Acoustic Room Treatments

A great way to start is to use cushions (couch and other), heavy blankets, pillows to experiment with to get the hang of it. Then companies like ATS and GIK can help provide better looking and more effective treatments. They also do sonic analysis. Personally, I have found it better to listen and learn better than all the "sonic analysis"... but that is me. 

Ditto to what @jastralfu said.  Recommendations regarding room treatment will not be meaningful without measuring the in-room performance of your current system.  Every room will exhibit different sonic characteristics even if the dimensions are equal. The materials used, carpeting versus hardwood floors, etc. will impact the response you get in the room.  The other critical factor is placement of your speakers which will activate different room modes depending on placement in the room.  REW will help you identify frequency response issues with your current. speaker placement.  Take measurements with your current speaker position and then move speakers around till you get the best response possible.  Once you have optimized your current setup then the measurements will help you determine what type of room treatment is necessary to fix the remaining problems. I have done this and have worked with GIK. They are terrific.  Good luck.

Joeradio,

11' x 15' x 8' is not a bad shaped room, so you should be able to treat it well with some assistance.

Give GIK Acoustics a call, and see if John Dykstra is available for a chat; Chris and Paul are also excellent, but John is who I've work most with. They'll walk you through the entire process, including the EQ Wizard software, and will make realistic recommendations based on your budget and desire.

It's mostly absorption and diffusion with proper placement, and in the proper amount......more is not always better. It's not rocket science nor complicated once you get into it.

Hey thanks for your replies. I have a basic two channel setup with Infinity RS IIb speakers so I definitely need something. 

@joeradio 

Don’t be afraid you will overdamp the room. A smaller room needs to be controlled. Plus you can always undamp it. if you are serious about this room I highly recommend consulting Jeff at hdacoustics. He is very good with smaller rooms. He designed my room and it turned out fantastic ! Good luck !