Originally Posted by systemlayers
Yeah I use DEQ. I haven't really done much side by side comparison of on v.s off but I guess I've just been going off most around here keeping it on. How does DEQ affect music since that's much more of a constant sound?
That's a good question since DEQ was really designed for movies played at below Reference volumes on home theater systems. As you probably know, DEQ is a separate software program, or app, which is independent of the filters that Audyssey sets to EQ your speakers.
According to what I have read, and seen, most people prefer to watch movies at about -10 to -20 MV, and DEQ tries to maintain tonal balance at those volumes, and lower, by boosting the bass and treble slightly, while leaving the mid-range (where our hearing is most acute) untouched. In theory, we will then hear the movie soundtrack the way the film mixer intended for us to hear it, even if we listen at volumes well below Reference. As you note, music doesn't have a Reference to start with, and may not have as wide a dynamic range, so it was always a bit of a kludge for that.
DEQ adds about 1db of boost for every 5db below Reference. So, at -15 MV, DEQ would add 3db of both treble and bass boost. At -20 MV, it would add 4db, and so on. This is one reason dialogue can become harder to hear at lower volumes with DEQ engaged. Because DEQ is boosting everything except the mid-range where dialogue is found.
If you are listening at -15, for instance, and using +6 sub trim, you are actually at +9 compared to where Audyssey set your subs relative to Reference. Not so far from my +12 without DEQ.
DEQ also boosts the surrounds by about that same 1db per 5db below Reference. And this is one of the main complaints you may hear about DEQ. Some people love the surround boost, and some don't. What I found was that a lot of movies and TV shows already have pretty loud surround effects. With some of them, DEQ made the surrounds overwhelming for me, particularly since I have a 7.1 system, and it was boosting 4 of my 7 speakers.
I never liked DEQ at all for music, although I did use it off-and-on for movies for a couple of years. But DEQ boosts the bass not only for the subs, but for all of the channels. I eventually got to the point where I found it better to just apply my own sub boost to movies and leave my music pretty much the way it was recorded, just increasing or decreasing the MV, as I needed to, or using the tone controls (which are disabled when DEQ is engaged) to make slight adjustments.
But all of this is purely a matter of personal preference, and I respect other viewpoints on the use of DEQ. Some people I know use it for everything and love it. YMMV! Incidentally, if you like DEQ, you might want to experiment a little with the Reference Level Offset feature (RLO) in your AVR as a way to adjust the effect of DEQ. The FAQ, linked below, explains RLO in some detail.