Thanks, Dr. Mark. Always great to hear from you. That's exactly what I was wondering about, the lobing and the other problems. I know the issues with MTM's have been well documented and I figured the issues would be somewhat similar.
I have to say, I'd still be interested in hear one
Thank you. The center really is the most difficult to design speaker in the whole HT area by far. In terms of the technical challenge it leaves all other speakers in the HT system way in the shade. When it comes to speech the ear is just not easily fooled. I have heard quite a few systems at dealers now and the center always lets the show down. I'm yet to hear a natural integrated center in any showroom yet.
I do believe a center has to be as close as possible to point source and any crossover must get as close as they can to getting out of the speech discrimination band. Cone type coverage over the listening area works best.
I just built this 4" JW driver from scratch for the center at our Eagan home. It is full range and BSC, what little it need as it is wall mounted is built into the cone.
So the single cone is connected directly to the amp.
It is really natural and my wife, an excellent audio critic, loves it. It has natural speech with excellent speech discrimination at very low volumes.
Audyssey crosses it over to the isobarik subs in the R & L mains at 90 Hz, which is correct. The unit is sealed, and by the way, I think a center speaker should NEVER be a ported design. So since it is sealed it is second order roll off, so the acoustic and electrical crossover is composite fourth order.
The 4" center speaker is 8 ohm, the mains are four ohm. However the sensitivities of the 4" unit and the drivers in the mains are virtually identical. However the Audyssey settings showed the single 4" cone to be 3 db more sensitive. So you can see how even a low part count crossover in the mains, consumes half the amplifier power. So the center only takes one quarter of the amp power the mains do for the same spl.
It really holds its end up on music also. I played the Mahler 8, that has a large number of soloists at a volume I was afraid might garner complaints from the neighbors. The unit showed no sign of distress. It blends with the mains perfectly.
This will get me into further refinement of this driver. This is technology from 1959 that has been wrongly ignored and not further developed which is a tragedy. Although I have to admit, the cone is very expensive to manufacture. However with modern techniques may be not any longer.
