Most effective Room Treatment for slap echo, etc

I have had very good results with GIK Acoustic products, which are reasonably priced. They also have great customer service. The GIK products have made a HUGE improvement in the sound of my system.

I thought about the DIY route, but it is hard to build for much less than GIK prices. If you do go the DIY route, you may want to check out gearslutz.com and look under studio construction and acoustics forum and the sub-forum for bass traps, acoustic panels, etc., which has a lot of DIY info.

I use Ready Acoustics. Some come with a frame that you can just lean against the wall. I use 2 like this at the first reflection points of my speakers as well as wall mounted ones. I think they also have stand mounted ones.

Just a follow-up to Magfan's comments: Most fabric stores will carry burlap in a number of colors. Burlap is one of the most widely used fabrics for acoustic treatments because of it's open weave. And it's inexpensive.

Thanks, JD.
I live down the street from UFO (fabric store) and they have some burlap which just makes me itch to look at. They have exactly 1 fabric billed as 'grill cloth' which is ugly.
They DO have a VERY light / open weave fabric in white which I'd use as a liner if I ever went with something like OC703.

I live an hour+ train ride from LA and another 20" bus ride to The Garment District which is hours of just walking....fast. One day I'll migrate up there for a look-see. I understand there to be whole block of nothing BUT fabric.

On the way? Stop at Phillipe's for a french dip and some pie. yum yum.

Your Constraint: “Easily removable adhesive so as not to strip the paint or stucco.” -> This may limit the weight of what you can hang on a wall which is correlated to acoustical thickness, generally speaking. Because the popular fiberglass filled resistive-type absorbers should be a minimum of 4” thick (with 6” being better) and an air space of another 6”, the total depth is now quickly approaching what a bookshelf depth would entail. So you might need to place acoustical treatments where you can afford them to stick off the walls which may be your front and back walls, presumably, and use thinner devices for the side walls and ceiling.

Your Need #1: “Eliminate slap echo.” -> Luckily, slap echo is more of an upper frequency phenomenon usually above 1kHz so it takes thinner treatments to deal with it than lower frequencies. Have someone stand by each speaker clapping their hands while you sit in the listening position to see if you can hear the slap echoes and then try placing a thickly folded or rolled up towel at various positions along the wall and repeat the clap-listen tests until you’ve found the wall position where the slap echo is minimized. Then replace the towel with something more permanent to break up the hard parallel surfaces. A tapestry or thick drape was suggested and will work well. If you have some art work / pictures on the walls, then try placing a tennis ball between the wall and the bottom of the picture to angle the picture upwards. You might consider the lightweight RPG Skyline diffusers that are 2’*2’ square which can be hung with Velcro or sticky tape and shouldn’t damage your walls/ceiling.

Your Need #2: Improve focus and imaging. Reducing the indirect reflections by eliminating the slap echoes will help drive the ratio of direct-to-indirect reflections higher and help with focus and imaging. So too will listening in a near-field arrangement and toeing in your speakers. Try absorption on the front wall to attenuate the damaging reflections coming from there – the absorption should improve the perceived soundstage depth.

Lastly, a little education on room acoustics will go a long way. Try picking up Dr Floyd Toole’s latest book and F. Alton Everest’s textbook and plough your way through them. In the long run it’ll help you assess your needs, the quality of manufacturer’s products and help with knowing what to place where.

Good luck.