Best 12" for midbass horn?

[Music is life]

I'm working on a 3 way horn top project.
On the midbass I've done some efforts which sound very nice. One from 80Hz to 500 using 4 beta 6a's. 19" deep, 14" high and 24" wide. Folded with two smooth wide turns. A little shy on horn mouth area though not supper light either. 42" path.

Anyway I want to do something somewhat similar, a single 12" and then compare the two. Have a Delta Pro 12 on hand so my actual question is:

Is there a better 12" for this application than the Delta pro 12.

I would consider a smaller driver too like the kappalite 3010HO but the OTS might be a little low and I suspect it won't beat 4 Beta 6a's though it would be lighter cab.

kappalite 3012HO looks both interesting (and expensive) and might be tempted to try it.

Any thoughts on a good 12" for midbass horn loading?

[wg_ski]

Re: Best 12" for midbass horn?

Delta Pro 12 and Kappa Pro 12 both work well in 40-ish inch horns. Getting smooth to 500 is a matter of keeping the internal reflections down. A normal offset driver horn where the frame diameter determines the placement, you'll get a null at 380 Hz. The problem would be minimized with the 6" - the driver is placed closer to the end so the frequency of the null goes up. If your build is closer to a true end fed horn you won't get this, but it's way harder (but not impossible) to build.

[Music is life]

Re: Best 12" for midbass horn?

Delta Pro 12 and Kappa Pro 12 both work well in 40-ish inch horns. Getting smooth to 500 is a matter of keeping the internal reflections down. A normal offset driver horn where the frame diameter determines the placement, you'll get a null at 380 Hz. The problem would be minimized with the 6" - the driver is placed closer to the end so the frequency of the null goes up. If your build is closer to a true end fed horn you won't get this, but it's way harder (but not impossible) to build.

Thanks for the info.

[Cuppa Joe]

Re: Best 12" for midbass horn?

Thanks for the info.

Check out the B&C 12PE32.

[[email protected]]

Re: Best 12" for midbass horn?

What is your intended passband?

I've found there seem to be three categories of driver in the 12" size class for pro audio. The first category has a lightweight cone and very stiff suspension, and is extremely well suited to a front-loaded horn for midrange. Examples of drivers in this category are the Eminence Delta Pro 12A and the Electro-Voice EVM-12L. The second category has a softer suspension, but not a very low Fs, and these are good for high-efficiency direct-radiating mid-bass applications, or mid-bass horns. Most 12" pro woofers fall into this category. The third category use thicker, heavier cones, soft suspensions with lots of travel, and strong motors, and have low resonant frequencies. These are good choices for direct-radiating mid-bass woofers and subwoofers, and they'll 'do' midrange, but their strengths clearly lie in the low end and mid-bass range. Examples of these are the B&C 12TBX100, Dayton Audio PA310-8, and Eminence Definimax 4012HO.

If your passband is above 300 Hz but below 4000 Hz, look for a driver in the first category. If your passband is above 150-ish Hz, but below 2000 Hz, look for a driver in the second category. I wouldn't recommend drivers in the third category for horn-loading in a midrange horn, though they might work well in a folded bass horn. If you use a driver in the third category as a mid-woofer, I wouldn't recommend horn loading, and I would recommend mating it with a 1.4"-exit or 2"-exit compression driver on a large-format HF horn playing as low as it can comfortably play.

[wg_ski]

Re: Best 12" for midbass horn?

Check out the B&C 12PE32.

If you horn is end fed and you want to get above 800 Hz the B&C is the bomb. It's the go-to driver when you can't get a used EVM12L. The Eminence is fine on the low end (just as good on a 40" horn), but I'd suspect the B&C's higher price will buy lower power compression. It seems to in every other category they sell.

[Cuppa Joe]

Re: Best 12" for midbass horn?

If you horn is end fed and you want to get above 800 Hz the B&C is the bomb. It's the go-to driver when you can't get a used EVM12L. The Eminence is fine on the low end (just as good on a 40" horn), but I'd suspect the B&C's higher price will buy lower power compression. It seems to in every other category they sell.

Inlow Sound has a free 100Hz midbass horn plan for the 12PE32 at www.inlowsound.com, and I've heard some bragging on other forums about getting 1200Hz out of this driver with the right throat in a midrange horn. The equation, Fs x 0.8 x Qes x Vas gives a throat equivalent to 5.25" per side, which might be an easy place to start.