Don't get any on your leg :^)
I get from this that you have the impression that a TL is only for generating low bass.
If the 3" is the only driver in our system we would still like to get the best, lowest distortion extension we can out of it, but i feel the following 2 points are of even more imporatance:
One of the most important aspects of a well done TL is that it "sucks" the output of the back of the driver down the and disipates it (except, ideally, for the fundemental) so that it does not reappear as a time-smeared output back thru the cone. This, for instance, is why all 4 drivers in the B&W Nautilus (and propagated thru-out the entire product line to some extent) are TL loaded. There are a number of other examples.
The other is to flatten out the systems impedance curve as much as possible. An amazingly flat (magnitude & phase) can be achieved with a TL.
dave
SteveG said:
I get from this that you have the impression that a TL is only for generating low bass.
If the 3" is the only driver in our system we would still like to get the best, lowest distortion extension we can out of it, but i feel the following 2 points are of even more imporatance:
One of the most important aspects of a well done TL is that it "sucks" the output of the back of the driver down the and disipates it (except, ideally, for the fundemental) so that it does not reappear as a time-smeared output back thru the cone. This, for instance, is why all 4 drivers in the B&W Nautilus (and propagated thru-out the entire product line to some extent) are TL loaded. There are a number of other examples.
The other is to flatten out the systems impedance curve as much as possible. An amazingly flat (magnitude & phase) can be achieved with a TL.
dave
Planet 10 has a cool web site. He is right, the black stuff is ABS not PVC. It is cheaper and lighter I think, but seeems pretty well damped.
The way he tapers the transmissionline with a tapered 2x4 is pretty darned clever.
The magnet could indeed block a 3" pipe excessively.
For more traditional speakers like D'apollito configuration
the 6" PVC might work better. A 5.25 speaker like they often use would fit right in the end I think. Make a baffle out of MDF, cut 2 holes the diameter of the outside of 6" PVC, and glue the pipes in. screw the frames into the MDF. (better to make a recess in the baffle for the frames)
just cut a hole for the tweeter in the baffle. and leave the back exposed.
The baffle extends to the floor and a base. The pipe goes straight back or turns 90 degrees and heads for the floor, vented somewhere in there for a vented or trans line configurations.
Best idea would be to copy a good existing speaker design geometry and drivers.
Line the pipes in Bitumin if you need more damping of the walls
Waddayou thnk?
Mark
The way he tapers the transmissionline with a tapered 2x4 is pretty darned clever.
The magnet could indeed block a 3" pipe excessively.
For more traditional speakers like D'apollito configuration
the 6" PVC might work better. A 5.25 speaker like they often use would fit right in the end I think. Make a baffle out of MDF, cut 2 holes the diameter of the outside of 6" PVC, and glue the pipes in. screw the frames into the MDF. (better to make a recess in the baffle for the frames)
just cut a hole for the tweeter in the baffle. and leave the back exposed.
The baffle extends to the floor and a base. The pipe goes straight back or turns 90 degrees and heads for the floor, vented somewhere in there for a vented or trans line configurations.
Best idea would be to copy a good existing speaker design geometry and drivers.
Line the pipes in Bitumin if you need more damping of the walls
Waddayou thnk?
Mark
Sorry for being a realist! There's no way in heck that you will be able to get decent bass response out of these drivers! It's just not in them to do it. You also have to consider that a transmission line tends to have the same effect on a driver as a sealed box- the driver is required to have good excursion. If you're going to play with $7 drivers, why not look at what they're good at and find a suitable design. I think a mini array would be cool- by that I mean 4 or 8 drivers together, maybe with a tweeter, maybe not. My thoughts were of building a small surround system for my home theater- 4 drivers per speaker, with the surrounds being a dipole type.
Alright, I have spoken my last on this. I'll let you guys have fun. I'll quit damping your enthusiasm. You gotta know that it wasn't my intention to do that. I just think that there are compromises in any design,and you have to work within the capabilities of your hardware. In my OPINION, TL's are totally unsuitable, and line arrays will have comb effect problems unless crossed to a tweeter. Still, as the point has been made, why not experiment with a $7 driver. I'll be watching to see what happens, but I have spoken my last.
Alright, I have spoken my last on this. I'll let you guys have fun. I'll quit damping your enthusiasm. You gotta know that it wasn't my intention to do that. I just think that there are compromises in any design,and you have to work within the capabilities of your hardware. In my OPINION, TL's are totally unsuitable, and line arrays will have comb effect problems unless crossed to a tweeter. Still, as the point has been made, why not experiment with a $7 driver. I'll be watching to see what happens, but I have spoken my last.
Point taken
Steve, to tell you the truth my enthusiasm hasnt been influenced at all.
I figure if the TL PVC doesnt workout I can always reassemble it into an ht setup using sections of the PVC, I was thinking 3 per front 2 per a back and 3 for the middle. housing each driver in a seperate little PVC unit you can easily experiment with steped baffling, and you can also add or subtract to the number of drivers, once again the legos concept comes to mind.
