New CDWG's NOW available

PLMONROE · « **Reply #20 on:** 2 Apr 2011, 04:17 pm »

Quote from: Hipper on 2 Apr 2011, 08:05 am

How do the steak knives affect the sound?

And how do you install them?

Perhaps they cut up standing waves and sharpen the sound.

As to installation, there is a rumor that they function best when driven in the walls at the first reflection points.

Paul

John Casler · « **Reply #21 on:** 2 Apr 2011, 04:46 pm »

Quote from: PLMONROE on 2 Apr 2011, 04:17 pm

Perhaps they cut up standing waves and sharpen the sound.

As to installation, there is a rumor that they function best when driven in the walls at the first reflection points.

Paul

An April Fools joke gone wild

Hi Paul, missed you in Vegas this year.

PLMONROE · « **Reply #22 on:** 2 Apr 2011, 08:20 pm »

Yeh, me too! Hope we, Dave, and all can make it next year. Any thoughts on what Brian has up his sleeve for then?

Paul

John Casler · « **Reply #23 on:** 3 Apr 2011, 07:14 pm »

John Casler · « **Reply #24 on:** 3 Apr 2011, 07:21 pm »

Another

Brian Cheney · « **Reply #25 on:** 3 Apr 2011, 07:47 pm »

Time to explain how the CDWG works, and why it works well in this application.

The principal of the diffraction slot is well known and is the basis for almost all constant directivity devices for 30 years now. With planars, unfortunately, simply making them narrower is no solution, as their sensitivity would be very low if made wide enough (2/3") for CD dispersion up to 20kHz.

BG in its PDR versions of the Neo 8 panel simply masks off part of the diaphragm to make a narrower slot. This causes a lot of energy to be reflected back into the driver, and the resulting IM distortion is quite objectionable.

My solution was a damped slot, with substantial absorbtive as well as reflective components. This is what made our CDWG patentable over the prior art. Many opponents objected to the granting of the patent, but after 5 years, we prevailed.

In the second generation CDWG, the device is reduced to its simplest components and attached directly to the driver frame. The opening here is about 1", corresponding to a 12 kHz CD characteristic. This is fine for our panel, which rolls off mechanically at that frequency. Only half the diaphragm is forced into constant directivity, and then there is a gradual transitiion to narrow dispersion. In this fashion, there is little or no audible treble rolloff for the on-axis listener, and insertion loss is very low. The panel now mimics the cardioid dispersion pattern of many musical instruments and voice. The difference in disprsion patterns is what makes speakers sound so different from live sound as far as directivity is concerned.

A similar CDWG with a narrower opening, designed for planar tweeters, is also available, as are antiffraction masks for tweeters that are already narrow enough for CD behavior to 20 kHz.

It takes a pair of CDWG masks to treat a single panel or tweeter, and these are $20pr. You would need two pair to treat the panels in a pair of single panel speakers like the 626, or the single tweeter in any FST speaker.

Brian Cheney · « **Reply #26 on:** 3 Apr 2011, 09:32 pm »

We have 4 sets of steak knives still available.

JakeJ · « **Reply #27 on:** 3 Apr 2011, 10:10 pm »

Hey, I thought they were "stake" knives! I just booked my flight to Transylvania for vampire season and was all stoked to bag my limit.

Just wanted to mention I really appreciate the great sense of humor you and many of our sponsor manufacturers have, it makes the place all the more enjoyable.

Pez · « **Reply #28 on:** 3 Apr 2011, 11:34 pm »

I'm actually impressed, these attachments are... Good looking. I don't know why, but in my mind I imagined giant foam half cylinders glued to the front of the speakers face.

Don't take any of this the wrong way.

Hipper · « **Reply #29 on:** 4 Apr 2011, 08:36 am »

Perhaps the idea of knives was inspired by Housteau. I notice he uses swords.

Brian Cheney · « **Reply #30 on:** 4 Apr 2011, 04:46 pm »

The CDWG's are kinda slick-looking. It's their positive influence on sound quality that's important, tho.

fredgarvin · « **Reply #31 on:** 4 Apr 2011, 06:28 pm »

Are these recommended on the spiral tweeters?

Brian Cheney · « **Reply #32 on:** 4 Apr 2011, 06:47 pm »

Yes, there is a new CDWG for the spiral ribbon. Optimally mounted, it provides constant directivity up to 20kHz.

John Casler · « **Reply #33 on:** 4 Apr 2011, 06:51 pm »

Quote from: PLMONROE on 2 Apr 2011, 08:20 pm

Yeh, me too! Hope we, Dave, and all can make it next year. Any thoughts on what Brian has up his sleeve for then?

Paul

He always wears long sleeves

But I'm sure something is up there.

rbbert · « **Reply #34 on:** 4 Apr 2011, 07:36 pm »

I'm anxiously awaiting mine

boatride · « **Reply #35 on:** 4 Apr 2011, 09:05 pm »

Would these be recommended to use with the ST3/STE speakers, mids and the Ravens?

Brian Cheney · « **Reply #36 on:** 4 Apr 2011, 11:33 pm »

Yes, they can be used with that system.

mjosef · « **Reply #37 on:** 4 Apr 2011, 11:37 pm »

About the spiral ribbon tweeters...
In the other thread there was mentioned new foam surrounds being also available, how does these differ with the current foam rectangle that borders the tweeter? More interested in sonic improvement info vs. cosmetic.
The current tweeter foams are very difficult to remove.

Brian Cheney · « **Reply #38 on:** 5 Apr 2011, 12:49 am »

Heat the foam with a hairdryer or heat gun to loosen it.

Foam alone makes an antidiffraction mask. Foam with the plastic overlay makes a waveguide.

BobMajor · « **Reply #39 on:** 5 Apr 2011, 09:12 pm »

Previously, without wave guides, the optimal positioning of the speaker was to toe in the speakers so that they crossed 2 feet in front of the sweet spot. Does this change if you use these new wave guides?