Unusual Speaker Designs

[pozz]

These 11.25 inch tall speaker cabinets are truly "Bookshelf Speakers", but what makes them unusual is that they were designed to place in a bookshelf and blend in with the books already there. They were made by a company called Stanford Advanced Acoustic Technology which was affiliated with Allison Acoustics. A very simple MTM design that was inexpensive and became invisible in the right setting. They sound better than not being able to have any speakers...

View attachment 159057

I like that they included Vol. I & II

 

[Tom Danley]

Værøy, up in Lofoten. It's a six-hour ferry ride from Bodø airport. Tiny yet gorgeous place. Good spot for the Aurora borealis if you can stomach the cold in winter.

If you're feeling flush, I recommend the helicopter ride

View attachment 158966

Here are some other fun ones.

A 40-inch Powersoft M-Force linear motor subwoofer tuned to 17 Hz that a friend owns:
View attachment 158967
The 180-degree wide, asymmetrical vertical coverage full-range SharcFin by Mr @Tom Danley:
View attachment 158968

I forget who makes this - it looks like a rejected Dr Who bad guy - but it led to some fun discussions:
View attachment 158969

And these very sexy "is wall" massive multiple-entry horns with 4 metre folded horns attached to the rear of the LF drivers. Probably a touch close to the Synergy patent for comfort, but I still covet them *hard*:
View attachment 158972View attachment 158973


Just saw the ESA stuff. I don't think that monster is using any manufacturers in particular, but NASA commissioned a portable version of that test via Maryland Sound. They use custom-built fully horn-loaded vertical arrays, mostly loaded with drivers from the B&C family of companies and driven with custom high-power Powersoft amplifiers.

Blog post: https://blogs.esa.int/orion/2019/05/31/solar-wings-installed-and-acoustic-testing/
There's a conference paper here:

NASA Handbook 7010: Direct Field Acoustic Testing - NASA Technical Reports Server (NTRS)

Instruments, spacecraft, antennas, reflectors, and other mechanical hardware have been undergoing acoustic qualification testing over the last decade using loudspeakers. This speaker-generated Direct Field Acoustic Test (DFAT) method offers cost, mobility, and schedule advantages over the...

ntrs.nasa.gov

I have lots of behind-the-scenes photos of the DFAT from someone who worked on it, but sadly can't share them.

Hi Kyle
Man that giant CNC masterpiece is something!!
My daughter is learning how to program the cnc in my shop so i sent those two pictures of it to her as "our next project".
Not sure why but she didn't think it was funny.
Hey if that part of Norway is where you are now, man that is nice to look at.
Best Regards
Tom

 

[HammerSandwich]

In the picture you can see the mouth of his horn. Horn mouth in the floor in the living room.

What's the Swedish translation for "Crap, I dropped my keys into the subwoofer again!"?

 

[Kal Rubinson]

What's the Swedish translation for "Crap, I dropped my keys into the subwoofer again!"?

Isn't there a magnet in there somewhere?

 

[DanielT]

What's the Swedish translation for "Crap, I dropped my keys into the subwoofer again!"?

Once upon a time, in a small town, there was a wilding...

Translated links below through Google translate.

Bernt Jansson writes in this thread:

HiFiForum.nu - Legenden lever!!! Hemma hos Bo Hansson.

www.hififorum.nu

I will make it easy for me here and translate what Bosse [Bo Hansson, Designer of the horn] wrote in English on his website.

"In order to be able to make good recordings, it is important to have a good listening system to assess the work. In this case, a room with non-parallel walls and a soft ceiling was specially built to attenuate resonances with a high Q.

The speaker system was inspired by articles in Hi-Fi News in 1966. The articles were written by Rex Baldock, who was a guiding light for many of us amateurs in speaker construction. I visited Rex with my friend Hubert Shutrick in the early 70's to listen to his system, and I was very impressed. Hubert is a professor of mathematics and was more suited to absorb the message in the article "Acoustic Compensation" written by Rex. Hubert helped me with the calculations to make the bass horns and the room work together in the system I built in 1972.

