Is it blasphemy to consider this a FR?

AJinFLA

Banned
2005-02-09 4:35 am
Tampa
I've seen posts here about Tannoys, which use coaxial tweeters, so I thought I would post this here as well as the Loudspeakers forum. I guess the mods will let me know if I erred calling this thing a Fullrange.
Anyway, pic of the weekends ongoing project - still under way. KEF Ci-200QR (I've been promising to use a ceiling speaker in a project for a while now)+ 6 Audax VP170G0's on 48"H x 14.5" W Baffle. XO between 125-150hz TDB. Will be used with sub, but should be fine for most music without. No 120db @ 20Hz required. More details (hopefully) later...
[IMGHTTPDEAD]http://www.openbafflespeakers.com/images/PSDipole_web015.jpg[/IMGHTTPDEAD] [IMGHTTPDEAD]http://www.openbafflespeakers.com/images/PSDipole_web011.jpg[/IMGHTTPDEAD]

Cheers,

AJ
 

Pallas

Member
2004-08-23 5:59 am
Nice!

Very cool idea. I think I'm going to steal it, except that instead of the 8" KEF ceiling speaker I'll use a pair of KEF KAR 160Q's that were in my currently nonrunning Citroën.

Nice find on those buyout Audaxes, too. What do you think of them so far? Have you taken any measurements? Does the plastic basket provide ventilation under the spider? I wonder how they'd work in quantities of, say, 8 per side under a dual concentric.....
 

AJinFLA

Banned
2005-02-09 4:35 am
Tampa
I'm far, far from finished, but the results so far have way exceeded my expectations. I thought for sure they would be screaming for a sub. The Audax's have suprised me. The nearfield measurement (without the dipole cancellation) shows dead flat extension down into the 30s. At this point I am using a MCM buyout sub amp that has a 6db bass boost @ 35hz. That would help explain the extension. But they will play quite loud without distress, the bass is full and extended, open baffle clarity and non-boominess, not quite like my Orions, but I can still feel the bass on my solid wood floor. The KEF sounds very nice, but again at this point of development, I'm using the stock XO. The treble is a tad too hot (there is a small hump on axis @ about 15k - which smoothens off axis, typical of a coaxial driver) if the speakers are toed in, pointed straight at you. I suspect this may be deliberately engineerd in by KEF since it would be advantagous in a ceiling position for the treble to be boosted slightly. Most ceiling speakers have the tweeter way forward of the woofer so a wider area is illuminated w/ treble. That of course comes at the expense of coherence. The KEF is much more of an "audiophile" type driver. The high Qts is tailor made for OB - since it is intended for IB. They cleverly used a larger VC then mounted the tweeter in a very small waveguide (something else that I'm working on), so that the motion of the cone has less of a boundary effect on the tweeter. It's not something I had realized just looking at the Uni-Q drivers. I don't thing the Seas coax's (which I believe are licensed from KEF) have this feature.
The point source /time aligned nature of the KEF gives it that fullrange type naturalness to the mids. It does have an XO, but the treble, once smoothened will be superior to a tweeterless fullrange. The holiday is almost done but I will do my best to post some more info and hopefully a few measurements. So far so good!

Cheers (and happy 4th),

AJ[IMGHTTPDEAD]http://www.openbafflespeakers.com/images/bcc5.jpeg[/IMGHTTPDEAD]