http://www.diyaudio.com/forums/attachment.php?s=&postid=1313563&stamp=1191168822
Half Chang with Pioneer B20 will sound good with a typical home theater receiver because the driver is less revealing than Fostex.
The box is about 47 inches tall so your 50 inch max should work fine.
Maybe the Hemps will work in this box... i dont know, but for the $50 a pair of B20s it might be worth it to include them in the price of the build... dont forget to add a pair of tweeters too... and use the Hemps for another project.
Good luck!
Godzilla
Half Chang with Pioneer B20 will sound good with a typical home theater receiver because the driver is less revealing than Fostex.
The box is about 47 inches tall so your 50 inch max should work fine.
Maybe the Hemps will work in this box... i dont know, but for the $50 a pair of B20s it might be worth it to include them in the price of the build... dont forget to add a pair of tweeters too... and use the Hemps for another project.
Good luck!
Godzilla
thanks Godzilla and Scottmoose
good suggestions from both and where I was probably going to end up after I realized how ******* big the BiB needed to be for the Hemps.
The B20 and a tweeter would make sense, and no real need for a sub. He just doesn't feel the need, and he's had pretty decent ones in the past.
A Demetri may be an alternative too, small enough to get within the (as corrected by scott) 60" X60" sheets available. Bass is pretty reasonable. And if he doesn't like em, I'll keep the enclosures
I did try a design concept of a triple folded BiB, but it was just going to be way to "girthy"
good suggestions from both and where I was probably going to end up after I realized how ******* big the BiB needed to be for the Hemps.
The B20 and a tweeter would make sense, and no real need for a sub. He just doesn't feel the need, and he's had pretty decent ones in the past.
A Demetri may be an alternative too, small enough to get within the (as corrected by scott) 60" X60" sheets available. Bass is pretty reasonable. And if he doesn't like em, I'll keep the enclosures
I did try a design concept of a triple folded BiB, but it was just going to be way to "girthy"
Re: Re: scottmoose, godzilla and GM
1. Are these dimensions and the associated plot are for the Hemp FR8?
2. Are these internal dimensions?
3. "CSA" = cross sectional area?
4. Is Zdriver is distance down from top of baffle?
5. Is zport is distance down from top of baffle?
I guess that's it. Cheers in advance for the help.
Ryan
Just a couple of questions/clarifications for GM and Scott:GM said:
1. Are these dimensions and the associated plot are for the Hemp FR8?
2. Are these internal dimensions?
3. "CSA" = cross sectional area?
4. Is Zdriver is distance down from top of baffle?
5. Is zport is distance down from top of baffle?
I guess that's it. Cheers in advance for the help.
Ryan
GM,
Thank you for the reply. What is the difference between the FR8 and the FR8C? Is the FR8 a non-starter in this box? I just acquired a pair of Hemp Acoustics that don't have documentation except is says FR8 on the pole piece. Also a manufacturing date of late-ish 2005.
To expand the question... if it's an 'old' FR8, somebody please push me off the fence:
Metronome
BIB
Open Baffle
Something else?
Tommy Chang is too big. My room has 8ft ceilings and is mostly open.
Cheers,
Ryan
Thank you for the reply. What is the difference between the FR8 and the FR8C? Is the FR8 a non-starter in this box? I just acquired a pair of Hemp Acoustics that don't have documentation except is says FR8 on the pole piece. Also a manufacturing date of late-ish 2005.
To expand the question... if it's an 'old' FR8, somebody please push me off the fence:
Metronome
BIB
Open Baffle
Something else?
Tommy Chang is too big. My room has 8ft ceilings and is mostly open.
Cheers,
Ryan
The FR8 specs I have are labeled HempTone from 4-2006 and the only difference is the Sd, Vas spec, so BL is different, but the sim in the FR8C's MLTL is ~identical, so should be fine if both's published specs are reasonably accurate. Even though Vas is smaller, the BIB is still going to be around 21 ft^3.
Attachments
Hemptone...
is not Hemp Acoustics.
There always seems to be some confusion. If it has a cannabis leaf on the sticker, then it is a Hemp Acoustics, if a flexing arm then a Tone Tubby ASFAIK. Also the Hemp Acoustics have a cast basket, whilst the Tone Tubbys have a stamped steel one.
Vas of 83 litres for the TT, 95.5 for the FR8c, and 99 litres (if I remember correctly) for the "original" Hemp Acoustics.
And that could be part of the story about various designs (although I'm sure scottmoose would know what he's modelling, and GM too...)
is not Hemp Acoustics.
There always seems to be some confusion. If it has a cannabis leaf on the sticker, then it is a Hemp Acoustics, if a flexing arm then a Tone Tubby ASFAIK. Also the Hemp Acoustics have a cast basket, whilst the Tone Tubbys have a stamped steel one.