The bass system consists of two 6 meter long bass horns. They are built of brick and concrete. The mouth comes up under the sofa. The horns have hyperbolic expansion and go down to 18 Hz; you can not hear much down there but it shakes you and the glass in the windows.
The bass horns are equipped with a pair of 15-inch sound film elements. They have a resonant frequency of about 80 Hz which drops to about 20 Hz when mounted in the horns. "

-------

About Bo Hansson:

Bo Hansson, born April 6, 1940, died May 20, 2011 in Karlskoga [1], was a Swedish record producer, designer and entrepreneur. Hansson, who has long worked with the development of advanced hi-fi equipment, founded and ran the company AudioProdukter [2] in Karlskoga in the 1970s and formed in the early 1980s together with Lennart Bergstedt and Olle Neckman the sound technology company Rauna with the advanced hi-fi equipment they designed themselves, such as turntables, amplifiers and cast speakers. In 1984, he founded the competing company and record company for acoustic music Opus 3, first with Jan-Eric Persson and later under his own auspices. In 2003, he acquired Rauna and the Swedish speaker element manufacturer Sinus [3]. His broad perspective on music recording, record production and hi-fi equipment made him a well-known profile among many audio and music enthusiasts.

Bo Hansson (producent) – Wikipedia

sv.wikipedia.org

But the story lives on:

On general request, we are putting out this summer's test of the new old Rauna speakers Vale and Vidar. The test was published in Hifi & Musik no. 7-8 / 2019.

Helgjutet!

På allmän begäran lägger vi ut sommarens test av de nygamla Rauna-högtalarna Vale och Vidar. Testet publicerades i Hifi & Musik nr 7-8/2019.

hifi-musik.se

More wildings in Hifi. That's what makes hifi fun and exciting, I think. To Bo in his Hifi heaven:

 

[DanielT]

Isn't there a magnet in there somewhere?

Kal, you mentioned in another thread that in the past, it was more or less a necessity to DIY, in order to get good sound.

Speaking of DIY and Rauna, Bo Hansson. DIY now because it's fun. Here's a thread about an enthusiastic DIY who puts the saw in a pair of Bo Hansson's constructed concrete speakers, Rauna Njord.

What conclusions are drawn in the thread after lots of different modifications and measurements and more modifications? Well, it's not the easiest thing to get good sound plus with DIY concrete speakers, then you save money on the gym.

https://www.faktiskt.io/phpBB3/viewtopic.php?f=3&t=68377&start=210

 

[kyle_neuron]

Hi Kyle
Man that giant CNC masterpiece is something!!
My daughter is learning how to program the cnc in my shop so i sent those two pictures of it to her as "our next project".
Not sure why but she didn't think it was funny.
Hey if that part of Norway is where you are now, man that is nice to look at.
Best Regards
Tom

That’s some family jigsaw for the festive season it’s the kinda thing I’d do over a (very) long period of time if I moved back out to the middle of nowhere. Don’t have to worry about ‘WAF’ if your speakers are supporting the ceiling, right?

I often wish I was able to head back to that island, but the event haemorrhaged cash after a storm cut all the transport links for a day. A friend’s sister runs a little farming coop on another island nearby though. If things keep heading toward Mad Max in real life, it’ll be a toss up between heading there or getting you to help make a badder version of the doof truck from Fury Road.

That truck is for sale, by the way… reckon @amirm can get it on the NFS?

 

[Tom Danley]

Exciting!

Feel free to tell us a little more about it. How did you do? If you feel like telling a little more about it and if it is not classified, of course.

Hi
Well here is a type of test that was kind of fun.
To fly anything in a sounding rocket or on the space shuttle, the payload needs to go through a number of tests.
Among them is a vibration test using a "shaker table"
This was at a testing lab called Wyle in Huntsville (our contract office was at Marshall Space flight center nearby).

So being a cone head speaker guy at heart, what do i see but a 200KW LING TUBE amplifier that's 8 feet tall and takes up an entire wall of the room, it was huge!.

It had a pair of very large triodes behind glass glowing away and some large triodes as drivers next to them. Everything was water cooled, we walked on a suspended floor when near the amplifiers because of the all the cables and plumbing below..
So what do you do with 200KW RMS?

