Thanks for the feedback. Any other materials you could recommend I should try out?

I haven't pulled out the mod since I originally put it in. Anyone have trouble with left behind adhesive, and what did you use to clean it up?

Cotton ball and rubbing alcohol should work fine.

Yup. 

Best to dab the Creatology foam on your t-shirt first before applying.  This will reduce the need for removing adhesive later on. 

It's good to have a backup plan.

Sigh...the HD800 is just so tough to get consistent measurements with. I'm finding that all sorts of differences in the modded cup itself and the coupler of choice interact differently. Using a CD against the foam gives all sorts of weird treble resonances, while using without any hard material (including high density foam) gives cleaner treble but with serious roll-off below 200Hz. Position on coupler alters things greatly as well, much more than other headphones.

I think if we want the best representation of how the mods to the cup affect the perceived sound, we should be looking at measurements that get closest to a "free-air" system. Coupling directly to the foam (or sponge) might be the answer since we only care about decay in the treble. Maybe I should try sticking a mic in the HD800 without any coupler at all to see what sort of results I would get.

Quote from: OJneg on October 19, 2014, 02:24:11 AM

Sigh...the HD800 is just so tough to get consistent measurements with. I'm finding that all sorts of differences in the modded cup itself and the coupler of choice interact differently. Using a CD against the foam gives all sorts of weird treble resonances, while using without any hard material (including high density foam) gives cleaner treble but with serious roll-off below 200Hz. Position on coupler alters things greatly as well, much more than other headphones.

I think if we want the best representation of how the mods to the cup affect the perceived sound, we should be looking at measurements that get closest to a "free-air" system. Coupling directly to the foam (or sponge) might be the answer since we only care about decay in the treble. Maybe I should try sticking a mic in the HD800 without any coupler at all to see what sort of results I would get.

That's what we did.  No CD or plate.  We also found the same as you that just millimeters off in positioning could alter the measurements.  Same with certain materials used for modding.  Tried explaining this to some folks who seemed to just roll their eyes. 

omg no wonder, I get funny arse resonances with the CD and foam as well. I found putting the mic close to the driver to get the closest results but thought that you guys still used some kinda coupling mechanism.