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Bookshelf-Sized CBT array - Constant Directivity through 5,000hz

H

HookAudio

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Audio Company
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Location
Brooklyn, NY
Hi,

My name is Vadim Gordin. I've started a new speaker company called Hook Audio based in Brooklyn, New York. With the help of Don Keele (formerly of Klipsch, Harman, JBL, Electrovoice, and Crown Amp), I've designed a bookshelf-sized open baffle CBT array called the H1 with constant directivity through 5,000hz.

The H1 stands 15" tall and on top of near-perfect directivity has the detail retrieval and dynamics that line arrays are known for. I've attached photos and measurements to this post.

More available at www.hookaudio.co. Cost for the speakers is $925 per pair.

Happy to answer any questions.

Thanks!
-Vadim

[edit 2/3:

After a request on another forum, I've added a risk free 60 day in-home audition to our policies.

Most people have never experienced the clarity and dynamics of music played on a CBT array, and I'm confident that the experience is one that they won't want to go back from. ]
 

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This looks very interesting. Could you send one in to Amir to test and review. Would be an interesting review and item to test with the Klippel.

Would this be suitable for a desktop sized setup, but one that would let you listen from well across a fair sized room?
 
@jtwrace Amir and I connected well ahead of this post and one is on its way to him to review :) The LS50 measurements were used with his prior permission.

@Blumlein 88 CBT arrays have no separate nearfield or farfield (see explanation here from Presonus, about 3/4 of the way down), so it works equally well for a living room or as a desktop setup. Up close, you'll benefit from a much more uniform and well-controlled soundfield than you're used to getting with conventional "nearfield" monitors. A few feet away, you'll benefit from in-room reflections being less destructive.

Love your username. Have you seen John Cuniberti's One Mic sessions on youtube? https://www.youtube.com/channel/UCGQDixBKOy2ZqIXABrAD__g
 
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Between 150Hz and 800Hz they loose ca.12db. Thats a lot. From just looking at FR i would say they need eq?
 
tomtoo said:
Between 150Hz and 800Hz they loose ca.12db. Thats a lot. From just looking at FR i would say they need eq?
Click to expand...

@tomtoo Did you mean to say between 150 and 200hz? Yes, they do benefit from EQ in the lower octaves, although its not essential if crossed with sub(s).

Because there are 12 drivers in each array, there is ample headroom for the application of EQ if you choose to go that route.

@Blumlein 88 , I misunderstood your question about "walking away" from a desktop setup before. Yes, they would be perfect in that sort of use case. Their volume dropoff with doubling of distance follows the line array pattern of 3db per doubling rather than 6db per doubling of conventional speakers.
 
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After a request on another forum, I've added a 60 day in-home audition to our policies.

Most people have never experienced the clarity and dynamics of music played on a CBT array, and I'm confident that the experience is one that they won't want to go back from.
 
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(In case anyone missed this great picture on the Hook Audio website...)

Hi Vadim
Seeing the Pabst Blue Ribbon makes me ask, is the driver some kind of planar device? Would be interested to hear more about it.


imageonline-co-roundcorner_540x.png
 
amadeuswus said:
(In case anyone missed this great picture on the Hook Audio website...)
is the driver some kind of planar device? Would be interested to hear more about it.
Click to expand...

Good catch! It is indeed a planar device.

One of the keys to good line array design is to start with a good driver! The driver in the H1 is planar through most of its operating range, although it does so a little bit differently than the Tectonic BMRs that most people are familiar with.

The BMR drivers have a cardboard honeycomb backer behind the "cone" to stop flex. By contrast, this driver is woven from multiple layers of fiberglass and then driven on opposing sides by neodymium magnets. The magnets are huge relative to the surface area, a full 1" diameter each for a "cone" that's only itself 1" tall. The even motor force across the face of the "cone" is what helps keep it planar throughout its operating range. A proper rubber surround keeps things orderly.

2 neodymium motors per driver (24 per speaker) is also how the assembled array is able to get to such a nice 93 db efficiency.

I'm sure some internet sleuth would find it eventually, so I'll just share it here. The driver is the excellent Dayton HARB252-8.

https://www.parts-express.com/Dayton-Audio-HARB252-8-1-x-5-Dual-Motor-High-Aspect-Ratio-295-246
 
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TimW said:
The crossover is made up of resistors only?
Click to expand...

Correct. Resistors and the other drivers.

Its a shading array rather than a crossover. Each driver sees the full frequency range, although the amplitude decreases gradually from full amplitude for driver #1 down to an 8db drop at driver #12.
 
That's pretty decent extension for an OB that size, and a departure from sealed boxes in previous designs. Otherwise I could imagine a sealed box with a small side-mounted sub driver crossed at 140Hz
 
Very interesting speakers!

@HookAudio From a visual / marketing perspective, if you can find directivity graphs for 'vocals, drums, and strings' to compare against, it helps push your point across to prospective customers much faster.
 
HookAudio said:
Correct. Resistors and the other drivers.

Its a shading array rather than a crossover. Each driver sees the full frequency range, although the amplitude decreases gradually from full amplitude for driver #1 down to an 8db drop at driver #12.
Click to expand...
Is it necessary to have shading for CBT? I thought only straight line array need shading because the timing difference from mid of array and end of array.
 
jtwrace said:
Since he's using @amirm data on his website it would only be fair to send one for a proper set of measurements.
Click to expand...
Ah, saw he used my graph of the horizontal off-axis data. I don’t mind at all, and it’s Amir’s data anyway.
_____

One thing on the website about this speaker vs LS50 that caught my eye:

For comparison, here is jagged and messy phase and impendence response for the $1,500 KEF LS50.
In terms of listening experience, this means that fast transients like drums and plucked instruments are "smeared" in time domain.
Click to expand...

How does impedance/phase affect transients? Doesn’t it simply and only relate to how much wattage/current/power the amplifier needs to supply?

I know altering phase via DSP and whatnot will alter time-allignment, but doesn’t the native phase not play a role?
 
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