You have a suitable speaker to hook it to haha.
The picture is a small shaker table, look at the pallet it's on and imagine a larger one.
This had a DC field magnet made and water cooling and it had a "voice coil" made of square hollow tubing filled with water (keep in mind how large a shipping pallet is).
For our test, the "speaker" was pointed sideways and the experiment bolted to the shaker moving bit and the experiment's weight sitting on an oil plate (oil forced up under the plate to make if free to move sideways)
This first test was on a sounding rocket payload which is a 4 1/2 foot tall 1pc turned aluminum can with a door one each side held on with about 80 #8-32 machine screws.
Inside was the high temp furnace assembly, the levitation sound source and some of the electronics.
This test was the first one to establish the stuff inside could survive launch and that we built the experiment to what we our spec sheet said.

It turns out, the space shuttle spec is for pretty intense low frequency vibration and very little up high.

So the test begins and a fellow comments "well here's 8G' up to 8K" and the slow sweep began..
As i had an attachment to the payload, i stood next to it wearing hearing protectors. 8G's is "significant"
Somewhere around a KHz or so, the weirdest thing happened.

About a dozen or more of the screws that held the covers on, backed out and fell as if attached to a motor and traces of white dust were leaking out.

The experiment weighed about 250 pounds so it was hard to imagine it moving so quickly, visibly at a KHz but that's what 200KW is for.
At some point it was also clear "something was wrong inside", like the furnace insulation was reduced to dust.

Surprise, turns out our payload build sheet (from NASA) included the vib spec for the shuttle payload (we built and flew several years later) and NOT for a sounding rocket which is way way more severe.

We went there for tests there a number of times and got so we could chit chat and one fellow talked about something fun. They assembled a large flat square 2x4 and plywood radiator and attached it to the shaker. The shaker is on little railroad wheels with a track in the floor leading to a garage door and they played Christmas music for the area one afternoon.
Best,
Tom

 

[DanielT]

Hi Tom,
Thank you for sharing and telling us. Very interesting!

It is clear that rigorous testing is needed. I guess that the test specification is rather tough.

I have an old friend, we meet in the summers, he works with testing mechanical endurance regarding satellites on:

Advancing humankind. | Beyond Gravity

www.ruag.com

However, in the summer we usually swear on old sour two-stroke outboard motors. Not so much job talk then.

Interesting that you mention tubes. Here about computers, NASA and tubes:

NASA develops speedy vacuum tube prototype for computers in space

NASA develops speedy vacuum tube prototype for computers in space

Researchers have developed a vacuum tube prototype that is both fast and tough against radiation, making it ideal for computers in space.

www.theverge.com

 

[nagster]

Owned one of the very first sets of these for some time. The manufacturer laughed at me when I tried to order them with handles, wheels, and flight cases.

Among other places, we took them from the northwest of the UK to an island up in the Arctic circle at the top of Norway where the sun didn't set for the entire two weeks we were there.

Fun times, although you wouldn't say that if you had to stack the bloody things.

As for loud, this is the silliest thing I've done; this level was maintained with broadband pink noise at an average of seven mic positions for 30 minute periods, with 15 minute breaks, for ten hours.

The bell on the outside of the test chamber was vibrating so loudly that you had to wear ear defenders. On the other side of a two layer-deep 6 ft concrete wall with insulation.

There was an owner! I am very surprised. thank you.
What kind of sound is it? Are there speakers that sound similar?

 

[pozz]

Yes, i think so.
The researcher was a lady named Joyce Poole but the other person's name i don't recall, this was from Cornell university. I remember they published an article in National Geographic about their Elephant communication discovery in (I think) 1988.
Hope that helps
Tom

I found this paper, with references to a bunch of others, one of which probably the 1988 piece you had in mind: http://www.engdes.com/sigwin/company/biblio/papers/Signals and assessment in African elephants (Poole 1999).pdf

Poole, Joyce. "Signals and assessment in African elephants: evidence from playback experiments". Animal Behaviour, 1999, 58. 185–193.

It's very interesting and mentions your speaker directly.

Thanks again.

 

[kyle_neuron]

Assuming that's a linear SPL measurement, 116 dB of 10 Hz at 1 metre in 1988 is crazy impressive

There was an owner! I am very surprised. thank you.
What kind of sound is it? Are there speakers that sound similar?