Vas of 83 litres for the TT, 95.5 for the FR8c, and 99 litres (if I remember correctly) for the "original" Hemp Acoustics.
And that could be part of the story about various designs (although I'm sure scottmoose would know what he's modelling, and GM too...)
So HempTone is Tone Tubby? I admit I'm thoroughly confused with all that's been published. Anyway, the Vas I used for the FR8 was 88 L Vs the FR8C's 95.5 L.
I also have some HempTone FR8 V2 specs with a 40 Hz Fs, 88 L Vas that require a much larger Vb, so where does it fit in which company's time line?
I also have some HempTone FR8 V2 specs with a 40 Hz Fs, 88 L Vas that require a much larger Vb, so where does it fit in which company's time line?
I haven't heard of a version with a Fs that low. My early pair (preproduction, not the pair I use now) has a shorting ring (which creates an mid hf rise like the FE206 that I can't tolerate, 5 more db than no shorting ring). This driver is similar to some of the earliest drivers in Omega's Hemp Speakers. I don't think any DIY versions were sold.
I saw a graph where the same hemp driver with and without shorting ring, was overlayed on the same graph as an FE206E and FE207E (same test environment). It was really interesting, as the Hemp with the shorting ring (Qts. .5ish) was very similar to the 206, and without (Qts. .4ish), very similar to the 207. The frequency response differences between the Fostex drivers are often ascribed to the higher Q of the 207. However, it just ain't so, it's the shorting ring.
The earliest Hemp also has a different edge treat on the surround: sticky goop instead of the cloth stuff. From what I understand, the sticky stuff is less leaky. However, it led to to a higher VAS of around 100L and picks up dust. If I recall, the Fs was 44 or so. Greg, I think I emailed you those specs in my early days on the fullrange forum. Interesting drivers, those. Huge box required. I think they are candidates for an OB with some sort of hf shelving circuit.
pj
I saw a graph where the same hemp driver with and without shorting ring, was overlayed on the same graph as an FE206E and FE207E (same test environment). It was really interesting, as the Hemp with the shorting ring (Qts. .5ish) was very similar to the 206, and without (Qts. .4ish), very similar to the 207. The frequency response differences between the Fostex drivers are often ascribed to the higher Q of the 207. However, it just ain't so, it's the shorting ring.
The earliest Hemp also has a different edge treat on the surround: sticky goop instead of the cloth stuff. From what I understand, the sticky stuff is less leaky. However, it led to to a higher VAS of around 100L and picks up dust. If I recall, the Fs was 44 or so. Greg, I think I emailed you those specs in my early days on the fullrange forum. Interesting drivers, those. Huge box required. I think they are candidates for an OB with some sort of hf shelving circuit.
pj
Basic technical difference is the claimed Vas for the original FR8, which is 88 litres, as opposed to the 95.5 litres claimed for the FR8C. I'd take both with a ton of salt -they're far too pat to be believable.
Re the hemp confusion, as I understand it, there are two companies: Hemp Acoustics & A Brown Soun, under whose umbrella are Tone Tubby (guitar speakers) and HempTone (hifi speakers). Hemp Accoustics used to have the 'proper' John Harrison hemp cone material originally made famous in the Tone Tubby range of bass guitar drivers, but they lost them, I gather via differences, and sharp practice by a certain person who shall not be named. They now have their own 'matrix' of various materials, including kevlar. AFAIK, HempTone now have the Harrison cones (he started with sister company Tone Tubby anyway) & they have a rival range of units to the Hemp Acoustics drivers. So if you want the 'proper' hemp drivers, these should be the ones to go for -remember, hemp as a material became famous primarily because of the tone the Harrison Tone Tubby cones are supposed to provide. You'll find them here: http://hemptonespeakers.com/
Re the hemp confusion, as I understand it, there are two companies: Hemp Acoustics & A Brown Soun, under whose umbrella are Tone Tubby (guitar speakers) and HempTone (hifi speakers). Hemp Accoustics used to have the 'proper' John Harrison hemp cone material originally made famous in the Tone Tubby range of bass guitar drivers, but they lost them, I gather via differences, and sharp practice by a certain person who shall not be named. They now have their own 'matrix' of various materials, including kevlar. AFAIK, HempTone now have the Harrison cones (he started with sister company Tone Tubby anyway) & they have a rival range of units to the Hemp Acoustics drivers. So if you want the 'proper' hemp drivers, these should be the ones to go for -remember, hemp as a material became famous primarily because of the tone the Harrison Tone Tubby cones are supposed to provide. You'll find them here: http://hemptonespeakers.com/
well I have alittle more insight...
but won't belabour the point. It's been discussed elsewhere ad nauseum.
A.Broun Soun/Hemp Acoustics have shared some of their early history together. Tone Tubby is A.Broun Soun/John Harrison.
