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).
[quote="Tuma"]The driver doesn’t bother me. I am looking for some opines and ideas on how to start constructing and testing this enclosure.[/quote]
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 [b][i][u]speed of sound in inches[/u][/i][/b][b][i][u]divided by the frquency you choose[/u][/i][/b]. 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).