[chlorofille]

Good evening everyone,

Has anyone had experience using these drivers? Would you recommend these drivers? I am thinking of putting one of these hemp drivers in a straight transmission line for soft listening.

Their t/s parameters seem to suggest a vented box of sort as the EBP is around 45/0.5 = 90


I am using Anthony Holton's amp modules( VFET mosfet), the NXv200 which is very detailed. They can be found at aussieamplifiers.com

Best Regards,

[planet10]

I bought 2 pair of 4.5c (actually 3 pr -- a pair for a buddy)... these are pretty good sounding (ours are in a set of Brynn), but... one of the pairs i got was WAY off in specs and Perry Pecker (Mr HA) asked me to send it back directly to him so they could use them for QC. That was over 17 months ago and i still don't have any replacement drivers.

dave

[chlorofille]

Dave,

Thanks lots for the insight. Will think twice before buying stuff from Hemp Acoustics ><
Their use of hemp which resulted in a lighter moving mass cone seemed to grab my attention.

Regards,
-D-

[planet10]

Their use of hemp which resulted in a lighter moving mass cone seemed to grab my attention.

Measurements indicate cone mass to be pretty close to that of the FE12x drivers.

And what kind of hemp they are made of is also a question. There are at last 15 kinds of plants called hemp, only one of which is cannibus hemp. Perry says his are canabis hemp, but he also told me on another occasion that the north american OEM that makes these uses manilla hemp (a close relative of banana BTW). Given the number of "stories" i've been fed i don't know what to believe ...

dave

[rjbond3rd]

Dave, have you ever heard of abaca fiber?  They grow it in the Philippines and it's unbelievably strong for its weight.  I don't believe it could be torn, i.e. it's more like a cloth than a paper. 

[chrisby]

Good evening everyone,

Has anyone had experience using these drivers? Would you recommend these drivers? I am thinking of putting one of these hemp drivers in a straight transmission line for soft listening.

Their t/s parameters seem to suggest a vented box of sort as the EBP is around 45/0.5 = 90


I am using Anthony Holton's amp modules( VFET mosfet), the NXv200 which is very detailed. They can be found at aussieamplifiers.com

Best Regards,

Well, IF you can get a pair of the FR4.5 that are reasonably close to the T/S paramaters of our remaining captive pair - I can tell you they work quite well in Scott Lingren's Brynn enclosure, which is a very simple and not obtrusive build.  I have at least as many different types of amps in my collection as single driver speakers, and generally prefer them with low power SET (2A3 or 300B), but have also liked them with a 20 Class-T amp (Kingrex T20U) 

By all accounts from folks who've heard the one pair extant, the prototype pair of AudioMagus White Lotus MLV with the 8" were quite a hit as well. 



Notice the capitalization of the second word in first paragraph above.  I think it's fair to say there is much anecdotal evidence to support the thesis that anything related to "mr Hemp Acoustics" should be predicated with a very big "IF".

   
Regarding "papers" - there is also the very special hand-made mulberry fiber based paper used by Feastrex, and Fostex has been using blends of banana and kenaf among others for years. 

[planet10]

Yes. It's actually one of the fibres sometimes called hemp... here is the list of things your hempcone could be made from:

Cannabis Sativa L | true hemp | canibus hemp
Agav Tequilana Weber | Mazatlan hemp | Mescal
Apocynum Cannabinum L | Indian Hemp
Corchorus Capsularis L | Jute
Crotalaria Juncea L | Sunn Hemp
Crotalaria Sp | Sunn Hemp
Furcraea Gigantea Vent | Piteria, Cocuiza Mansa 8 Furcraea
Gigantea Weber | Piteria, Cocuiza Mansa 9 Hibiscus
Abelmoschus L | Kenaf Family 10 Hibiscus
Cannabinus L. | Kenaf
Musa Textiles Nee | Abaca
Phorium TenaxSt Helana Hemp 13 Sansevieria
Kirkii Bak | Pangane hemp
Sansevieria sp | Ife hemp
Sida Rhombifolia L | Queensland Hemp

The preferred recipe as outlined in the hemptone patent application is manilla hemp.

dave

[planet10]

Regarding "papers" - there is also the very special hand-made mulberry fiber based paper used by Feastrex, and Fostex has been using blends of banana and kenaf among others for years. 

Kenaf is on the list above and if one considers that banana is a "close-enuff" relative to manilla then those particular Fostex drivers could also be called hemp cones

dave

[chlorofille]

Guys,

I fear that the hemp cone might be eated up by insects as i live in a humid country (Malaysia). Guess I'll need some grilles.

I have settled on a design for the FR8C. A bass reflex cabinet of dimensions 1200X400X175mm with internal volume of about 90l. With a baffle of 400mm in width, would I still need a BSC? THe predicted F3 point of the baffle is at 285Hz. Im trying to keep the drivers free of any compensation circuits to reap the uncoloured sonics of a clean signal. I cannot seem to find the Le and Impedance Vs Freq curves for the driver, thus I do not know if a Zobel network is needed. I have emailed them but as usual no reply !!

Port is at the very bottom, which gives the enclosure a half TL, half BR property. Stuffing will be placed only behind the driver and kept to a minimum for maximum bass output. Box will be made of a combination of 30mm plywood and 30mm MDF to control resonances.

Sounds good?

-D-

[Telstar]

Any more projects based on FR8(C)?