And I still do like the Beyer DT770 pads as well.
These headphones are amazing for electronic music.
I got bored and thought hmm maybe switch the pads from the JVC HAMR77X to the Q40 and it fits pretty good ( the Q40 pads fit on the JVC but not perfectly because of the angles it has but it works) tried the sounds and not bad more - dare I say more bassy IMO - would like to see if anyone has tried this combo and their thoughts :)
You're in the same boat as me but I gave up looking personally, that's how well I think they sound, especially if you're into electronic kinda music then these have a very very nice fitting sound signature. I'm addicted to their punchy/impactful bass and non-recessed meaty mids and non aggressive smooth natural highs that lets me listen at a reasonably loud vol without getting ear-fatigued and that's what eletronic dance music needs IMO. I prefer these over Signature DJs that often are seen as some kind of "king for electronic music" but to me the highs were slightly too aggressive and while the bass quality was close to Q40 I still think it was slightly worse, in the sense it wasn't quite as tight and punchy, sounded slightly more bloated as in bleeding into the rest of the music but it was the closest to Q40 bass quality I've heard so far but the mids/highs balance was more U-shaped and Q40 sounds reasonably balanced to me so.
I'm personally into euphoric hardstyle music and they do the kicks of hardstyle so nicely!
I've used XB500 before and still own the pair, the Q40 packs in an entire different league as far as sound quality goes while still providing that nice bass impact (quantity of bass isn't as much as XB500 but the impact vs quantity bass ratio is better though). The XB500 requires EQing to get a decent sound while the Q40 doesn't need any EQing. I did enjoy XB500 for a little while when I had dialed in the perfect EQ settings but when swapping to Q40 it was like no turning back ever.
overall xb500 is similar in that it have smooth bassy sound, without recessed mids or harsh treble, the problem with xb500 is that it has to much mid and upper bass, easily corrected with eq, q40 needs aftermarket earpads to truly shine
the problem for me with q40 was the small soundstage and rolled off treble after 10k
and they needed sub bass eq, they start to roll off below 50hz, xb500 has no roll off at all
xb500 can output 20hz sine wave strong and clean without distortion and eq
the q40 driver (similar to xb500) is incredibly powerful, it can literally shake your head without distortion