Small room....treating 1st reflection points

This advice was given to me by Roy Johnson of Green Mountain Audio speakers. If the foam you have is high density foam, like what's used for seat pads of furniture, you'll get very good benefit at the highs and mids if you cut a 4' by 4' piece of peg board in half and make a pair of 2' by 4' panels about 2" apart on the one side by spray gluing your foam to the peg board, then wrap it with a very transparent (easy to see through) fabric. Spray the glue on the peg board, not the foam--that way it doesn't clog the pores of the foam. Hang them on the wall spacing four 1" thick spacers on each panel so the sound may travel behind the them. 2 on each side would require double the materials, but would be highly effective at the 1st reflection points. If your foam isn't high density, go online and buy 2" and get even more benefit--it will cost you about $100-125 for all 4 panels for everything needed.

I have a 10x11 room and I recently treated my side walls with Vicoustic Cinema Round panels. I am absolutely stunned the difference it made. Please check out my system thread for more details.

Tom6897, Look at the link I posted. Table shows sound absorption vs frequency. I was mostly interested in taming slap echo and mid-bass frequencies. These panels are glass rigid foam. I've read that organic foam has non-linear characteristic (of absorption vs. frequency, I assume).

36.75Hz is pretty good. As long as room doesn't amplify around 60-80Hz, where many speakers have "hump" it is OK and might even help to reinforce extension.

IME, absorptive and/or diffusing treatments at the first reflection points can help with high frequency problems. As you go lower in frequency, these devices become less effective. Below 100hz or so, Hemholtz resonators are the only reliable treatments that I've found (other than room correcting EQ schemes).

It's hard to say whether 1" foam will work for high frequency issues until you try that foam in that room. OTOH, it's easy to say that you'd be very unlikely to get any benefits from 1" foam at low frequencies.

1" foam/treatment will work to some degree, in particular with higher frequencies as noted, just not as much as equivalent 2" foam product.

No way to know what will "sound best" without trying.

I like the "lego" approach with wall treatments. Start with smaller measured amounts of treatment, like 2'X2'X1". Add more or less as needed until best results achieved at primary listening location(s).