[Android Software Development] ephexxis:
its not a simple problem honestly. it can be aggravated by certain effects files, effects settings in v4a or your media player, and while savvy use of an EQ that allows for fine band definition (neutron/the atmos eq at least if one were to use the config file, im not sure how it works in the UI, if you can enter frequencies manually or not) is a very effective tool for isolating and removing the frequencies driving the issue, you can still end up with a mix that sounds like crap if say, you're using a version of the mod or configuration that just doesn't provide the ideal, defined low frequency presence that we're looking for. im sure I'm not the only one who throughout this whole process has landed on the occasional "miracle" release where you just load it up and everything sounds brilliant from the go, Crystal clear, separated, unobtrusive and powerful. the ideal soundspace is something you'll know when you can basically boost and cut all day like an amateur, with overlapping bandwidths and omitting any shelves without ever overpowering upper levels with lower levels or at least not enough to cause any distortion or loss of detail.

It's a tall order but we've definitely been there a few times before. for the time being, as I've mentioned before, your best bet is to use notch filters and hunt within the 200Hz-500Hz and 950Hz-1.5kHz ranges for problem frequencies. in neutron, on the eq screen when configuring your bands, make one of them either a "peak eq" using q factor or bw, doesnt matter they're just adjusted inversely, but i like the q factor for potentially sharper curves at the reference freq... or you can just select a "band stop" filter if you want to entirely remove the problem frequency which is very effective given the right width adjustments. this is pretty much a notch filter and is preset for this task. use the slider while a bassy, boomy ducky track is playing, and slowly pan in those ranges if you can manage to even pull that off. i find the sliders rather sensitive at such high res, so you might want to just use the value box and pick freqs spaced maybe 30 Hz apart in the 200-500 range and 50 or 70Hz apart in the 950-1.5k range to start. it's okay to use multiple notch filters too, since they're very narrow they're awesome for removing crap and letting the good stuff shine through. you should be able to at least improve the mix this way. obviously check your gains too, lower them if you can, and also check to make sure you don't have any compression turned on. in v4a there's the AGC up near the activating switch and fun fact, the master limiter at the very bottom also uses compression to do what it does, so that's another thing you might try setting back to 0. it's very useful obviously but compression can sometimes cause ducking in a sense; what it does is sets a threshold at a certain level and while cutting peaks that reach above it, also boosts everything else in the mix to varying degrees to try and push the overall volume towards the threshold, the idea being that its desirable for a songs volume to stay relatively consistent throughout, regardless of instrument. one can see how this may cause wonkeyness in your levels though and it can sound like ducking in my experience