectional reflections get muffled – obviously at the expense of the sonic freshness in the case of the foam pad. But I wouldn't want to miss the slight reflection-absorbing effect from a thin fabric between the drivers and my ears – in favor of contour and accuracy. Of course that's a matter of taste.

JaZZ

 

[LTUCCI1924]

JaZZ
HI: With the mode the 580s seem more lively but I might try a pice of panty hose to cover the drivers. I noticed that when you take the valor pads off that they are set in a grove that might streach the nylon but I never had any rerflection by my skin with the portapros or 35s with the open drivers. Maby at age 60 I can use all the mids and high end that I can get. LOL. Also the bass still seems to be there with the mode.
PS
What about cutting a small hole in the foam about the size of a quarter?

 

[lonestar]

>"What about cutting a small hole in the foam about the size of a quarter?"

See what I mean? The most obvious solutions are often overlooked.

 

[JaZZ]

Lou...
Quote:

«What about cutting a small hole in the foam about the size of a quarter?»

I don't think this will effect the same (measure of) clarity and vividity – anyway there will be no complete driver protection this way (against dust, e.g.). But why not try it...

I've done this with the Portapro, too. And there was a limit of the hole diameter, otherwise the sound tended towards coolish and slightly reverberative and «glossy». But the HD 580/600's open design without touching the ears creates different acoustics, and therefore the behaviour isn't strictly comparable.

Maybe you would succeed with the stretching of the pantyhose piece as you mentioned, though not a very tight tension that's useful for the protection function and optimal sound permeability. Or you can try to stretch and fix it with some double-sided adhesive tape... There are a lot of possibilities.

JaZZ

 

[Taphil]

Well, here's how I did it...

My mom has a new package black pantyhose, so no problems there. I found one that was really thin, so the sound properties of it would be negligbile. At the leg part, the hose was the same width as the foam covers, so I just cut out a piece in the shape of the foam cover, using it as a pattern. So now you have a 2-ply piece of nylon. Cut out 2 more. So now you have 3 pieces of 2-ply nylon in the shape of the foam cover.

Then you can experiment to see what you like better, 1-ply or 2-ply. With one of the nylon pieces, cut it into two. Then just put inside the headphone, and put on the velour cover. Be sure to push down on the edges until it snaps into place. That'll hold it. When the velour earcup is put on, it also stretches out the nylon a bit, so it's not wrinkly or flabby, but rather even and barely stretched out. You can then replace the 1-ply nylon with the 2-ply piece to see if there's a difference in sound, or use a 1-ply piece in one ear and a 2-ply piece in the other ear.

 

[j-curve]

Can't you just put the stockings over your head before you put the headphones on?

For superior acoustic transparency I would suggest fishnets.

Seriously though, I tried the no-foam mod, one side at a time, listening to music in mono and periodically putting the HD580's on back-to-front to listen for differences. Nothing heard so far. Not to say there is no difference, but it must be subtle.

I got a bit of shock to look inside the headphone though. It looked a bit ordinary, even cheap. If the guys at Sennheiser aren't laughing then they probably need to move more of their production to China. Looks can be deceptive of course, and there is obviously some fancy stuff happening in the driver. Speaking of which, I wanna get technical with some dimensions and daydreaming, at the risk of thread-crapping.

HD580
Diaphragm diameter: 37mm
Voice coil (and dome) diameter: 18mm

A short tube sits over the central dome of the driver, attached to the frame (ie. not a moving part). This tube is also 18mm diameter and about 4.5mm long. It sits only about 2mm off the voice coil, so that the dome actually protrudes slightly into the tube. The tube itself is open but everything around it covered by a fine gauze which would apply a mild restriction to sound from the surround of the transducer (ie. the bit from 18mm out to 37mm).

I wonder what this tube is for, other than to protect the dome from finger-poking. An open tube has a half-wavelength fundamental resonance, in this case at about 36 kHz, which is where the HD580 treble response is dropping off. Could this tube be to extend the top end? I doubt it. There should also be a quarter-wave null associated with the tube at about 18kHz. The Headroom graph of the HD580's frequency response shows a dip there, which could be handy when listening to old FM radios which might not cut the 19kHz stereo pilot tone adequately, but again this doesn't seem to be a reason for the tube to be there.

I think the tube is probably there to help direct the sound waves from the dome into the ear, and to help reduce the influence of sound from the surround of the diaphragm.

What I'd like to know is how the "diffuse field" dip at 8kHz is achieved, but I don't know enough about the physics of domes and short tubes to guess whether the tube has anything to do with it.

> End Crap < Have I killed another thread?

 

[LTUCCI1924]

HI: Ok I took the foam off and put a quarter in the center of them and then traced around the quarted with a ball point pen and it cut a perfect round hole in the foam. When I reinstalled the foam I had better mids and better highs but still had all the bass. I know that the drivers are open but very small, the size of a quarter and will leave them like this with no fear of any problems with the drivers.

 

[acs236]

Taphil,
You don't happen to own a digital camera -- do you?

J-curve,
At first I tried listening one ear at a time. I wasn't able to discern much difference, although I did when I took both foam coverings off and compared it to when they were both on.

 

[Taphil]

No, I don't, but it's not hard at all....just cut out some nylon with the same size as the foam cover, put it over the driver area, and put the velour earcups back on.

 

[lonestar]

Okay, I exaggerated a little bit, there's no danger.

BUT, this is not going to be universally "good" tweak.

The first CD I played after pulling out the foam, displayeto be a little bit too much for my tastes. Sibilance was increased being noted particularly with vocals and cymbals. This particular CD has a lot of energy in the top to begin with however.

The second CD had much lower amounts of treble energy and the mod really showed it's worth. Vocals were "closer", more personal without the increased sibilance noted with the first CD. I do NOT believe that this was a case of my ears simply adapting to the sound. I would have had a second go with the first disc to make certain but time didn't permit.

If you find you don't like it, I think Taphil's suggestion to try different numbers of layers to tailor the mod to your taste should be tried before ditching the idea altogether.

As at least one person has indicated that he heard no differences, so I think this tweak ultimately may be highly dependent upon equipment/recording/listener preference. Your satisfaction with it may vary.

LTucci1924--your statement about the cut foam leaving the bass intact makes me ask, do you think that the bass is better with the foam in place than au natural? If so, perhaps cutting the hole AND using one layer of nylon to protect the driver and/or attentuate the highs somewhat, could be implemented.

The really nice thing about this tweak though is that it's EASY and FREE! And it can be easily reversed.

 

[LTUCCI1924]

lonestar:
HI: With the foam out the bass was still there but I think it is better with the foam in so I just cut a quarter size hole in the foam and put it back in and it seems that the bass is better. With the foam out It seems to be to much whatever renasonce or something but with the foam in and hole cut in it the bass is all there and I get better mids and better highs but no renasonce or what ever the open cans get with out the foam. When I put the 580s on the 890s stand I tilt them down so nothing can get in to the drivers and I leave the cut hole open with nothing covering the drivers as not to defeat the mode. I think this mode really does improve the 580s mids and highs and not a trace of muffle but I am useing the equniox cable also.