Hemp FR8C Enclosure Suggestions

[Telstar]

I've used them in OB, very extended response, but inadequate dynamics. (actively crossed above 300hx, otherwise things would become embarassing)

 

[ra7]

Hmmm.... I'm planning to use the FR4.5C in an OB too... with some support down below and up top. Let's see how it goes... I want to find out what all the fuss is about regarding the hemp cones.

 

[planet10]

In my short experience, I've found that MLTLs have a very boxy sound.

That is probably more down to the detail than the basic design... i have some Twin MA#6 ML-TLs that don't sound boxy at all.

dave

 

[AmadeusMozart]

When Hemp disappeared last year, so did the website, all with out a trace. Not even a puff of smoke.

I have been unable to find even archived copies of their driver specs or plans.

I have a pair of Hemp 4" drivers and would like to have seen what they recommended.

Any leads would be appreciated.

Bruce

A tad late but it is in the archive:

https://web.archive.org/web/*/http://www.hempacoustics.com

 

[GM]

Clicking on the link in the WBM returns this: Oops! Google Chrome could not find www.ecologicacoustics.com as opposed to 'http://www.hempacoustics.com', so are you able to see the supposedly archived data?

GM

 

[Scottmoose]

Works for me (in Internet Explorer though), but you need to go with 2008 or earlier archives; later & I get something that's probably IE's equivalent of what you're getting in Chrome Greg.

 

[GM]

Clicking on individual years does nothing in Chrome....... I haven't kept IE updated in probably a decade now and not sure I want to allow it since I'm still using XP Pro/S2, so may try updating Firefox again to see if it will 'play nice'. It use to work great, but one day it starting causing the processor to run WFO, locking the computer up, which numerous updates over time didn't correct, so finally gave up and switched to Chrome.

GM

 

[Scottmoose]

That's very odd re Firefox. And Chrome for that matter. Hopefully the locking up is just a bug they've now fixed.

 

[AmadeusMozart]

Last few years images are from a period that the website had disappeared without trace and you'll get some error message. Try some earlier ones, worked fine with IE 10 / Windows 8. Clicking on the years does nothing, you'll have to go down the page and click on an individual date.

Downloaded three pdf's for the FR8C (have just bought a pair of these as new in box). Do not yet know what they'll be used for, Decware NFX, Decware ZOB, Jensen Ultra-flex, Hemp Open Baffle, Metronome, Demitry, MLQW. Too many choices and cannot decide. I love my FF105WK and FF125WK metronomes, bass and mids coming out of these is amazing but with a 1.7 (triode) / 3 W (UL) SE amplifier on the way I need something that has a few dB more sensitivity.

 

[chrisb]

I'd be inclined to start with a simple build - which probably moves the first 2 named down the list - as much as none have ever really worked for me, it's hard to beat the simplicity of an OB

 

[AmadeusMozart]

I'd be inclined to start with a simple build - which probably moves the first 2 named down the list - as much as none have ever really worked for me, it's hard to beat the simplicity of an OB

The first two have disappeared off the list. The NFX does not follow the design principles remarked in the Jensen Ultra-flex documentation. What many do not know is that an engineer (Robert Novak) working for Jensen had worked out all the BR stuff before Thiele and Small. (thanks kelticwizard - http://www.diyaudio.com/forums/multi-way/15722-external-ports.html ).

And there is a remark Jensen that they prefer ultra-flex above bass reflex.

The plan is to try OB first and if that fails to go to the ultra-flex. If that does not work out then I suppose there is no alternative but to go for a metronome - my two metronomes are good performers although for an 8" they get pretty imposing.

 

[Scottmoose]

I believe you're referring to:

Novak, James F. Performance of Enclosures for Low-Resonance High-Compliance Loudspeakers (JAES: Vol.7, Issue 1 [January 1959]) pp. 29-37

 

[GM]

What many do not know is.....

When folks claim that the pioneers of audio were mostly clueless WRT to speaker cab alignments before T-S is to show a profound ignorance of the subject.

The Bell Labs/W.E. inventors worked it all out with their compression horn and reflex patents, which the latter BTW included multiple ducted ports plus a driver-in-port variation, and why speaker cab alignment theory hasn't fundamentally changed since the early 1930s.

GM