Ron, Thanks for repeating what I just said above..."I do not have extensive experience with those designs..." All I can reiterate is what I've read on Internet websites and Internet articles. What point are you trying to make? I think my statement above qualifies in stating that I've never built transmission line speakers but have read some articles and have a general idea what they're trying to do. Unless you have something to add to my deficiencies in knowledge rather than criticizing my posts your becoming tiresome.
"I've built my own QWTL design, updated from Joseph D'Appolito's original design, with help from an Electronic Acoustic Engineer who designs radar used in Submarines, he understands "special mathematical formulas"
I'm happy for you but what does that do for me? I don't need to become an expert on QWTL to listen to others who have experience with those designs. I have no Desire to become an expert there because unless your building a straight tl pipe or voight triangle pipe the cost and complexity are not something I'm interested in.
"The Voigt pipe is a type of loudspeaker enclosure that embodies a combination of transmission line, ported enclosure and horn characteristics. It is highly regarded by some speaker designers, as evidenced by established manufacturers such as Castle. Due to its relatively high efficiency the design is frequently employed in full-range loudspeaker designs. The concept is that the sound emitted from the rear of the loudspeaker driver is progressively reflected and absorbed along the length of the tapering tube, almost completely preventing internally reflected sound being retransmitted through the cone of the loudspeaker. The lower part of the pipe acts as a horn while the top can be visualized as an extended compression chamber. The entire pipe can also be seen as a tapered transmission line in inverted form, that is, widening rather than narrowing from top to bottom. The driver is usually positioned close to the middle of the baffle or slightly lower. Its relatively low adoption in commercial speakers can mostly be attributed to the large resulting dimensions of the speaker produced and the expense of manufacturing a rigid tapering tube. The Voigt pipe was designed in 1934 by Paul G. A. H. Voigt and is also referred to as a tapered quarter-wave pipe (TQWP) or tapered quarter-wave tube (TQWT)."
"Transmission Line (TL)
has either no taper, or is largest at the closed end and tapers down to the vent. The TL normally has the driver very close to the closed end. There may be an expansion chamber immediately behind the driver. The term transmission line comes from electronics where the ideal transmission line does not reflect power back into the source. To make a TL a true transmission line, it must be stuffed sufficiently to completely damp any output from the vent.
Mass-Loaded Transmission Line (MLTL)
is a term coined by Martin King that applies to a TL terminated by a port that is smaller in area than the area of the pipe at the termination.
Tapered Quarter-Wave Tube (TQWT)
is the reverse of a tapered transmission line, that is, it is smallest at the closed end tapering up to the open end. The driver is normally set about half way down the tube. The TQWT may also comes in a mass-loaded variety, the ML-TQWT. As with the MLTL, the port area is smaller than the pipe area at the termination.
Voigt Pipe
is a TQWT that comes to a point at the closed end. It is interesting that this configuration should be called a Voigt pipe, since it appears that Voigt himself did not advocate it. This configuration can have some very bad characteristics that require careful consideration. The most common implementation is the Lowther Club of Norway TQWT, which, unfortunately, is not the best of designs."
"I've built my own QWTL design, updated from Joseph D'Appolito's original design, with help from an Electronic Acoustic Engineer who designs radar used in Submarines, he understands "special mathematical formulas"
I'm happy for you but what does that do for me? I don't need to become an expert on QWTL to listen to others who have experience with those designs. I have no Desire to become an expert there because unless your building a straight tl pipe or voight triangle pipe the cost and complexity are not something I'm interested in.
"The Voigt pipe is a type of loudspeaker enclosure that embodies a combination of transmission line, ported enclosure and horn characteristics. It is highly regarded by some speaker designers, as evidenced by established manufacturers such as Castle. Due to its relatively high efficiency the design is frequently employed in full-range loudspeaker designs. The concept is that the sound emitted from the rear of the loudspeaker driver is progressively reflected and absorbed along the length of the tapering tube, almost completely preventing internally reflected sound being retransmitted through the cone of the loudspeaker. The lower part of the pipe acts as a horn while the top can be visualized as an extended compression chamber. The entire pipe can also be seen as a tapered transmission line in inverted form, that is, widening rather than narrowing from top to bottom. The driver is usually positioned close to the middle of the baffle or slightly lower. Its relatively low adoption in commercial speakers can mostly be attributed to the large resulting dimensions of the speaker produced and the expense of manufacturing a rigid tapering tube. The Voigt pipe was designed in 1934 by Paul G. A. H. Voigt and is also referred to as a tapered quarter-wave pipe (TQWP) or tapered quarter-wave tube (TQWT)."
"Transmission Line (TL)
has either no taper, or is largest at the closed end and tapers down to the vent. The TL normally has the driver very close to the closed end. There may be an expansion chamber immediately behind the driver. The term transmission line comes from electronics where the ideal transmission line does not reflect power back into the source. To make a TL a true transmission line, it must be stuffed sufficiently to completely damp any output from the vent.
Mass-Loaded Transmission Line (MLTL)
is a term coined by Martin King that applies to a TL terminated by a port that is smaller in area than the area of the pipe at the termination.
Tapered Quarter-Wave Tube (TQWT)
is the reverse of a tapered transmission line, that is, it is smallest at the closed end tapering up to the open end. The driver is normally set about half way down the tube. The TQWT may also comes in a mass-loaded variety, the ML-TQWT. As with the MLTL, the port area is smaller than the pipe area at the termination.
Voigt Pipe
is a TQWT that comes to a point at the closed end. It is interesting that this configuration should be called a Voigt pipe, since it appears that Voigt himself did not advocate it. This configuration can have some very bad characteristics that require careful consideration. The most common implementation is the Lowther Club of Norway TQWT, which, unfortunately, is not the best of designs."
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