[jerg]

  I've been testing my JergulorX pads the past few days, fiddlin' and tweakin', and discovered that the back vents with the Creatology foam were produce a serious bass response to the point that it was rather "bloomy".  For some songs that already have a serious low end, that tended to intrude into neighboring frequencies, making certain mid frequencies recessed, esp. rhythm guitar, etc.  Mids like vocals and such were fine.  While the thumping, rumbling bass was fun at times, the overall sound was less than accurate.
 
I did a quick test by covering the open back sections with electrical tape, which definitely reduced the bloom.  In the end I redid the mounting rings with just the double-sided, hole-punched photo stickies (I doubled them), and now the sound is much more accurate, but those songs that have some serious low end are still quite satisfying.
 
My chain is:
24/96 FLACs -> foobar2000 with Output set to U2 USB DAC in WASAPI Event Mode -> USB extension cable -> HiFimeDIY USB isolator into U2 Sabre DAC -> AudioQuest Golden Gate mini-to-RCA -> Schiit Lyr running Super Cryo Reflector 6N23P-EV Military Matched Pair  -> plusSounds custom cable -> HE-500.
 
I've also got custom grills like jerg's, with a sheer organza fabric dust shield (quite see-through).  Oh, and I did the felt mod taped to the metal frame behind the grills.
 
Not sure if that's of any interest, but figured I'd share it.
 
For now, I'm a happy camper 

Did you do the outer ports step on the pleather pads?

 

[Clemmaster]

I might come back to the HE-500 in the near future (switching back from the HE-5LE now that I have the HE-6).
 
Is it too late to be part of Modulor round 2 event?
I don't want to pollute his PM box for nothing...

 

[ThurstonX]

  Did you do the outer ports step on the pleather pads?

 
The cutting?  Yep, I did almost all the cutting.  The only variation I made was not putting the small "top and bottom" holes when cutting on the inside, as I made the initial holes really large.  But it sounds good to me.  I was a little surprised the back vents made that big a difference.  Can you explain why that is?  I'm very curious.
 
Also, do you think the felt mod on the metal frame is less of a big deal, given the sheer piece of fabric I have on the grills?  I didn't do a proper before-and-after test.  It doesn't seem to have had a negative impact.

 

[bcpk]

Of course family matters come first, please take your time modulor.

 

[jerg]

   
The cutting?  Yep, I did almost all the cutting.  The only variation I made was not putting the small "top and bottom" holes when cutting on the inside, as I made the initial holes really large.  But it sounds good to me.  I was a little surprised the back vents made that big a difference.  Can you explain why that is?  I'm very curious.
 
Also, do you think the felt mod on the metal frame is less of a big deal, given the sheer piece of fabric I have on the grills?  I didn't do a proper before-and-after test.  It doesn't seem to have had a negative impact.

I think you are confusing the purposes of these different mods.
 
The openness of the back grills are important because if they are not, then they produce reflected soundwaves that has a subtle but definitively negative impact on the openness of the sound.
 
The felt (or other high damping factor material like creatology foam) applied onto the inner face of the drivers, is to absorb or at least partially absorb the backwaves INSIDE the enclosure between the drivers and the ears. The flat metal grids that hold the magnets are an easy target for ringing at specific frequencies. My hope with this recent mod is to hopefully bring about better damping inside the driver-ear space and give it even more clarity, and subjectively that does seem to be the case.

 

[ThurstonX]

  I think you are confusing the purposes of these different mods.
 
The openness of the back grills are important because if they are not, then they produce reflected soundwaves that has a subtle but definitively negative impact on the openness of the sound.
 
The felt (or other high damping factor material like creatology foam) applied onto the inner face of the drivers, is to absorb or at least partially absorb the backwaves INSIDE the enclosure between the drivers and the ears. The flat metal grids that hold the magnets are an easy target for ringing at specific frequencies. My hope with this recent mod is to hopefully bring about better damping inside the driver-ear space and give it even more clarity, and subjectively that does seem to be the case.

 
I guess I was.  One last question re: the felt damping mod.  That's applied inside then, not on the frame visible through the grills?  If so, to access the inside (driver), the pads need to be removed, at the very least.  I haven't really studied the structure of the HE-500.  Sorry for my ignorance.  Just trying to get it right  

  It seems I mistook your photo for the frame directly below the grills.  If so, then the shapes are very similar.
 
Thanks for your patience!

 

[jerg]

   
I guess I was.  One last question re: the felt damping mod.  That's applied inside then, not on the frame visible through the grills?  If so, to access the inside (driver), the pads need to be removed, at the very least.  I haven't really studied the structure of the HE-500.  Sorry for my ignorance.  Just trying to get it right  

  It seems I mistook your photo for the frame directly below the grills.  If so, then the shapes are very similar.
 
Thanks for your patience!

Yeah ofc, it's pointless to apply the strips of felt to the outer face of the drivers, as we don't have face/ears/earpads blocking that way reflecting back the majority of soundwaves.
 
