While I agree that most music doesn't reach frequencies below 40Hz, my library is primarily EDM  . I would still be very interested in seeing measurements without the vent. Would you mind trying it out? If you have a ziplock/sandwich bag, you can just stick the foam pieces to that and I can reapply or ditch them once you send them back.

Already on it. Taping over the vent. Gimme a second.

I already know the "culprit" if it can even be called that. Tape over the back of the fuzzy Jerg pads to make sure the seal is good. IMO, the boosted 50Hz (despite the rolloff at 35Hz) sounds better and is probably more in accordance with Jerg's vision.

I already know the "culprit" if it can even be called that. Tape over the back of the fuzzy Jerg pads to make sure the seal is good. IMO, the boosted 50Hz (despite the rolloff at 35Hz) sounds better and is probably more in accordance with Jerg's vision.

 

That's why we needed to send these in for measurement haha, so that you could do some ad hoc diagnoses on things that seem off, but that can't be known for sure without measuring before and after. So it's basically due to a lack of seal then...

If it's just the 1/4 of the pads (with those rubber risers) that need to be taped over, then it could be an easy additional step in the mod process.

I'm still adamant that the rubber risers are good mostly because with HE500, they distance the ears from the metal bars glued across the drivers, and the slight angling helps center-staging. It might need to be renamed from "back-vent mod" though, maybe just "slant mod". And perhaps recommend it for HE500 only (since HE400s don't have those nasty metal bars strewn across the drivers).


Depending on how the measurement comes out with Modulor's batch 2 Jergpads being sent to Marv for HE500, there might be the need for some major revision with regards to the adhesion tape step and the backside riser step.

I would definitely say that this troubleshooting is a success! Thanks to jerg for the idea, modulor for the pads, and purrin for the measurements 

I think the vent mod is still something that should be noted on the jerg pad thread (even for the HE-400). Angling the pads will help some with comfort but it will also give more room for your ears, as you have stated. Then, whether or not you want a bass hump or for the bass to be untouched, add/remove the tape layer.

I reckon I'm going to probably remove the vent all together. I don't need the angle or the extra space for comfort as I have no issues. I had noticed a fair amount of hollowness with these pads compared to my 1.0 pads and I'm guessing it is a result of the vent now... that or possibly the broader recession range in the upper mids? Something tells me that the upper mid behavior is going to be the same with the 1.0 pads. I think the hole mod is what is causing the difference in that range anyway. I guess I got some things to try out when I get my babies back 

Yeah the damping holes are the meat and gravy of the mod, they help remove the midrange resonance inherent with these earpads. As to what exactly causes the dip around 1.5-2kHz (observed in both the early version I sent to Marv, and this one, measured across HE500 and then here HE400), it may very well be due to the holes. Ditto goes for the reshaping of the upper midrange / treble region.

Overall the pads when modded do change the sound signatures of either HE400 or 500 it's used on in a complex manner. Clarity is boosted, while the tonal balance shifts toward a very cohesive yet relaxed state.

It's not terrible for HE400 persay, because the upper midrange recession is actually slightly raised by the mod, which coincides with this drop in the mid-midrange, so midrange ends up being smoother / more cohesive (it no longer feels like there's a "chunk missing", so midrange is less wonky and treble is more natural). It's all quite readily presented if you toggle between the graphs in this thread.

As for HE500... I can't say much until Marv measures the pads that Modulor's sending in.