Page 1 of 2

Hybrid TL

Posted: Fri Jan 13, 2006 9:19 am
by Tuma
The design is basically a hybrid TL. Expect for it uses chambers and ports instead of stuffing to control the different resonant frequency. This will be a three chamber, multi reflex enclosure with SoloX S18X Kicker driver. When I get done, this is going to be a large heavy box. The wall construction will be made from 25mm HDP (high density particle board) + sound deadening pads + 18mm MDF + "Barrier Mat". There is a lot of theory and logistics behind TL designs and constructions. Has any one hear of an enclosure like the one I am trying to describe or has any information on designing this? I am not too sure where to start. :argh :help:

Posted: Fri Jan 13, 2006 9:27 am
by sinister audio
sounds like a bandpass of some sort. why are you using that driver?

Posted: Fri Jan 13, 2006 9:33 am
by Tuma
I am willing to use any driver. I just have a buddy that has S18X and he would give me a good deal.

Posted: Fri Jan 13, 2006 9:40 am
by Bwcad1
not a fan of kicker def. not a fan of that driver sound like a good idea though

Posted: Fri Jan 13, 2006 10:01 am
by sinister audio
i have seen 2 of those drivers break for no reason what so ever. they had a piece of plastic around the coil and it broke and wedged and through the driver off center and rubbed the coil through. and no warranty and it wasnt very loud. i would say it was lucky if it was 132dbs when it was running good.

Posted: Sun Jan 15, 2006 10:24 am
by Tuma
The driver doesn’t bother me. I am looking for some opines and ideas on how to start constructing and testing this enclosure.

Posted: Sun Jan 15, 2006 10:40 am
by Tuma
http://www.bladeice.com/forum/viewtopic ... 1a105fe409
Looks like AMG has this enclosure design figured out.

Posted: Sun Jan 15, 2006 2:37 pm
by Ranger SVO
Tuma wrote:The driver doesn’t bother me. I am looking for some opines and ideas on how to start constructing and testing this enclosure.
TL's are unique because they represent a class of non-resonent enclosures (whew, way to much time learning), with TL's the enclosure functions as a low pass filter filter with a 90-degree shift. Unlike ported enclosures almost all of the rear wave energy is used.

No mathematical modeling that I am aware of exist for TL's. Here is what I do know. The transmission line itself should be 1/4 of the length of the wave that you would like it to produce. Lenght of a wave is given by speed of sound in inchesdivided by the frquency you choose. he result will be the length of the wave. The transmission line should equal 1/4 of that length.

Next, The area behind the driver should have a cross sectional area 2 -2.5 times greater the effective surface area of the cone of the driver (Sd). It should then taper down to an area equal to Sd.

Two really good articles are both by A R Bailey and can be found in Wireless World October 1965 and May 1972. One is titled "A Non-Resonant Loudspeaker Enclosure Design" and The Transmission Line Loudspeaker Enclosure"

The only successful transmission line enclosures that I am aware of used KEF drivers , but with this type of enclosure anything that moves air (makes sound) should work.

PLEASE send or post any info that you might find on this subject.

I have built one transmission line enclosure, it worked, however the design is not effiecient. Minor tuning can be accomplished by lightly filling the line with accoustic fill. (slowing down the sound wave is equal to a slightly longer port).

Posted: Sun Jan 15, 2006 8:59 pm
by MobileAudio219
sinister audio wrote:i have seen 2 of those drivers break for no reason what so ever. they had a piece of plastic around the coil and it broke and wedged and through the driver off center and rubbed the coil through. and no warranty and it wasnt very loud. i would say it was lucky if it was 132dbs when it was running good.
I dont know if you are talking about one or two drivers, but either way something wasnt "running good" if it was only doing 132db. I'm not a big fan of kickers square subs but we both know that sub is capable of alot more than that. Right?

Posted: Sun Jan 15, 2006 9:04 pm
by audiobass10
MobileAudio219 wrote:I dont know if you are talking about one or two drivers, but either way something wasnt "running good" if it was only doing 132db. I'm not a big fan of kickers square subs but we both know that sub is capable of alot more than that. Right?
Yes..sealed it can break a 140 on the TL. One of the loudest sealed drivers next to the W7.