I am only guessing here, but this is what I think is going on.
The design is a Mass Loaded Tapered Quarter Wave Pipe (MLTQWP).
It has a single fold with an 18hz tuning (88" x 20" x 18").
Since the access panel for the driver is "mid-ship", the driver "taps-in" with an offset 25% from the start of the pipe.
The rear of the driver "taps-in" with an offset 25% from the mouth.
That's my theory, and I'm sticking to it...
The design is a Mass Loaded Tapered Quarter Wave Pipe (MLTQWP).
It has a single fold with an 18hz tuning (88" x 20" x 18").
Since the access panel for the driver is "mid-ship", the driver "taps-in" with an offset 25% from the start of the pipe.
The rear of the driver "taps-in" with an offset 25% from the mouth.
That's my theory, and I'm sticking to it...
Attachments
I do not believe it can be modelled yet.
Martin has stated that it is not currently on his "to do" list.
He does say, however, that it can be done (see here) ...
http://www.diyaudio.com/forums/showthread.php?postid=879165#post879165
Any ideas / suggestions?
Martin has stated that it is not currently on his "to do" list.
He does say, however, that it can be done (see here) ...
http://www.diyaudio.com/forums/showthread.php?postid=879165#post879165
Any ideas / suggestions?
I do believe BOXCAD can model this type of enclosure.
At least three forum members have BOXCAD...
Any takers?
At least three forum members have BOXCAD...
Any takers?
There's some talk about the tapped horns over at AA hi-eff board
http://www.audioasylum.com/forums/hug/messages/106681.html
Rob.
http://www.audioasylum.com/forums/hug/messages/106681.html
Rob.
I dunno!
I've not really been looking at this design - I saw your post about it and posted that I'd seen talk about it on AA.
I've just read the Tom.D white paper
http://www.danleysoundlabs.com/pdf/danley_tapped.pdf
And it's very interesting. However I use a a pair of labhorns in my room, so don't need to be looking at smaller horns. Would be up for building a prototype for fun...
Rob
I've not really been looking at this design - I saw your post about it and posted that I'd seen talk about it on AA.
I've just read the Tom.D white paper
http://www.danleysoundlabs.com/pdf/danley_tapped.pdf
And it's very interesting. However I use a a pair of labhorns in my room, so don't need to be looking at smaller horns. Would be up for building a prototype for fun...
Rob
Yes, I know.
I have been following your progress with great interest.
This design is by the same guy as your lab-horns (as you well know), but is allegedly the next generation.
According to his marketing blurps (a direct quote from his website)....
"The Tower of Power is simply the most powerful, lowest frequency reproducing subwoofer on the planet"
Hey, I know he is highly regarded on this forum.
Therefore the question begs -- "why is there so little interest in this major new tapped-horn technology?
Is it because the patent is still pending?
I have been following your progress with great interest.
This design is by the same guy as your lab-horns (as you well know), but is allegedly the next generation.
According to his marketing blurps (a direct quote from his website)....
"The Tower of Power is simply the most powerful, lowest frequency reproducing subwoofer on the planet"
Hey, I know he is highly regarded on this forum.
Therefore the question begs -- "why is there so little interest in this major new tapped-horn technology?
Is it because the patent is still pending?
Re -reading the white paper it looks like the tap is working at the higher freq's.
It looks like the horn in the white paper is approx 1/4wl 38Hz horn. the back of the driver will be driving the horn from near the mouth, and drives it at the point where it's 1/2 wl from the throat. Putting the back of the driver near the mouth, say 180cm from the throat will mean the tap will be working at around 95Hz.
This makes sense as the paper says you can drive a 1/4 length horn with a suitable driver, but it won't work at the higher freq's as its not a 'conventional' horn driver. Looks like the tap makes the driver appear more like a conventional one at the higher freqs.
Rob.
It looks like the horn in the white paper is approx 1/4wl 38Hz horn. the back of the driver will be driving the horn from near the mouth, and drives it at the point where it's 1/2 wl from the throat. Putting the back of the driver near the mouth, say 180cm from the throat will mean the tap will be working at around 95Hz.
This makes sense as the paper says you can drive a 1/4 length horn with a suitable driver, but it won't work at the higher freq's as its not a 'conventional' horn driver. Looks like the tap makes the driver appear more like a conventional one at the higher freqs.
Rob.
Clearly the white paper is not referring to the Tower of Power.
The TOP has a tuning 18hz (16hz - 150hz, +/- 3db)
The outer dimensions of the TOP are 88" x 20" x 18"
For that tuning and those dimensions, it has to be a single-fold pipe.
The driver is in the middle (well, the access panel is)
The line is tapered (Mark Seaton mentions this in an email).
