cowanaudio said:
After Moray posted that patent, I started messing around with designs in Mathcad. The driver that I modeled was a $25 MCM 55-2421. These are the 'real' specs. Zaph posted these, and they're nearly identical to the results that I measured. I'm running these in both of my cars.
Actual measurements:
Fs=30.95 hz
Qms=12.2863
Qes=0.2365
Qts=0.2320
Vas=23.88 l
SPL=86.59 1w/1m
Re=3.4
Le=2.42
BL=13.15
Xmax=16mm P-P
open idea...
Just spoke to an associate of Arnold Klayman who was involved in developing the design from patent number 5, 177, 329 and it seems that driver selection at the time was the issue that caused the project to be dropped. Arnold is 82 now and retired. I passed along the info regarding this thread so if we are lucky we might see one of them here which would be very nice.
I also found another patent that came out about ten months after Klayman's Hayakawa US # 5, 197, 103 which is almost the same thing. Then there is also a patent US 4, 064, 966 worth looking at as well. Going back to 1962 you can see another similar patent US# 3. 047, 090 look at fig. # 4. Regards Moray James.
Just spoke to an associate of Arnold Klayman who was involved in developing the design from patent number 5, 177, 329 and it seems that driver selection at the time was the issue that caused the project to be dropped. Arnold is 82 now and retired. I passed along the info regarding this thread so if we are lucky we might see one of them here which would be very nice.
I also found another patent that came out about ten months after Klayman's Hayakawa US # 5, 197, 103 which is almost the same thing. Then there is also a patent US 4, 064, 966 worth looking at as well. Going back to 1962 you can see another similar patent US# 3. 047, 090 look at fig. # 4. Regards Moray James.
freddi said:
How does a footprint of 10" across sound? And what if you could build it in an hour?
The one that I modeled was based on a sonotube. But with a twist. Instead of mounting the driver on one end of the tube, imagine a sontube tapped horn. Basically you get a 10" sonotube, and slide a 10" piece of MDF right down the center. The 10" piece of MDF splits the sonotube into two seperate chambers.
The drawback is that there's no flare. You can fix this by "stepping" the divider. You could also angle the divider, a bit more work though.
Does that make sense?
I'd post the results, but they're on my PC in another state. (I'm a "road warrior.)
haha PB - sounds pretty cool - I've never had sonotube
lets see measurements when U get time to stop.
hey William - what happens flex-wise, excursion-wise and distortion-wise on your 30Hz sub when it plays a 20vrms (or more) 30Hz sine-wave? does it have (and need) bracing for the canted board? is max excursion around 50? - does it sound deep nuff for most pipe-organ cds?
lets see measurements when U get time to stop.
hey William - what happens flex-wise, excursion-wise and distortion-wise on your 30Hz sub when it plays a 20vrms (or more) 30Hz sine-wave? does it have (and need) bracing for the canted board? is max excursion around 50? - does it sound deep nuff for most pipe-organ cds?
G'day Freddi
Bracing is easy to install, and pretty important on the big sub. I have driven one channel of my sub amp (Australian Monitor AM1600) into clipping into the small sub and both channels driven into clipping into the dual driver TH with no problems. I have used a HPF in both cases. The big sub goes low enough to produce waves of pressure that shake the house and make you think you were just spoken to by God. The 30Hz sub will reproduce just about anything recorded on a rock/dance track. My listening room is pretty big, at around 220M^3 and this opens into the rest of the house. The 18Hz TH has little trouble flooding it with bass.
Time for you to whip out the B&D and throw together a box. They are very simple to construct.
Bracing is easy to install, and pretty important on the big sub. I have driven one channel of my sub amp (Australian Monitor AM1600) into clipping into the small sub and both channels driven into clipping into the dual driver TH with no problems. I have used a HPF in both cases. The big sub goes low enough to produce waves of pressure that shake the house and make you think you were just spoken to by God. The 30Hz sub will reproduce just about anything recorded on a rock/dance track. My listening room is pretty big, at around 220M^3 and this opens into the rest of the house. The 18Hz TH has little trouble flooding it with bass.
