Fostex T50RP Incremental Mods and Measurements
Apr 8, 2013 at 4:37 AM Post #466 of 2,829
jgray91,
bluemonkeyflyer,
 
I've been and still using beyer gels on a DBV-like mod without much problem. I don't really recall precisely how they sounded initially, before the first adjustments, but now their sound doesn't produce any fatigue. Granted, I do listen with stereo convolution plugin, which makes the sound significantly more comfortable, but even before I've started using that plugin, the sound was bright, but not fatiguing.
 
Initially, I've attached them using electician tape, and stuffed cotton into chamber between baffle and pad around the opening. The sound was fatiguing, with spikes in lower treble, and I've added acoustic foam lining on the earpad opening, which improved things greatly, but there were still some ocassional spikes. I have slapped a chunk of foam over the center square of the driver, which fixed things.
 
Not so long ago, I grew tired of tape attachment, as it precluded easy opening\closing of the headphones, and made lips out of pleather, and attached them to pads with rubber cement. As a result, pads became angled (it was intentional) and much further spaced from the headphone than with tight tape attachment. I still used cotton under the pad, foam lining and foam on driver center. I've also added the foam circle from pads' package, so that the now-loose cotton would stay in place. The sound didn't change much, to my surprise. Imaging has improved somewhat, and feeling of pressure upon eardrum, which was making previous iteration somewhat uncomfortable for long listening, has vanished completely - now my ears don't feel the presence of headphones, it's just like some open phone with velour pads. Isolation was also reduced, but I tend to think that's not due to isolation, but that because now presence of headphones doesn't trigger ear safety reflex - I recall hearing noise in my ears with tape attachment, and nearly no noise at all with proper lips. I'm happy with them.
 
On the measurements side, my current setup is pretty flat, with +10db buildup of lowest bass (20-30hz) even despite having nearly everything closed( they do have a baffle port, but everything else is closed either with plasticine or electric tape.
 
Apr 8, 2013 at 8:48 AM Post #467 of 2,829
Quote:
jgray91,
bluemonkeyflyer,
 
I've been and still using beyer gels on a DBV-like mod without much problem. I don't really recall precisely how they sounded initially, before the first adjustments, but now their sound doesn't produce any fatigue. Granted, I do listen with stereo convolution plugin, which makes the sound significantly more comfortable, but even before I've started using that plugin, the sound was bright, but not fatiguing.
 
Initially, I've attached them using electician tape, and stuffed cotton into chamber between baffle and pad around the opening. The sound was fatiguing, with spikes in lower treble, and I've added acoustic foam lining on the earpad opening, which improved things greatly, but there were still some ocassional spikes. I have slapped a chunk of foam over the center square of the driver, which fixed things.
 
Not so long ago, I grew tired of tape attachment, as it precluded easy opening\closing of the headphones, and made lips out of pleather, and attached them to pads with rubber cement. As a result, pads became angled (it was intentional) and much further spaced from the headphone than with tight tape attachment. I still used cotton under the pad, foam lining and foam on driver center. I've also added the foam circle from pads' package, so that the now-loose cotton would stay in place. The sound didn't change much, to my surprise. Imaging has improved somewhat, and feeling of pressure upon eardrum, which was making previous iteration somewhat uncomfortable for long listening, has vanished completely - now my ears don't feel the presence of headphones, it's just like some open phone with velour pads. Isolation was also reduced, but I tend to think that's not due to isolation, but that because now presence of headphones doesn't trigger ear safety reflex - I recall hearing noise in my ears with tape attachment, and nearly no noise at all with proper lips. I'm happy with them.
 
On the measurements side, my current setup is pretty flat, with +10db buildup of lowest bass (20-30hz) even despite having nearly everything closed( they do have a baffle port, but everything else is closed either with plasticine or electric tape.

 
Nevod,
 
Very clever. Thanks for sharing this information. Can you post some "how to" pictures?
 
Apr 8, 2013 at 5:11 PM Post #468 of 2,829
Quote:
What are the dimensions compared to FA-003 pads? Or, are they Too Big, Too Small, or Just Right?
 
RE: Cotton balls, rolls, etc - Different weights, densities, dimensions....What you have may work, or not. As you know, there's only one way to find out.  :)

 
Just like the FA-003 pads, the NVX angled pads take a bit of stretching to get onto the cups. And like the 003 pads, I doubt they'll hold up over repeated removals and replacements. 
 
In the picture below, I stretched both the NXV (left) and 003 pads over some cardboard templates I created for another ear pad experiment. The templates have the same size and geometry as the T50RP cups. 
 

 
The ear hole of the stretched NXV pad is 4.7 cm x 6.2 cm. On the  003 pad, it's 5.6 x 6.6 cm. 
 
Other dimensions of the stretched NXZ pad are 9.0 cm x 10.7 cm (outside) and 1.5 cm (depth of the thin side) and 3.2 cm (depth of the thick side). The depth measurements are from seam to seam and exclude the flaps on the bottom and the "puffiness" on top. Comparable measurements on the 003 pads are 9.2 x 10.5 (outside) and 2.0 cm (approx average thickness).
 
Apr 8, 2013 at 6:33 PM Post #469 of 2,829
Quote:
 
Just like the FA-003 pads, the NVX angled pads take a bit of stretching to get onto the cups. And like the 003 pads, I doubt they'll hold up over repeated removals and replacements. 
 
