Stuffing materials. How do they affect sound?

[Bojamijams]

For example, how would stuffing the cups of a closed headphone with fiberloft affect the sound? How about a damping material like dynamat? What about cloth?

I'm trying to figure out how to get rid of the harshness and sibilance of my custom MD2000 phones. I removed the fiberloft thinking it adds to sibilance but its still there.. There is some dynamat around the driver and the driver ring as part of the markl mod, but I've been unable to find out what exactly that does.

I need to know how to tame the harshness/sibilance but not affect the rest of the SQ at all.

Any input appreciated

 

[b0dhi]

You might try what's used in the DT-990 Pro enclosure. It's a medium density felt placed on the rear plane of the enclosure. Generally that type of material will absorb high frequencies. Check out the Driver Pictures thread to see pics of it.

Removing the dynamat will not make much of a dent on sibilance.

If all else fails (meaning the sibilance is inherent to the driver), you can place a foam disc in front of it (again much like the DT-XXX series). The denser the foam, the moar of the high freq's will be absorbed.

 

[Bojamijams]

I'm not having any luck finding that driver pictures thread

Can you expand on it please? Medium density felt (cloth?) placed on the rear of enclosure.. you mean behind the driver?

 

[b0dhi]

http://www.head-fi.org/forums/f4/hea...22/index4.html

This shows felt along the inner-rear of the enclosure:

 

[Bojamijams]

Ahhh I see. Thanks for that. What would this felt be called as a product that I could search for?

 

[Shoewreck]

Heavy stuffing materials, like dynamat and blue-tac dampen housing vibrations (that's generally good), but these materials also reduce internal volume, so headphones may get somewhat detuned after such threatment.

Light stuffing materials, like felt, synthetic wool, fabric and foam can do two things:
1) Obstruct air flow, improving dampening. That makes bass tighter but less prominent. Almost every headphone I own has an additional piece of foam inside - that's just the way I like it.
2) Convert high frequency acoustic energy into heat. Synthetic wool is particularly efficient in this. I.E. stuffing a Grado resonant air chamber with synthetic wool would alter it's high-mid and low-treble frequency response.

 

[Bojamijams]

Would fiberloft be an exception to this? Because I've read that fiberloft can increase sibilance, which to me is not taming the highs, but exagerating them