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#1
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building speakers
hello!
please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. thanks, hrvoje |
#2
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Also try your post at alt.audio.pro.live-sound
-bg- -- www.thelittlecanadaheadphoneband.ca www.lchb.ca "hrvoje" wrote in message ... hello! please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. thanks, hrvoje |
#3
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On Mon, 29 Nov 2004 23:14:12 +0100, hrvoje wrote:
hello! please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. thanks, hrvoje Look for books by David B Weems... he makes it simple... I have many enjoyable years of enclosures deisgned by him.. I built some in the 60s ... and still have them today. cheers the islander |
#4
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Subscribe to the DIY Speaker list.
To subscribe or unsubscribe via the World Wide Web, visit http://diyspeakers.net/mailman/listinfo/diyspeakers Ask away, and you'll more than likely find answer and leads. Best regards, John Hallliburton |
#5
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"islander" wrote ...
hrvoje wrote: please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. Look for books by David B Weems... he makes it simple... I have many enjoyable years of enclosures deisgned by him.. And more recently (in the Thiele-Small era) by Vance Dickason. I built some in the 60s ... and still have them today. I had my pair of Weems design boxes for many years. JBL LE-20 woofer, PR-20 passive radiator, and JBL dome tweeter and passover. Surrounds on the LE and PR-20 finally crumbled into dust. I had them re-coned, but they seem a lot stiffer than the originals. Might have to measure new T-S parameters and design a new box for them. Old box fell apart, too (cheap particle board). |
#6
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**bg** wrote: Also try your post at alt.audio.pro.live-sound For a *transmission line* design ! I don't think so. Graham |
#7
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I am interested in transmission line speakers.
Bad, bad idea unless you want to waste materials, time and money. I hope you mean that in terms of making mistakes (which is possible) rather than in terms of sound quality. Transmission lines tend to be overdamped. The result is tighter, more-detailed bass. "High Performance Loudspeakers" states that listeners usually prefer overdamped bass (which is also achievable in a sealed enclosure), even when the corner frequency is higher. Some years back, Bud Fried played his model O transmission line woofer for me at his home. It was the first time I'd heard a woofer whose transparency, detail, and lack of coloration were comparable to a good midrange driver. In theory, this should be achievable from a properly designed sealed box, assuming the Q is the same and the box is suitably rigid and dead. |
#8
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Actually, that is a good question. Why AREN'T the live-sound
guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. |
#9
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"hrvoje" wrote in message
please, is there any website having complete schematics for speaker enclosures building? Tons of them. Many are actually pretty good You might try searching for them with google. I am interested in transmission line speakers. Bad, bad idea unless you want to waste materials, time and money. |
#10
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In article ,
Richard Crowley wrote: "islander" wrote ... hrvoje wrote: please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. Look for books by David B Weems... he makes it simple... I have many enjoyable years of enclosures deisgned by him.. And more recently (in the Thiele-Small era) by Vance Dickason. I don't think either of these guys really address transmission-line designs very much, though. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#11
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Pooh Bear wrote:
**bg** wrote: Also try your post at alt.audio.pro.live-sound For a *transmission line* design ! I don't think so. Actually, that is a good question. Why AREN'T the live sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#12
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Transmission lines tend to be overdamped. The result is tighter,
more-detailed bass. "High Performance Loudspeakers" states that listeners usually prefer overdamped bass (which is also achievable in a sealed enclosure), even when the corner frequency is higher. That's all fine and good, particularly if its true. But, you don't have to waste time, materials, and valuable space in the listening room to do a TL, if you want an overdamped speaker. Agreed. The question is, does a sealed-box overdamped woofer sound the same as a transmission line? I don't know the answer. |
#13
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Actually, that is a good question. Why AREN'T the live-sound
guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. I thought the big deal was that the cabinet with the folded path was comparatively much smaller than a huge sealed box with the same resonant frequency? I don't think so. Look at acoustic-suspension speakers, for example. |
#14
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"William Sommerwerck" wrote in message
I am interested in transmission line speakers. Bad, bad idea unless you want to waste materials, time and money. I hope you mean that in terms of making mistakes (which is possible) rather than in terms of sound quality. I'm speaking in an engineering sense, which I'm prone to do. Transmission lines tend to be overdamped. The result is tighter, more-detailed bass. "High Performance Loudspeakers" states that listeners usually prefer overdamped bass (which is also achievable in a sealed enclosure), even when the corner frequency is higher. That's all fine and good, particularly if its true. But, you don't have to waste time, materials, and valuable space in the listening room to do a TL, if you want an overdamped speaker. |