Kinda hard to describe. The subs are insanely powerful and very deep in response. They're a high order bandpass design with 3x 21" B&C 21SW152 in each box. The group delay is relatively low compared to other bandpass boxes, and they took the full output of a Powersoft K20 DSP without a sweat. We used to run three drivers per amplifier, which is about 4000 W peak per driver when you take into account the measured electrical impedance of the cabinet.

The 'kick' section I was less enamoured with. All four 15" per box share a smaller rear chamber, lined with damping material. It's a simple straight horn with an offset loading at the throat from there, one horn per driver. The issue we found is that the drivers were subjected to immense pressure from the sub response, which was directly below. Essentially, the 15" cones would meet their excursion limit much earlier than you'd expect due to the high output of the lower frequencies, which the horn didn't load correctly.

With 16 of those 15" drivers per system, it was very costly when they ripped apart... eventually I found a sweet spot in crossover slopes and limiters that stopped this, but it took some of the joy and impressiveness out of the system in that region. Running the subs up higher to compensate only brought the issue back, while also increasing the onset of thermal compression in the subs themselves - subs build up the heat more quickly driving higher frequencies due to the reduced excursion causing less heat exchange via the ports.

This is something they fixed in the later Nexus Q box, which uses a cardioid port at the rear, but it never made it back to this Incubus Hyperfold.

The full-range element sounded really good outdoors. It was a nightmare to set up, at 150 kg with the bracket we had made. Most of the time, we used either a telehandler forklift or a series of steps made out of steel staging to lift it up on the 2.5 m stack. I think that section could also do with a revision, as the polar response seemed to be quite inconsistent from the 100 Hz to 20 kHz region. No problem outdoors, but the issue with what appeared to be diffraction from the simple arced array of straight line array waveguides, and the opposite orientation of the LF dual 12" bifurcated horns caused some unpredictable problems when we took the system into venues.

The nominal dispersion on the spec sheet doesn't feel right to me, and I think it's based on some predictions. In practice, it's quite a wide coverage both vertically and horizontally. Certainly not conical, but broad in both dimensions. So the output is obscene, but it doesn't 'throw' very far because the DI is low. For 2000 or so people, on a square-ish dancefloor, it's really damn good. For a long rectangular one, delays are needed after ~ 20-30 metres as the bass is still going *very* strong but the highs not so much.

That's never been properly measured though because frankly, it's not really feasible to mount something that huge and heavy on a robot arm to generate balloon data. There was a more conventional line array cabinet based on the same design in the works, which we did measure and deploy as part of a development process, but for various reasons it never made it to market and focus went onto a smaller product which became the (very good) Arcline 8.

Thing is, I can't grumble too much as it's an install system, and we asked to tour it. These issues can be mitigated in a venue that is likely to afford the system via treatment, aiming, and tuning. A great example of this is the utterly crazy Blitz club in Munich that has FOUR stacks of this system in a room for 500 people. It runs without limiters, has no HPF, and plays to 20 Hz with ease. They don't drive it to silly levels, even if it's capable, so the dynamic range is obscene. Not only that, they spent as much on the room as they did the system - it has custom-designed hybrid absorptive and diffusive treatment all down the walls, in the roof, a sprung floor, decoupled DJ booth, and more. Put it on the bucket list, if you're ever in the area!

As for us, we had a great run with the system despite my nitpicking. It made us a bunch of cash, a good name for doing crazy things in beautiful places, and my approach to tweaking and refining the processing and usage of the rig got us huge accolades from discerning producers who claimed it was the closest thing to a giant version of their studio monitors that they'd ever heard.

Edit: I've attached some photos from over the years.

While it was primarily used for DJs (the looks don't really make it fit many bands!) at the Arctic circle gig which is the island one in the pictures, I mixed a really great six-piece neo-classical band on it with great results. Super easy to dial in good sound for violin, cello, double bass, and vocals. Wish we had more chance for that, frankly.

Since then, however, we started using some Danley products. I got a pair of Jericho J1-94 from them on loan for a summer, and it was another level entirely - similar sonic qualities, but easier to drive and far more consistent coverage. They also have subs and full-range speakers that do similar things, in terms of frequency response, output level, and directivity, but at different scales that allow for more 'regular jobs' to benefit from the same goals. That also means I don't have to be on every gig or install to get great sound; my preset library just rolls out and the rest is intuitive for front of house guys to work with when it comes to applying EQ or aiming.

