I have been grappling with a couple of familiar issues, subwoofers and bass trapping, with of course the WAF lurking in the background. I am interested in trying to use Gauss 18" driver(s) that I currently have, in a sonotube arrangment, similar to Pass' efforts documented in other sites. This will be used in a very large, irregularly shaped room. One of the corners is 25 feet tall, and is at an angle slightly less (tighter)than 90 degrees. I plan to use 4" rigid fiberglas floor to ceiling across the corner as part of an overall bass trapping scheme. The question is, can I place the sonotube "chimney" in the corner, behind the trap? I would then have a 20-24" diameter tube running up the corner, shielded or covered by the fiber sheets. Would the existence of the sonotube in the "dead zone" behind the trap material render the bass trap any less effective? Would the placement of the sonotube sub in the corner cause more problems than the bass trapping would solve? Is this potential solution to my issues one of those that will cause more problems than it will solve? Thanks in advance for your patience and attention.
Pargon

Pargon,

> I am interested in trying to use Gauss 18" driver(s) that I currently have, in a sonotube arrangment, similar to Pass' efforts <

I'm not familiar with that arrangement. But I will say that as a general rule, a subwoofer should not be placed behind a bass trap. Unless this "tube" thingie has an opening that comes out from and extends beyond the corner. Is it like a North drum or something?

--Ethan

Ethan, Thanks for your response. The diy project that I referred to was Nelson Pass' El Pipo, http://www.passdiy.com/el-pipe-o-1.htm , but is similar to other sonotube efforts. It could be terminated outside the trap zone, either to the exterior of the wall, making an ersatz infinite baffle arrangment, or by sealing the tube making a very large volume sealed cabinet. As I understand, your point is that the speaker should not vent within the bass trap area, yes?

Pargon,

> Nelson Pass' El Pipo <

I couldn't get that link to work, but I found this through Google:

http://www.passdiy.com/pdf/el-pipe-o.pdf

It looks like a fun project, if a bit impractical for smaller rooms.

> your point is that the speaker should not vent within the bass trap area, yes? <

Yes.

--Ethan

This is way beyond my experience and in your proposed usage looks more like an audiophile project rather than one done for acurate response. The world of acurate audio and the world of audiophile sound often come into conflict.

But right off the bat, the design asks that the speaker be placed near the supporting speakers for best performance, so are you going to place your mix position right in front of a giant bass trap? Then we come to the amp choise issue.... a couple of Pass amps would be fourth on my list, below the Cello I already have, the Lipinski I'd like to check out again, and the Bel Cantos that inspired the Lipinskis. All of these choices require a large investment. I'm just wondering if a pair of Dunlavy V-A or VI-As and a decent amp (like a Paragon ...) might not give a more coherent response for about the same investment.

So your goal becomes the question... what are you building, and for what purpose? What speakers and amps are backing it up?

(PS. Used to really like those Gausses. Haven't heard them in about 20 years though...)

Bill

This is an audiophile project, with of course desire for accuracy as well. The room in question is a very large living room requiring extensive treatment. I am in the planning stages on the bass traping, and was thinking about addressing this and a subwoofer project that I would like to experiment with simultaneously. As this is a living space there are considerations that are at odds with both audiophile and accuracy criterion. The reference to Pass was having to do with one of his diy projects (see url's listed above) using large runs of sonotube to load large subwoofer drivers. It is a project that I have been considering, and before hacking and hewing would like to work out the predictable details cranially. The bass trapping will go on whether or not it makes sense to integrate the "tube". It looked like an opportunity, but I am not sure that isolation of the sub vent products from the bass trapping area is feasible.

I know. Transmission lines. but you have to power them, and the sound going to be greatly influenced by the choice of amp.
You could probably use the transission line but you would need to vent it outside of the trap, of course. The square inches that it eats up would affect the trap performance, but in a trap that size, to what degree? Probably minimal.

Bill