Time for you to whip out the B&D and throw together a box. They are very simple to construct.
G'day William - - I don't have much rock but do listen to electronic & pipe organ plus bunch of gobbleygoop
-almost afraid to ask 18Hz sub's dimensions & would like ~20Hz and have gotten 20 at low levels in smlaler oorm with retuned k15 tuned/boosted~like exemplar. my room is only about 46 sq. meters area w. 2.39M ceiling height (ugh)
what crossover and EQ are you using? - does the 30Hz sub play nice taut bass when blended correctly? a lot of things I like have upright bass and real drums
I've had problems lately and still sick w. flu/old-age but want some LF baddddddddd! - even if means my lopsided carpentry.
Best,
Freddy
ps - I've been trying FR open-baffle - ain't workin' yet - gargle, not much dynamics..even a K sounds better :^)
-almost afraid to ask 18Hz sub's dimensions & would like ~20Hz and have gotten 20 at low levels in smlaler oorm with retuned k15 tuned/boosted~like exemplar. my room is only about 46 sq. meters area w. 2.39M ceiling height (ugh)
what crossover and EQ are you using? - does the 30Hz sub play nice taut bass when blended correctly? a lot of things I like have upright bass and real drums
I've had problems lately and still sick w. flu/old-age but want some LF baddddddddd! - even if means my lopsided carpentry.
Best,
Freddy
ps - I've been trying FR open-baffle - ain't workin' yet - gargle, not much dynamics..even a K sounds better :^)
Hi William,
Reading over your suggested driver specs just now, I thought of the tiny but mighty Tangband W61139SG in a very slim TH with a footprint of perhaps 50 in^2. Could a ~30Hz TH function correctly with a narrow cross section of maybe 40 in^2 at the mouth? I imagine reduced efficiency would be the primary result...
Reading over your suggested driver specs just now, I thought of the tiny but mighty Tangband W61139SG in a very slim TH with a footprint of perhaps 50 in^2. Could a ~30Hz TH function correctly with a narrow cross section of maybe 40 in^2 at the mouth? I imagine reduced efficiency would be the primary result...
G'day Freddi, Bill
My crossover is a Behringer DCX2496. The two Tapped Horn subs blend seemlessly with my system. Distortion and crossover frequency are low, so this is almost a given, when eq'd and delayed correctly.
Bill, That driver would be worth a try, especially if you have one. I agree that efficiency would be low, but the footprint would be tiny. Not much wood required for the box, either.
Cheers
William Cowan
My crossover is a Behringer DCX2496. The two Tapped Horn subs blend seemlessly with my system. Distortion and crossover frequency are low, so this is almost a given, when eq'd and delayed correctly.
Bill, That driver would be worth a try, especially if you have one. I agree that efficiency would be low, but the footprint would be tiny. Not much wood required for the box, either.
Cheers
William Cowan
Maybe not so known patents on the matter
http://www.freepatentsonline.com/2604182.pdf
http://www.freepatentsonline.com/2337213.pdf
http://www.freepatentsonline.com/2604182.pdf
http://www.freepatentsonline.com/2337213.pdf
It's just a snail horn folding, virtually the same as his Lab 12 design.
Where the two 12s mount in the Lab 12 there are two 15' passive radiators driven by the servo-motor via a toothed belt.
A smaller version from a different angle show how the passive radiators mount, the servo motor would be in the middle between the PRs.
Photos from Tom Danley.
Where the two 12s mount in the Lab 12 there are two 15' passive radiators driven by the servo-motor via a toothed belt.
An externally hosted image should be here but it was not working when we last tested it.
A smaller version from a different angle show how the passive radiators mount, the servo motor would be in the middle between the PRs.
An externally hosted image should be here but it was not working when we last tested it.
Photos from Tom Danley.
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