If anyone is looking for a new 8in speaker project, you could do a heck of a lot worse than checking this out guys: http://www.vitalstates.co.uk/ -click on the vofo tab. Ed's a friend of mine & there's some really good stuff on his site. As well as this project there's a write-up of an Ariel, and an Electrostatic build, plus plans for an adjustable mitre-jig available on request etc.
These folded 206 pipes are by a long way the best traditional type TQWT I've ever heard. In-room Clio response is also given on the page. It's basically flat to 50Hz in a smallish room -in a larger room it goes lower. I've run MathCad sims on this design as well. The in-room plots tally almost exactly with the measured response. If anyone's concerned about the slight peak at 200Hz, don't be, it's a room, not a speaker effect. They kick like mules, especially in the mid and upper bass. Punch and weight is superb, they do dynamics as well as some horns I can think of, and they've got a lovely throaty roar for rock. Imaging is razor-sharp -the lage radii combined with 206 clearly help here. Up top the 206 is as good on female vocals as you'd expect -no need for me to waffle on about that. Normally I wouldn't consider the 206 for a box speaker. I've changed my mind on hearing these. For the pretty minimal cost, it's a great project, and an interesting alternative to some of the other designs out there.
Regards
Scott
These folded 206 pipes are by a long way the best traditional type TQWT I've ever heard. In-room Clio response is also given on the page. It's basically flat to 50Hz in a smallish room -in a larger room it goes lower. I've run MathCad sims on this design as well. The in-room plots tally almost exactly with the measured response. If anyone's concerned about the slight peak at 200Hz, don't be, it's a room, not a speaker effect. They kick like mules, especially in the mid and upper bass. Punch and weight is superb, they do dynamics as well as some horns I can think of, and they've got a lovely throaty roar for rock. Imaging is razor-sharp -the lage radii combined with 206 clearly help here. Up top the 206 is as good on female vocals as you'd expect -no need for me to waffle on about that. Normally I wouldn't consider the 206 for a box speaker. I've changed my mind on hearing these. For the pretty minimal cost, it's a great project, and an interesting alternative to some of the other designs out there.
Regards
Scott
They should sound pretty similar. Ed is exceptionally good at building things, so he puts a lot into the fine details. The Sonotube idea is a good one -I like that. I suspect the curved ones will have a slight edge, but there probably won't be a great deal in it. One way to find out! The basic design is good enough to experiment with to your heart's content.
Hi Scott - so these are only about about 48 inches tall? - are the plans dimensions internal? What do you think would happened if bottom deflectors were omitted? Those distributed vents at the floor boundary might account for some of its magic. How might you describe its virtues vs a BLH 206 horn of similar bulk?
Freddy
Freddy
flatVs curved reflectors...
Freddy & Scott: from a theoritical point of view the flat reflector should work more in your favor than curved ones. This is also the place where a layer of felt should also be of good use. With a curved reflector mid frequencies will have an easier time of making it around the bend. In this design where the terminus is deflected to the lower sides of the cabinet there is probably less issue of hearing the midrange output especially with the grate vent style used.
With front firing BLH considerable midrange output can be detected from the front mouth. This has a tendency to then alow you to localize midrange ftom the driver as well as the mouth so you get smear. Flat deflectors tenf to diffuse midrange more than smooth curved deflectors do. Best regards Moray James.
Freddy & Scott: from a theoritical point of view the flat reflector should work more in your favor than curved ones. This is also the place where a layer of felt should also be of good use. With a curved reflector mid frequencies will have an easier time of making it around the bend. In this design where the terminus is deflected to the lower sides of the cabinet there is probably less issue of hearing the midrange output especially with the grate vent style used.
With front firing BLH considerable midrange output can be detected from the front mouth. This has a tendency to then alow you to localize midrange ftom the driver as well as the mouth so you get smear. Flat deflectors tenf to diffuse midrange more than smooth curved deflectors do. Best regards Moray James.
Give or take. Dimensions are external I believe. I'd keep the bottom defletor in this case as the pipe is run over a wide passband.