So you did that? It doesn't hurt I suppose, but I would just remove it.

 

[ThurstonX]

  Yeah ofc, it's pointless to apply the strips of felt to the outer face of the drivers, as we don't have face/ears/earpads blocking that way reflecting back the majority of soundwaves.
 
So you did that? It doesn't hurt I suppose, but I would just remove it.

LOL, yeah, I feel like a complete idiot.  Now I wonder about the felt on the outer frame.  Could it actual counteract slightly the point of opening the grills?  I prefer to have the dust shield, as my house can be rather dusty, and it is really sheer.  Easy to see the metal through it, and even the black felt now.  I guess I'll try them with that outer felt in place, once I finish the actual mod (shakes head... again  If it doesn't hurt, it has the aesthetic benefit of masking the silver showing through the grills.
 
Hey, on the bright side, I'm now well-versed in applying the felt!  Shouldn't be long now 

 
Thanks for kickin' my ass in the right direction.

 

[jerg]

 
LOL, yeah, I feel like a complete idiot.  Now I wonder about the felt on the outer frame.  Could it actual counteract slightly the point of opening the grills?  I prefer to have the dust shield, as my house can be rather dusty, and it is really sheer.  Easy to see the metal through it, and even the black felt now.  I guess I'll try them with that outer felt in place, once I finish the actual mod (shakes head... again  If it doesn't hurt, it has the aesthetic benefit of masking the silver showing through the grills.
 
Hey, on the bright side, I'm now well-versed in applying the felt!  Shouldn't be long now 

 
Thanks for kickin' my ass in the right direction.

You can tuck away the 2 wires at the back of the drivers, and with that the silvery drivers don't look too bad...not to me at least.
 

 

[ThurstonX]

  You can tuck away the 2 wires at the back of the drivers, and with that the silvery drivers don't look too bad...not to me at least.
 

 
Good point, and thanks for the pic.  I did that, and I left the outer felt on, for now.  Stealthy  

 
Just finished the real felt mod.  Don't know if it's helping, but I'm willing to go on your word.  What I'm listening to now sounds awesome.  Bass nice and tight yet full, all mids and highs in their places, soundstage just fine.  But after wearing the Q701 while working, these things weigh a TON!  I'm selling them....
 
 
 

 

[hans030390]

  I've been testing my JergulorX pads the past few days, fiddlin' and tweakin', and discovered that the back vents with the Creatology foam were produce a serious bass response to the point that it was rather "bloomy".  For some songs that already have a serious low end, that tended to intrude into neighboring frequencies, making certain mid frequencies recessed, esp. rhythm guitar, etc.  Mids like vocals and such were fine.  While the thumping, rumbling bass was fun at times, the overall sound was less than accurate.
 
I did a quick test by covering the open back sections with electrical tape, which definitely reduced the bloom.  In the end I redid the mounting rings with just the double-sided, hole-punched photo stickies (I doubled them), and now the sound is much more accurate, but those songs that have some serious low end are still quite satisfying.

 
This was demonstrated in stages of measurements for the jergpad mods. The back vents slightly rise the response around 50Hz and also noticeably increase harmonic distortion. The harmonic distortion in particular gives more of the rumble and bloom. The pad adhesive mod helps smooth this area out a bit and lowers the distortion some. Taping up the vent further flattens the bass and lowers the distortion. Entirely skipping the vents gives a flatter bass response and less harmonic distortion. 
 
Personally, I don't mind (might actually prefer) a bit of a hump around that area, and I don't find the additional rumble and bloom to be unpleasant (might even be tastefully "fun").

 

[jerg]

If the user doesn't appreciate the additional soundstage introduced by the open backvents, and doesn't care much for sub-bass emphasis (and more rumble, less growl), then by all means skip the backvents mod. I personally think the benefits far outweigh the (on paper) negatives.

 

[hemipowered007]

Wonder how this new felt mod may change the he4. Don't even have it in my possesion yet(still in transit) but will be trying all mods on it. Already have my ugly pads ( self modded superglued velour topped jergpads) and grills, which actually look nice. Just very interested in this new mod. Probably should try it while I still have the 400, isn't selling anyways.

 

[hans030390]

  If the user doesn't appreciate the additional soundstage introduced by the open backvents, and doesn't care much for sub-bass emphasis (and more rumble, less growl), then by all means skip the backvents mod. I personally think the benefits far outweigh the (on paper) negatives.

 
I agree, but the HE-500 regardless has never had much in the way of a large soundstage for me. The vents did help, sure, but the biggest change is in the bass to my ears.

 

[Thujone]

Wonder how this new felt mod may change the he4. Don't even have it in my possesion yet(still in transit) but will be trying all mods on it. Already have my ugly pads ( self modded superglued velour topped jergpads) and grills, which actually look nice. Just very interested in this new mod. Probably should try it while I still have the 400, isn't selling anyways.

It's not possible with the HE-4 since they are single ended (and the magnets are on the backside of the driver). Not sure about the HE-400 though... as I understand it, the white driver housing would need to be removed first?