I searched and searched for the systems I'd seen. Thought I had them bookmarked, but no. Will keep looking. All of them that I remember were stereo bass horns that then combined - or touched on the sides.
The systems were basically of three types.
The systems were basically of three types.
- Folded horn built into the floor or ceiling.
- Straight horn. Horn driver extending outside the building.
- Vertical woofer arrays with horn walls curving into the room.
Google is your friend. 😉
For the rest I managed to miss your earlier post and for now just going to attach the high QT modded specs driver HR sim I did to confirm as much as I could, so of course it doesn't account for the damped terminus/mouth/wall and how much BW at each end might get rolled off, i.e. may need to be a [much] wider BW where you're 'chasing your tail' trying to get at least a -25 dB outdoors.
Awesome, thanks for pulling these out. The first one, the royal device, is the closest to what I'm envisioning, because they did a lot of modifications to the room to make it act like a continuation of the horn and channel the bass to the listening position. Best I can remember they achieved 110db at one watt at the listening position.
The last one seems to have a very low expansion rate. I can't quite tell, is it straight sided? I'd be very interested to know the physical measurements and specs on it.
logicaly what you want is your room to be a planar wave tube as this has uniform SPL. The neareast thing to this is a double bass array or single bass array. So you should build a simple recangular room and just cover the front wall with subs (they can also be spaced upto a quarter wavelength) and the rear with the absorber.
Another query I have is that on a lot of the bass horns, it seems little effort is put into making the transition from driver to throat smooth. Does it just not matter that much at that low of a frequency? I would think any little perturbance at the "compression chamber"/throat interface would cause significant distortions further down the horn.
And what's the best compression ratio for a conical low bass horn? To my understanding higher compression ratio allows higher bandwidth and better loading of the driver, but too high and it causes too much distortion. If I recall I was being told long ago that a 2:1 ratio was something to aim for for low bass..?
And what's the best compression ratio for a conical low bass horn? To my understanding higher compression ratio allows higher bandwidth and better loading of the driver, but too high and it causes too much distortion. If I recall I was being told long ago that a 2:1 ratio was something to aim for for low bass..?
Dusty,
Using the freeware "Wine" can create a virtual windows machine, allowing you to run Hornresp on mac.
David McBean has been busy adding features to Hornresp since you last used it.
You can now model multiple entry horns, which combine multiple pass bands on a single horn. MEH solve lots of problems that are unavoidable when using separate multi-way horn systems like you are dreaming of.
Here is what you are contemplating as far as a flat response 20-200 Hz straight horn:
Coming in at over 30 feet long, folding it would eliminate at least 50% of the materials needed, and acoustically filter harmonic distortion when driven at high SPL, which could crumble adobe...
Art
Dan the audiophile guru built those 15m long bass horns to finish his six way horn system when he was in Cyprus. This project clearly put him into legendary status. The info is all over the net and makes for interesting reading about the human condition, dreams and the pursuit of excellence.
"He had a 6-way custom hornspeaker system with two very long straight bass horns. On stilts, those protruded deeply into his garden, pipes tightly wrapped in moisture seals and terminated in dual woofers each at the far end. In the room, their rectangular horn mouths were large enough to walk in for a bit. Some light pipes all the way to their ends made for moody ambiance at night. Both side walls of his room were entirely covered in LPs floor to ceiling. He had a vast selection of truly rare NOS tubes. Further rooms sported assorted Avantgarde Acoustic hornspeaker systems. His wine cellar contained an enviable selection of exotic valve amps from Kondo, Supratek, Yamamoto, Wavelength, Wyetech Labs and many more" 6moons
He used four drivers:
Hanging in the garden
Installation needed concrete footings and a construction team:
Bass horn mouths coupled for deeper bass extension
Pretty glowing stuff
Nice build
Dan moved back to Switzerland. This is his new sub:
Could it be dipole bass from what looks like a single ripole might be better then heroic horns?
Do we really need to go bigger and more complex?
"When done strategically and with the forethought of hindsight, a far simpler setup of far lower maintenance and for relative pennies on the dollar can be superior."6moons
OK, I give up! I saw a post where the sub horn was for 20-60 Hz, which I did, but can't find it or this 20-200 Hz either.
How was the bass? Did Poinz get to listen to any other music and say how that complex horn system sounded?
I wish that I could remember, but Poinz wasn't a bass-head anyway. He did say that the system failed to convince him that there was a real band playing right in front of him, which I found surprising.
The sound waves at the frequencies of interest won't even "see" these bends.
What's the point of this exercise? You want super-low distortion in the bass region? Why not just fill the front and back walls with drivers and create a double bass array (the kind with delayed opposite polarity)? You'll probably end up saving time, money, and get better in-room response anyway.
It seems to me that every time a pressure wave bends a corner it would cause a lower pressure region which would cause a secondary wave to be created, or at least a disturbance to the wavefront.
Yes, I want as little distortion as possible. Eliminating the room from the equation will get rid of a lot of potential problems. Also, having super high efficiency will practically eliminate distortion related to modulation; for the same output the cone has to move very little.
The double bass array sounds interesting, but there is no way that it can be cheaper than what I'm proposing. And I'm not sure about better response. I still have to think about the other frequencies and going back to a box shape room will just reintroduce all those problems.
Making the horn the room will just eliminate so many potential problems and have many advantages.
Can Hornresp model a horn that is the room? Is a room that is shaped like a horn but with a rear wall and absorber, actually a horn at all?
Without a classic mouth outlet what happens to the acoustic impedance at the throat? Is there coupling?
So many questions.
You could save years of frustration with an experts opinion. Maybe ask @David McBean or one of the other guys on the Hornresp thread?
Without a classic mouth outlet what happens to the acoustic impedance at the throat? Is there coupling?
So many questions.
You could save years of frustration with an experts opinion. Maybe ask @David McBean or one of the other guys on the Hornresp thread?
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