We now own a full warehouse of Danley, and our Void rental stock all moved into installations - where it was meant to be used anyway - or was sold onto people who continue to do good things with it. The silver Incubus system lives on the west coast of the USA now, with a great guy who runs a little shop called Specter Audio. He got it with a full rack of Powersoft X series, pre-loaded with my final tweaked presets, a bunch of 'how to' guides and all the clever cabling and distribution you need to send 16 channels of high power audio to each stack for maximum flexibility. I believe he covers Oregon and California mostly; you can find them on Instagram to look out for it in your area or I'm sure he'd be keen to demo the system at his warehouse.

Here's a shot of one of the gigs we do regularly now; this is a fireworks show with a 125 m x 125 m audience area, or 50,000 person capacity. We deploy a pair of Danley J3-94 per side flown at 10 m height, 50 m apart, with a pair of their SH96HO stacked on some subs for the middle front section. The system uses two 8-channel amplifiers, and we do it in a single van instead of the 40 ft truck the previous supplier used. At the back of the crowd, it's ~89 dBA slow.

If you look closely, you can see the white speaker horns on the towers and along the edge of the crowd. Forgive the music and phone video!

For all the joys of objective measurements and science, there's still a lot to be said for the experience of going to listen to crazy stuff

 

[richard12511]

As a Technics fan I was lucky some years ago to get a pair (they are very rare with only few pairs sold outside Japan having a type writer written manual and being also part of the permanent collection of the Museum of Modern Art in New York) which I have since then in my vintage loudspeaker collection. I miss though the 2 huge optional subwoofers SST-25Hz and SST-35Hz, some sellers offer those all together for more than 20k :-s

About us - Technics

www.technics.com

https://www.hifiengine.com/gallery/images/technics-sst-1.shtml

Damn! That sounds really good for youtube and a moving camera!

 

[Tom Danley]

I found this paper, with references to a bunch of others, one of which probably the 1988 piece you had in mind: http://www.engdes.com/sigwin/company/biblio/papers/Signals and assessment in African elephants (Poole 1999).pdf

Poole, Joyce. "Signals and assessment in African elephants: evidence from playback experiments". Animal Behaviour, 1999, 58. 185–193.

It's very interesting and mentions your speaker directly.
View attachment 160907

View attachment 160908

Thanks again.

Hey thanks!
Yeah that was the one and a nice overview of their work after too. The Elephants talk long distance with low bass haha.
That speaker we made was a somewhat larger version of the ContraBass that had 2X 15 inch servomotor driven radiators and 4X 18 inch passive radiators. That was one of the easier and smaller acoustic projects we had back then but a cool one.
Anyway, good find!
I ran across the T&S parameters for that old Contra-Bass Servomotor driver the other day which might be fun for others to model. This (all of the servodrive's) used a low inertia DC servomotor instead of a voice coil. When the rotary motion is converted to the more familiar "in and out" motion and connected to radiators, it became a loudspeaker with no motor Xmax..
Fs 19.4Hz
Re 2 Ohms
Le =.26Mhy
Qm=14
Qe = .235
Qt = .231
Mms =960Gm
Vas = 287L
Sd = 1710cm^2
BL = 31.5
Xmax (suspension limited) =34mm

Best
Tom

 

[Tom Danley]

Assuming that's a linear SPL measurement, 116 dB of 10 Hz at 1 metre in 1988 is crazy impressive

Kinda hard to describe. The subs are insanely powerful and very deep in response. They're a high order bandpass design with 3x 21" B&C 21SW152 in each box. The group delay is relatively low compared to other bandpass boxes, and they took the full output of a Powersoft K20 DSP without a sweat. We used to run three drivers per amplifier, which is about 4000 W peak per driver when you take into account the measured electrical impedance of the cabinet.

The 'kick' section I was less enamoured with. All four 15" per box share a smaller rear chamber, lined with damping material. It's a simple straight horn with an offset loading at the throat from there, one horn per driver. The issue we found is that the drivers were subjected to immense pressure from the sub response, which was directly below. Essentially, the 15" cones would meet their excursion limit much earlier than you'd expect due to the high output of the lower frequencies, which the horn didn't load correctly.

