ASC Tube Traps Are The Real Deal

[jimtranr]

Originally Posted by chessman

More renegade experimentation - added a second trap to the "mini attack wall" on the right main. Left main is "naked."

Randy, have you played at all with rotating either of the "renegade" traps to determine whether--and if so, to what degree--rotation (e.g., facing the absorber-only center or some similar orientation toward the listener) affects the channel balance issue you noted earlier?

And with the new trap lineup do you perceive a bump in bass solidity (and perhaps extension) on the right side?

Looks like you're having fun.

Jim

[chessman]

Jim, you are spot on. The "audio center" moved barely to the right (towards center). My audio center is intentionally not the visual center because I am dealing with an accursed pole. I have the reflection sides pointing directly at the listening position.

But the big news is that the stereo image seems more sharply focused and the bass is weightier. I think both effects are the result of clearing up some mid-bass haze. Right now "The Girl In The Other Room" is playing and Diana Krall and sounds like she is in the room with me. The piano is completely authentic sounding. I think I am going to declare victory.

[jimtranr]

Originally Posted by chessman

But the big news is that the stereo image seems more sharply focused and the bass is weightier.

Randy, that replicates my experience with adding the inboard 11" speaker traps. Except that in my situation the absorptive centers face the listener.

Of particular note with that setup and the near-ceiling-height augmentation of the center trap is the sharpness and impact of bass attack coupled with "rolling thunder" decay on appropriate program (e.g., with bass drum and/or tympani). Largely if not wholly the result of that midbass haze cleanup you allude to.

Jim

[chessman]

I just tried adding a single 3' x 11" trap immediately adjacent to the outside of the left main. The image became congested, with either reflection or absorption facing the listening position. Back out it went and the image sharpness returned. It looks asymmetrical, but I am going with my ears on this one.

[jimtranr]

Originally Posted by chessman

I just tried adding a single 3' x 11" trap immediately adjacent to the outside of the left main. The image became congested, with either reflection or absorption facing the listening position. Back out it went and the image sharpness returned. It looks asymmetrical, but I am going with my ears on this one.

Asymmetrical or not, your ears have to be the ultimate judge.

I've found that in my case the inboard 11-inch "supplementals" to the 9-inch "clamping" traps work best with the forward edge of the 11-inchers set back about 2 inches from the plane formed by the forward edges of the left and right 9-inch traps (which themselves are "flush" with the speaker baffle board). Aligning the 11-incher on the 9-inchers'-and-speaker plane introduces the same congestive effect you've noted. (Sounds anal as heck, I know, but it works.)

As Michael Adams has indicated, positioning the attack traps relative to the speakers to get the best result will vary. Certainly true here.

[chessman]

I was reading the ASC site tonight looking at tube trap layouts and decided to "improve" mine by matching more closely a diagram on the site. Bad idea. My 16's are more effective as 3 foot lowers with 11's as uppers. So back to my original setup. For me the acid test was the first song on John Legend's "once again" CD. With the 16's behind the Wilson's the bass had a realistic vibrato. With the 11's no vibrato, just thud. It is admittedly a bass heavy cut, but if you are going to be a bear, be a grizzly.

[jimtranr]

Originally Posted by chessman

I was reading the ASC site tonight looking at tube trap layouts and decided to "improve" mine by matching more closely a diagram on the site. Bad idea.

Not surprising, Randy. The site diagrams look to be based on ideal rooms with who-knows-what dimensions and where the only furniture is the listening seat. We know how additional furniture, wall-mounted pictures, etc., can muck things up, as can the standing waves tied to the dimensions, proportions, and shapes of real-world rooms.

The standard 16" trap is spec'd as effective down to about 55Hz, the 11" to about 90Hz. Sounds like there's some bass boogeying going on between 55 and 90 behind your Wilsons that smears the Legend's vibrato with the 11's on the floor.

Jim

[chessman]

Jim, all true except the last. I play 2 channel with the subs off. The ASC tube traps clean up the mid-bass so much that people swear the subs are on.

[jimtranr]

Originally Posted by chessman

The ASC tube traps clean up the mid-bass so much that people swear the subs are on.

That doesn't surprise me, either, Randy. Had the same experience with unsupplemented Maggie 1.6's in a well-trapped room. Visitors kept asking where I hid the subs. With the current, again-unsupplemented Paradigm setup, a neighbor who has a sub shakes his head every time he comes over for a listen--and I think his wife is worried that she's going to come home one of these days to find traps littering their listening area.

[chessman]

Originally Posted by jimtranr

That doesn't surprise me, either, Randy. Had the same experience with unsupplemented Maggie 1.6's in a well-trapped room. Visitors kept asking where I hid the subs. With the current, again-unsupplemented Paradigm setup, a neighbor who has a sub shakes his head every time he comes over for a listen--and I think his wife is worried that she's going to come home one of these days to find traps littering their listening area.