Hi
You thinking same as me ? This looks also good
http://www.boxen-baustelle.de/
And kits
Papparazzi
You thinking same as me ? This looks also good
http://www.boxen-baustelle.de/
And kits
Papparazzi
How does it sound?
Looks like you've actually built this system with Hemp 8FR. How does it sound? Did you have to use any correction elements to fix the rising response?
I am planning to build a back-loaded horn for this driver. Already ordered both the drivers and the cabinets, but have not got any yet. In case this approach does not work right, I am very interested in alternative solutions.
Any info would be greatly appreciated.
Vadim
Looks like you've actually built this system with Hemp 8FR. How does it sound? Did you have to use any correction elements to fix the rising response?
I am planning to build a back-loaded horn for this driver. Already ordered both the drivers and the cabinets, but have not got any yet. In case this approach does not work right, I am very interested in alternative solutions.
Any info would be greatly appreciated.
Vadim
With its higher Qts and higher Vas, I don't think the Hemp driver would work optimally as a drop-in replacement for the FE207E in Martin's design. I think you'd get a significant hump around the 100-200Hz region.
AFAIK you would have to increase the cross-sectional area. I don't think you'd have to change the length or port dims.
If you have the ability to run his worksheets (Windows machine), you could start with the FE207E worksheet (make sure it matches what he has on his web site), then substitute in the Hemp params, then work with them until you like what you see.
AFAIK you would have to increase the cross-sectional area. I don't think you'd have to change the length or port dims.
If you have the ability to run his worksheets (Windows machine), you could start with the FE207E worksheet (make sure it matches what he has on his web site), then substitute in the Hemp params, then work with them until you like what you see.
Hm, which horn design? I'm not sure the FR8 would be terribly well-suited for rear horn-loading, but am prepared to be shown wrong.VadimB said:
See my post above for how I would approach the driver. I would make the cabinet cross-section relatively wide-and-shallow because I am of the "large baffle" school.
I have the drivers with about 30 hours on them. They are becoming extremely impressive. I can understand why so many electric guitarists are swearing by them; the critical midrange is a high calorie treat, let there be no doubt. Abit hot on top, but this is evening out fairly quickly now. More than alittle alike the B200, which is The Best thing I could say about it.
With a Qts=.42 I would not recommend backhorns.
Scottmoose: you reading this? Here is the ideal 8" BIB driver.
Highly Impressed thus far. A+
With a Qts=.42 I would not recommend backhorns.
Scottmoose: you reading this? Here is the ideal 8" BIB driver.
Highly Impressed thus far. A+
Jimmy
The Hemps are in a cab of about 40L, I would say. They are the latest Omega SuperHemp, the pair sent by Louis for me to audition and show.
In the larger cabinet, they dig very deep into some real bass, using a Pass F2, and the 41Hz test is easily passed, with some fundamentals exhibited due to room gain, etc. They are pushed very nicely by 2 watts parafeed as well, to mention.
Vadim
I stuck a pair of Fostex FE167E into the Fostex Rx horn load while I waited for the FE166esr to arrive last year from Madisound. With a lower Q than the Hemp, by quite abit as I recall, the balance was still waaaaay off in a horn load. ,but I personally would NOT build a pair of horns specifically for a driver sporting a Qts=.42. Thorsten Weber has built a MLTL which looks like a great idea. (see above link) Also, I should mention that a rear loaded tractrix horn, or The BIB, idea of Terry Cain, calls for a mid Q driver exactly like the Hemp. In fact, I intend to build a pair soon, these are perfect, and the BIBs are as easy as pie to build. So there is your better alternative. Scottmoose is the resident Jedi Master of running the BIB numbers thru Martin King's spreadsheets. In BIB load, the hemps will certainly deliver. We would be talking about stunning full range sound.
These have a crisp, warm, organic sound not unlike the Altec coaxials as I recall. Again, very early days with these drivers, I would not say they are near loosened up, and yet already starting to really sound sweet.