With 16 of those 15" drivers per system, it was very costly when they ripped apart... eventually I found a sweet spot in crossover slopes and limiters that stopped this, but it took some of the joy and impressiveness out of the system in that region. Running the subs up higher to compensate only brought the issue back, while also increasing the onset of thermal compression in the subs themselves - subs build up the heat more quickly driving higher frequencies due to the reduced excursion causing less heat exchange via the ports.

This is something they fixed in the later Nexus Q box, which uses a cardioid port at the rear, but it never made it back to this Incubus Hyperfold.

The full-range element sounded really good outdoors. It was a nightmare to set up, at 150 kg with the bracket we had made. Most of the time, we used either a telehandler forklift or a series of steps made out of steel staging to lift it up on the 2.5 m stack. I think that section could also do with a revision, as the polar response seemed to be quite inconsistent from the 100 Hz to 20 kHz region. No problem outdoors, but the issue with what appeared to be diffraction from the simple arced array of straight line array waveguides, and the opposite orientation of the LF dual 12" bifurcated horns caused some unpredictable problems when we took the system into venues.

The nominal dispersion on the spec sheet doesn't feel right to me, and I think it's based on some predictions. In practice, it's quite a wide coverage both vertically and horizontally. Certainly not conical, but broad in both dimensions. So the output is obscene, but it doesn't 'throw' very far because the DI is low. For 2000 or so people, on a square-ish dancefloor, it's really damn good. For a long rectangular one, delays are needed after ~ 20-30 metres as the bass is still going *very* strong but the highs not so much.

That's never been properly measured though because frankly, it's not really feasible to mount something that huge and heavy on a robot arm to generate balloon data. There was a more conventional line array cabinet based on the same design in the works, which we did measure and deploy as part of a development process, but for various reasons it never made it to market and focus went onto a smaller product which became the (very good) Arcline 8.

Thing is, I can't grumble too much as it's an install system, and we asked to tour it. These issues can be mitigated in a venue that is likely to afford the system via treatment, aiming, and tuning. A great example of this is the utterly crazy Blitz club in Munich that has FOUR stacks of this system in a room for 500 people. It runs without limiters, has no HPF, and plays to 20 Hz with ease. They don't drive it to silly levels, even if it's capable, so the dynamic range is obscene. Not only that, they spent as much on the room as they did the system - it has custom-designed hybrid absorptive and diffusive treatment all down the walls, in the roof, a sprung floor, decoupled DJ booth, and more. Put it on the bucket list, if you're ever in the area!

As for us, we had a great run with the system despite my nitpicking. It made us a bunch of cash, a good name for doing crazy things in beautiful places, and my approach to tweaking and refining the processing and usage of the rig got us huge accolades from discerning producers who claimed it was the closest thing to a giant version of their studio monitors that they'd ever heard.

Edit: I've attached some photos from over the years.
View attachment 160969
View attachment 160970
View attachment 160971
View attachment 160972
View attachment 160973
View attachment 160974
View attachment 160975
While it was primarily used for DJs (the looks don't really make it fit many bands!) at the Arctic circle gig which is the island one in the pictures, I mixed a really great six-piece neo-classical band on it with great results. Super easy to dial in good sound for violin, cello, double bass, and vocals. Wish we had more chance for that, frankly.

Since then, however, we started using some Danley products. I got a pair of Jericho J1-94 from them on loan for a summer, and it was another level entirely - similar sonic qualities, but easier to drive and far more consistent coverage. They also have subs and full-range speakers that do similar things, in terms of frequency response, output level, and directivity, but at different scales that allow for more 'regular jobs' to benefit from the same goals. That also means I don't have to be on every gig or install to get great sound; my preset library just rolls out and the rest is intuitive for front of house guys to work with when it comes to applying EQ or aiming.

We now own a full warehouse of Danley, and our Void rental stock all moved into installations - where it was meant to be used anyway - or was sold onto people who continue to do good things with it. The silver Incubus system lives on the west coast of the USA now, with a great guy who runs a little shop called Specter Audio. He got it with a full rack of Powersoft X series, pre-loaded with my final tweaked presets, a bunch of 'how to' guides and all the clever cabling and distribution you need to send 16 channels of high power audio to each stack for maximum flexibility. I believe he covers Oregon and California mostly; you can find them on Instagram to look out for it in your area or I'm sure he'd be keen to demo the system at his warehouse.

