That tunes below the Fs according to my model? Would one get smoother response by tuning higher?
You are correct in that the optimal box tunes to 60 Hz, but the box volume is 0.3 cu.ft, and it is impossible to get a port in that size box that would work. So I enlarged to the box to get rid if that headache, and there is no ripple. The response peaks at 400 Hz, and there is smooth roll of to -3 db at 49 Hz. The reason this driver can tune a little below Fs is that it is a high Qtc driver, but that leads to the port problem. I actually think that box would work very well.
I tried the driver sealed, but F3 is then 115 Hz. So ported is the best option of the two. I have been looking closely at this driver for a TL. The numbers are about as perfect as they could be for a small TL. Options would be a small tower with two drivers, or a small bookshelf labyrinth type TL. I have only ever built one pair of bookshelf labyrinths. They were for my eldest sister, built just over 40 years ago. They are in hers and my brother in law's dining room and still going strong. They still love them.
So a TL does not have to be huge. I can't recall a commercial small TL previously except from TDL.
There is a relatively new
British speaker manufacturer PMC, who has developed a large range of aperiodically damped lines, exactly the way I design them.
Their entire range if speakers are TLS and they have now teamed up with Bryston and have some active TLs. May be someone has been reading my posts!
Their speakers have been generating a lot of favorable comment in both domestic and professional circles, especially for their natural bass. They are now staring to penetrate the US market.
I think TLs have a huge advantage especially in the HT arena, where bass muddle and high Qtc speakers are far less then desirable. My wife an I were watching calender girls last night and the speakers are seamless between dialog and the music parts. You get addicted to them.
My best friend who has the B & W 800 D speakers was here again recently, he visits often. He and his wife listened longer than usual here last time, unfortunately, and has become sensitized to the ported tuning of the 800 Ds. Now the 800D has a very subtle bass tuning in my view, but you can hear port kick in, at least I can, and now he is sensitized to it. I regret to say he has bought a top end pair of Grado headphones since his last visit, and using them more than the 800 Ds. He says the bass is like my TLs, but I have not heard his phones yet.
So I think HT because of the need for clear speech and bass not splashing over everything may well bring the TL into general currency so to speak. By this I mean true aperiodically damped lines, and not variants with odd tuned cavities and two peaks of impedance.
I finished up all the outside work yesterday. The final job was hanging the Christmas lights round the balconies. So today is the official first day of my winter hibernation, which will give time to devote to that type of nonsense, and start some serious design and R & D. The design work for the speakers here took a lot out of me and I vowed they would be my last. However I'm having a change of view.
