Transmission Line Bass

As a long time proponent of good bass without subs, I like tinkering with different ways of approching the age old problem of recreating all energy below 100Hz.
Seriously, if you look at loudspeaker responses, everything seems goes to hell just below that point, swinging wildly in output response, almost independent of many of the typical factors that would be indicators of performance.
So, the question.
Who among us has had extensive Transmission Line Bass Experience in listening, (like me with the IMF's in days gone by, with Bud Fried being a wonderful mentor to me).
In Jim Thiel's lab, one time he told me 'candidly' that Transmission Line Designs 'in theory' don't work. (Another discussion for another time). But he, like me was a bass freak of the first order, loving a rich full bottom end, hence some of his equalized designs early on. They were an all out attempt to bend the laws of physics.
So, what do we think of Transmission Line bass--so, if you're familiar with the sonics though actual listening, and can express first hand opinions let us hear your impressions of the differences between ported, passive radiators and transmission.

Thanks in advance...


Showing 2 responses by sounds_real_audio

In the late 70's I built a pair of Frieds 12" subs, I think they were called the OM12 or OM2's. Can't remember. I thought the bass was very realistic sounding. Deep bass sounded like real instruments. The only problem was it was a little slow so probably not suitable for todays speakers.

Heard the Intersound speakers at the RMAF, I think he uses a 10" transmission like below the electrostatic. Sounded really good, so there must be potential.

Not extensive experience...............intensive however.
I think that the most important improvement in the bass when using a Transmission Line is not so much the depth of the bass but the quality.. I attribute that to the face that the rear waves off the back of the driver is not just absorbed by the MDF (in most speakers) but rather has an outlet. This must reduce the resonance considerably. I remember when I built the Fried's using Bud's 12" driver I asked him if it would be better to use MDF the the plywood in his plans, (they were do it yourself) speakers. He told me that he didn't feel any resonance in his cabinets that were made from plywood.

Of course I ignored him, who wouldn't, he was just an old man, and I was young and much smarter then he was... then the wisdom of his choice came to light when I had to carry the speakers up stairs from my shop in the basement.

Larry lets us know how your experiment goes.

Sounds Real Audio