Enclosures for Hemptone FR8

[dobias]

Is there any formula for increasing the dimensions for smaller driver enclosures to suit the 8 inch Hemptone FR8?
Most of the interesting plans are for much smaller drivers.
I'm hoping for a tall enclosure (hopefully an air column)to keep the footprint to a minimum.

[chlorofille]

Interesting, did they take over Hemp Acoustics? The driver looks like the Hemp Acoustics FR8C with slightly different specs. I modelled the specs in BassBoxPro, assuming 9grams moving mass, and a 110L enclosure tuned to 35Hz suits it nicely. (F3 of 35Hz).

[chlorofille]

Here is the PDF showing specs of H.A FR8C.

[Scottmoose]

No, there was some bad blood between the companies though, which was probably why the defunct HA changed their cone material. A lot of debate too re both about whether the cone material can strictly be called hemp, although personally, I never cared one way or the other. Either way, IIRC the hemptone units are the basis for Omega's OEM drivers.

Not really any practical way of scaling smaller T/S based boxes upward except in the sense of redesinging from scratch. What box did you have in mind?

[dobias]

Chlorofille,
I don't think they're quite the same speaker, The Hempacoustic appears to be a more robust speaker. I think Hemptone was acquired by Audire.

Scottmoose,
I'm not versed on the terminology, but I'd like either a quarter wave folded horn with the port aimed up towards the ceiling, or an air column type with the horn aimed up.
I'm hoping for a box that doesn't sound (to me) like a box. I want a small footprint & will gladly accept a very tall unit. Does that make sense?
Damn! I've been converted to OB's but can't find one that's tall & narrow & suitable for the Hemptone FR8 (much less any small FR speaker).
Frank

[GM]

Originally Posted by dobias

Is there any formula for increasing the dimensions for smaller driver enclosures to suit the 8 inch Hemptone FR8?
Most of the interesting plans are for much smaller drivers.
I'm hoping for a tall enclosure (hopefully an air column)to keep the footprint to a minimum.

Well, in the good ol' days, DIYers scaled based on Fs, effective driver radius, but this was based on the assumptions that the vent area [Av] = driver effective area [Sd] and cab tuning [Fb] = driver resonance [Fs] which makes for very large cabs or ~8.738 ft^3 for this driver [~1.82x larger than a T/S max flat alignment].

Stretched out into a MLTL, this equates to a ~60" internal height with a width x depth [CSA] of ~252"^2 to get the driver up to ear level.

Maybe a math whiz can figure out how to manipulate the T/S formulas to scale an existing cab, but so far, none have published one AFAIK.

Regardless, as Scott noted, best to design from scratch and oversize the cab a bit if using published specs since with rare exception they tend to make for a too small cab in reality for optimum performance IME.

GM

[GM]

Originally Posted by dobias

........ but I'd like either a quarter wave folded horn with the port aimed up towards the ceiling, or an air column type with the horn aimed up.

Think BIB pipe horn then and use whatever Fs is required to get the folded length long enough to get the baffle up to right at ceiling height and notch out the sides, back as required to get the audibly best compromise between sense of 'spaciousness' and LF BW loading.

GM

[planet10]

Originally Posted by dobias

I don't think they're quite the same speaker, The Hempacoustic appears to be a more robust speaker. I think Hemptone was acquired by Audire.

Hempacoustics OEMed the 1st runs of Hemp Acoustics/Perry Pecker drivers. Then they servered ties. Hemp Acoustics then had small runs of drivers made by Misco and other OEMs. Adire was merged/aquired by HA. Then the assets were aquired by AudioMagus who soon after packed it in. Perry Pecker screwed a lot of people during this period.

As to the receipe for the paper in the Hempcone driver, the receipe they are tryng to patent has no cannibis hemp in it, and when Loius (Omega) tried to clarify he says he was stonewalled.

It matters not -- except for any dishonesty factor -- there are a zillion paper receipes, the question comes down to how it works after execution.

Hempcones primary focus is musical instrument speakers. We do know that MI speakers have been successfully repurposed for hifi use.

dave

[bigdh31]

The have the original HA FR8, the specs are darn close to the Hemptone FR8, and I built a tall bass reflex box of about 90 liters and used a 4 x 4 port from parts-express and it turned out pretty good. I get suprising amount of bass.

[dobias]

After searching, the closest I can find is Terry Cain's TQWT. Now if I could only find a BIB size for the FR8.