I decided to pop open my MK3's today and mess with the guts to see what happens. So far I have: -covered the driver with two layers of cotton bandage material (non-woven sheet). Good idea, as it brought the treble spikes way down into humane territory. -covered 4 vent holes around the driver side of the baffle, leaving the other 4 open. Probably a good idea, assuming these do indeed vent bass away from the driver, lowering the bass entirely. -tried dynamat over the cup vents. Bad idea, removed too much bass. Removed dynamat, which tore off the original tape material that covered the vents. Bad idea. Luckily I had automotive felt tape handy, and replaced it with that. Good idea. -Covered two of four vents with dynamat over this felt tape. Bad idea, since the felt tape is already less air permeable than the original paper/cloth tape. Removed dynamat, which didn't affect the felt tape, but did bring the bass back! -stuffed the cups with about 1,5 or 2 grams of medical cotton that I fluffed a bit first. I have no idea if this did anything worthwhile yet. Does anyone have specific ideas for mod procedures that they would like to share? I'd love to know some of the secret sauce! I'm considering blocking off ALL the vents on the baffle, and maybe blocking the vents on the cups a little to compensate. I want less of a peak at 100Hz and more sub bass, while hopefully keeping the overall bass quantity. The treble just needs to be lowered, which I accomplished pretty well so far. If I can lower the treble and increase the bass, while making the peaks wider and lower in general, I'll have succeeded. Has anyone gotten there successfully?