Can room treatment improve bass accuracy?


Most of us can agree that a big part of a highly enjoyable system is it's ability to produce accurate, tight and full-sounding low bass. In an attempt to squeeze more bass out of my system I am considering making room changes. Looking for suggestions and comments on my considerations.
I am considering using a large amount of material through out the room that will absorb low frequencies therefore limiting or greatly reducing reflective low frequencies. Will this help and any suggestions on which materials will work best?
Also I would like to enclose the sub-woofer in a Five sided box with the one side that is open facing the listener. This box will be made out of material that has low resonance characteristics. It will reflect the sound waves toward the listener and not the back wall or side walls. Wondering since the box surrounding the sub is so near to the sub how will this effect the listening experience of bass. I expect the box to be heavy so that it will be solid and highly reflective of low frequencies and it will be suspended therefore avoiding transmission to the floor.
Would like to hear suggestions and comments. thanks
pedrillo
Realtraps! They provide the most absorption to prevent flabby bass in the smallest space... Check my system out as I use 4 Mondo Traps, 4 MiniTrap HF (1st order reflection points), 4 Minitraps for corners..

If you are looking to intergrate subs (especially building) consider a Tact 2.2x with 2 DAC cards and an upgraded powersupply then you can even time align the corner loaded subs and change everything about the crossover in real time. Ultimate in integration.. not the last in audiophile but WOW! You have to spend way more to beat that combo!
I do not think the 5-sided box will work.

The bass wavelengths are simply too long to "see" the box and be contained by it. For instance, at 40 Hz the wavelenghs are 28 feet long. Those wavelengths simply will not be significantly affected by features less than about 7 feet across.

For information on bass traps, you might find this article useful:

http://www.audioholics.com/techtips/setup/acoustics/BassTraps.html

Aside from the bass-smoothing technique I described in another thread, there is another active technique that come to mind.: Use a monopole and a dipole subwoofer, and time-delay the signal to the dipole (by how much, I don't know). The combination of a monopole and time-delayed dipole produces a cardioid (heart-shaped) radiation pattern. The bass system used in the Martin Logan Prodigy and Odyssey was a passive cardioid-pattern type. Meyersound makes active cardioid-pattern prosound subwoofers.

Best of luck to you!

Duke
I'll just add this note I made on another thread before you think a TACT can do everything for you (in reality you need a TACT or PEQ as well as acoustic treatment)

You will find that a parametric equalizer is ineffective above about 80Hz for standing waves room mode equalization.

A typical room of 25 feet by 16 feet by 9 feet will have a total of six room modes below 60 Hz. At 120 Hz this jumps to thirty five room modes (many sharp peaks and troughs in the frequency response and spatially too).

In practice it becomes impossible to do much parametric equalization above 60 HZ to tame bass standing wave modes.

Concentrate on acoustic broadband absorption and speaker placement for modal issues above 60 Hz.

I find that four GIK corner Tri-Traps offer a modest improvement in room response above 100 Hz (subtle clarity improvement in lower mid range vocals was just audible and sweetspot became noticeably larger). See my virtual system to get an idea of the aesthetics. Any less size/surface area of treatments and you are unlikely to make an audible change. I should probably do twice as much treatment to get my RT60's even lower, but, for aesthetic considerations, I stopped at four of these thick broadband absorbers.
Yes treatment can improve room accuracy. But not much impact below 100 Hz ( unless you use specific tuned tube traps and you really need to know what you are doing ). I'd suggest treating all four corners with broadband absorbers. You need something at least a couple of feet wide and an average of at least 6 inches thick, IMHO (3 pounds per cubic foot or up to 8 pounds per cubic foot...foam, fibreglass, mineral wool...)..and as a minimum I'd shoot for 16 linear feet for treatment....that is what I have and it barely makes any difference in the ultra LF (although I am happy with what it does in the 100 to 600 Hz range...again a slight improvement in my room at the listening position).

For ultra LF - use a PEQ, something such as a Rives TACT - it seems to work well.