If one could do that on an 80x80 square, would you gain 18dB on 20x40?
Can a Paraline lens be configured to cover 20x40?
I just looked up the layered combiner patent and that's crazy stuff! Pushing the boundaries of acoustics indeed.
How many compression drivers can feed into a single Layered Combiner - 3 or 4? Would it be plausible to have the Layered Combiner coupled to a vertical Paraline in the throat of the horn? That should be able to produce some serious SPLs with the desired directivity, but what about the lower frequencies?
Holy smokes... But all those drivers aren't going into a single combiner, are they? From the patent it looks like you could have a group of 4 going into a single combiner. Using that logic with that picture, each group of 4 drivers goes into a single combiner whose output goes to a vertical paraline, and 8 of those paralines are stacked on each side of the cabinet!
My knowledge of line arrays is nowhere near guys like speakerdave.
But if I understand the technology correctly, the maximum output at 20khz is going to be the maximum output of a single driver.
IE, you could have a line array of ten thousand 3" drivers, the maximum output at 20khz is going to be about 95-105dB.
This is because two sources will act like one if they're withing approximately 1/3rd to 1/4 of a wavelength. At 10khz, that necessitates a distance of less than 1.13cm. That gives you two options:
1) A low efficiency line source like the Keele CBT. Although the efficiency of a single unit is just 75dB, there's ninety six of them. That raises the power handling significantly, though the high frequencies will always be limited by the low efficiency of the high frequency units. (This also illustrates that the CBT 96 could really use a little bit of horn loading for the highs, maybe a very shallow waveguide that restricts the beamwidth of the top two octaves. It wouldn't have to be big, a fraction of a centimeter would do it.)
2) For high output applications, you want something that can combined two diaphragms into one exit. That's what BMS does with their coaxial midranges, it's what JBL does with their D2430K, it's what Danley does with the layered combiner.
The Paraline has always been interesting to me. Though it doesn't combine outputs, it narrows the beam so much, it allows you to use multiple compression drivers as if they were one larger unit. Note that the maximum output of a Paraline at 20khz will still be the same as a single unit. (If I understand things correctly.)
That's why JBL combines the output of two diaphragms like this. And uses quite a hefty voice coil. That gets your maximum output at 20khz up to around 130dB or so.
It just occurred to me that a lot of this comes full circle. Back in the day, Danley was doing acoustic levitation. To do that, you need to generate maximum output at a single point in space. The Jericho horns kinda follow the same ideal. But now that 'point in space' is an arena that's a hundred feet away from the loudspeaker. IE, they're still trying to generate as much output as possible over a point, that point has just become larger than this:
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
In the Facebook comments, I believe Ivan commented that they're using the microphone on the camera.
With a focused array you can cross to a point forward of the diaphragm where the acoustic centers match almost perfectly with a theoretical +3db for each doubling of sources (and +3db for halving of impedance depending on amplifier). Of course before and beyond this point you will incur combing (assuming the offset is vertical in nature, so will the combing be), with a sufficient waveguide though it's moot. (..as opposed to a relativly "free-field" condition as seen below.)
As for waveguides, remember that as you "squash" the directivity pattern from the driver's output at any given freq. - that you obtain gain. In particular you can squash the horizontal to achieve vertically improved dispersion at the exit (to a point) - so what was once perhaps a 3/4 of an inch vertically around 18 kHz, could be 1/4" horizontally (squeezed) with the vertical expanding to MORE than 3/4 of an inch vertically at that freq.. Of course most waveguides that are designed to turn point-source compression drivers into line sources are "focused" more on a vertical that has little pressure BEYOND it's vertical exit - so that in combination with the same drivers: there is little combing interference when properly combined in a large vertical array.
This picture shows a speaker where the fullrange drivers are focused in order to achieve treble gain comparable to the gain of the drivers at lower freq.s without significant combing at a certain distance and over a much more narrow vertical window than the midrange.
Attachments
Yes, they usually do. I did look at the Facebook page, but never found the post.
BTW, I have heard that giant HF thing with all the compression drivers. It is amazing, like an audio flashlight. Very narrow beam.
A lot more than that.
Am I crazy wondering about compression with this set up?
Grant.
That's the J4 right? 64 HF drivers.
We had one of those with a J1 and a pair of 812's on the pavement out here in Vegas after INFOCOMM by the speedway. The pavement was about 145 degrees and at 300 feet out we couldn't even hear Mike turning the J4 on and off. Crazy how a strong temperature gradient will bend sound. A J4 can melt your hair if your in the coverage pattern.
Fun toys Tom and crew make.
Barry
We should have hung it high for sure. I was just crazy to be able to walk totally out of the pattern.
The other thing that was amazing was watching the 100 amp Whisper Watt generator rocking with the kick drum beat, Lenz Law in action.
I wish we would have had more time with all that stuff.
Barry.
The other thing that was amazing was watching the 100 amp Whisper Watt generator rocking with the kick drum beat, Lenz Law in action.
I wish we would have had more time with all that stuff.
Barry.
Hi Guys, Barry, Pano
The j4 is only hf augmentation (a tweeter) for the longest distance uses where the air itself is preferentially and strongly absorbing high frequency sound in addition to the inverse square loss. If one uses the calculator below with the existing numbers one can see that at 20C and 50%, the excess loss at 10K is 16dB.
