Anyone heard the new Hemp CO12VOB

[bvan]

Cant seem to find any info opinion on these.

I'm looking to build a second OB sytem to my present B200 one and am wondering if I could do much better than the B200 without breaking the bank on Fertins/Supravox etc. (not that the Hemps are cheep)

Any info greatly appreciated.

Cheers

B.

[planet10]

I don't know if anyone has even seen those in the wild.

dave

[tinitus]

Actually I think the Hemp coax is quite expencive and cost more than Fertins/Supravox

In another thread I have suggested to use 3 x B200 in OB, configured as a 1.5way ... will it work?? I dont know

[GM]

Originally posted by tinitus

In another thread I have suggested to use 3 x B200 in OB, configured as a 1.5way ... will it work?? I dont know

FWIW, it sounds like a good plan to me, or even as a two way if you mass load the two being used for woofers.

GM

[tinitus]

My immediate idea was to use an XO roughly like this below ... keeping in mind that this is fullrange, so no complicated xo ... but just a few more components may be needed, like RC ... but maybe not as B200 impedance seems pretty smooth

actually I have just now seen that Visaton has a design with 4 drivers, but honestly I dont quite understand their XO, which seems a bit complicated, but I havent studied it very closely

[bvan]

Thanks for the ideas.

I'm not sure more B200 would be much of an improvement for me as I have some nice dipole subs running with them, and I never listen at high volumes.

What I did come upon yesterday that seems like a pretty safe bet is the Hawthorn Audio Sterling coaxials that are just about to come out, at about $700 incl "boutique" crossover. Their $150 SI version has always been highly regarded and I'm betting the new version with Radian tweeter will likewise be competitive.

cheers

B.

[jimluu]

I recently bought a pair of co120bs for test use on an open baffle. Fired them up for the first time today. I don't have access to my usual test set up because we are in the process of moving, but I used the virtual crossover box, first order x-over at 1500hz. Sounds OK. I can't find any info on hempacoustics as far as crossover is concerned, but radian has a very similar driver and they recommend 1250hz 2nd order crossover, and padding down the HF unit.

I've wanted to try these 'prosound' coax for a while now. I've done some research and the Hemps are arguably the best coax out there.

I'm waiting for Perry so send me 4 sw150ob before I do any more work on this project. I'm thinking of experimenting with a coax-woofer-woofer 3-way design on a narrow 18" baffle with only passive equipment. Chances are even with 2x15" woofers, the baffle is too narrow for anything meaningful below 50hz....which give me an opportunity to put in my w-framed dipole subs and turn it into a 4 way design with woofer-coax-woofer-sub config.....

Sorry to get off topic. So far so good with the coaxs, and despite the bad rep, Perry is been great to work with.

[BHTX]

Originally posted by jimluu
I recently bought a pair of co120bs for test use on an open baffle. Fired them up for the first time today. I don't have access to my usual test set up because we are in the process of moving, but I used the virtual crossover box, first order x-over at 1500hz. Sounds OK. I can't find any info on hempacoustics as far as crossover is concerned, but radian has a very similar driver and they recommend 1250hz 2nd order crossover, and padding down the HF unit.

I've wanted to try these 'prosound' coax for a while now. I've done some research and the Hemps are arguably the best coax out there.

I'm waiting for Perry so send me 4 sw150ob before I do any more work on this project. I'm thinking of experimenting with a coax-woofer-woofer 3-way design on a narrow 18" baffle with only passive equipment. Chances are even with 2x15" woofers, the baffle is too narrow for anything meaningful below 50hz....which give me an opportunity to put in my w-framed dipole subs and turn it into a 4 way design with woofer-coax-woofer-sub config.....

What you describe is what I've been very interested in doing for quite a while now.. except using a pair of Hawthorne 15" Augies for the woofers, maybe even 4 if I later decided..with two on the bottom and two on top with a coax in the center. For the longest time, I was thinking of trying the Radian 5208C, yet lately I've been considering the 12" 512/2B in-ceiling version, in hopes of maybe being able to obtain a bit lower xo point on the OB than I might with the 8" version...although the stamped steel frame on the 12" is a big turn off imo. I've come to the conclusion that it's pretty much just gonna be trial and error with these coaxes, as even the relatively small amount of data that Radian provides seems a little odd, and possibly inaccurate. For instance, ever noticed the specified xmax for their coaxials? They give inches, which ends up being less than 0.8mm xmax for the 8", and less than 0.9mm for the 12" version. Add to that the smallish blurry smoothed FR graphs that don't correspond to ANY similar coaxial I've ever seen, and it's just confusing. Also, ever noticed how Hemp uses those same shady FR graphs as Radian? What's up with THAT?? I guess the hemp cones don't do anything then?

Basically, I'm still waiting for at least some kind of indication of which coax to go with until I decide to invest anything in this.

[jimluu]

BHTX:
The Hemp 12" coax is essentially the Radian ceiling coax with 2 differences: a Hemp cone, and a cast aluminum frame. The T&S parameters are given by Hempacoustics, but the FR graph is taken directly from the radian website. This FR graph uses a radian crossover ($60) which use a 1250hz 2nd order crossover, with the HF unit padded down by around 12db. If you use the same crossover parameters, you can assume that everything north of 1khz is the same as the radian. 1khz down may be a bit different due to different cone material. From what I can gather in talking with Perry, the biggest different with Hemp cone is probably less cone break up at above 1khz. If this is correct, then the FR graph should be close to the radian overall.

Depending on how you plan one using the coax, Hemp acoustic has 2 models- the one intended for OB use is expectedly less expensive. If you like the 'ceiling coax', but don't like the stamped steel frame, the Hemp is the way to go. I personally chose the Hemp b/c I'm interested in the sound of Hemp cones. btw...this is banana hemp, not the type of hemp other people think of. Anyways, the overall appearance is much nicer then the radian ceiling coax (I gave mine away recently). The Hemp cone has a very slightly green, woven look that's much more attractive than plain paper. The xmax on the driver is 6mm. If this is the way you want to go, I'd talk to Perry. I'll bet he can close the price gap between his driver and the radians.

btw....if you are considering augies, consider the lampda dipole from John at AE speakers. Probably lots better than the augies in terms of apperance and performance. They are on sale at around $450 a pair. Well worth it IMHO. I'll be buying 2 pairs to make a high end clone of the CS2. Maybe I'll post my builds here if I'm not embarrassed by the results.

[pjanda1]

Originally posted by jimluu
BHTX:
The Hemp 12" coax is essentially the Radian ceiling coax with 2 differences: a Hemp cone, and a cast aluminum frame.

The Xmax difference is huge too. The Radian 512 has less than a mm, versus the 6mm of the Hemp coax. Still, I wonder why more folks don't use the regular Radian ceiling coax for hi-fi. The price is steep, but that tweeter is supposed to be something special. I wonder about a BIB with the 8" (508), then the 1mm xmax should work o.k. The crossover doesn't appear to be optimal. What's with the big hole from 1k to 5k?

pj