|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
66.75.8.80
...blowing out the windows of your listening room or frying your ear drums? Pro Audio Technology has one. Designed by veteran Paul Hales, this 88" tall monster is capable of 140dB output! More than enough for even the most jaded metal head.
Follow Ups:
I ran these for awhile over 11ft tall. 5 way front horns.
did you check with the guy who designed that loudspeaker at the front end of "Back to the Future" part 1?
Ha! That's cool!
Here's some awesome stuff...
http://www.meyersound.com/products/
(Not for home use, unless you've got a really big home.)
Meyer speakers are ear bleed imho... Then, I had the oppurtunity to speak to John Meyer about my experiences during one of his installs that was utter pain to my ears. His response: "We set the system so it is beyond the pain threshold before we get to driver damage" Sad on his part.
"We set the system so it is beyond the pain threshold before we get to driver damage"
I think what he was probably saying is that the system has headroom for days, and that the audio engineer can crank it as loud as he wants without destroying it. :)
He said they had 3K tilted up 11dB. I should have said this originally.
nt
Observe, before you think
What about imaging and soundstage?
Don't think the math adds up for that part of the speaker system.
N/T
"One this was all Black Plasma and Imagination" - Michael McClure
How much are they?
Maybe I'd go 1500.
How about NS1000M's for $1400? Love em or hate them, they sound damned good.
I've been looking online at mod paths and resources.
Do you have any favorites?
I like them stock, although new input terminals is a bonus. I also have a room where 0 (normal) on all of the l-pads is the best balance. I heard a recapped set..sounded too brassy for me.
Ummm, I always thought that music should not be painful
A true 120dB at 16Hz "breaks things" in adjacent rooms. 140dB is noise to the human hearing system..well beyond the scope of any sort of fidelity.
(other than fidelity to noise)
...they talk about 8th order acoustic slopes with "time alignment" but no mention of phase correction. You can't fix group delay with a single physical offset or time delay.
The only thing worse than LR4 transient response is LR8 transient response!
Cheers,
Presto
My god, if I had a nickel for every time I've said that.
... and can do group delay (phase) correction. You don't even need to use convolution of impulses, which is tricky business. You can use sneaky software like the Thuneau Phase Arbitrator. This uses "forward/reverse" processing to do it's magic. Because playback can tolerate latency (delay) what they do is roll phase FORWARD in time, which is mathmatically the opposite of group "delay"... it's group "move forward in time". You tell the program the frequency and roll off rate of your (known) system and then it pre-processes the music stream to be "forward group delayed" so that when the crossover functions add "regular group delay", they (in a sense) cancel out.
I've tested this software with square wave input. Square wave in, square wave out - AFTER summing LR4 low and highpass filters.
It's really quite amazing with the only penalty being a small delay. For video apps, you'd need a "video sync" function.
Will analogue guys digitize their precious analogue stream so they can unravel the phase distortion of an LR4 speaker design? I would say most would consider the detriment of digitization to outweigh the benefits.
That opinion may vary from person to person!
Cheers,
PResto
If your looking for something like that but even more powerful a system, one that acts like it only had one driver (no crossover phase shift) and so will reproduce a square wave over a broad band and can fill a stadium sized place with “hifi” and if you have headphones and facebook, go to the facebook page here;
http://www.facebook.com/DanleySoundLabs?ref=ts
The in the center find “recent posts by others” and hit “see all”
Scroll down to the video posted by Mike (from July 31) and watch that with headphones.
That was recorded at about 700 feet from a stereo pair of 3 over 3 of these;
http://www.danleysoundlabs.com/products/loud-speakers/jericho/j3/
http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/04/TH812-spec-sheet.pdf
If you don’t have facebook, a fellow that attended the first outdoor demo of these took U tube video that also works well.
http://www.youtube.com/watch?v=5MOG_sPejGA
This was loud, adjust the headphone volume to scale the voice around 1:40.
Around 2 min he pans out to the field where the people were (150 yards)
Best,
Tom
I love hifi.
Tom:
Can you generalize on the math of how this type of system achieves transient accurate performance? Is this done with DSP?
Don't stretch the limits of the forum rules on my account, though.
This is indeed a speaker system I want to get in front of one of these days!
Cheers,
Presto
Hi
Sure but an explanation of the concept will tell you more than math (or at least it does for me haha).
Also, since these are more of an acoustic system than a set of drivers, it makes sense to think of them that way while an explanation is limited to a “serial” explanation. Think of these things in parallel.