I knew all the guitarists addicted to using Tone Tubby hemp cone drivers could not be wrong. Have a look.. www.tonetubby.com
The Hemps are in a cab of about 40L, I would say. They are the latest Omega SuperHemp, the pair sent by Louis for me to audition and show.
In the larger cabinet, they dig very deep into some real bass, using a Pass F2, and the 41Hz test is easily passed, with some fundamentals exhibited due to room gain, etc. They are pushed very nicely by 2 watts parafeed as well, to mention.
Vadim
I stuck a pair of Fostex FE167E into the Fostex Rx horn load while I waited for the FE166esr to arrive last year from Madisound. With a lower Q than the Hemp, by quite abit as I recall, the balance was still waaaaay off in a horn load. ,but I personally would NOT build a pair of horns specifically for a driver sporting a Qts=.42. Thorsten Weber has built a MLTL which looks like a great idea. (see above link) Also, I should mention that a rear loaded tractrix horn, or The BIB, idea of Terry Cain, calls for a mid Q driver exactly like the Hemp. In fact, I intend to build a pair soon, these are perfect, and the BIBs are as easy as pie to build. So there is your better alternative. Scottmoose is the resident Jedi Master of running the BIB numbers thru Martin King's spreadsheets. In BIB load, the hemps will certainly deliver. We would be talking about stunning full range sound.
These have a crisp, warm, organic sound not unlike the Altec coaxials as I recall. Again, very early days with these drivers, I would not say they are near loosened up, and yet already starting to really sound sweet.
I knew all the guitarists addicted to using Tone Tubby hemp cone drivers could not be wrong. Have a look.. www.tonetubby.com
I'm no expert on horn theory, but I believe you can think of it this way:VadimB said:
High Qts drivers have relatively low motor (i.e. magnet) strength. That is why they resonate more at their Fs (that is one definition of Q).
Low Qts drivers have relatively high motor strength. That is why they resonate less at their Fs, because the electromagnetic force on the cone predominates.
A horn converts a high energy, low magnitude signal (at the driver) to a low energy, high magnitude signal (in free air). A large magnet, low Qts is therefore much better suited to horn-loading.
Aha. A BIB for the hempsters. Sorry I've been away from the board for a while -I've hand my MA thesis to finish, which took priority over audio.
OK, so, a nice hemp-coned mid Q 8" driver. And a matching BIB cabinet for its specs. Well, I'd build something like this: 10" wide, 17" deep, 70" tall (external measurements -I won't go taller than 70" now though). Driver 39" from the base. Terminate internal baffle 7 6/16" from the floor and front and rear internal walls. Assumes 3/4" build material. That's first pass dimensions though. I can probably get something better out of it with a little more time, but I only just found the thread.
Hey, Dan -you know I built an enlarged pair of BIB's for the FF225K a while back for some friends? Well, yesterday evening I was round at their house for a beverage or two to celebrate handing my thesis in, and we decided to try a little experiment. It's funny you shoud mention the B200s... because that's what we screwed into them. OK, they shouldn't work. And in some ways they didn't -Q's too high, so there was a big peak, as you'd expect. But, and I'm not joking, the bass shook ornaments off a granite window-ledge. These things couple to the room like nothing else I know, bar big horn loaded Tannoy DCs. With some DSP applied to kill the peaks (yes, shoot me for crimes against purity) they could really be very good indeed. Good for stadium rock, and you can't say that about many single drivers. That natural rising response might've helped flatten things out too.
OK, so, a nice hemp-coned mid Q 8" driver. And a matching BIB cabinet for its specs. Well, I'd build something like this: 10" wide, 17" deep, 70" tall (external measurements -I won't go taller than 70" now though). Driver 39" from the base. Terminate internal baffle 7 6/16" from the floor and front and rear internal walls. Assumes 3/4" build material. That's first pass dimensions though. I can probably get something better out of it with a little more time, but I only just found the thread.
