Cleanest 12" high efficiency mids for the money?

[Brett]

Originally posted by jamikl
Several weeks ago I asked whether anyone had experience of some of the Celestion Pro, not guitar drivers, but got no response. Two of the 10" ones look reasonably smooth both in the frequency response and impedance curves. Like you I have been looking for a bigger upper bass and mid speaker that was fairly efficient. I think one was the TF1020 and the other was the Neo version. The ferrite version looked a bit smoother but I have never heard either and have no idea as to pricing. Nobody seems to have experienced them.
jamikl

The difficulty you have is that pro drivers are rarely used by philes and DIYers, and the ones you chose are not mentioned by anyone anywhere else. Without more info than an FR curve, I'd be hesitant unless I could return them after measuring them.

Some brands like JBL and Altec are well known and there is some experience with them. The further you move away from the known, the less experience there is out there. They may be great drivers, but they could also be dogs.

Originally posted by jamikl
I saw a bit about Smiths horns on another forum so I'm trying to find out more about them now.

I've built and tried a number of rectangular horns of varying types. Rectangular horns of high aspect ratio with throat discontinuities generally sound awful, IME. The Smith's are a very old design and I think you could do much better with a more modern design like an Azura.

I think I know where you are talking about, and they are definitely fan-boys (no offence, just my impression) so take what you read with a grain of salt.

[Brett]

Originally posted by BHTX
Obviously still in the conceptual stage here. Electronic LR4 crossover will be used. 12" midbass in a sealed chamber, supported by a 15-18" vented woofer, crossed around 150-250 Hz. Probably end up with a 1" CD up to 1.2 KHz or so, no idea which yet. I keep coming across positive experiences with the DDS CFD ENG 1-90 90°x90° waveguide, so I might try that. The most interesting 12" midbass drivers I've come across are all discontinued, mainly the Fane M4-12LF and D.A.S. 12BN and a couple others. The Fane in particular might have been the perfect choice, but so much for that. B&C 12PLB76 might do well, if it weren't for its low Qts. JBL 2206H/J looks good too, but very pricey of course. Seen a couple from RCF that look nice, but their Qts is too low as well (around .2 or less). Beyma 12G40 looks really good ($220 tho). A couple others from Beyma would probably work well, but they're even more expensive.

Out of all these drivers and dozens more similar to these, there's one that really sticks out as possibly being a clear winner as far as my wallet is concerned, and that's the Eminence Delta Pro-12A. For $110 each (I've seen it for $60 too!), I'm starting to question whether or not any of these other drivers would really be worth the increased cost. Only thing is that I haven't seen anything other than the PDF from Eminence. I'd sure like to see some more measurements of this driver. Anyway, for the money, it looks really nice, and I'd definitely be very interested in hearing from anyone who's had experience with it..
http://www.eminence.com/pdf/deltapro-12a.pdf

..Would be perfect for 1 ft^3 sealed, crossed around 150-200Hz & 1.2-1.5 KHz to a large woofer and waveguide. What do you think?

If you're going for a 15 or 18, why not try a 10 or 8 instead. This will give you a better dispersion match to a CD+WG/horn in the 1k2-1k6 region (bit higher for the 8 maybe).

Suggested 10's are the JBL 2123, 2012, 18Sound 10NDA and NMB series. in 8" the 18S 8NDA looks interesting. For cheap and old-school, the EV EVM12L and EV-10 look good. I like the sound of the 12L as a sealed mid (great harmonica speaker too BTW).

The Beyma's have also been consistent and excellent drivers that seem to match their specs, but I have no experience of the 10's, only the 15G40 I use in bass rigs.

I gave up a bit in sensitivity in my current design, by moving from the pro drivers to AE TD15X and TD10M, but gained a better motor. Mains and sides will both be WMTMW, with the AE in the mains all sealed, and JBLs in the sides, with the LF ported. HF will be Geddes WG's. All 4 speakers will be active.