Cel,
You've got a couple issues with the bassiness and the lack of brightness in your mixes. There is some low-end mud in the low-mid frequency area. You need to cut a little of that out. You also need to enhance your high-end. I can hardly hear any of the highs. Also check how low the bass goes. You may need to use a high pass filter set at ~40 Hz and/or turn the low frequency stuff down a dB or two with a low shelf EQ. I'd bet that it's taking up a lot of headroom in the mix also. It actually sounds like you have some compression going on in the low end. It hits my ears hard and won't let go, so maybe the best approach is to remix and focus on a lower compression ratio so that you hear stuff evenly, but that it doesn't wear the ears down. The basses in particular are either too high in volume or need to be controlled more with compression or limiting. EQ after compression. Compression usually brings up the "mud", so you've got to EQ the mud out after the compression (mainly cutting frequencies... then boosting slightly for a little air and high-end detail).
Hope this helps,
Rev E