Hey, Dan -you know I built an enlarged pair of BIB's for the FF225K a while back for some friends? Well, yesterday evening I was round at their house for a beverage or two to celebrate handing my thesis in, and we decided to try a little experiment. It's funny you shoud mention the B200s... because that's what we screwed into them. OK, they shouldn't work. And in some ways they didn't -Q's too high, so there was a big peak, as you'd expect. But, and I'm not joking, the bass shook ornaments off a granite window-ledge. These things couple to the room like nothing else I know, bar big horn loaded Tannoy DCs. With some DSP applied to kill the peaks (yes, shoot me for crimes against purity) they could really be very good indeed. Good for stadium rock, and you can't say that about many single drivers. That natural rising response might've helped flatten things out too.
Scott
Somehow I am not surprised to hear this about the B200. There is magic in that thing, and this is the first time I have heard about its use in anything other than either an aperiodic load, www.omegaloudspeakers.com (A8) or of course, the open baffle. The DarkStars. for example, are some of the very best speakers I had ever heard, when I completed them, truth being stranger than fiction. For myself, I find the larger baffles just abit much for condo life, and the rear loaded tractrix B.I.B. is a perfect compromise. A very spacious sound, overall.
I figure DSP is okay as long as any doctoring of the sound is done in The Digital Domain. So, you have broken no laws. I would be interested in knowing what they were powering it with.
I recommend laying your hands on a pair of Hemp drivers. These SuperHemps of Louis' in my living room are in fact 2.5 ft^3 cabinets, nice wide baffle does wonders for the high calorie wave launch. In a BIB, all the better. A KILLER Project!!
Somehow I am not surprised to hear this about the B200. There is magic in that thing, and this is the first time I have heard about its use in anything other than either an aperiodic load, www.omegaloudspeakers.com (A8) or of course, the open baffle. The DarkStars. for example, are some of the very best speakers I had ever heard, when I completed them, truth being stranger than fiction. For myself, I find the larger baffles just abit much for condo life, and the rear loaded tractrix B.I.B. is a perfect compromise. A very spacious sound, overall.
I figure DSP is okay as long as any doctoring of the sound is done in The Digital Domain. So, you have broken no laws. I would be interested in knowing what they were powering it with.
I recommend laying your hands on a pair of Hemp drivers. These SuperHemps of Louis' in my living room are in fact 2.5 ft^3 cabinets, nice wide baffle does wonders for the high calorie wave launch. In a BIB, all the better. A KILLER Project!!
Hi Dan, sorry it's been a while! Amp was a Pass DIY Zen V5 (the PP one). We also tried it with Simon's Audiolab pre/power, which also worked pretty well, once we'd added some series resistance -5ohms did the trick.
The major peak was around 55Hz (I'm going by bass guitar notes here), F3 circa 40Hz. Rolled off pretty quickly below that, 30Hz was just about audable, but only just. Ripple wasn't bad -oddly, it worked better with most of the stuffing ripped out, just a layer on the base and a touch in the point above the driver. We reverted to the FF225K after a couple of hours as it was more refined, but it worked. If you're interested, the external dims were 10" x 19" x 70". Not small then. But not impossibly large either. I'm tempted to run some numbers on the B200 and try to optimise things as far as possible. I suspect just a fractional widening should do the trick.
Cheers
Scott
The major peak was around 55Hz (I'm going by bass guitar notes here), F3 circa 40Hz. Rolled off pretty quickly below that, 30Hz was just about audable, but only just. Ripple wasn't bad -oddly, it worked better with most of the stuffing ripped out, just a layer on the base and a touch in the point above the driver. We reverted to the FF225K after a couple of hours as it was more refined, but it worked. If you're interested, the external dims were 10" x 19" x 70". Not small then. But not impossibly large either. I'm tempted to run some numbers on the B200 and try to optimise things as far as possible. I suspect just a fractional widening should do the trick.
