Spatial Black Hole - Active Bass Trap?

JDUBS · « **Reply #20 on:** 6 Feb 2012, 08:14 pm »

Guys, great discussion so far. Let's keep it up.

I heard back from Clayton:

"Hello Jim,

Thanks for your email.

The Black Hole is new product. It has been shipping for about 45 days, so there are no reviews yet. Several media reviews are in the works, such as 6moons.com and Absolute Sound.

Here are some comments from customers and a link to headfi.com where a thread has started about the Black Hole:

http://www.head-fi.org/t/583355/spatial-computer-black-hole-anti-wave-generator ..."

I directed him to this thread and asked that he please participate as there are some questions that folks are asking that it would be great if he could address.

-Jim

JDUBS · « **Reply #21 on:** 9 Feb 2012, 03:39 am »

Guys, just an update. I heard again from Clayton that he is planning to show us some Black Hole measurements that address the questions that have been asked here. Specifically, he said he's planning on showing 3D waterfall measurements to illustrate time decay.

He said he's planning on putting together these measurements this weekend.

-Jim

Russell Dawkins · « **Reply #22 on:** 9 Feb 2012, 04:14 am »

I was very skeptical at the start of this thread and still don't really understand how controlling bass at one point in the room can affect the whole room to any great extent. The results reported thus far are intriguing, and I remain open minded and looking forward to further information.
That Clayton Shaw is involved lends credibility to this, too.

Rclark · « **Reply #23 on:** 9 Feb 2012, 05:20 am »

I can almost imagine them at work, intercepting and cancelling out waves. I bet it's very cool.

please ask him if there will be smaller room models and whether pairing devices is effective.

Rclark · « **Reply #24 on:** 9 Feb 2012, 05:25 am »

...wonder if this eliminates the need to have a swarm of subs....

spiritofmusic · « **Reply #25 on:** 9 Feb 2012, 09:43 am »

I too was totally skeptical, and after a slow start (ie really unsure of purchase), it is transforming my system. Clearing hash in room from bottom octave (my spkrs go down to 16hz), has opened up the rest of the frequency range. Bass solid as before but more nimble, allowing greater detail retrieval further up the spectrum. Best improvement is palpable increase in dimensionality, soundstage widens and deepens. This is best noticed on cds which prev sounded v.flat and uninviting (perfect sound forever?), now not just tolerable but totally involving. I'm really amazed. The only other upgrade I've made recently which has been just as dramatic was move from expensive filters/conditioners to clear mains hash to inexpensive balanced power (4kv at least) which has expanded dynamics and headroom dramatically.

John Casler · « **Reply #26 on:** 10 Feb 2012, 12:08 am »

Just came across this thread and find it interesting. A few years ago we had a thread regarding something similar. One of the posters mentioned a German company who was exploring it also.

I had 4 subs that I had placed in the room (2 in front and 2 in back) in a way and phase that made them "push/pull" and the idea was to negate the room issues of a single sub, and the push pull was to create the largest energy in the center of the room (sweet spot).

I think with this set up, if you employed a DSP device like the ANTIMODE (or similar units) and ran the program with ALL subs operating at the same time so the mike saw all subs as ONE, the result should be about as good as you can get. Too bad I haven't had a chance to try this, but in theory it should read the multiple responses as ONE, and adjust to the Sweet Spot. Now this would only apply to the freqs that are covered in whatever DSP device you use, but the higher frequencies are more pliable to and easier to treat with passive devices.

JohnR · « **Reply #27 on:** 13 Feb 2012, 09:58 am »

Jim/JDUBS - any news?

JDUBS · « **Reply #28 on:** 13 Feb 2012, 04:30 pm »

JohnR, I shot Clayton an email to prompt his response. Hopefully we hear from him soon. I know I'm definitely looking forward to learning more about the technology and seeing some resulting measurements.

-Jim

Spatial Audio · « **Reply #29 on:** 19 Feb 2012, 05:03 am »

Hello Guys,

My name is Clayton Shaw, and as the manufacturer of the Black Hole, I will try to explain the product and provide some background.

The Black Hole (BH) is an active, acoustic pressure reduction device designed to improve sound quality in domestic environments. This is the only known means of dealing with room-induced anomalies in a compact form factor.

An active acoustic pressure absorber was first mentioned by H.F Olsen in his 1957 book "Acoustical Engineering" - a reference text still in common use today. Later, Nelson Pass was awarded US Patent 4,899,387 in 1990 entitled "Active Low Frequency Acoustic Resonance Absorber", in which he outlined a clever embodiment of the concept, along with application and performance criteria.

A production design was released by Pass known as the "Phantom Acoustics Shadow. Robert Harley (then at Stereophile) reviewed the Shadow and found it highly effective: http://www.stereophile.com/roomtreatments/1289phantom/index.html

"After becoming acclimatized to the sound, I switched in the Shadows. I was listening to "Twiggs Approved," from the Dixie Dregs' album Dregs of the Earth, which has a very powerful low end. The change was startling. The entire tonal character of the bottom end changed for the better. Low bass sounded deeper and more powerful, while the midbass seemed thinner, probably due to the attenuation of resonant colorations. In addition, the bass drum sounded lower in pitch and lost its unpleasant wooden character, and bass guitar suddenly had more detail and clarity." Robert Harley

Unfortunately, the Shadow was only produced for a few years. Its relatively high price and the lack of awareness about acoustics among audiophiles at the time are sited as possible reasons for its short life in the market.