Various blends or matrix or recipe or whtever you call it have been used since the 1920s and earlier in loudspeakers. In the early/mid 90s Mission had a Hemp driver used as a midrange in one of their larger loudspeakers. Eminence has their Cannabis Rex as well. And that's about all I will say.
but won't belabour the point. It's been discussed elsewhere ad nauseum.
A.Broun Soun/Hemp Acoustics have shared some of their early history together. Tone Tubby is A.Broun Soun/John Harrison.
Various blends or matrix or recipe or whtever you call it have been used since the 1920s and earlier in loudspeakers. In the early/mid 90s Mission had a Hemp driver used as a midrange in one of their larger loudspeakers. Eminence has their Cannabis Rex as well. And that's about all I will say.
RKH said:
The BIB is an option if you have good corners (or at least a wall) against which to load them, and can handle the size and weight.
My room is too small for the BIB's. I have the Hemp Acoustics FR8's (the full name is FR810HQDIY) in the Metronome cabinets. I think they work quite well. They are decidedly smaller than the BIB's, and will work away from a corner. I'll have them at Burning Amp today, maybe you can get an unbiased review from an attendee. The group that met in Sacramento yesterday seemed to like them.
Bill
Ryan, do the BIB's if you can. You won't be sorry. If you can't, do the Metronomes (as they look the coolest, IMHO), or the MLTL. If you don't want to use BSC and have corners, look through this thread for a corner loaded triangular TL that GM proposed. Best option: build the BIBs and the Metronomes. And, you can always cut a whole in some ply to listen to them OB while you're getting the enclosures built. You'll then know how everything sounds and be through some of the break in.
Rather then engaging in the same old who took what from whom, just keep in mind that the shorting ring makes the Hemptone/TT driver a whole different thing than the Hemps most of us listen to. Take it from the guy who has both types, if you get the Hemptone/TT version, you better plan on shelving that treble down. Check out the response graphs and compare. Some folks will like the sound (again, like a 206 in BRs, and some like the "detail"). Most wouldn't be able to tolerate it, and will be confused as to what all the fuss was about.
pj
Rather then engaging in the same old who took what from whom, just keep in mind that the shorting ring makes the Hemptone/TT driver a whole different thing than the Hemps most of us listen to. Take it from the guy who has both types, if you get the Hemptone/TT version, you better plan on shelving that treble down. Check out the response graphs and compare. Some folks will like the sound (again, like a 206 in BRs, and some like the "detail"). Most wouldn't be able to tolerate it, and will be confused as to what all the fuss was about.
pj
Almost equal? I see 105db at 10k versus 97db at 10K. Part of that is due to a peak at 10k that the matrix cone doesn't have. I see 4 more db with the shorting ring, even discounting the Tone Tubbys peaks at 3.5 and 10k (I have a graph of the old cone Hemp Acoustics model with the NuWay cone so I can compare those points). 5K and 8K are better reference points, given that both drivers appear to have a similar plateau and peak (respecitively) there. I'm pretty sure both measurements were taken on the same test baffle in the same facility, so you can't chaulk differences up to measurement conditions.
I'm afraid that too many are letting personal feelings towards the parties involved speak here. I'm just stating my views about the hemp drivers I have personally heard, and referencing the current models by each manufacturer to my personal opinons and unique experience with them. I'm not sure any of this is helping the BIB thread.
I also just want to point out the effects of shorting rings. I've seen so many mention the Qts as being responsible for the different HF response of the Fostex 206/207 and the 166/167. If it a slightly higher Qts meant such dramatically reduced hf response (which is better in this case), then many higher Q vintage drivers (or even the B200) shouldn't have any treble at all. But they do, and I don't understand why folks tie Qts and hf extension together in the way they do.
pj
I'm afraid that too many are letting personal feelings towards the parties involved speak here. I'm just stating my views about the hemp drivers I have personally heard, and referencing the current models by each manufacturer to my personal opinons and unique experience with them. I'm not sure any of this is helping the BIB thread.
I also just want to point out the effects of shorting rings. I've seen so many mention the Qts as being responsible for the different HF response of the Fostex 206/207 and the 166/167. If it a slightly higher Qts meant such dramatically reduced hf response (which is better in this case), then many higher Q vintage drivers (or even the B200) shouldn't have any treble at all. But they do, and I don't understand why folks tie Qts and hf extension together in the way they do.
pj
pjanda1 said:
Personally I couldn't care tuppence about any of the primadonnas lurking in the background. I've had no involvement & no dealings with any of them; and that's not going to change as I have little interest in either of their products -nothing against them, they just don't match my interests / requirements especially well; at least, the 8in units don't. The mid Q combined with highish Vas means they need a hefty box -larger than many people are comfortable with, and despite their rising midrange response, they'll struggle against their rivals, with higher motor-power, if called upon to drive a long horn for example, to say nothing of the other benefits a high-power magnet provides. YMMV of course.