[Rick Craig]

What are the benefits of the curved front?

The curved front and shading work together to produce smoother vertical frequency response and better driver phase coherence. This sets it apart from any other type of straight array design.

[Rick Craig]

How long until an Illuminator version is available? 

You mean Illuminator woofers and RAAL tweeters? 

[kingdeezie]

Since I have spent a lot of time cultivating a preamp and amplifier that I like, how would someone like me utilize a design like this? Is it impossible?

I am not very familiar with DSPs and the like, and don't understand how they work.

Would it be a waste or completely impossible to use these in a passive configuration since you couldn't utilize the digital crossovers to garner the desired effects?   

[JoshK]

I think one of the coolest aspects of this design is how it controls the floor and ceiling bounce, which is a pretty big deal in a typical domestic environment.  Look at the comparison of the Revel to the CBT array at 3m distances in the presentation.  Look at the huge dip in response of the Revel right in the presence region where hearing acuity is at its best.  No such dip for the CBT array which proves this point.

Secondly, the power law of this array means that for a stated 1w/1m sensitivity, the CBT is actually much more "efficient" because the volume drops more gradually then a traditional speaker.   This means less amp power, but also more uniform volume across multiple seating locations, especially depth wise (great for HT). 

My only complaint about the concept is that it doesn't explicitly control the horizontal directivity** like modern waveguide speakers do (which typically do less for the vertical).  So its a trade of hor. dir. for vertical dir.   Which matters more depends on who you ask.

** hor. dir. seems to be controlled more from driver choice, xo topology and steering for forward lobe.

[Rick Craig]

Since I have spent a lot of time cultivating a preamp and amplifier that I like, how would someone like me utilize a design like this? Is it impossible?

I am not very familiar with DSPs and the like, and don't understand how they work.

Would it be a waste or completely impossible to use these in a passive configuration since you couldn't utilize the digital crossovers to garner the desired effects?   

A passive version might be possible but I can't really give you a good answer without doing some further testing.

[Rick Craig]

Interesting note - the shop door is 20 ft. from the nearest array speaker. From the time you enter the door and walk to the array the volume level doesn't change! You can also sit 5-6 ft. away and have a perfect soundstage - no large listening room needed.

As far as the horizontal directivity there is some control beyond what the drivers and crossover supply but I'll let Don and Earl argue the math on that. If the goal is to maximize the speaker's power response for the best room interface then I think the CBT is going to prevail. The room we have it in for demos is very reflective and untreated but the sound is still  impressive. In a normal home environment it would be even better.

I think one of the coolest aspects of this design is how it controls the floor and ceiling bounce, which is a pretty big deal in a typical domestic environment.  Look at the comparison of the Revel to the CBT array at 3m distances in the presentation.  Look at the huge dip in response of the Revel right in the presence region where hearing acuity is at its best.  No such dip for the CBT array which proves this point.

Secondly, the power law of this array means that for a stated 1w/1m sensitivity, the CBT is actually much more "efficient" because the volume drops more gradually then a traditional speaker.   This means less amp power, but also more uniform volume across multiple seating locations, especially depth wise (great for HT). 

My only complaint about the concept is that it doesn't explicitly control the horizontal directivity** like modern waveguide speakers do (which typically do less for the vertical).  So its a trade of hor. dir. for vertical dir.   Which matters more depends on who you ask.

** hor. dir. seems to be controlled more from driver choice, xo topology and steering for forward lobe.

[cstory]

One thing I've been wondering about is...with so many drivers is there an issue with playing soft? Now I know that these are intended for larger rooms and effortless dynamics, but what about low level dynamics? I would think that with so many drivers there is sort of a minimum input signal that is required to put all those drivers into motion. Do you need a certain minimum signal to overcome the rest mass of all those drivers before they start produce sound? Kind of like, you don't hear anything then it's like a switch is flipped and the make sound, but louder than what you would get with a simpler system.

Probably way off base, I know they have good efficiency, but I can't seem to wrap my mind about all those drivers just barely vibrating and still maintaining an accurate sound at low levels.

Chuck

[Rick Craig]

Actually a larger room isn't needed for these but they will fill a big space if needed. Low level detail is excellent because the distortion is so low. Maybe I need to bring a pair up to Ohio for demo?

One thing I've been wondering about is...with so many drivers is there an issue with playing soft? Now I know that these are intended for larger rooms and effortless dynamics, but what about low level dynamics? I would think that with so many drivers there is sort of a minimum input signal that is required to put all those drivers into motion. Do you need a certain minimum signal to overcome the rest mass of all those drivers before they start produce sound? Kind of like, you don't hear anything then it's like a switch is flipped and the make sound, but louder than what you would get with a simpler system.

Probably way off base, I know they have good efficiency, but I can't seem to wrap my mind about all those drivers just barely vibrating and still maintaining an accurate sound at low levels.

Chuck

[arthurs]

Maybe I need to bring a pair up to Ohio for demo?

Bring em to Texas Rick!  Lone Star Audio Fest?

[Rick Craig]

Bring em to Texas Rick!  Lone Star Audio Fest?

I've suggested that to my partners. Thanks for reminding me!

[arthurs]

Hope you guys can make it.  It's a really interesting design and reading through the PowerPoint really piques interest in hearing it. 

[Rick Craig]

Here's a great deal on a DEQX ...

http://www.audiogon.com/cgi-bin/cls.pl?preatran&1306961418&/DEQX-PDC-2.6P-Digital-Correcti

[bernardo]

I had the privilege of listening to the curved line arrays last Thursday night. I read over Rich’s review and agree with everything he stated. I’m not sure what I can add that wasn’t already addressed. A couple of things I will mention are the speakers are probably the best I have ever heard even considering the room they are in (Rick’s picture should get my point across – certainly not an ideal set-up with respect to room acoustics and the stuff in the shop) and that the electronics in use were stacked on top of each other and sitting on a stool. I have no doubt they will sound even better in a suitable room with some attention to equipment isolation and set-up - something I would really like to hear. The only reservation I had was the treble but I believe this to be a personal bias for me in preferring a slightly rolled off treble – I have the same reservation about my present system. That said it is worth noting that the DEQX unit will allow tailoring the sound so I feel confident that my personal bias could be accommodated. Unfortunately we did not have the time to experiment with the DEQX unit. This was my first experience with a line array design - I was very impressed with the soundstage and imaging - definitely the best I have heard.  The curved line arrays are an impressive design that should be a winner – it is certainly worth the effort to go and take a listen.

[Jumpin]

What ever happened with these?

[gme109]

With some of the drivers being so close to the floor, and others aimed at the ceiling, would this not cause more room interaction?

[Rick Craig]

What ever happened with these?

Setting them up soon for a demo in Florida. 

[Rick Craig]

With some of the drivers being so close to the floor, and others aimed at the ceiling, would this not cause more room interaction?

The beamwidth is controlled by the curve and tapering of the output along the line. This actually makes it less sensitive to room issues. Don Keele is the genius behind this and you can read more here...http://www.xlrtechs.com/dbkeele.com/CBT.php

[Tyson]

Rick,
Now THESE are the speakers you should bring to RMAF this year

[Rick Craig]

45" tall array (woofer base is 14"x14"). Ten 4" woofers and thirty tweeters per side.

[Tyson]

!