I want to do a Sonotube TL with two woofers in a push-pull arrangement where one of the woofers is hooked out of phase and installed backwards in the enclosure. Basically, it'll be sort of like this. http://www.t-linespeakers.org/projects/steve/index.html

I have 8 foot ceilings in my listening area so I suppose I could probably get away with a stuffed 6 footer, but what I'd really like to do is build a TL long enough to take advantage of the 21Hz free air resonance of my 12" drivers.

Woofer specs:

Dual voice coil 8ohm/4ohm

FS 21Hz

QTS .38

QMS 4.2/4.4

QES 0.44/0.42

VAS 13.3 ft³ (376.6L)

SD 0.0532 m²

XMAX 0.460 (11.7mm)

(let me know if I forgot any important ones)

A little basic math tells me...

1128 ÷ 21 Hz = 53.71 feet full wave length

53.71 x 0.25 = 13.428 feet ¼ wave length

13.428 feet = 161.14 inches TL length

Assuming my math is correct, this 13+ foot length presents a problem in my listening area.

I came up with an idea that includes just one 90° bend. The top will only reach as high as about 7'2" leaving some breathing room between it and the ceiling. The rest will be on the floor run along a wall. I have easy access to some 14" x 14" x 14" (1 ft³ internal volume) 3/4" MDF boxes meant for 12" woofers and can probably find some 6' long x 12" diameter Sonotube nearby. I bet I could trim the tubes a little (if necessary) and cut a couple more holes in the boxes and have this thing together pretty quickly.

What do you guys think of this idea? Is there any chance of comb filter effects or any other undesirable operation possible from this design? Should I add something like a 45° reflector to the box in the middle? Thanks.

I have 8 foot ceilings in my listening area so I suppose I could probably get away with a stuffed 6 footer, but what I'd really like to do is build a TL long enough to take advantage of the 21Hz free air resonance of my 12" drivers.

Woofer specs:

Dual voice coil 8ohm/4ohm

FS 21Hz

QTS .38

QMS 4.2/4.4

QES 0.44/0.42

VAS 13.3 ft³ (376.6L)

SD 0.0532 m²

XMAX 0.460 (11.7mm)

(let me know if I forgot any important ones)

A little basic math tells me...

1128 ÷ 21 Hz = 53.71 feet full wave length

53.71 x 0.25 = 13.428 feet ¼ wave length

13.428 feet = 161.14 inches TL length

Assuming my math is correct, this 13+ foot length presents a problem in my listening area.

I came up with an idea that includes just one 90° bend. The top will only reach as high as about 7'2" leaving some breathing room between it and the ceiling. The rest will be on the floor run along a wall. I have easy access to some 14" x 14" x 14" (1 ft³ internal volume) 3/4" MDF boxes meant for 12" woofers and can probably find some 6' long x 12" diameter Sonotube nearby. I bet I could trim the tubes a little (if necessary) and cut a couple more holes in the boxes and have this thing together pretty quickly.

What do you guys think of this idea? Is there any chance of comb filter effects or any other undesirable operation possible from this design? Should I add something like a 45° reflector to the box in the middle? Thanks.