#15
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http://www.t-linespeakers.org/
It's a fascinating, and often frustrating, project. I'm also interested in building one; keep me posted. hrvoje wrote: hello! please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. thanks, hrvoje |
#16
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William Sommerwerck wrote:
Actually, that is a good question. Why AREN'T the live-sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. I thought the big deal was that the cabinet with the folded path was comparatively much smaller than a huge sealed box with the same resonant frequency? --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#17
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In article ,
William Sommerwerck wrote: Transmission lines tend to be overdamped. The result is tighter, more-detailed bass. "High Performance Loudspeakers" states that listeners usually prefer overdamped bass (which is also achievable in a sealed enclosure), even when the corner frequency is higher. That's all fine and good, particularly if its true. But, you don't have to waste time, materials, and valuable space in the listening room to do a TL, if you want an overdamped speaker. Agreed. The question is, does a sealed-box overdamped woofer sound the same as a transmission line? I don't know the answer. One of the interesting things about the transmission line sub is the degree of directionality in the radiation pattern. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#18
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"Scott Dorsey" wrote in message
William Sommerwerck wrote: Actually, that is a good question. Why AREN'T the live-sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. I thought the big deal was that the cabinet with the folded path was comparatively much smaller than a huge sealed box with the same resonant frequency? Not at all. TL's are kind of interesting because there is no formal definition of what they are. Depending on how you make them they can be thought of as being vented boxes with well-damped ports, or sealed boxes (i.e., a really small-diameter or very short or very long TL). Every analysis or experimental evaluation I've seen says that you can get at least the same or more bang for the box volume by just doing a sealed or vented box, and coming in through the front door as it were. |
#19
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"William Sommerwerck" wrote in message
Transmission lines tend to be overdamped. The result is tighter, more-detailed bass. "High Performance Loudspeakers" states that listeners usually prefer overdamped bass (which is also achievable in a sealed enclosure), even when the corner frequency is higher. That's all fine and good, particularly if its true. But, you don't have to waste time, materials, and valuable space in the listening room to do a TL, if you want an overdamped speaker. Agreed. The question is, does a sealed-box overdamped woofer sound the same as a transmission line? I don't know the answer. That hangs on the question of which actual transmision line you are speaking of. There are a lot of different things that are called TLs. |
#20
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One of the interesting things about the transmission line
sub is the degree of directionality in the radiation pattern. Bud has been saying that for decades. Do you have any references? |
#21
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Agreed. The question is, does a sealed-box overdamped woofer
sound the same as a transmission line? I don't know the answer. That hangs on the question of which actual transmision line you are speaking of. There are a lot of different things that are called TLs. I suppose "anything Bud designs" grin. Would that be a quarter-wave at the drivers fundamental resonance, heavily stuffed? Does anyone remember sulfur hexafluoride (as in William Michael Watson Dayton-Wright)? In principle, filling the line with sulfur hexafluoride would permit a significantly shorter line. (By the way, the Dayton-Wright sealed-box "Watson" woofers were among the best I ever heard.) |
#22
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TL's are kind of interesting because there is no formal definition
of what they are. Depending on how you make them they can be thought of as being vented boxes with well-damped ports, or sealed boxes (ie, a really small-diameter or very short or very long TL). Every analysis or experimental evaluation I've seen says that you can get at least the same or more bang for the box volume by just doing a sealed or vented box, and coming in through the front door as it were. That's true simply in terms of bass extension. It's not necessarily true in terms of sound quality. The raison d'etre of transmission lines is that they "sound better." Clearly, someone should do research comparing sealed boxes and transmission lines with the same (or similar) Qs, rolloffs, etc. |
#23
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I suppose "anything Bud designs" grin. Would that be
a quarter-wave at the drivers fundamental resonance, heavily stuffed? What is the cross-section of the tube? Roughly the size of the driver. Not much larger. Does anyone remember sulfur hexafluoride (as in William Michael Watson Dayton-Wright)? Yeah, their electrostats, right? Yes, and some fantastic cone woofers. They got a clean 16Hz that rattled everything in the room from a two-cubic-foot box. In principle, filling the line with sulfur hexafluoride would permit a significantly shorter line. I hear tell that heavy stuffing is an effective if less-exotic way to accomplish a similar end. It does, but the speed of sound in sulfur hexafluoride is significantly slower than it is in air, so combining the two... |