Here's a shot of one of the gigs we do regularly now; this is a fireworks show with a 125 m x 125 m audience area, or 50,000 person capacity. We deploy a pair of Danley J3-94 per side flown at 10 m height, 50 m apart, with a pair of their SH96HO stacked on some subs for the middle front section. The system uses two 8-channel amplifiers, and we do it in a single van instead of the 40 ft truck the previous supplier used. At the back of the crowd, it's ~89 dBA slow.

View attachment 160977

If you look closely, you can see the white speaker horns on the towers and along the edge of the crowd. Forgive the music and phone video!

For all the joys of objective measurements and science, there's still a lot to be said for the experience of going to listen to crazy stuff

Kyle your last sentence says it all and some of your jobs would be a riot to attend!
Was that Road Warrior / sound truck your work? That was wild.
Take care
Tom

 

[kyle_neuron]

Kyle your last sentence says it all and some of your jobs would be a riot to attend!
Was that Road Warrior / sound truck your work? That was wild.
Take care
Tom

Thanks! Conferences and trade shows were genuinely one of the biggest losses I felt during the last two years. Demo rooms are far from perfect, but the shared experience of actually listening to things always 'brings it all together' when there are questions about some aspect of design. Hopefully we'll get to chat at one again soon

The 'doof truck' isn't mine, sadly. Although one day the world will finally stop getting in the way of me answering the call to go and engineer this monster of a party bus from Robot Heart at Burning Man:

I'd like to check out the Sanctuary truck too while there, which features a whole bunch of your designs. Not that you can see them!

Another 'crazy' speaker design that uses arrays of soft domes in custom milled waveguides:

Design & Manufacturing | Traction Sound

Learn about the design & manufacturing of our high-fidelity sound systems for professional use.

www.tractionsound.com

 

[DanielT]

Assuming that's a linear SPL measurement, 116 dB of 10 Hz at 1 metre in 1988 is crazy impressive

Kinda hard to describe. The subs are insanely powerful and very deep in response. They're a high order bandpass design with 3x 21" B&C 21SW152 in each box. The group delay is relatively low compared to other bandpass boxes, and they took the full output of a Powersoft K20 DSP without a sweat. We used to run three drivers per amplifier, which is about 4000 W peak per driver when you take into account the measured electrical impedance of the cabinet.

The 'kick' section I was less enamoured with. All four 15" per box share a smaller rear chamber, lined with damping material. It's a simple straight horn with an offset loading at the throat from there, one horn per driver. The issue we found is that the drivers were subjected to immense pressure from the sub response, which was directly below. Essentially, the 15" cones would meet their excursion limit much earlier than you'd expect due to the high output of the lower frequencies, which the horn didn't load correctly.

With 16 of those 15" drivers per system, it was very costly when they ripped apart... eventually I found a sweet spot in crossover slopes and limiters that stopped this, but it took some of the joy and impressiveness out of the system in that region. Running the subs up higher to compensate only brought the issue back, while also increasing the onset of thermal compression in the subs themselves - subs build up the heat more quickly driving higher frequencies due to the reduced excursion causing less heat exchange via the ports.

This is something they fixed in the later Nexus Q box, which uses a cardioid port at the rear, but it never made it back to this Incubus Hyperfold.

The full-range element sounded really good outdoors. It was a nightmare to set up, at 150 kg with the bracket we had made. Most of the time, we used either a telehandler forklift or a series of steps made out of steel staging to lift it up on the 2.5 m stack. I think that section could also do with a revision, as the polar response seemed to be quite inconsistent from the 100 Hz to 20 kHz region. No problem outdoors, but the issue with what appeared to be diffraction from the simple arced array of straight line array waveguides, and the opposite orientation of the LF dual 12" bifurcated horns caused some unpredictable problems when we took the system into venues.

