Hi there!
Acoustics and "the room" are one of the most important items to address first when putting a new stereo room together. I've used these folks for both products and detailed information. Top shelf products that work and do what you intended.
Realtraps.com
Excellent resource for anyone interested in acoustics. No affiliation - just a happy customer.
I decided to use these Real Traps after reading how many professional music people use them.
Another resource I found that really helped was a book by Jim Smith - Get Better Sound. With these two resources you'll get excellent results if implemented.
Enjoy!