Originally Posted by hifisponge
The graphs do look a lot better with Audyssey ON, don't they? Shame that is not what I hear.
I'm 90% sure that I have solved the problem I was having with peaky sounding upper bass with Audyssey ON. This was a rather tangled knot of a problem, but no one said this hobby was easy if you want to do it right.
The short explanation is that all it took was moving the crossover from 80 to 60 Hz for both the main speakers and the sub.
The long explanation is as follows:
I started by setting the crossover where I wanted it -- at 80 Hz for all speakers including the sub. I then used the RTA built into my Velodyne DD sub and measured the effects Audyssey ON and OFF at the couch. The first thing I noticed was that with Audyssey ON the response looked virtually ruler flat! Flatter than I have ever achieved using the parametric filters in the sub. Normally this would be great, but of course I didn't like what I was hearing. So I turned Audyssey OFF and saw that there was a broad dip centered at 80 Hz, like I was used to getting. Obviously, Audyssey saw this dip and tried to correct it. This is where it gets complicated, but I will try my best.
The first problem was that I had been using the dynamic loudness function of my Lexicon prepro prior to Audyssey. I always made sure to turn it off while calibrating and measuring, but turned it back on without thought right after. With Audyssey ON, the dynamic loudness function was elevating the overall bass too much from 100 Hz down and making the problem I was hearing in the upper bass worse-- duh. I always liked the dynamic loudness function without Audyssey, but it was too much of a good thing with Audyssey engaged.
Along the way, I discovered that I am much more tolerant of excessive low bass (below 40 Hz) than I am of any boost in the upper bass. Low bass has no tone, it only adds weight to the sound, whereas peaks or elevations in the upper bass do have tone and stand out much more as hot notes.
When I turned off the dynamic loudness, things got a good bit better, but the upper bass still sounded a little too hot. What's interesting is that at the couch, the bass sounded very close to flat, but the moment you stepped three feet away from the couch into the room, the upper bass demon returned in full force. I think there is some psychology involved here because I have to walk across the room from my couch to turn Audyssey OFF. And right next to the AV cabinet is what I call "the bass pit". Bass energy tends to pool up right there and it sounds awful. Part of what I believe was happening was I was carrying the memory of the elevated upper bass in the majority of the room with me as I walked to sit down to listen at the couch. My focus was on the excessive upper bass as I walked through the rrom, so I was possibly hearing it when it wasn't there at the couch or would otherwise not find it objectionable.
I decided to take some measurements around the middle of the room. Sure enough, with Audyssey ON there was either large peaks at 45 Hz and 75 Hz, or a broad elevation from 45-90 Hz depending on the location. With Audyssey OFF, the peak from 60-90 Hz was greatly reduced but from 40-60 Hz it remained. Remember I find elevated low bass much less objectionable than upper bass so this sounded better. I may be wrong here, but I also have a feeling that all of that excess upper bass energy in the room everywhere except at the couch was in fact being heard somehow at the couch position.
Knowing now that I wanted to try and at least reduce the upper bass, I started playing with the cross over points. I moved the sub crossover down to 70 Hz and kept the other crossovers at 80 Hz to try to force a dip in the upper bass. Didn’t work. So I moved the sub crossover to 60 Hz. Much better, but now it sounded like there was a bit of hole. So finally I moved the crossover for just the L/R speakers down to 60 Hz and wah-lah, it all snapped together—better bass than I have ever heard in my room. The low end was all there, the upper bass sounds pitch-perfect and I now have punch and kick. The upper bass even sounds pretty good throughout the rest of the room, and tolerable in the bass pit.
I don’t know why I couldn’t just pick any crossover point that I wanted, and I don’t know why I heard excessive bass between 60 and 80 Hz when there is nothing in the graphs that says I should (at the couch anyway), but I’m glad I have a solution. Still, I’m the type that likes, no needs, to know “why”.
Hope that was at least a little bit interesting or helpful to someone other than me.