Originally Posted by AustinJerry
Overall this looks pretty good.
I see resonances at 30hz, 40hz, 50hz, and around 70hz. These aren't exact/specific frequencies, but as close as I can tell.
From our PM's and in looking at your room dimensions/layout, it appears these are your first order length, width, and height modes. The 70hz resonance would be easiest to deal with as it's most likely a height mode and is high enough in frequency that velocity based absorption (pink fluffy cheap insulation) would probably be able to get rid of this.
The very lowest resonance at and below 20hz will always be there. There's really nothing you can do about it, but most people don't complain about explosions sounding too boomy.
Music (other than some classical music) doesn't really have much info down that low, so that first resonance and even the 30hz resonance probably isn't too bad.
The only thing that really concerns me is the 40hz resonance. I have the same thing in my 20'x26.5'x8.8' room and have a Behringer DSP1124p coming soon to hopefully help with this last remaining pesky peak/resonance in my room.
The 40hz mode is important because it is a fundamental bass guitar mode, is high enough in frequency to be present on most recordings and actually heard, not mainly felt.
It is very difficult to suppress the effects of this mode but Audyssey has at least flattened it out nicely. That's the good news. The bad news is that unless you have a foot or more to spare, just for insulation (the back wall would be the best candidate for this) you won't be able to get rid of it cheaply.
This is a great opportunity to use pressure based tuned absorption but it's not really a DIY project unless you have a lot more skill than I do.
GIK Acoustics makes a Scopus tuned trap, tuned right at 40hz (so you don't over absorb other frequencies which is very easy to do when trying to trap such troublesome low frequencies like 40hz) at a pretty reasonable price. I'd check them out. (I have no relationship with them whatsoever other than I am a happy customer and they've treated me great)
If you play some bass heavy tracks, something with Victor Wooten, Stanley Clarke, etc and you don't hear the resonances and/or they don't bother you, then honestly, I wouldn't worry too much about it.
If it were my room, I'd concentrate first on the highest frequency where there is a problem, which is around 70hz. Corner mounted SSC (super chunks, which work best when using cheap pink fluffy insulation and not high gass flow resistivity expensive stuff like OC 703/705) very thick, using the 34" wide corner chunk as a minimum (I do square soffit style corner absorbers using 4 pieces of R30 insulation for $15 at Lowe's, hung vertically, to make an 18" x 30" trap and haven't found anything that works better yet!) should take care of your problem at 70hz and put a dent in the 40hz to get it at least in line with the other resonances.
Once you get to that point, I'd say you are good to go.
Remember, there is always room for improvement, but in looking at this graph, it really isn't all that bad. You should be proud of your efforts.
Would you mind now showing us the same graph, with the same settings, with Audyssey OFF?
Then we can compare and see if Audyssey made everything better or made some things worse while making other things better.
Also, it appears your crossover is set around 80hz. Is this correct? If so, no problem, but if it's much lower or higher, I'd work with the distance tweaks a bit more and see if you can smooth out the FR around that area, which the top line of the waterfall (closely but not totally accurately) represents.
It would also be of assistance in comparing, especially if you decide to add more treatment to make sure the room isn't too dead (and hopefully it isn't too dead already) to show us an RT60 (just use the TOPS/green line and uncheck all the others in REW) and in controls set it to 1/3'd octave and to show as bars. There shouldn't be a difference in this with Audyssey on/off, but shouldn't and does/doesn't is not always the case.
There are more things we can check and I'll be happy to continue to work with you via PM or in another thread, but they're not necessarily appropriate for an Audyssey thread, so to stay on topic, I'd like to see the aforementioned/requested charts/graphs both with and without Audyssey at this point.
If you were to leave everything alone as far as treatment goes, I'm sure you will continue to enjoy your system for years to come, but if like me, you strive for perfection, I'd seriously consider investing in more treatment for the low frequencies, being careful not to over deaden the room, and before adding more, it's also wise to maybe try some different locations for your existing treatment, which is FREE!
Last but not least, using the ETC, you'll be able to see EXACTLY where you need treatment and where you don't so you can surgically insert the amount (and in the proper location) you need treatment. However, I believe that is straying a bit too far off topic for this thread, so might we continue (if you're interested, of course) that in another thread?
Thanks for sharing!