The acoustic transformation that gives horns an advantage in efficiency has a “high pass” corner which is set by the expansion rate.
For example a 30Hz horn can expand no faster than doubling it’s area about every 2 feet while for a 300Hz horn it’s every 2.4 inches.
While an exponential horn has a constant rate of expansion, a conical horn has a variable rate of expansion, the farther from the apex you are, the slower (lower frequency) the expansion rate is. Fig#4 here shows that “high pass” corner relative to the distance from the throat for an SH-50 horn.
http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/01/The-Tapped-Horn.pdf
Once above a first order slope, all of the ”named” crossover slopes produce a phase shift going from well above to well below crossover. That shift is 90 degrees times the filter order so a 24dB/oct (4th order) crossover has a total phase shift of 360 degrees.
That phase shift in the time reference is a delay with the lower frequencies coming out after the high frequencies.
While it is asserted that this “all pass” type phase shift is inaudible, it is one of the primary things that prevents a multiway speaker for preserving the input signals waveshape, the upper range arrives first and the lower range last (his assuming the acoustic centers are aligned as per usual).
Also two acoustic sources only add coherently into one new source IF they are less than a quarter wavelength apart, that is easy with subwoofers and very rare once the wavelength is shorter. Wavelength in feet is 1132 / Frequency in question.
With a larger spacing, they radiate as independent sources which don’t couple or combine, they produce an interference pattern which is seen by a pattern of lobes and nulls if you take a polar measurement. Here (where most loudspeakers operate) the idea is to make the main lobe pointed forward and all the other lobes and nulls not .
In large scale sound, room problems are always more problematic AND as the distance is greater, much more acoustic power is required.
All of the energy radiated outside of the desired area (where he ears are) is harmful and makes it hard to hear or competes with the direct signal. The most popular solution for the power issue is a long array of individual sources and these produce a complex interference pattern (obvious if the wind blows) which is in part what makes "concert sound".
With an impulsive signal into the system, each source produces a separate arrival delayed slightly so the energy is stretched out in time according to the closest to farthest source.
So the speakers in the video are an entirely different solution, the Synergy horn which is a single point source.
The idea here is that with a large conical horn, you radiate a single spherical wavefront with much less energy outside the desired pattern than a large but self interfering array.
By having all the drivers less than a quarter wavelength from each other where they interact in the horn, they combine into what appears in the measurements a single driver with no lobes or nulls.
If you look at Fig5, you can see the hf driver is behind the mids, the mids are behind the woofers and you hopefully can picture both the horn transformation “high pass” aspect and that the spacing is related to the wavelengths at play.
The remaining issue is time and by using the inherent time offset in the driver spacing, it is possible even with a passive crossover to have a crossover that has no apparent phase shift, all the harmonics emerge in time as they were input electrically, by any measurement, it appears to be a single driver.
The speaker in Fig5 can reproduce a square wave, over more than a decade bandwidth and has only one constant directivity radiation lobe, has a sensitivity of 100dB 1w 1m and projects a very low SPL to the sides and rear.
With any of the Synergy horns, you can walk up to one and put your head into the horn mouth and you never hear anything that suggests there is more than one driver, one source of sound.
The J-3 Synergy horns in the video are a much larger and more powerful system that works the same way. In addition there are TH-812 subwoofers that have a response corner in the upper 30’s and are very powerful (the six in the stadium video are loafing).
The other picture, a Former Omnimax converted to Imax movie theater at the Museum of Science and industry Chicago speakers are SH-96’s larger than the SH-50’s but smaller than the J-3’s in the stadium video.
http://www.danleysoundlabs.com/products/loud-speakers/synergy-horn/sh-96/
Best,
Tom
Here is a nice video demo of just three J-3’s, a job that has been put on hold;
http://www.youtube.com/watch?v=e_usTlJi2NA&feature=share
Wow! Thanks for that detailed explanation Tom!
So because the horns natural (physical) acoustic rolloff is 1st order, the simple physical offest can be used to time-align the various bands... which does not work on crossovers with a non-constant group delay...
Those things just look so fatastically bizaare! The three boxes filling that stadium is indeed impressive.
Any plans for a home-sized version? ;)
Cheers,
Presto
That's pretty impressive for 88" tall speaker...
Won't work for accurate reproduction of a space shuttle launch at the VIP station: 140 dB at 10 Hz.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
...until you pointed that out.
LIBERTY ONCE LOST,
IS LOST FOREVER
-JOHN ADAMS
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: