I have built myself some voigt pipes using the lowther club of norway dimensions.
I was intending to purchase fostex fe206e drivers for these, but have since heard good things about the Tang Band W4-1320SB.
Would this driver suit the voigt pipes? i have heard it is smoother sounding than the fostex.
If so, what BSC would be required?
Cheers guys.
I was intending to purchase fostex fe206e drivers for these, but have since heard good things about the Tang Band W4-1320SB.
Would this driver suit the voigt pipes? i have heard it is smoother sounding than the fostex.
If so, what BSC would be required?
Cheers guys.
As no-one else has stepped forward...
Short answer -no. OK, that's not much help is it, so I'll try to give a longer one. I feel a little awkward pointing this out, as you've already built the cabinets, with all the time, money and effort that goes into this sort of thing, but I think you might be taking the wrong approach here.
Remember, an enclosure is designed for a specific driver (or it should be), and it's rare that another can be shoe-horned in to good effect. Still, you've got them now, and it'd be a crying shame to waste them. Now for the good news: The Lowther Club of Norway Voigt Pipe is in my view rotten for the drivers it was intended for -specifically, the Lowther PM6C. I've simulated it in Martin's MathCad software, and the results aren't at all pretty. In fact, they're dreadful. Oddly though, the FE206E suits it better, as does the FE207E for that matter. I haven't simulated it with the Tang Band, but for what it's worth, the T/S parameters look good, they seem a pleasant, mid Q device, and they are supposed to be pretty nice drivers to listen to all round, but in my opinion they are too small, and will be lost in these enclosures -boom would be an issue. Better to use 2 per cabinet if you went down that road. Personally, I'd go for either one of the aforementioned Fostex drivers.
Different people will tell you different things here. Some say that the 206, with its low Q is unsuitable for TQWT loading, as it will have a rising response, and that the higher Q 207 is the better choice. Well, it's probably a more natural option, but you can use the 206 too -you just listen slightly off axis, which negates the rise in the response curve, and use an amp or speaker cable that controls the driver better -narrow gauge is the key here: a run of 24AWG magnet wire is where I'd start, and you can always add some additional series resistance if you still find things a bit hot. The larger magnet of the 206 provides a whisker better detail than the 207 -your call.
This cabinet has a few general issues that you might want to address, so, this is Scott's infamous quick and dirty rescue job for the LCON Voigt Pipe cabinet design.
1) The top at present comes to a point, which makes it an So=0 pipe (So is the area of the top or closed end of a TQWT). This, except in very specific conditions is Not A Good Thing. It means the pipes will cut off higher than they need to, and will also give a fair bit of ripple in the frequency response. You can ease the latter a bit by using plenty of stuffing, but that isn't the best option -the stuffing should only be there to damp higher harmonics a bit. So, a suggestion: cut yourself 2 pieces of MDF that's 1" x 8 3/4" (or 2.5cm x 22cm if you prefer the metric version), and ram one up each pipe, so that it jams there. This will increase the internal area of the pipe, which the driver will thank you for. The driver will not be optimally positioned, but it's the lesser of two evils. Ripple should be substantially reduced. The line length will probably end up being around 61", give or take.
2) Mass-load it by reducing the area of the vent. This shouldn't be too difficult to achieve aesthetically. I suspect something like a 4" wide port would be best using the Fostex drivers, or you could try an oval shape like Terry Cain's done with his Abby -that's about 6 1/4" wide x 3" tall, give or take, though those use a smaller driver. Avoid a square or rectilinear opening if possible, and position it a few inches up from the base -this will reduce ripple in the mid-bass still further.
3) Stuff from the (new) internal top of the line to just below the driver fairly lightly, and then add another 1/4 lb in the base of each, which should again go some way to damping things nicely. Might not be necessary in your room -try and see is the best policy here.
4) I mentioned this above -24AWG magnet wire as internal cable at least, and possibly as speaker cable too -nice and cheap, and works well in my experience.
Note -all of these changes are completely reversible, and cost almost nothing, so if you didn't like them, you've lost very little.
BSC is another issue -try the above first, then go to www.quarter-wave.com and look at the variable circuit Martin has designed, along with the other articles.
Hope some of this helps & good luck with the project
Regards
Scott
Short answer -no. OK, that's not much help is it, so I'll try to give a longer one. I feel a little awkward pointing this out, as you've already built the cabinets, with all the time, money and effort that goes into this sort of thing, but I think you might be taking the wrong approach here.
Remember, an enclosure is designed for a specific driver (or it should be), and it's rare that another can be shoe-horned in to good effect. Still, you've got them now, and it'd be a crying shame to waste them. Now for the good news: The Lowther Club of Norway Voigt Pipe is in my view rotten for the drivers it was intended for -specifically, the Lowther PM6C. I've simulated it in Martin's MathCad software, and the results aren't at all pretty. In fact, they're dreadful. Oddly though, the FE206E suits it better, as does the FE207E for that matter. I haven't simulated it with the Tang Band, but for what it's worth, the T/S parameters look good, they seem a pleasant, mid Q device, and they are supposed to be pretty nice drivers to listen to all round, but in my opinion they are too small, and will be lost in these enclosures -boom would be an issue. Better to use 2 per cabinet if you went down that road. Personally, I'd go for either one of the aforementioned Fostex drivers.
Different people will tell you different things here. Some say that the 206, with its low Q is unsuitable for TQWT loading, as it will have a rising response, and that the higher Q 207 is the better choice. Well, it's probably a more natural option, but you can use the 206 too -you just listen slightly off axis, which negates the rise in the response curve, and use an amp or speaker cable that controls the driver better -narrow gauge is the key here: a run of 24AWG magnet wire is where I'd start, and you can always add some additional series resistance if you still find things a bit hot. The larger magnet of the 206 provides a whisker better detail than the 207 -your call.
This cabinet has a few general issues that you might want to address, so, this is Scott's infamous quick and dirty rescue job for the LCON Voigt Pipe cabinet design.
1) The top at present comes to a point, which makes it an So=0 pipe (So is the area of the top or closed end of a TQWT). This, except in very specific conditions is Not A Good Thing. It means the pipes will cut off higher than they need to, and will also give a fair bit of ripple in the frequency response. You can ease the latter a bit by using plenty of stuffing, but that isn't the best option -the stuffing should only be there to damp higher harmonics a bit. So, a suggestion: cut yourself 2 pieces of MDF that's 1" x 8 3/4" (or 2.5cm x 22cm if you prefer the metric version), and ram one up each pipe, so that it jams there. This will increase the internal area of the pipe, which the driver will thank you for. The driver will not be optimally positioned, but it's the lesser of two evils. Ripple should be substantially reduced. The line length will probably end up being around 61", give or take.
2) Mass-load it by reducing the area of the vent. This shouldn't be too difficult to achieve aesthetically. I suspect something like a 4" wide port would be best using the Fostex drivers, or you could try an oval shape like Terry Cain's done with his Abby -that's about 6 1/4" wide x 3" tall, give or take, though those use a smaller driver. Avoid a square or rectilinear opening if possible, and position it a few inches up from the base -this will reduce ripple in the mid-bass still further.
3) Stuff from the (new) internal top of the line to just below the driver fairly lightly, and then add another 1/4 lb in the base of each, which should again go some way to damping things nicely. Might not be necessary in your room -try and see is the best policy here.
4) I mentioned this above -24AWG magnet wire as internal cable at least, and possibly as speaker cable too -nice and cheap, and works well in my experience.
Note -all of these changes are completely reversible, and cost almost nothing, so if you didn't like them, you've lost very little.
BSC is another issue -try the above first, then go to www.quarter-wave.com and look at the variable circuit Martin has designed, along with the other articles.
Hope some of this helps & good luck with the project
Regards
Scott
Since I wrote the above, I've been playing around with So=0 pipes, since recieving a little gentle re-education from GM, so some of my views are now revised. So=0 is a bit of a pain to get working right compared to trunkated versions, but it also does provide some benefits: you simply have to design it right from the offset to take advantage of these and avoid the pitfalls. So I'd leave the throat-choke idea for the moment, and look at something else.
You see, in the case of the Lowther Club of Norway Voigt Pipe, contrary to popular myth, it's not actually the So=0 that's the major problem so much as the lack of cabinet volume and a vent area that's far too large to do anything productive. As your pipes are already built, increasing the cabinet volume is out, but you can mass load them properly by reducing the vent area. Blank off the original vent -a nice piece of MDF, painted satin black, or a piece of ply, oiled and stained would do the trick, and look pretty good too. Then use a circular port in that, 3in diameter x 3in long (if you let me know what drivers you're using, I can tell you specifically what port dimensions will give your pipes the best response). On average, you'll get another 20Hz of bass, and completely kill the worst of the ripple. Efficiency drops a bit to 'only' ~92db with the FE206E for example, but better that than 20db holes all over the shop. And no -that doesn't turn it into a bass reflex box!
If you want to try the throat choke (though if you mass-load them properly you won't need it), then just get some normal 3/4in material, and cut a strip 1in deep x 8 3/4in wide. Then ram them up the throat until they jam there. But try the mass-loading first. It'll make much more of a difference.
