What to do with Hemp CO8Vs?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi all,
1st post here.

I have been offered a pair of NIB Hemp CO8Vs. I thought they were able to be used without a crossover but they aren't. I am still interested in trying these out though.

I do have a CNC machine so cabinet building is not a problem. I was thinking about a Transmission Line (similar to these) cab using Trans-Laminated ply. Cabinet volume of approx 25-30lts.

Would this be the correct choice for these drivers?

Many thanks.
 

GM

Member
Joined 2003
http://www.hempacoustics.com/products.php
http://www.hempacoustics.com/CO8V_-_Hemp_Spec_Sheet_ready.pdf

25-30 L implies a ~T/S max flat vented or old tech TL alignment which for the latter equates to anemic bass and excessive loss of efficiency due to baffle step compensation (BSC) if either not corner loaded and/or a high Q driver and/or a 'sub' is used. Plus, due to a relatively high Fs, low Vas, then if tuned to fill in the mid-bass there's no bass of consequence, so another type of cab design may be desirable.

GM
 
Thanks GM.

As posted above (once moderator clears) the cabinet type isn't a problem. I would like some advice on the cabinet style best suited for them.

Cabinet type, volume etc.
I am very excited about starting to use full range drivers having done a MTM. I would prefer no crossover but the Hemps just have an appeal and are waiting for some music to be played through them.
 
frugal-phile™
Joined 2001
Paid Member
spacies said:
I have been offered a pair of NIB Hemp CO8Vs. I thought they were able to be used without a crossover but they aren't. I am still interested in trying these out though.

A co-ax is a 2-way, needs an XO.

You can actually touch these drivers? Actually finding a pair of these drivers is a feat.

I wouldn't trust the factory specs BTW.

dave
 
Unfortunately I haven't the equipment to measure anything.

The build quality is A1. Absolutely perfect.
They smell nice too.

I will take some more pics tomorrow outside because it is dark here right now and I only have my phone to take pics with.

Here are some I took indoors in poor light.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
-Rant-

Hemp Acoustics can't even be bothered to supply a half decent set of figures. No Bl factor mentioned. No Sd for pity's sake. Pathetic. Sure, you can calculate it yourself, but why on Earth don't they refer to it themselves, with the rest of the figures? And, while I'm on the subject, those figures that they do supply are suspiciously rounded off. OK, so as a ROT, most manufacturers figures seem to be a trifle 'optimistic', but at least, say, Fostex, make an effort of providing some figures that, with a very charitable disposition, one eye shut & a bottle of Polish Bison grass vodka close at hand, could be swallowed without gagging too much. Clearly, HA are not actually very serious about selling their own products. I note too that several of their DIY cabinet designs have been 'Coming Soon' on their site for roughly a year, with marginally less than zero sign of them ever actually appearing. I don't believe they exist. I think they're just trying for some publicity. (don't like it HA? OK, prove me wrong. Ball's in your court, not mine.)

While I'm in the mood for dishing out a damned good roasting, how about Hemptone? Same remarks apply, albeit to a slightly lesser extent, about the driver measurements. Utterly miserable website that seems to update about as often as your average Quad II valve amp owner, and almost 0 information. Is this good enough? It isn't good enough.

-rant over-

OK, box for the CO8V, & assuming the claimed parameters are accurate (cough), here's an MLTL to chew over.

48in x 12.5in x 5.25in (internal HxWxD). Zdriver 17in, Zvent 44in, Vent 3in diameter x 2in long. Line top, back & one side-wall with 1in acoustic fiberglass or stuff 0.45lbs ft^3 from the top 30in down. It will also go straight into the Chang or Half-Chang cabinets.
 

Attachments

  • mltl.gif
    mltl.gif
    5.6 KB · Views: 345
spacies said:

The price was too good to turn down.

Considering the street price of 508s, this begs the question of how good was too good? I mean IMO you'd have to at least match the average 508 price to justify it unless of course there's more to this 'custom' driver than the cast frame and lack of DC the available info implies. For sure, $475 seems a bit much for an 8" co-ax when there's good 12"ers in this price bracket last time I checked: http://estore.websitepros.com/1736754/Categories.bok?category=HEMP+ACOUSTICS

GM
 
seanzozo said:

I think Radian's model with the same cast frame, connectors etc. is the 5208c ~$240 each. Presumably HA had hemp cones made for a 5208c.

OK, thanks, but where are they on their website? Googling turned up nothing either. Obviously, I don't have a clue about its diaphragm design, but this doesn't jive with the pics and published plots, so pardon me for being skeptical WRT the spec differences, though arguably its material could have an audibly different tone than the 508's.

If it does, it would be interesting to A/B/C them to see if they're even remotely worth the pricing differences between them.

GM
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.