Difficult to compare to a BLH as they're utterly different. Although TQWTs are notionally horns insofar as they are expanding lines, that's about it. It's smaller, the sound is not as massive as you'd get from a full-blown, well designed BLH (pretty big though), but it's far easier to build, and has more punch in the midbass regions. Goes lower for a given cabinet size too. A more natural comparison would be to an MLTL; though it has a flavour of both cabinets. Reminded me of a BIB actually in some aspects to the sound. Which is a good thing generally. I believe Ed got the idea for the vents from the Ariel V6c he built a while back.
Difficult to compare to a BLH as they're utterly different. Although TQWTs are notionally horns insofar as they are expanding lines, that's about it. It's smaller, the sound is not as massive as you'd get from a full-blown, well designed BLH (pretty big though), but it's far easier to build, and has more punch in the midbass regions. Goes lower for a given cabinet size too. A more natural comparison would be to an MLTL; though it has a flavour of both cabinets. Reminded me of a BIB actually in some aspects to the sound. Which is a good thing generally. I believe Ed got the idea for the vents from the Ariel V6c he built a while back.
Thanks Scott - I want really pretty performance on bowed and plucked bass viola plus some sock on drums and am used to limited LF but good load of Karlson type. (200-400W input peaks on a drum can be good with K)
Hi Moray - (flat reflector might work well in some Karlson? )
what do you think about the curved routing pieces for Vofo's vents? - is there a viable option to simplify or might attempts ruin the design?
(Bill's Fulmer/Karlson-slot BLH might not have a lot of HF leakage ?)
Freddy
Hi Moray - (flat reflector might work well in some Karlson? )
what do you think about the curved routing pieces for Vofo's vents? - is there a viable option to simplify or might attempts ruin the design?
(Bill's Fulmer/Karlson-slot BLH might not have a lot of HF leakage ?)
Freddy
Scott - is there an impedance curve available of the Vofo ? (did I overlook one?) how were the vent's proper area figured? with MJK's sheets? - a modeling program? - "experience"?
Moray - this is a pretty cabinet. I wish the Karlson builders (all two or three - if that many? - out of 6.6 billion people would kome out of the woodwork - there is a page to be found under "Carlson-coupler" which has a cryptic calculator.
Freddy
Moray - this is a pretty cabinet. I wish the Karlson builders (all two or three - if that many? - out of 6.6 billion people would kome out of the woodwork - there is a page to be found under "Carlson-coupler" which has a cryptic calculator.
Freddy
Re: flatVs curved reflectors...
Yeah I know. That's why I always advise people not to put deflectors in a BIB. I suspect the construction Ed's used for the curves, with the loght ply and the compressed foam helps damp someof it, and the mild mass loading of the terminus (vent CSA=82% of Sl) filters it, especially as they vent sideways, as you note. The Clio chart indicates it's flat to 1KHz, ignoring the blip caused by a room mode at 200Hz. It's a fairly wide passband design by nature though, so if we're accepting some HF / midrange leakage, as we do with, say, a BIB, or other types of horn, it's as well to make it as smooth as possible! Ed stuffs the first half of the line, and a layer over the bottom deflector. I'm not sure if he's put any around the top -if not, probably a good tweak to experiment with as that's where we usually put a layer in a BIB (well, the other way around, but you kow what I mean!). As always, YMMV. My apolgies BTW -I somehow missed your post earlier.
MathCad generated impedence trace attached. Not bad at all for a TQWT. Using a Karlson instead of the multiple side vents could be a fantastic variation on the idea. What I love about this design is that the basics are nicely refined, but being a large TQWT, they leave plenty of scope for people to experiment with their own variations on the theme.
moray james said:
Yeah I know. That's why I always advise people not to put deflectors in a BIB. I suspect the construction Ed's used for the curves, with the loght ply and the compressed foam helps damp someof it, and the mild mass loading of the terminus (vent CSA=82% of Sl) filters it, especially as they vent sideways, as you note. The Clio chart indicates it's flat to 1KHz, ignoring the blip caused by a room mode at 200Hz. It's a fairly wide passband design by nature though, so if we're accepting some HF / midrange leakage, as we do with, say, a BIB, or other types of horn, it's as well to make it as smooth as possible! Ed stuffs the first half of the line, and a layer over the bottom deflector. I'm not sure if he's put any around the top -if not, probably a good tweak to experiment with as that's where we usually put a layer in a BIB (well, the other way around, but you kow what I mean!). As always, YMMV. My apolgies BTW -I somehow missed your post earlier.
MathCad generated impedence trace attached. Not bad at all for a TQWT. Using a Karlson instead of the multiple side vents could be a fantastic variation on the idea. What I love about this design is that the basics are nicely refined, but being a large TQWT, they leave plenty of scope for people to experiment with their own variations on the theme.
Attachments
Hi Scott - many thanks for Vofo's Z - prediction - interesting to see equal amplitude peaks.
Not sure how a Karlson or Fulmer opening would affect things although could give a more "merged" sound of vent to driver - ?
would you mind looking at my existing line pic and Z curve and give guestimate of where Z-minimum should be set for Beta 12LTA? - just an off the head guess would be good nuff. Internal volume of the line is about 130 liter/4.7 cubic foot. Its on old pipe meant for sub but in lieu of having any good saw, etc I'm trying to make it play as a FR.
Z-minimum with a 3.5" hole at the end of the line looks to be around 28hz and Beta 12LTA has fs ~45Hz
http://img160.imageshack.us/img160/7643/linenr9.jpg
http://img479.imageshack.us/img479/2586/12ltz1gw5.jpg
Freddy
Not sure how a Karlson or Fulmer opening would affect things although could give a more "merged" sound of vent to driver - ?
would you mind looking at my existing line pic and Z curve and give guestimate of where Z-minimum should be set for Beta 12LTA? - just an off the head guess would be good nuff. Internal volume of the line is about 130 liter/4.7 cubic foot. Its on old pipe meant for sub but in lieu of having any good saw, etc I'm trying to make it play as a FR.
Z-minimum with a 3.5" hole at the end of the line looks to be around 28hz and Beta 12LTA has fs ~45Hz
http://img160.imageshack.us/img160/7643/linenr9.jpg
http://img479.imageshack.us/img479/2586/12ltz1gw5.jpg
Freddy
Hi Guys
Vent is indeed cushioned, in this case 1/2 inch felt underlay(not shown on original plan). Internal dimensions are shown on the plan, I appreciate you have to work a bit harder here, but thats half the fun. Bottom section shows internal dimensions. Port area is shown as percentage of mouth area and is designed as max before mass loading to allow further experimentation with blocking. I had intended to progressively block and measure with clio to record the effect.
the design was not a result of mathcad, it was pure experiment on my part....I'm still not convinced its worthy but I'm coming round due to Scotts enthusiasm, for which I thanks him.
I will probably update the design plan in due course(as long as Dave get's off my case regarding the 'old-fashioned' web site)
heres the port:
Regards
Ed
Vent is indeed cushioned, in this case 1/2 inch felt underlay(not shown on original plan). Internal dimensions are shown on the plan, I appreciate you have to work a bit harder here, but thats half the fun. Bottom section shows internal dimensions. Port area is shown as percentage of mouth area and is designed as max before mass loading to allow further experimentation with blocking. I had intended to progressively block and measure with clio to record the effect.
the design was not a result of mathcad, it was pure experiment on my part....I'm still not convinced its worthy but I'm coming round due to Scotts enthusiasm, for which I thanks him.
I will probably update the design plan in due course(as long as Dave get's off my case regarding the 'old-fashioned' web site)
heres the port:
Regards
Ed
Attachments
you sure built beautiful enclosures - is there any hint of "one-note" bass or pipe resonance? I'm totally inexperienced with pipes and pipehorn other than a 10ft t-line and a 7 foot line both which seem to "drone" wideband and they're were probably not properly matched to driver.
