I received an email recently from someone who was questioning my approach to transmission line speaker design as a special case of acoustic suspension speaker design. He said his first speakers were AR 2A speakers. He said he is “a big advocate of sealed boxes since there's no question properly designed they have better bass control than ported designs(no matter how well they are designed.”
His said his “second speakers were IMF Studio 2 transmission lines and living in Philadelphia [he] became a life long pal with Bud Fried.” He said he knows something about transmission lines and “don't get the comparison I make with transmission line and acoustic suspension speakers.” To quote: “I might add that Bud would be rolling in his grave with the comparison. He [Bud Fried] disliked acoustic suspension speakers. “I'm not trying to be smart [He said.]. It's just that your comments take me back to my early days and I'm seriously asking for an explanation that I didn't find on your web site.”
In my reply I mentioned that I met Bud Fried at summer CES in Chicago 1992/1993 where we were both exhibiting and that at the time I had no particular interest in transmission line designs and that I hope Bud is tolerant of other ideas and is resting peacefully.
Rather than write a long treatise defending my approach, I referred him to roleaudio.com to read reviewers' comments about the following acoustic suspension speakers: Skiff, Kayak, Discovery, and then to read reviewer's comments about the acoustic suspension speaker's transmission line analogues: Sampan, Windjammer, Enterprise, especially with reference to the Sampan, Windjammer and Enterprise bass performance. In each case the transmission line speaker is using the same exact driver and the same crossover components as its acoustic suspension analogue. The primary difference is the cabinet.
I have a totally different approach to TL design and as you can see it works.
As an addendum, I note the following quote regarding Bud Fried's role in promoting TL designs:
"Of course, Bud, had called it the IMF, and therefore, perhaps mistakenly we registered IMF and formed an IMF company... At no time did Bud Fried have any input on the designs. We sold him speakers and he was the US Distributor... Bud Fried was never a Director or shareholder of IMF Electronics. IMF electronics were the only company manufacturing the transmission line speakers. The name IMF was adopted because Bud Fried had demonstrated the first prototype speakers at the New York hi fi show, and because of the publicity and the fact that he had used his name on the then unnamed speakers, we stuck with the name which was a mistake on our part. It was never his company. After our lawsuit he called his speakers Fried."
It seems Bud Fried may not have been the theoretician of TL speaker design he and others claimed he was. You can read more here under "Classic era transmission line loudspeakers."