looking for BIG sonotube transmission line advice

[zobsky]

In my new place, .. I have this ridiculous 15 - 20 ft high ceiling in a " relatively small" living room and my vintage MG-I maggies are having a hard time filling the room with bass (they weren't bass shy in my previous apartment, .. at least the witch of a neighbour didn't think so)

I have convinced (conned? ) the wife to let me build a sub to fill in the bass. I would have wanted to build a bass horn, .. but it'll be some time before I have the time to study up horn design so a sonotube seems acceptable for now.

fundamental question: is TL bass fast enough to keep up with the planars? the one thing i don't want (or minimize, .. practically speaking) is a disjoint sound.

use, .. music / HT

Currently, .. I have had to place the TV in the corner flanked by the planars on either side. I was thinking of a vertical TL sonotube placed against the corner.

Initial specification considerations
1. single woofer design. budget around $120 or so for the woofer and a few more dollars for MDF / sonotube, ... thinking of adire shiva 12",. but feel free to offer alternative suggestions. Would a 10" or 15" be better considerations. The mains seem to start rooling off in the ballpark of 50Hz - 60Hz . I have an MTX 4000 12" autosound woofer ( http://www.mtxaudio.com/caraudio/arc...der4000Ref.pdf )lying around but not sure if it would be suitable

2. amplification: i have a 105w x 2 mcintosh 2100 lying and an active crossover lying around around to serve up the juice until (if) I purchse some dedicated sub amplification

3. With the sub so near to the TV, .. will magnetic interference be an issue, ..

4. woofer orientation: the simplest design would seem to be a downward facing design, .. any disadvantages with this vs. building a box to house the driver

5. As I said, .. the roof is very high,.. so I CAN build a very tall tube if it is desirable. What size is available out there and what would be desirable to use.

6. What advantages / disadvantages would I expect to get using a TL sonotube vs. a sealed / ported sonotube. I would think deeper smoother bass, .. but I'll let the experts answer this one.

7. The only 2 links I've found useful on TL sonotubes are

http://www.passdiy.com/projects/el-pipe-o-1.htm
http://www.t-linespeakers.org/projects/steve/index.html

Also some useful info here http://diyaudio.com/forums/showthrea...threadid=16286


I'd like to study up martin kings alignment tables, .. but looking for starting points for now to give me a head start.


thanks, V

[ThomasW]

http://www.passdiy.com/projects/el-pipe-o-1.htm

[bogoes]

To match a set of planars, you might want to consider dipole or infinite baffle subs if your budget, room layout, and SO allow. Both offer the speed and transparency to keep up with planars.

IBs...
Cult of the Infinitely Baffled

Dipole...
http://www.diysubwoofers.org/dipole/
http://www.euronet.nl/users/temagm/audio/dipolesub.htm

CG

[azira]

Two comments that are totally not going to help you at all...

1) Get yourself out of the corner and along a wall.

2) I have the same halogen lamp.

Ok, more serious... that I've heard of commercial stuff, I prefer a pair of 10's in a sealed box over anything with 12s or 15s. I say build yourself a sealed box with 10's and experiment with your MTX 12 in a tall TL or whatever.
--
Danny

[zobsky]

Thanks for the replies:

1. unfortunately, .the corner is the only reasonable place I can set up my rig (believe me , i have tried alternatives), .. the dimensions of this room are rather curious .. the height slopes from 15ft to 20 ft and is greater than either the width or the breadth !! the other walls are taken up by furniture. my horns have occupied the music room, so these will stay here.

regardless, .. interestingly, some planar-philes prefer the corner alignment, .. its not too bad IME, .. seems to load the room better, .. except for the bass (rear wave cancellation, ceiling hieght ?? )


anyway, . this isn't a placement thread so lets leave it at that. i'll also consider the IB / dipole baffle, . but I may have to abandon that as I don't have much real estate to work with.

any more suggestions, .. please post

thanks

[qi]

You have everything you need.

Why not just give it a try?

Mount a 12" x 12' (24hz) sonotube on top of your existing 12" woofer.

Hook it into your system with your extra active xo and extra amp.

[zobsky]

i think i will

i'll see if i can make some time this weekend

watch this space

[Timn8ter]

Boy, am I out of touch. I had no idea Plano had been annexed by India.

[zobsky]

Originally posted by Timn8ter
Boy, am I out of touch. I had no idea Plano had been annexed by India.

you have no idea, .. it's been outsourced! )

[planet10]

Originally posted by zobsky
I have an MTX 4000 12" autosound woofer

According to the factory specs & GMs alphaTL spreadsheet (mine has beta constants & i haven't updated it yet), with its high Qt, small Vas it fits into an amazingly compact alphaTL.

I'd try a 10" (ID) tube, 59" long, stuffed with 6/10 of a pound of fiberglass insulation. (GM tells me the stuffing is actually lbs/ft^3)

dave