[spence]

I've got a drop ceiling in my room, with standard Armstrong acoustical tiles. Would there be any benefit by having bass trapping in the wall/ceiling corners if there is already 15" of regular insulation above the whole ceiling? I've also got a 6' x 6' cloud of 2" rigid fiberglass in the grid between my listening position and the speakers. My concerns are around the ceiling perimeter of the room just below the drop ceiling. I've read that bass frequencies pass right through drop ceilings, so hopefully I can avoid the trouble of hanging panels or soffits, and conserve the space.

[Big Red Machine]

Well bass will definitely blow right through the panels.  You will get some absorption from the insulation above, but limited to the density of the insulation, which if pink will be higher in frequency grab than denser material which can grab lower frequencies.  So the drop ceiling can preclude the need for ceiling-wall intersection traps if the ceiling insulation is doing its job.

My drop ceiling is at 8 feet and the floor above the drop is at 9 feet-ish.  I have zero insulation in that space and have no need for bass trapping as evidenced by the sound and my plots.  Since I am renting I am happy not to invest in this for my landlord.

Do you feel you have a need for trapping?  Boomy bass?  Any measurements taken?  What are your room dimensions including your height with and w/o ceiling panels?  This info will help the responders to formulate their responses.

[spence]

Thanks for your reply. I have not taken any measurements. It's a basement home studio room. No boomy bass at all. The room is about 11' wide, and has 2 depths in the rear - 16 1/2 ft. deep on one side (there's a bathroom behind this wall) and 22' deep on the other. It's 7'3 to the drop ceiling, and 9' to the floor above. There is 6" of insulation in the joists, and a 9 1/2" layer laying right on top the ceiling tiles. There's a couple inches of air gap between the layers of insulation.  I've got large soffits from floor to ceiling in the corners. I've also got a bunch of GIK 244 traps. The insulation above the drop ceiling is standard fluffy stuff. My main concern is the wall/ceiling corners around my listening position just below the drop ceiling.

[Big Red Machine]

I'd measure it before doing any more.  You can overdamp a room pretty quick and the ceiling sounds packed and with the cloud, you should have minimal reflections.  I switched to diffusion on the sides years ago and love it in 2 rooms now.  They have a great totorial on Home Theater Shack on using REW and what gear to buy.  With a laptop and less than $200 you have the ability to get some answer pretty quick.

[spence]

I've looked at REW before, but never attempted it because it seems so confusing. I guess I should just tackle it anyway and learn as I go. Will it tell me exactly where to put room treatments, or does it just point out problem frequencies, then it's trial and error to fix them? 

[Big Red Machine]

It will give you the response of your room and then you make a change and remeasure until you get either a pretty graph or a sound you like.  Sometimes they are not one in the same.

Overall most of spend way too much time worrying about how well the graphs represent a "good" room versus trusting our ears.  But for the beginner you might be surprised how badly a room can measure versus how good you thought it sounded.   sounds like double-speak, but it can happen.

[drummermitchell]

If what they say is true about bass trapping,that you can't have enough and you CAN'T make a room perfectly flat,but you can have to much HF absorbtion which will deaden the room I'd say the more bass trapping the better.
I believe Ethan Winer states that also that you can't have enough bass trapping,but you can have to much HF absorption.
I have redone my room with Realtraps and the only HF I have is my side wall reflections and my drop ceiling reflections.
I have to say that since just changing out the panels on the side wall reflection with the RT HF panels,using the same music that it was quite a revelation at to what was buried underneath using the other panels even though they did provide a clearer midrange ect.
The RT's dug into the macro of the recording whether just a hint more of re verb or whatever,they sure opened up the window a lot more.
Even though a VW and a Lamborghini can do 100 mph,there is a huge difference between the two and with music you hear it.
I have my drop ceiling cavity filled with Roxull and I installed some RT tiles which I believe is OC-703-05 with membrane for more bass trapping which I use around the outer edge.
For walls I'm using the 13 Mondo modules(6")and 3X mega traps in my right rear corner and it's not to dead at all.
I will say I have some scary mid bass punch that I never had before with the other panels.
If all this bass trapping sucked the life out of my music,they would be for sale or out of the room(which I did with the others as there is a huge difference.
On Music player forum Ethan has an acoustics thread,worth the read and very informative.

[Rob Babcock]

I've looked at REW before, but never attempted it because it seems so confusing. I guess I should just tackle it anyway and learn as I go. Will it tell me exactly where to put room treatments, or does it just point out problem frequencies, then it's trial and error to fix them?

It's very basic but here's a brief tutorial that will at least get you started.  There are some other good ones on youtube as well.  Trapping corners is almost always a good idea no matter what other treatment you have.

[Glenn Kuras]

If a drop ceiling then you need to treat above it in the "real" corner. You can just stuff fluffy fiberglass in the corner. Just make sure it is large, as in make it the whole 15" and as wide as your budget will let you.