In the picture below, I stretched both the NXV (left) and 003 pads over some cardboard templates I created for another ear pad experiment. The templates have the same size and geometry as the T50RP cups. 
 

 
The ear hole of the stretched NXV pad is 4.7 cm x 6.2 cm. On the  003 pad, it's 5.6 x 6.6 cm. 
 
Other dimensions of the stretched NXZ pad are 9.0 cm x 10.7 cm (outside) and 1.5 cm (depth of the thin side) and 3.2 cm (depth of the thick side). The depth measurements are from seam to seam and exclude the flaps on the bottom and the "puffiness" on top. Comparable measurements on the 003 pads are 9.2 x 10.5 (outside) and 2.0 cm (approx average thickness).

 
Thanks for this, micmacmo. Wow! The NXZ pads are smaller than FA-003 pads. I wonder how the NXZ pads would perform taped in place with double sided tape underneath and electrical tape around the edges? I'm pretty sure the SQ will change from non-stretched to stretched on, for all pads. Have you compared this variable?
 
Apr 9, 2013 at 12:21 AM Post #470 of 2,829
Quote:
Could be. I don't know. I'm just the messenger.
cool.gif
Don't shoot.

 
Interesting that many of them seem to have this crazy narrow dip at 8kHz. Although if I think about it, the half wavelength there is roughly 2cm which is probably about the distance from driver to ear, so I shouldn't be so surprised. 
edit: I misspoke... cancellation should occur when the driver is roughly a quarter wavelength away, assuming strong reflections off the ear/face then again off the driver/baffle surface
 
The Shure840 graph looks remarkably nice, as well as the Alpha pads. 
 
Apr 16, 2013 at 2:00 AM Post #471 of 2,829
Quote:
I wonder how the NXZ pads would perform taped in place with double sided tape underneath and electrical tape around the edges? I'm pretty sure the SQ will change from non-stretched to stretched on, for all pads. Have you compared this variable?

I listened to log sweeps with the angled pads either 1) stretched and properly mounted on the cups or 2) seated on top of the baffles and unattached. The most obvious difference was at the top end (roughly 4 kHz and above), where the sound from the stretched pads warbled up and down. The unstretched pads were smoother, but still had my telltale ~8 kHz chasm.  (I have no measurements because I'm pretty sure my setup is misbehaving since I remounted my mics.) 
 
I won't be repeating that experiment; stretching the pads over the cups introduced some little tears in the flaps.
 
Apr 16, 2013 at 8:38 AM Post #472 of 2,829
Thanks for the pad mounting comparison tests. I'm sorry about your flap tears. Did you use tape to seal around the pad-to-cup junction in condition "2" ?

Related: As the pad flaps stretch from multiple tuning cycles, pad-to-cup seal is diminished. Once you have them tuned just right and if you decide to put on new pads, get ready for a different sound quality. I find that bass becomes much more prominent and treble more recessed when installing new pads After tuning is completed. So, I either tune with this in mind or make modified bass ports at the cup vents.
 
Apr 16, 2013 at 11:13 AM Post #473 of 2,829
But on the stretched pads, was the overall shape of the pad also affected? (like the Shure pads becoming rounder for instance)
 
I would expect seal to affect bass response, but not treble. Conversely, I would expect shape to affect more treble, but not so much the bass (unless it were a significant change in ear-side volume)
 
Apr 16, 2013 at 11:25 AM Post #474 of 2,829
Quote:
But on the stretched pads, was the overall shape of the pad also affected? (like the Shure pads becoming rounder for instance)
 
I would expect seal to affect bass response, but not treble. Conversely, I would expect shape to affect more treble, but not so much the bass (unless it were a significant change in ear-side volume)

 
Good questions. I don't think stretching directly causes diminished treble but the net effect is the same.  I believe greater bass over-whelms or "covers" the treble that's still there but cannot be heard. Just a guess and my .02.
 
Apr 16, 2013 at 6:43 PM Post #476 of 2,829
Quote:
I'm sorry about your flap tears. Did you use tape to seal around the pad-to-cup junction in condition "2" ?

In condition two, the flaps were held in place by the clamping pressure of the headphones and sealed with the flaps acting as a gasket. Not perfect, but not bad either. 
 
Quote:
But on the stretched pads, was the overall shape of the pad also affected? (like the Shure pads becoming rounder for instance)
 
I would expect seal to affect bass response, but not treble. Conversely, I would expect shape to affect more treble, but not so much the bass (unless it were a significant change in ear-side volume)

 
For comparison purposes, the pad on the left is stretched and properly attached to the cup. The one on the right is unstretched and unattached. 

 
Apr 18, 2013 at 10:10 PM Post #477 of 2,829
Has anyone here tried cutting holes into the under/inner-side of the pads similar to the Jerg mod for the HiFiMans?
 
Apr 18, 2013 at 10:28 PM Post #478 of 2,829
Quote:
Has anyone here tried cutting holes into the under/inner-side of the pads similar to the Jerg mod for the HiFiMans?


You want to be very careful with that. Those suckers get lethal shrill in a hurry
basshead.gif

 
Apr 19, 2013 at 12:58 AM Post #480 of 2,829
Well yes, I know there are some holes in the 840. Not that many though. Just wondering if anyone's cut them up some more. 
 
The various Beyer pads have them too in varying degrees. Or for some of the bigger/deeper pads with a definable inner wall, I wonder if cutting those out a bit would make a difference. There has been mention of lining those inner walls which has been beneficial to some degree; perhaps cutting out holes would accomplish a similar thing.
 

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