Originally Posted by Antripodean
However, I agree the WG approach should be better.
To be sure, I prefer concentrics. However, if reliable driver supply is an issue, IMO the currently available concentrics just aren't that good. If reliable and consistent supply is not at issue, then one can wait for those Pioneer-TAD CSTs
or KEF R-Series Uni-Q's
or Tannoy Dual Concentrics to pop up for sale.
That said, there's an concentric driver available from a German supplier I find interesting. I haven't seen measurements - still waiting for the K+T Archiv DVD I ordered in November - but it looks like it has a smooth transition and a phase plug on the tweeter. A WCW with the DIYSG Anarchy midwoofer might be a fun speaker. Erich, if you want more info, PM me.
Originally Posted by MD28
if the seos is better than any coaxil design... why isnt mark seaton using waveguides? his monitors are far superior compared to a seos. of course, a lot more expensive to. like others, im interested in a design very similar to mr. seaton's design
Well...good waveguides were not readily available when Mark designed the Catalyst. Also, a good speaker designer can take a flawed driver and make a wonderful speaker out of it. While I’ve not heard Mark’s speakers, their reputation is superb even though the B&C concentric is a solid half-step behind the KEF, TAD/Pioneer, and Tannoy devices. He also has the DSP horsepower to do whatever he wants with it.
Another speaker made from a sub-par concentric driver that I’ve heard and judged a superior reproducer is the Gradient Revolution, which uses a variant of the 7” Seas concentric with a fiberglass (“G” in Seas-ese) cone rather than the translucent poly (“T”) cone of the stock models.
Originally Posted by tuxedocivic
Doing speakers that are similar is interesting. Like the 8" coax with an 8" woofer that I mentioned. ***
There actually is a speaker similar to that: the KEF Q900.
Sure, it’s too big and it has those annoying PRs and that crossover could use some improvement (steeper slopes and a notch filter on the woofer). But frankly if one wants an elite-grade speaker based on a concentric driver, buying a pair of KEF Q900s, throwing away the cabs, selling the PR’s, and engineering a 3-way crossover might just be the most cost-effective way to go (!). FWIW, my nearfield monitors use those concentrics, with this measured performance:
Originally Posted by pitviper33
Can you elaborate on how poor mouth termination manifests itself in speaker performance? How would one recognize an issue related to unsatisfactory mouth termination when viewing on axis frequency response or polar plots?
HF roughness, subjective "nasal" quality to the treble as things get louder.
Originally Posted by A9X-308
Originally Posted by tuxedocivic
Maybe even high pass the coax to make it a 3 way if cone modulation affected the tweeter response to much. That can be extremely critical with coaxials, which is something I haven't seen discussed all that much.
Always HPF it to the coax. I've had many of the classic Tannoy's and a few others and they invariably sound better with the LF/MB removed from them. I've been discussing it for at least 15 years since I first tried it.
FWIW, I found it necessary to throw a highpass on 8" concentrics even in a nearfield system. However, in my previous home I ran 12" Tannoy duals full-range ("LFE + Main") in fairly small closed boxes, and heard no issues. Perhaps those who listen very loudly would need to highpass larger concentrics, too.
Originally Posted by mhutchins
Although this does not answer the questions you posed, it is relevant. I read a post by Tom Danley from several years ago that he auditioned a large number of 8" coax drivers before he settled on the B&C 8CX21. He mentioned that this speaker had the best transition area between the CD and the horn. This speaker might make a decent midvalue unit between the Eminence series and something like the Beymas.
There's the obvious caveat in Mr. Danley's coment: "of those available on the hobbyist/OEM market."
Also, my experience with Beyma is that they are not going to equal the B&Cs, let alone exceed them, regardless of price.Edited by DS-21 - 1/29/14 at 5:56pm