[Prof.]

Hi,

I have two book shelves covering my front corners. If I put a bass trap behind them will they have any affect?

I doubt they would be very effective in that situation since you're already getting sound reflected off the bookcase along with some absorbtion..
Can the bookcases be moved elsewhere?

My second question is if I put bass traps on a stand in my rear corners do the edges of the traps have to be touching the walls? Or can the traps be spaced away from the corners.

They can be spaced off the corners..Infact they may be even more effective with a gap..

 

[Prof.]

Are you using triangular chunks for your corner traps or flat panels?

 

[Prof.]

If they are only 2" thick panels, then that's not going to be enough thickness..
You really need to have 3 layers of 2" in each corner to be effective..
Ideally, the edges of the front panels should be touching the side and back wall..leaving a gap between the back of the panels and the corner..
The distance between the back of the panels and the corner is determined by how wide you make the face panel..The wider the face panel..the greater the gap..

I hope I've explained that clearly enough...

 

[Prof.]

D..I've just had a look at the ATS website and they don't seem to list any actual bass traps..They all appear to be acoustic wall panels of different types..

Generally speaking, effective bass traps should be higher than 4' and preferably floor to ceiling..That is what's used in most theatres, mine included..
I realize that it's not always practical to have them that big, so a bass trap that's only 4' high needs to be at least 6" thick..

Wall panels are generally made 2" or 4" thick..

Did they sell them to you specifically as bass traps or as acoustic panels?

 

[Prof.]

Certainly try them without the bases and see if there's any improvement..
If you find that they are not making a lot of improvement, I would get a sheet of OC703 fibreglass and build up the thickness..