#24
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"Scott Dorsey" wrote in message
... William Sommerwerck wrote: Actually, that is a good question. Why AREN'T the live-sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. I thought the big deal was that the cabinet with the folded path was comparatively much smaller than a huge sealed box with the same resonant frequency? Well, sealed boxes don't really have a resonant frequency, other than standing waves if you're not careful. Speakers have resonant frequencies when mounted in closed boxes, inevitably higher than their free air resonance frequency. Transmission lines, in theory at least, have the same equivalent resonance frequency as the free air frequency, which would require (theoretically) an infinitely large closed box. So yes, you can get low bass from a transmission line with a smaller (smaller than infinite) box than a closed box. But typically a vented box is smaller still for an equivalent bass response, and easier to build, and lighter to carry. (Although less well-braced than a TL!) Peace, Paul |
#25
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"Scott Dorsey" wrote in message
... In article , Richard Crowley wrote: "islander" wrote ... hrvoje wrote: please, is there any website having complete schematics for speaker enclosures building? i am interested in transmission line speakers. Look for books by David B Weems... he makes it simple... I have many enjoyable years of enclosures deisgned by him.. And more recently (in the Thiele-Small era) by Vance Dickason. I don't think either of these guys really address transmission-line designs very much, though. I think Dickason does in his newer editions. Peace, Paul |
#26
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One of the interesting things about the transmission line
sub is the degree of directionality in the radiation pattern. Bud has been saying that for decades. Do you have any references? I will see what I can dig up. I think the point is that the vent is very far away from the main driver acoustically, and so there are all kinds of interference things going on between them. My suspicion is that this results in a pattern that changes wildly with frequency too, but I don't think I have actually seen measurements. Let me poke around in the file cabinet for a bit. One of the theories of TL design is that the rear wave marches down the line and disappears, with little or nothing coming out the opening. (I don't like calling it a port, because that implies a fourth-order transfer function.) But as Arny pointed out, TL design is not well-defined. |
#27
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"William Sommerwerck" wrote in message
Agreed. The question is, does a sealed-box overdamped woofer sound the same as a transmission line? I don't know the answer. That hangs on the question of which actual transmision line you are speaking of. There are a lot of different things that are called TLs. I suppose "anything Bud designs" grin. Would that be a quarter-wave at the drivers fundamental resonance, heavily stuffed? What is the cross-section of the tube? Does anyone remember sulfur hexafluoride (as in William Michael Watson Dayton-Wright)? Yeah, their electrostats, right? In principle, filling the line with sulfur hexafluoride would permit a significantly shorter line. I hear tell that heavy stuffing is a effective if less-exotic way to accomplish a similar end. (By the way, the Dayton-Wright sealed-box "Watson" woofers were among the best I ever heard.) No comment. |
#28
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On Tue, 30 Nov 2004 09:39:55 -0800, "William Sommerwerck"
wrote: That hangs on the question of which actual transmision line you are speaking of. There are a lot of different things that are called TLs. I suppose "anything Bud designs" grin. Would that be a quarter-wave at the drivers fundamental resonance, heavily stuffed? This brings up two factors not yet mentioned. The driver's fundamental resonance is affected by coupling to a considerable air mass in the line and by the line air's compliance, making the whole model messy. And, the stuffing reduces the speed of sound in the line, up to as much as a factor of three. For homebrewers, transmission lines have a great advantage. A perfectly good one can be made from a cardboard tube, like a concrete pouring form. No wood. Chris Hornbeck |
#29
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In article ,
William Sommerwerck wrote: One of the interesting things about the transmission line sub is the degree of directionality in the radiation pattern. Bud has been saying that for decades. Do you have any references? I will see what I can dig up. I think the point is that the vent is very far away from the main driver acoustically, and so there are all kinds of interference things going on between them. My suspicion is that this results in a pattern that changes wildly with frequency too, but I don't think I have actually seen measurements. Let me poke around in the file cabinet for a bit. I think you can get similar directionality with stacked subs, too, and that is a common technique in the PA world. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#30
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Scott Dorsey wrote:
Pooh Bear wrote: **bg** wrote: Also try your post at alt.audio.pro.live-sound For a *transmission line* design ! I don't think so. Actually, that is a good question. Why AREN'T the live sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Most live sound gear seems currently to be optimised for low weight and compactness. This design seems popular with some.... http://www.speakerplans.com/page182.html Graham |
#31
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Chris Hornbeck wrote:
