How to treat room acoustics? Retail sources?


I need some advice regarding my room. Speakers are in the middle of an L-shaped room, with sloping ceiling. The room is big: long side of the L is 24x15 feet, with an additional 8x8 foot attachment, speakers are firing lengthwise down the 24 foot space of the room.

I am a complete noob: I have some 3x4 foot sound panels (2 behind the speakers, 3 on the sides) to prevent reflections. Other than that, what products do I need? These are supposedly bass traps that capture resonance in the lower frequencies. Is this enough to treat a large room, or do I need corner and wall reflection panels as well?

Budget is around $500 or less. Hopefully it will have a high WAF as well.

I assume it would be helpful to post pictures of my room?
Yeah, Dawg, post some pictures please. After that, we'll have some fun with you...[smile]

GIK acoustics makes some affordable panels and they have info on there site about how to start treating your room. They are also quite helpful if you give them a call.
GIK corner Tri-traps are just the ticket - you don't want to deaden the room any further with too many panels just add some big broadband absorbers in the corners....
another vote for GIK... give 'em a call. They were very helpful.
Here's an alternative to GIK. I looked at both and finally bought from ATS below. EXCELLENT quality and price. I'm very happy with my choice. They have more color choices and are a little cheaper.
I just did some photographs for Modwright over at CES. Dan shared his room with Audio Machina (great speakers) and Art and Acoustics which are acoustic panels designed by Pacific Northwest artist Stephen Yates. He has a variety of designs that I'd guess would have a high WAF factor. Check out the link to see them. I'm particularly fond of the botanical series (love the one called "hill mist" which is actually kind of abstract). In person at the show, all of his designs were quite striking. His site was a bit confusing to me at first - I'd click on one of three categories and seemingly got only one choice. I did not notice the "Enter" button below till later which accessed more designs in that category. You can see my pics of Dan's room with the Audio Machina speakers and a set of his more abstract panels here and closer here. Beyond that there are a few companies that, at an added cost, will allow you to apply your own digital designs do their panels, but I cannot speak for the quality of that reproduction. Being in the visual arts all my life I can tell you that it is no small task to transfer vivid color imagery in digital form to an acoustic fabric. The digital files would have to be very large, and the color profile tags would need to be accurate. If you don't know what you are doing that may be a risky proposition, and I don't know what, if any guarantees you'd have. I spoke with Stephen Yates about his own process of working with printers and he told me that he had to work closely with the printers to get vivid, stable, and accurate reproductions on the acoustically transparent fabrics. It showed in the final results.
GIK all the way