Will painting an acoustic panel lower absorbency?

Thanks Sean and Clueless for your responses. I will read with great interest the links you provided, but the information you have already provided in your answers has convinced me to go in the direction I originally planned, which is to remove each panel, cover it with fabric, and reinstall.

I really appreciate your help.

The fabric is the right way to go. It does depend on what frequencies you are trying to absorb. Quite honestly if you are planning to cover the entire room in fiber board you are going to have an aweful lot of high frequency absorption, and while painting will reduce this, in your case it might be a benefit. Fiber board is a great acoustical tool, but needs to be used appropriately. It's frequency absorption typically starts around 640 Hz (depending on the fiber density) and is not doing very much at this frequency. Without knowing much else about your room I really can't add very much, except to be cautious with over damping even a challenging room. It will make it sound lifeless and dull. I'm actually re-engineering a dealer showroom that was 2/3 covered in fiberboard. It was a dreadful room to begin with, but the overdamping made it worse. We're going to fix it.

Rives...thanks for the comment.

The results from adding the panels have been very good. I started by completely covering the front and back walls with the 2" thick panels. I then installed panels 2" thick on the 4' tall knee walls along the left and right side of the room. Finally, I added 1" thick panels on the sloping ceilings along the left and right sides of the room. At that point is where I may begun hearing some of the effects of over damping, but the sound is much better now than ever before.

As I remove and cover the panels, I will be doing so in such a way that I can remove some panels, listen to the results, and see if the removal of a few of these panels will "brighten" the sound somewhat. Although my stereo sounds much better than ever, a little "less dead" would be better.

Jcambron: You probably need a combination of other acoustical devices, such as diffractors. You want to get a balance of absorption, so over damping won't work terribly well, which it sounds like you've discovered. You can actually tune (build) diffractors to certain frequencies, which is what we typically do in order to get a good balance in the room. These are not trivial things to figure out. The difficulty is the whole room works together and although it might seem that eliminating reflections with fiber board would get rid of some of the nasty reflections (it will), but at the expense of over damping the room. Our website has more on the subject, but does not go into diffractors. If you go to www.rivesaudio.com and go to the listening room. You can get to the listening room either by clicking on the tag line on the 1st page (not the intro page) or by clicking on "Issues" on the first page. It's a pretty basic tutorial section, and you may already know the information there, but hopefully it's helpful to you.

Rives, thanks for your additional comments. I will take your advice and visit your listening room to see what else you have there that might be helpful. I've always had a decent quality stereo and/or home theatre in my home, but this is my first high end system with a dedicated listening room.

As I listen to various recordings, the "dead" effect we've discussed is much more pronounced on some discs or LP's than it is on others. On many recordings, I don't notice the dead effect at all. It may be that the problem is more directly related to the source material than I first thought. I am going to clock a number of hours listening to my current set up before I start making changes. I want to have a good reference point as I go forward.