Hope this helps a bit
Scott
You see, in the case of the Lowther Club of Norway Voigt Pipe, contrary to popular myth, it's not actually the So=0 that's the major problem so much as the lack of cabinet volume and a vent area that's far too large to do anything productive. As your pipes are already built, increasing the cabinet volume is out, but you can mass load them properly by reducing the vent area. Blank off the original vent -a nice piece of MDF, painted satin black, or a piece of ply, oiled and stained would do the trick, and look pretty good too. Then use a circular port in that, 3in diameter x 3in long (if you let me know what drivers you're using, I can tell you specifically what port dimensions will give your pipes the best response). On average, you'll get another 20Hz of bass, and completely kill the worst of the ripple. Efficiency drops a bit to 'only' ~92db with the FE206E for example, but better that than 20db holes all over the shop. And no -that doesn't turn it into a bass reflex box!
If you want to try the throat choke (though if you mass-load them properly you won't need it), then just get some normal 3/4in material, and cut a strip 1in deep x 8 3/4in wide. Then ram them up the throat until they jam there. But try the mass-loading first. It'll make much more of a difference.
Hope this helps a bit
Scott
hi scott
thanks for your reply. the pipes i built have a 6-inch fr phillips car stereo speakers with specs close to the rat shack ones that others have used. i am planning to build another pair using bob brines' specs for a fostex206 -- in my case the decware modded ones - just waiting to for them to arrive. meanwhile i want to experiment with the one i hv to see how best i can prepare to build the new set. plywood or mdf? stuffing? even the braces for the speakers? . . . to see what works.
i think yr previous recommendation in another thread for a 2-inch by 4 inch port 4 inches from the base after closing off the rectangle port would suit the spkrs i hv currently.
fyi i have the klipsch la scalas and i am impressed with the voigt/cheapo car spkrs -- certain of its strengths, i like.
cheers
peter
thanks for your reply. the pipes i built have a 6-inch fr phillips car stereo speakers with specs close to the rat shack ones that others have used. i am planning to build another pair using bob brines' specs for a fostex206 -- in my case the decware modded ones - just waiting to for them to arrive. meanwhile i want to experiment with the one i hv to see how best i can prepare to build the new set. plywood or mdf? stuffing? even the braces for the speakers? . . . to see what works.
i think yr previous recommendation in another thread for a 2-inch by 4 inch port 4 inches from the base after closing off the rectangle port would suit the spkrs i hv currently.
fyi i have the klipsch la scalas and i am impressed with the voigt/cheapo car spkrs -- certain of its strengths, i like.
cheers
peter
Lowther PM6C in Voigt QW
Dear Scottmoose
Interested in your comments about the LCON Voigt design for the PM6C....I am considering building a set of QW pipes for a solar powered house we at the University of Illinois are building for a national competition in Washington DC. Lowther USA kindly donated a pair of drive units and the Voigt design is attractive because of its energy efficiency. We would be using these for a home theatre set-up which is part of the competition brief and could only fit in the QWs if we built a configuration rather like a mantel shelve which goes around the TV with the drivers in the upper corners and the ports at the bottom of the vertical legs. sounds weird but it is possible with this 90 degree bend to get almost 1800mm of pipe for each driver. We do not have extensive time for testing so any advice on getting it close to right first time would be helpful. As I am a displaced Brit, if this works out it will be a wholly British effort.
Dear Scottmoose
Interested in your comments about the LCON Voigt design for the PM6C....I am considering building a set of QW pipes for a solar powered house we at the University of Illinois are building for a national competition in Washington DC. Lowther USA kindly donated a pair of drive units and the Voigt design is attractive because of its energy efficiency. We would be using these for a home theatre set-up which is part of the competition brief and could only fit in the QWs if we built a configuration rather like a mantel shelve which goes around the TV with the drivers in the upper corners and the ports at the bottom of the vertical legs. sounds weird but it is possible with this 90 degree bend to get almost 1800mm of pipe for each driver. We do not have extensive time for testing so any advice on getting it close to right first time would be helpful. As I am a displaced Brit, if this works out it will be a wholly British effort.
https://mywebspace.wisc.edu/jstalnak/web/VoightPipeSpeakers/Dan Dicker DIY45vpipe.jpg
I like the classic look of the VP with an 8" Fostex. Based on what i've read i'd buy the 207e because i can use it in a simple ported box if i choose or even a BIB.
Enjoy,
Godzilla
I like the classic look of the VP with an 8" Fostex. Based on what i've read i'd buy the 207e because i can use it in a simple ported box if i choose or even a BIB.
Enjoy,
Godzilla
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