Cheers
Scott
BIB = Bigger Is Better. It's a giant TQWT / rear loaded folded tractrix horn based on one of Paul Voigts original ideas from the 1930s. Terry Cain is the man who brought it back into the public eye after spotting it in the Fostex Craft Handbooks I believe. Not to all tastes, but Dan and I are big fans. Well, when I say 'giant' I mean it's pretty slim, anywhere betwen 7 and about 12" wide depending on the driver, moderately deep -circa 12" - 20" depending, as before, on what driver you're using, and about 6ft tall, with a single fold, so a total of 12ft line-length. The cabinet is completely open at the top -that's the horn mouth, and is designed to be stuffed into corners. Loaded that way it couples to the room very nicely indeed. They measure much better than they simulate.
Best
Scott
Best
Scott
Well, Terry's originals are here: http://melhuish.org/audio/DIYTQ8.html
Apart from that, there isn't much, unless you can get the Fostex Craft Handbooks. I've tried, believe me! That said, both Dan Mason and I have spent a long time fooling around with these enclosures, and we can probably give you some tips / suggestions. If Greg is around (GM), I'm sure he'll be willing to help out too as he's forgotten more about horns and speakers in general than I'll ever know. I don't want to hijack the thread, so I'll keep this brief.
The line-length is basically set to 1/2 the wavelength of the tuning frequency. Drivers with an Fs of 50Hz or more are usually best tuned to their natural resonance freqency in these enclosures, or very fractionally less depending on various factors, not least of them being the driver excursion. 5Hz is about the practical limit, though there are exceptions, as you'd expect.
They're quite forgiving as enclosures go, about what drivers you use. Mid Q drivers of circa 0.3-0.4 are often the best bet, but low Q drivers can work very well too, if you know what you're doing: a low damping factor amplifier and high series resistance cables, or a small resistor in series with the driver are the key to getting them to work in that situation. High Q drivers are best not approached or you'll get a big hump in the bass. I was very surprised that the B200 worked as well as it did; call it the exception that proves the rule. It didn't have very low bass though -a direct consequence. 40Hz was about it in practical terms, but above that it thundered. The mouth area needs to be bwtween 3 to 4.5 times the surface area of the driver, and they really do need to go in corners as the rear boundary condition increases the mouth area and decreases reflections back down the line. The various Hemp drivers under discussion look like being an ideal match.
Best
Scott
Apart from that, there isn't much, unless you can get the Fostex Craft Handbooks. I've tried, believe me! That said, both Dan Mason and I have spent a long time fooling around with these enclosures, and we can probably give you some tips / suggestions. If Greg is around (GM), I'm sure he'll be willing to help out too as he's forgotten more about horns and speakers in general than I'll ever know. I don't want to hijack the thread, so I'll keep this brief.
The line-length is basically set to 1/2 the wavelength of the tuning frequency. Drivers with an Fs of 50Hz or more are usually best tuned to their natural resonance freqency in these enclosures, or very fractionally less depending on various factors, not least of them being the driver excursion. 5Hz is about the practical limit, though there are exceptions, as you'd expect.
They're quite forgiving as enclosures go, about what drivers you use. Mid Q drivers of circa 0.3-0.4 are often the best bet, but low Q drivers can work very well too, if you know what you're doing: a low damping factor amplifier and high series resistance cables, or a small resistor in series with the driver are the key to getting them to work in that situation. High Q drivers are best not approached or you'll get a big hump in the bass. I was very surprised that the B200 worked as well as it did; call it the exception that proves the rule. It didn't have very low bass though -a direct consequence. 40Hz was about it in practical terms, but above that it thundered. The mouth area needs to be bwtween 3 to 4.5 times the surface area of the driver, and they really do need to go in corners as the rear boundary condition increases the mouth area and decreases reflections back down the line. The various Hemp drivers under discussion look like being an ideal match.
Best
Scott
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