Best,
Freddy
Best,
Freddy
you have replaced your Stats....
To quote "I'm still not convinced its worthy" end quote. I think that you have done a great job. That fact that you did this by the seat of your pants proves to me that the "force" is strong with you. Not only that but they look fantastic as well. To replace a set of ESL's is a big deal. Sounds to me like you need to fit some phase plugs apply some duct sea land felt then try shorting the speaker basket to the neg terminal on the connector strip (centre rivit on strip to neg connection). All the best regards Moray James.
To quote "I'm still not convinced its worthy" end quote. I think that you have done a great job. That fact that you did this by the seat of your pants proves to me that the "force" is strong with you. Not only that but they look fantastic as well. To replace a set of ESL's is a big deal. Sounds to me like you need to fit some phase plugs apply some duct sea land felt then try shorting the speaker basket to the neg terminal on the connector strip (centre rivit on strip to neg connection). All the best regards Moray James.
freddi said:
Hi Freddy
thanks for the feedback. I find the bass very tuneful and very easy to follow. As for resonance, I havn't heard any. At a recent DIY meet one chap did report that they 'honked' and sounded like horns. I'm not qualified to respond to this so perhaps Scott might like to comment as he has more of a technicians ear and he's spent sometime listening.
Regards
Ed
Freddi -depends how long the line is, but I'd guess at 30Hz with that taper ratio, give or take so you're probably in the right regions.
FWIW, I disagreed with the comments re this design 'honking' made elsewhere. Without starting to drift off too far into technicalities and send everyone to sleep, to me, 'honk' is a euphanism for unbalanced bass, with gain above the driver's nominal sensitivity (in the case of the 206 theoretically 96db 1w / 1m) resulting in a hollow, boomy sound. These pipes do not display that, either in a sim, or on the Clio measurements, nor in listening; at least not to my ears.
TQWT does tend to have a certain type of presentation in my experience -a forcefulness in the upper and mid-bass, over and above what you would get from, say, a reflex cabinet, or even in some respects a straight MLTL. This is not an effect you'd read on a graph though -it's the way in which it goes about achieving that response. If I'm confusing anyone, take a different analogy. It's like having two cars. Both are limited to 155mph flat out. Both have identical acceleration times. One has a big V6, the other a turbocharged 4. Objectively the performance is the same on paper or a graph, but the feel of both is different due to the different manner in which they get the same result.
Back on these speakers, the horn analogy is quite a good one IMO as all tapered lines at a basic level can be regarded as such; the TQWT differs from most other horn variations however in being end loaded, and this pressure-approach is probably what gives it that characteristic punch. However, it varies according to the degree of taper, and the CSA of So (the sealed end) which determines pipe-gain and the passband across which maximum gain will be applied. You can hear a very slight touch of this effect in Martin King's Project 2 ML TQWT, but being a trunkated pipe, and with greater mass-loading the effect is muted. Put it back to back against a straight MLTL with the same driver though and it's still there.
Some like this sort of approach, some don't, YMMV, as ever. I do, because these are characteristics I happen to value in a cabinet, both for the way I listen, and the material I often listen to. I found they start and stop very well, dynamics subjectively similar to a full-blown horn, and hed plenty of grunt to handle rock as well as an FR driver can be expected to. I also suspect some people might well have been hearing a room-mode rather than the speaker itself as our listening positions at Eggfest were not ideal, with so many people . These are big transducers, with a large cone area, cabinet volume and vent area, and they shift a lot of air: more than a couple of small subwoofers, and this will excite room-resonances more readily than some other systems. Just my views of course.
FWIW, I disagreed with the comments re this design 'honking' made elsewhere. Without starting to drift off too far into technicalities and send everyone to sleep, to me, 'honk' is a euphanism for unbalanced bass, with gain above the driver's nominal sensitivity (in the case of the 206 theoretically 96db 1w / 1m) resulting in a hollow, boomy sound. These pipes do not display that, either in a sim, or on the Clio measurements, nor in listening; at least not to my ears.