Sort of a cool idea for a speaker company where you sell tweeter midrange and bass ranges in seperate units that can be snapped together, so you can add and subtract to your taste, or even upgrade to a better, say, tweeter if you feel so inclined.
I figure if the TL PVC doesnt workout I can always reassemble it into an ht setup using sections of the PVC, I was thinking 3 per front 2 per a back and 3 for the middle. housing each driver in a seperate little PVC unit you can easily experiment with steped baffling, and you can also add or subtract to the number of drivers, once again the legos concept comes to mind.
Sort of a cool idea for a speaker company where you sell tweeter midrange and bass ranges in seperate units that can be snapped together, so you can add and subtract to your taste, or even upgrade to a better, say, tweeter if you feel so inclined.
Since this thread was started with the idea of a full range driver,
that has been mixed in with the PVC ideas. I think it is important
to realize that they are 2 different ideas.
As St=Z points out, one could use the pipe idea to make modules
with midranges, bass drivers-what have you.
The pipe fittings (connectors) might be better to use for some drivers because they are larger diameter and address the crearance aroud the magnet.
For my modules I envision a straight connetor fitting with a driver
installed on one end, terminals bolted through the walls on the side, the back open to be connected to various torture devices-trans line, vented etc.
The fittings are expensive though. Another idea is to use bigger pipe, say 4", put a flat cap on the end, and cut a hole in the cap
for the driver. I know this takes away from the purity of the concept but would work better I think because then you have a place to bolt the flanges, the magnet has clearance, the volume is also probably more like what we need. 4" discs of wood could be glued into the end of pipet o accomplish the same-I'm off to look for 4" discs at the home depot.
Now-how are we going to make HORNS out of pipe?
that has been mixed in with the PVC ideas. I think it is important
to realize that they are 2 different ideas.
As St=Z points out, one could use the pipe idea to make modules
with midranges, bass drivers-what have you.
The pipe fittings (connectors) might be better to use for some drivers because they are larger diameter and address the crearance aroud the magnet.
For my modules I envision a straight connetor fitting with a driver
installed on one end, terminals bolted through the walls on the side, the back open to be connected to various torture devices-trans line, vented etc.
The fittings are expensive though. Another idea is to use bigger pipe, say 4", put a flat cap on the end, and cut a hole in the cap
for the driver. I know this takes away from the purity of the concept but would work better I think because then you have a place to bolt the flanges, the magnet has clearance, the volume is also probably more like what we need. 4" discs of wood could be glued into the end of pipet o accomplish the same-I'm off to look for 4" discs at the home depot.
Now-how are we going to make HORNS out of pipe?
We certainly agree with SteveG's two cents worth. That's why we a going to try something a little different.
BTW, a new distributor/seller for Tangband is in Canada at:
www.nuera-acoustic.ca
We are going to tinker with a CURVED 15 driver vertical array of the Tangband w3-593s ($11 ea. + assorted Canadian taxes and shipping in 100 lots) using a SINGLE tweeter in the center crossed over at about 3K, first order. Efficiency in the mid-band will be about 100db (2.83v in) and power handling of about 225watts continuous.
This arrary(s) will be used in a tri-amplified system with a low frequency crossover point of about 110Hz. Low pass will be fourth order and high pass second order. The second order high pass will mate with the second order high pass of the enclosed array giving a fourth order high pass. There will be about 4db of shelving to compensate for roll-off due to the narrow enclosure. Bass will be handle by 4 12" woofers per channel.
We expect the following results:
A very small sweet spot (about 2") on 2 axes.
Very high resolution (only in the sweet spot).
Ability to play very loud with minimal thermal compression.
I will post the results if anyone is interested. And of course if anyone has comments or suggestions, please offer them.
BTW, a new distributor/seller for Tangband is in Canada at:
www.nuera-acoustic.ca
We are going to tinker with a CURVED 15 driver vertical array of the Tangband w3-593s ($11 ea. + assorted Canadian taxes and shipping in 100 lots) using a SINGLE tweeter in the center crossed over at about 3K, first order. Efficiency in the mid-band will be about 100db (2.83v in) and power handling of about 225watts continuous.
This arrary(s) will be used in a tri-amplified system with a low frequency crossover point of about 110Hz. Low pass will be fourth order and high pass second order. The second order high pass will mate with the second order high pass of the enclosed array giving a fourth order high pass. There will be about 4db of shelving to compensate for roll-off due to the narrow enclosure. Bass will be handle by 4 12" woofers per channel.
We expect the following results:
A very small sweet spot (about 2") on 2 axes.
Very high resolution (only in the sweet spot).
Ability to play very loud with minimal thermal compression.
I will post the results if anyone is interested. And of course if anyone has comments or suggestions, please offer them.
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