acoustical treatment behind projector screen - needed???

I have 2 Sl3's, Theater i center and 2 JL Audio Fathoms along my front wall in front of my Screen. I have floor to ceiling bass traps in each front corner (6" thick). There is only about a 12" gap between the edge of the screen and each bass trap. I have always wondered if it would make sense to take the screen down and over the remaining wall with 2" - 3" thick fiberglass panels behind it wrapped in black fabric, thereby basically treating the whole front wall acoustically? My SL3's are about 3' out from the front wall and 2' from the side wall.

what do you guys think?
thanks
gordon:rocker:

Gordon, I just picked up a pair of Mondo Traps. I initially put them in the rear corners since that is where the advice seems to place them. Just for my own info, I placed them directly behind my rack which has a 46" TV on top of it. Not the best of a situation but the best I can do for now. My front wall is 11'3" wide and I have a total of four traps up there.

There are some big trade-offs between the rear corners and having them up front. The rear corners brought the bass into focus and was quite enjoyable. Having them upfront brought more precision to the presentation, perhaps the word would be "mechanical", but in a positive way. I'm going to have to get another pair to bring the bass back into focus for the back if I can get it past the war department.

I think Jonathan treated the whole front wall of his room, if I recall from the big trapping thread. I like what it has done for just my 2 Channel system and I'd do more if I could.

Gordon

Gordon, from you description I am guessing you only project between the
SL3's and the screen behind them is exposed and unused. Is this correct? Not that the screen being there matters just trying to get a mental picture of the situation.

I would think you would clearly benefit from some absorption panels at least behind the SL3's and possibly the entire wall. It'll be something you will need to try and see if there is any adverse effect on the sound. It may be OK for HT and not for 2 channel music depending on how your entire room reacts.

When I started adding panels from Owens Corning 705 (Full spectrum as opposed to 703 which leaves bass unabsorbed) on all of the front wall behind my CLS's I found covering the entire wall eliminated some of the depth of sound stage and focused the center image too intensely for my listening preference. I started removing panels until I found the sound I was happy with. Your results may be totally different from mine though.

You may want to get some 705 and make some panels and try it. If you find it works on the front wall, great.

If it's too much then try covering the face of some of the panel with thin foil scrim, plastic or craft paper to prevent absorbing too much of the high end, since the covering will allow the higher end waves to reflect while still letting the panel work as a bass trap. You will probably never have too many bass traps in the room so they can be used there or where ever you need them to gain the best results.

Forget the first question Gordon, I followed the link to your system and see that the speakers are out beyond the screen. Once I saw your room I remembered it but seldome to you put a name to a room. As I have mentioned before it is a great looking room you did very tastful job on it.

I’d say it can’t hurt, as most rooms need all the bass trapping one can put in.

As for materials, some basic fabric wrapped 703 or 705 would do the job fine.
BTW- 705 while denser is not necessarily that much better at bass absorption, and 703 is less reflective in the high-frequencies, which to me is important if they are going to be behind the ESLs.

I’m all in favor of also absorbing as much of the highs as possible in the front of the room as it leads to much clearer dialog and soundstage.

As for 2ch soundstages, it’s all a tradeoff between using the room to create an artificial ambiance that is not in the recording or manage the reflections get a more accurate (in both temporal and frequency domains) sound. But that’s a whole ‘nother thread

Would covering the front wall with Gik 244 bass traps or the Gik monster bass traps be a good idea, or is that going too far? Since my screen is not transparent, and high frequency sound will reflect off the material, would putting the panels behind it be of much benefit?

JonFo said:

I’d say it can’t hurt, as most rooms need all the bass trapping one can put in.

Click to expand...

I agree, can't have to much trapping!