TQWT does tend to have a certain type of presentation in my experience -a forcefulness in the upper and mid-bass, over and above what you would get from, say, a reflex cabinet, or even in some respects a straight MLTL. This is not an effect you'd read on a graph though -it's the way in which it goes about achieving that response. If I'm confusing anyone, take a different analogy. It's like having two cars. Both are limited to 155mph flat out. Both have identical acceleration times. One has a big V6, the other a turbocharged 4. Objectively the performance is the same on paper or a graph, but the feel of both is different due to the different manner in which they get the same result.
Back on these speakers, the horn analogy is quite a good one IMO as all tapered lines at a basic level can be regarded as such; the TQWT differs from most other horn variations however in being end loaded, and this pressure-approach is probably what gives it that characteristic punch. However, it varies according to the degree of taper, and the CSA of So (the sealed end) which determines pipe-gain and the passband across which maximum gain will be applied. You can hear a very slight touch of this effect in Martin King's Project 2 ML TQWT, but being a trunkated pipe, and with greater mass-loading the effect is muted. Put it back to back against a straight MLTL with the same driver though and it's still there.
Some like this sort of approach, some don't, YMMV, as ever. I do, because these are characteristics I happen to value in a cabinet, both for the way I listen, and the material I often listen to. I found they start and stop very well, dynamics subjectively similar to a full-blown horn, and hed plenty of grunt to handle rock as well as an FR driver can be expected to. I also suspect some people might well have been hearing a room-mode rather than the speaker itself as our listening positions at Eggfest were not ideal, with so many people . These are big transducers, with a large cone area, cabinet volume and vent area, and they shift a lot of air: more than a couple of small subwoofers, and this will excite room-resonances more readily than some other systems. Just my views of course.
Hi Ed - sounds like you nailed a good/smooth and eye-pleasing design.
Hi Scott - thanks for comments - I tend to like most horn - mine are old Edgarhorn system 100 with Monolith, Sentry IV, etc. Even FH1 (like better braced Belle) has merits although its limited to about 80-100Hz bottom
Hi Moray
"Just give me a link have been looking a long while for the cryptic calculator can-t find it. Please Thanks Moray James"
when searching for "carlson coupler", Google's translator pulls up the following
http://translate.google.com/transla...+coupler&hl=en&hs=yDz&lr=&client=opera&rls=en
this is buried within Walter Herman's speaker pages but I couldn't figure out what the calculator is trying to do - perhaps you can ask Walter and his experiences building "Carlson". phonetics can leave out some folks if looking for "Karlson"
http://www.walter-hermann.de/
Freddy
Hi Scott - thanks for comments - I tend to like most horn - mine are old Edgarhorn system 100 with Monolith, Sentry IV, etc. Even FH1 (like better braced Belle) has merits although its limited to about 80-100Hz bottom
Hi Moray
"Just give me a link have been looking a long while for the cryptic calculator can-t find it. Please Thanks Moray James"
when searching for "carlson coupler", Google's translator pulls up the following
http://translate.google.com/transla...+coupler&hl=en&hs=yDz&lr=&client=opera&rls=en
this is buried within Walter Herman's speaker pages but I couldn't figure out what the calculator is trying to do - perhaps you can ask Walter and his experiences building "Carlson". phonetics can leave out some folks if looking for "Karlson"
http://www.walter-hermann.de/
Freddy
Fostex 206esr?
Scott,
I have never built any FR speakers before and really like old rock music. I want to build a SE amp for my office ("My cave" as my family calls it
) I was wondering if the 206esr driver is worth the added expense and if this cabinet would be a proper for it. Your thoughts would be sincerely appreciated.
Scott,
I have never built any FR speakers before and really like old rock music. I want to build a SE amp for my office ("My cave" as my family calls it
) I was wondering if the 206esr driver is worth the added expense and if this cabinet would be a proper for it. Your thoughts would be sincerely appreciated.- Status
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