What can anyone say about Quarter Wavelength transmission line enclosure design ?


Hi All,

Just wondering if anyone experienced listening to the speakers based on transmission line enclosure design, as some people swear by it explaining that is the best think you could have once you audition them, as far as bass response \ impact concern. If anyone owned this type of speakers I would love to hear what you have to say and audition them some day. 

Thanks, 
coral3103
I came across a design for a 10" TL back in 1981 that I built using the 10" woofer from my JBL L-26 speakers. The result was a lot bigger than the JBL speakers, roughly 14" wide, 20" deep and 48" tall and heavy being made of 1" HDF. But they had MUCH better frequency response, not only flatter but a LOT deeper, way more than I ever expected, honestly deeper and flatter than anything I ever heard back then and frankly few I have heard since. Even more surprisingly they seemed to be about as sensitive (efficient) as the original ported JBL factory enclosure.

I forget the details but the folded taper design was not that complicated or hard to build. Basically it tapered from being a little bigger than the driver which was at the top front of the enclosure to maybe about 1/4 where it ended in a rectangular port at the bottom front. The taper went first from the front to the back, then folded down to the bottom, up again then back down and out the front. The whole thing was stuffed full of dacron fluff.

Never got the impression there was anything terribly difficult involved in the design either. In general, starting from about 125% of the driver area you taper down to about 25%, over a length of about 10'. The actual math I think has to do with the wavelength of 20Hz but that's just very old memory this was after all 1981!
@millercarbon- Did you happen to find that design in the Speaker Builder Magazine articles(circa- early 1980’s), written by Roger Sanders? In them, he outlined building a 10", TL woofer system, closely matching your description, to compliment his(then home-built) electrostatic panels.
That, Glass Audio and Audio Amateur, were my favorite rags(back in the day).   Inspiring!
Ohm Walsh speakers use a transmission line. The bass has real impact and slam. Nothing polite about the bass it produces.

Salk Sound also uses TL. Never heard them but the bass measurements are impressive for the speaker sizes.

Quarter wave is popular in the DIY community. Tabaq is a popular DIY quarter wave design. A company named Kvart & Bolge made a really cool and low priced commercial speaker from this design called the Sound Sommelier. I have a pair and they really disappear.