For homebrewers, transmission lines have a great advantage. A perfectly good one can be made from a cardboard tube, like a concrete pouring form. No wood. You can do vented boxes this way too! Hsu Research does. I think Tannoy used to do this with some of their installed-sound speakers too. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#32
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William Sommerwerck wrote:
Actually, that is a good question. Why AREN'T the live-sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. Transmission lines generally require large or long cabinets. I'd prefer to say that actually "doing bass" at high efficiency requires a large cabinet, whatever the type. Squeeze the box smaller and the cost is there in terms o loss of efficiency, bandwith, increased distortion or "all of the above, but more boxes in the same size truck". Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#33
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Actually, that is a good question. Why AREN'T the live sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. They do, it's just a special type, called a horn. ;) Best regards, John |
#34
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John Halliburton wrote:
Actually, that is a good question. Why AREN'T the live sound guys using transmission line subs? It would seem like a good way to get much deeper bass, and with some proper vent design even some directionality, out of small bass cabinets. They do, it's just a special type, called a horn. ;) Okay, YOU can help me move the Altec X-1s next time. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#35
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That's true simply in terms of bass extension. It's not necessarily true in terms of sound quality. The raison d'etre of transmission lines is that they "sound better." Clearly, someone should do research comparing sealed boxes and transmission lines with the same (or similar) Qs, rolloffs, etc. The conclusions presented assume that each type of alignment/system is designed for optimum performance. In terms of quality, a horn still has the lowest distortion, the best(or nearly best) impulse response, and the best chance at reproducing a waveform as presented. There are phase response lags in direct radiator designs that are nearly impossible to correct, hence many of the sound characteristics we take for granted in multi bandwidth speaker systems. When you hear something like a fully horn loaded design, full range electrostatics, nearly full range ribbons, the sound can be so much more realistic. Best regards, John Halliburton |
#36
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Okay, YOU can help me move the Altec X-1s next time. --scott Ungghhhhh. JHH |
#37
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"John Halliburton" wrote in message
In terms of quality, a horn still has the lowest distortion, the best(or nearly best) impulse response, and the best chance at reproducing a waveform as presented. There are phase response lags in direct radiator designs that are nearly impossible to correct, hence many of the sound characteristics we take for granted in multi bandwidth speaker systems. You may have forgotten to mention a very important advantage - directivity control. But like so many lunches, none of the advantages come free of serious practical disadvantages in most environments (other than live sound). Even in live sound applications, the popularity of linear arrays suggests that many find that the advantages of waveguides (proper name for what some people call horns) are outweighed. When you hear something like a fully horn loaded design, full range electrostatics, nearly full range ribbons, the sound can be so much more realistic. Due to the directivity control issue, waveguides seem to stand alone. The number of commercial electrostats and ribbons that are capable of operating effectively in the 20-80 Hz range is vanishingly small. |
#38
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"Chris Hornbeck" wrote in message
On Tue, 30 Nov 2004 09:39:55 -0800, "William Sommerwerck" wrote: That hangs on the question of which actual transmision line you are speaking of. There are a lot of different things that are called TLs. I suppose "anything Bud designs" grin. Would that be a quarter-wave at the drivers fundamental resonance, heavily stuffed? This brings up two factors not yet mentioned. The driver's fundamental resonance is affected by coupling to a considerable air mass in the line and by the line air's compliance, making the whole model messy. The usually stated solution to that is to *properly* damp the line. And, the stuffing reduces the speed of sound in the line, up to as much as a factor of three. It also dissipates energy, resulting in negligable audio output from the end of the line, perhaps. For homebrewers, transmission lines have a great advantage. A perfectly good one can be made from a cardboard tube, like a concrete pouring form. No wood. Ditto for ported and unvented enclosures. Seen it done many times. |
#39
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"Scott Dorsey" wrote in message
Chris Hornbeck wrote: For homebrewers, transmission lines have a great advantage. A perfectly good one can be made from a cardboard tube, like a concrete pouring form. No wood. You can do vented boxes this way too! Hsu Research does. I think Tannoy used to do this with some of their installed-sound speakers too. Also, after-market automotive sound. |
#40
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If the line is intended to dissipate or absorb the rear radiation of the
driver it would seem that a good one is simply another form of infinite baffle. True, but I tend to see overdamping as a fundamental element of TL designs, which is not a part of infinite baffling. My personal subwoofer system uses multiple drivers in a basement loaded IB system. So when I open the basement door can I call it a Transmission Line? Only if you stuff the basement with damping material! |
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