The nominal dispersion on the spec sheet doesn't feel right to me, and I think it's based on some predictions. In practice, it's quite a wide coverage both vertically and horizontally. Certainly not conical, but broad in both dimensions. So the output is obscene, but it doesn't 'throw' very far because the DI is low. For 2000 or so people, on a square-ish dancefloor, it's really damn good. For a long rectangular one, delays are needed after ~ 20-30 metres as the bass is still going *very* strong but the highs not so much.

That's never been properly measured though because frankly, it's not really feasible to mount something that huge and heavy on a robot arm to generate balloon data. There was a more conventional line array cabinet based on the same design in the works, which we did measure and deploy as part of a development process, but for various reasons it never made it to market and focus went onto a smaller product which became the (very good) Arcline 8.

Thing is, I can't grumble too much as it's an install system, and we asked to tour it. These issues can be mitigated in a venue that is likely to afford the system via treatment, aiming, and tuning. A great example of this is the utterly crazy Blitz club in Munich that has FOUR stacks of this system in a room for 500 people. It runs without limiters, has no HPF, and plays to 20 Hz with ease. They don't drive it to silly levels, even if it's capable, so the dynamic range is obscene. Not only that, they spent as much on the room as they did the system - it has custom-designed hybrid absorptive and diffusive treatment all down the walls, in the roof, a sprung floor, decoupled DJ booth, and more. Put it on the bucket list, if you're ever in the area!

As for us, we had a great run with the system despite my nitpicking. It made us a bunch of cash, a good name for doing crazy things in beautiful places, and my approach to tweaking and refining the processing and usage of the rig got us huge accolades from discerning producers who claimed it was the closest thing to a giant version of their studio monitors that they'd ever heard.

Edit: I've attached some photos from over the years.
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While it was primarily used for DJs (the looks don't really make it fit many bands!) at the Arctic circle gig which is the island one in the pictures, I mixed a really great six-piece neo-classical band on it with great results. Super easy to dial in good sound for violin, cello, double bass, and vocals. Wish we had more chance for that, frankly.

Since then, however, we started using some Danley products. I got a pair of Jericho J1-94 from them on loan for a summer, and it was another level entirely - similar sonic qualities, but easier to drive and far more consistent coverage. They also have subs and full-range speakers that do similar things, in terms of frequency response, output level, and directivity, but at different scales that allow for more 'regular jobs' to benefit from the same goals. That also means I don't have to be on every gig or install to get great sound; my preset library just rolls out and the rest is intuitive for front of house guys to work with when it comes to applying EQ or aiming.

We now own a full warehouse of Danley, and our Void rental stock all moved into installations - where it was meant to be used anyway - or was sold onto people who continue to do good things with it. The silver Incubus system lives on the west coast of the USA now, with a great guy who runs a little shop called Specter Audio. He got it with a full rack of Powersoft X series, pre-loaded with my final tweaked presets, a bunch of 'how to' guides and all the clever cabling and distribution you need to send 16 channels of high power audio to each stack for maximum flexibility. I believe he covers Oregon and California mostly; you can find them on Instagram to look out for it in your area or I'm sure he'd be keen to demo the system at his warehouse.

Here's a shot of one of the gigs we do regularly now; this is a fireworks show with a 125 m x 125 m audience area, or 50,000 person capacity. We deploy a pair of Danley J3-94 per side flown at 10 m height, 50 m apart, with a pair of their SH96HO stacked on some subs for the middle front section. The system uses two 8-channel amplifiers, and we do it in a single van instead of the 40 ft truck the previous supplier used. At the back of the crowd, it's ~89 dBA slow.

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If you look closely, you can see the white speaker horns on the towers and along the edge of the crowd. Forgive the music and phone video!

For all the joys of objective measurements and science, there's still a lot to be said for the experience of going to listen to crazy stuff

I'm trying to come up with something sensible to say, comment on, about your post but I can not do that so I just say: WOW. Good work..

 

[Juhazi]

Estelon Forza 150.000€/pair tested at Stereophile
- unusually low impedance...

 

[Vladimir Filevski]

Unusually low impedance? It is mandatory for loudspeakers costing $150,000 or more...

 

[mhardy6647]

Unusually low impedance? It is mandatory for loudspeakers costing $150,000 or more...

Part of that audiophile cachet. If it ain't potentially amplifier-lethal, it ain't worth ownin'.