Calculation method of absorption of sound by atmosphere air damping dissipation absorbtion high frequencies attenuation sound during propagation outdoors outdoor - sengpielaudio Sengpiel Berlin
Since some of the installations have an 800+ foot throw and some are 100 meters to the closest listener, there are times when one needs more hf….BUT only where it’s pointed, typically the far end of a foot ball stadium, hence the j4, “the mosquito burner” as it’s development name was.
Here is a video I took at one of the first installations using the J4, they are the little black things on the inside edges of the scoreboards. This was about 200meters from the speakers, taken win a canon vixia r300.
Oh and no, the pattern doesn’t collapse to get the level on axis, the object is to “paint” the entire seating area at the far end and make it the same spectral balance and spl everywhere (except on the playing field that is sometimes a separate system).
https://www.dropbox.com/s/lqeg3cf0daqv9ti/20120726114748.mts?dl=0
The box in the other video is something new, also a “long throw hifi” design, these very large systems that also have to sound good and be intelligible for voice seems to be a niche line arrays cannot fill.
It has several new variations on the paraline, combiner and Synergy horn themes and I am pretty pleased how it came out .
The Horn has a 20 by 40 pattern and should hold that (CD) down to about 1k (pending the polar measurement) and “it goes pretty loud”, a quick SPL measurement the other day with the NTI showed speaks of 114dB to 115dB using EIA pink noise, at 100 meters at onset of the line breaker protection limiters on peaks and driven by one 20k amp and 20A service. The amp has a cool feature that on 110V, you can set it to limit the input current at 15 or 20 Amps so the line breakers don’t trip during use.
Here is another video also taken with a canon vixia r300 at 100 meters at my lab although by then it was starting to get windy. I think by this time I had the Zoom part of the camera down too.
https://www.dropbox.com/s/ier3ehqpaugbrmz/20170428113522.mts?dl=0
Best,
Tom
The j4 is only hf augmentation (a tweeter) for the longest distance uses where the air itself is preferentially and strongly absorbing high frequency sound in addition to the inverse square loss. If one uses the calculator below with the existing numbers one can see that at 20C and 50%, the excess loss at 10K is 16dB.
Calculation method of absorption of sound by atmosphere air damping dissipation absorbtion high frequencies attenuation sound during propagation outdoors outdoor - sengpielaudio Sengpiel Berlin
Since some of the installations have an 800+ foot throw and some are 100 meters to the closest listener, there are times when one needs more hf….BUT only where it’s pointed, typically the far end of a foot ball stadium, hence the j4, “the mosquito burner” as it’s development name was.
Here is a video I took at one of the first installations using the J4, they are the little black things on the inside edges of the scoreboards. This was about 200meters from the speakers, taken win a canon vixia r300.
Oh and no, the pattern doesn’t collapse to get the level on axis, the object is to “paint” the entire seating area at the far end and make it the same spectral balance and spl everywhere (except on the playing field that is sometimes a separate system).
https://www.dropbox.com/s/lqeg3cf0daqv9ti/20120726114748.mts?dl=0
The box in the other video is something new, also a “long throw hifi” design, these very large systems that also have to sound good and be intelligible for voice seems to be a niche line arrays cannot fill.
It has several new variations on the paraline, combiner and Synergy horn themes and I am pretty pleased how it came out .
The Horn has a 20 by 40 pattern and should hold that (CD) down to about 1k (pending the polar measurement) and “it goes pretty loud”, a quick SPL measurement the other day with the NTI showed speaks of 114dB to 115dB using EIA pink noise, at 100 meters at onset of the line breaker protection limiters on peaks and driven by one 20k amp and 20A service. The amp has a cool feature that on 110V, you can set it to limit the input current at 15 or 20 Amps so the line breakers don’t trip during use.
Here is another video also taken with a canon vixia r300 at 100 meters at my lab although by then it was starting to get windy. I think by this time I had the Zoom part of the camera down too.
https://www.dropbox.com/s/ier3ehqpaugbrmz/20170428113522.mts?dl=0
Best,
Tom
Ah, thanks! I was starting to think some deal with the Devil was allowing you to get extreme efficiency AND a directive pattern at lower freq.s. (at distance).
That's the speedway where they do EDC, right?
Are you aware of any Danley installs in Vegas? I know there's a couple companies that sell his products, but I'm not aware of any installs. IIRC, Club Ra used to run SPL Unity horns, but that club was replaced by LAX quite a while ago.
Thats us. ED is a crazy time here.
A club called The Foundation uses a J3-94 hang but I am unsure of the subs, I think they are the 415's.
Hi Tom!
Dry air is the HF killer for sure.
I was in a hurry when I posted about the J4 and should elaborate. The pattern control on the J4 is very sharp and the shear HF power of that box is amazing! We set it on an asphalt lake of fire, something one would never do in practice and it was just crazy that the convection current could completely steer all that energy up and away.
I can't wait to hear the new box!
Barry.
That one is very impressive, when you realize the distance by the end of the video! Wow!
Is the LF drop around 1:27 an effect of the wind, or maybe some electronic compensation in the camera?
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.