The mouth is "undersized" (mass-loaded)...
The TOP has a tuning 18hz (16hz - 150hz, +/- 3db)
The outer dimensions of the TOP are 88" x 20" x 18"
For that tuning and those dimensions, it has to be a single-fold pipe.
The driver is in the middle (well, the access panel is)
The line is tapered (Mark Seaton mentions this in an email).
The mouth is "undersized" (mass-loaded)...
Attachments
Clearly you are correct😱
My mistake - was following the link from the other site, and assumed the t-o-p was a tapped horn.
sorry!
Rob.
My mistake - was following the link from the other site, and assumed the t-o-p was a tapped horn.
sorry!
Rob.
Hold on there, big fella!
The Tower of Power IS a tapped-horn (Tom has many configurations).
This one just happens to be an MLTQWP utilizing the tapped horn technology.
That is to say, I think it is
The Tower of Power IS a tapped-horn (Tom has many configurations).
This one just happens to be an MLTQWP utilizing the tapped horn technology.
That is to say, I think it is
I don't know MJKs new sheets, but I'm wondering if this could be modelled as a straight MLTQW with two offset drivers, (the second pretending to be the back of the first). This assumption rests on two guesses; a) you can just use the SPL from the port, and ignore the direct radiation, and b) you can change the phase of one of the drivers.
Does that make sense?
Does that make sense?
qi said:
Greets!
OK, then why don't you just build a proof-of-concept (POC) with whatever driver you have laying around instead of asking other's opinion of yours?
Even if the patent was available for it, how many folks do you figure can/will tolerate such a huge pipe and if the driver is indeed special, will he sell it to just anybody and/or divulge what makes it special?
GM
One of the purposes of this forum is to ask others their opinion and to get feedback on questions you have.
It certainly makes sense to me (but that probably is a BAD thing) 
MJK has stated that none of his worksheets will properly model the tapped horn design.
(other no-nos include the acoustic cannon, and the transflex design)
One might argue that this is a 6th order series bandpass design.
1. The 1st half of the pipe is the 1st chamber.
2. The fold is the "port" -- exiting to the 2d chamber.
3. The 2d chamber (the 2d half of the pipe) then ports to the world.
Yeah, I know, its a reach, but I think MJK's double bass worksheet can model this design...
MJK has stated that none of his worksheets will properly model the tapped horn design.
(other no-nos include the acoustic cannon, and the transflex design)
One might argue that this is a 6th order series bandpass design.
1. The 1st half of the pipe is the 1st chamber.
2. The fold is the "port" -- exiting to the 2d chamber.
3. The 2d chamber (the 2d half of the pipe) then ports to the world.
Yeah, I know, its a reach, but I think MJK's double bass worksheet can model this design...
Greets!
Rob, methinks you 'caved' too easily! 😉 One of the refreshing things I've found in reading TD's explanations is that I've never been able to find fault with them based on my understanding of pipe/horn design. I mean he gives you all the info you need to duplicate his designs in essence (if not detail due to any special drivers used); specs, accurate measurements, and a description of operation with no real misdirection. Not to mention he has other patents that gives you some insight into how he arrived at his, or any other's, 'latest n' greatest' 'invention'. Basically, he 'hides' it in plain sight, with no marketing BS.
WRT MJK's WS, it can only predict trends in the basic concept AFAIK, but no clue as to whether they are close enough beyond first approximations. Then again, when I plug some approximate numbers in and calc the driver positions, I get something that's certainly 'in the ballpark' once everything's factored in, so as always YMMV.
GM
Rob, methinks you 'caved' too easily! 😉 One of the refreshing things I've found in reading TD's explanations is that I've never been able to find fault with them based on my understanding of pipe/horn design. I mean he gives you all the info you need to duplicate his designs in essence (if not detail due to any special drivers used); specs, accurate measurements, and a description of operation with no real misdirection. Not to mention he has other patents that gives you some insight into how he arrived at his, or any other's, 'latest n' greatest' 'invention'. Basically, he 'hides' it in plain sight, with no marketing BS.
WRT MJK's WS, it can only predict trends in the basic concept AFAIK, but no clue as to whether they are close enough beyond first approximations. Then again, when I plug some approximate numbers in and calc the driver positions, I get something that's certainly 'in the ballpark' once everything's factored in, so as always YMMV.
GM
qi said:Hold on there, big fella!
The Tower of Power IS a tapped-horn (Tom has many configurations).
This one just happens to be an MLTQWP utilizing the tapped horn technology.
That is to say, I think it is
It looks like a transmission line to me, and I've never looked into them. Just about getting my head round basic horn theory at the moment.
Rob.
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