We have taken up the mantle with the recent introduction of the Black Hole. Our focus was to simplify and improve the technique where possible, in order to reduce the size and price of the product. Feedback from customers in the field confirm its effectiveness and broad range of benefits. It turns out that noticeable sonic improvements extend across the sound spectrum-not just the Bass range. We view this approach as an integral part of a total room solution that may also include passive treatment and equalization in order to optimize the listening experience. The Black Hole is even more useful when passive Bass traps are not practical in a given installation. Its compact dimensions (15" cube) allow most listeners to integrate it into their room plan.

Here are 3 examples of measured improvement in the frequency domain using the Black Hole:

/Users/LuxPC/Desktop/8in sub2.tiff
Small subwoofer with 8 inch driver

/Users/LuxPC/Desktop/Bookshelf test2.tiff
Bookshelf sized speaker

/Users/LuxPC/Desktop/2 FR Sine Sweep Bhnd Seat Mic Up-Notes.tiff
customer system- large speaker in large room

In each case, a clear improvement in response linearity is noted. Time measurements have been more difficult to sort out, but sonic improvements in terms of a larger sound field, greater clarity and less clutter throughout the midband and Treble suggest improved time domain behavior via shorter decay times.

One of the main advantages to the active approach is that greater levels of pressure reduction are afforded by simply turning up the amplifier gain level. The Black Hole employs a heavy-duty 12 inch subwoofer driver and 350W power amp in order to provide enough output to civilize a typical listening room of 15 x 25 ft or smaller. Larger rooms may require 2 Black Holes (3dB increase). The main requirement is that the unit be located against a wall boundary where acoustic pressure builds up. Along a wall, or in a corner behind the listening seat is normally recommended - some experimentation is usually required to find the best results at the listening position. A/B comparisons are easy, since the BH can be turned on and off during the listening session.

Clayton Shaw
Spatial Computer / Clayton Shaw Audio Technologies LLC

Rob Babcock · « **Reply #30 on:** 19 Feb 2012, 10:30 am »

Thanks for a very interesting and detailed responds, Clayton! Welcome to AC!

Rclark · « **Reply #31 on:** 19 Feb 2012, 10:56 am »

Definitely anticipating more reviews. Very cool.

JohnR · « **Reply #32 on:** 19 Feb 2012, 11:03 am »

Clayton - for the measurements to be visible, they will need to be on the Web. You can upload them here - click on the button

at the left of the editor toolbar when making a post.

Or, if they are on your own website already, just provide a link.

Spatial Audio · « **Reply #33 on:** 19 Feb 2012, 12:41 pm »

Thanks John,

Here are the response graphs from above:

small subwoofer 8 inch driver

bookshelf speaker

customer system-large room with large speaker - 0ne Black Hole
A second Black Hole in this installation would improve the peak reduction by 3dB.

Clayton Shaw
Spatial Computer / Clayton Shaw Audio Technologies LLC

Habs Fan · « **Reply #34 on:** 19 Feb 2012, 04:56 pm »

Thanks Clayton for responding in this thread . I do have a question regarding placement.I see you suggest that a corner in the rear of the room would be ideal but Pass seemed to suggest that the front corners behind the speakers was optimum for the Phantom.Since room corners are the areas of maximum pressure can I assume any corner would be prime hunting gound for modal cancelation or have you found the BH to be more effective with rear placement?

Spatial Audio · « **Reply #35 on:** 19 Feb 2012, 07:22 pm »

Habs Fan,

Good question - You are correct that the Phantom Acoustics Shadow was recommended for the front of the room. In some cases we recommend that as well, but testing showed that interference patterns with the main speakers could cause frequency response changes, due to close proximity. Much better results were typically found when the BH was placed away from the main speakers, so that only dips and peaks were affected. If the room is large and the mains are way out from the front wall, say 6 feet or more, front placement can work well.

As the designer of the Emerald Physics brand of full range, open baffle speakers, I confirmed another statement in the Pass patent- that placing absorbers behind dipole speakers can improve Bass performance by creating a low pressure environment, simulating a greater distance to the wall and thereby reducing dipole cancellation loss.

Clayton Shaw
Spatial Computer / Clayton Shaw Audio Technologies LLC

Rclark · « **Reply #36 on:** 19 Feb 2012, 08:58 pm »

Would this act as some kind of bass cancellation for apartment dwellers or does this act as a subwoofer beyond the confines of the listening space? Does this reduce spl outside the listening room?

still amazing, but it would be a bonus if so.

Russell Dawkins · « **Reply #37 on:** 19 Feb 2012, 09:13 pm »

It's worth reiterating that one huge advantage of dipole bass is that the total output into the room tends to sum to zero - in other words, there will be minimal bass sound bleeding into the environs (rest of house, other apartments) with this type of reproducer.
Clayton would certainly be the authority on this, as well as whether the "Spatial Black Hole" improves even the dipole bass situation in adjacent rooms.

JDUBS · « **Reply #38 on:** 19 Feb 2012, 09:32 pm »

Clayton, big time thanks for dropping in! This thread will benefit greatly from your contributions.

A very interesting piece of equipment, indeed.

-Jim

JohnR · « **Reply #39 on:** 20 Feb 2012, 12:28 am »

Clayton, do you have waterfall plots that yiu can share? The steady state plots don't really show that the unit acts as an absorber.