Cleanest 12" high efficiency mids for the money?

[BHTX]

Been considering a large efficient 3-way for the HT setup (LCR with matching center channel). If things worked out well enough in the end, I'd most likely use it for a lot of dedicated 2-channel music as well, plus occasional parties etc. Aside from playing around with a Radian coaxial, this will be my first time with high efficiency and compression drivers. 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?

[studiotech]

Lambda, Lambda, Lambda

You really can't do much better regardless of the price.

www.aespeakers.com

I have 4 of the TD12m on the way for a high power studio monitor.

Greg

[rinx]

And the price is?

[BHTX]

Ah yes. I've looked at these recently. They look very nice indeed. Only thing that's kept me from getting too hyped up about them is the lack of info (graphs, etc). I've seen some preliminary T/S data on his forum, which actually differs slightly from what's on the product pages, and entered all those drivers into WinISD a while back. But I have yet to see a response graph or even a price for any of these. And from what I remember about Lambda/AE/Stryke/etc (I dunno how all that works, I thought Stryke had their own site at one time?), they come and go fairly often, never to be seen for years at a time. I've never understood that. But anyhoo, he does make some nice drivers, that's for sure. Thanks for the reminder.

[JoshK]

You question is one I've been thinking of as well. I don't know the answer, but here are some of my considerations.

GPA 416 remake (see the Beyond the Ariel Thread)
18Sound 12ND520
Lambda 12TDM

I have Lambda 15TDX's for the bass and I have the DDS ENG1-90. I have a 12" WG of Geddes on order. I am also considering 10" mids and have a pair of JBL 2123H's already on hand. 18Sound 10ND520 & Lambda 10TDM are also being considered. Lots of choices and tough decisions to be made.

Some of your choices look more like midbasses then midranges to me. If you are going to cross ~200, I'd think a true midrange would be more ideal.

[John_E_Janowitz]

All of the Lambda TD12's are $259 each. The 10's are $239 and 15's are $279. There are discounts in multiples. The TD12M would be the highest efficiency version and probably what you are looking for. Parameters for all the drivers are here on our forum:
http://www.aespeakers.com/phpbb2/vie...php?f=3&t=1646

Here is info on the Lambda motor and what it does to lower distortion, inductance, power compression, etc:
http://www.aespeakers.com/Lambda001-1.php


There are quite a few people I am working with right now on various designs using the TD woofers over on a thread on AVS. This thread is really talking about what you are doing with the high efficiency HT system.
http://www.avsforum.com/avs-vb/showthread.php?t=1035126

You can see Jeff Babby's comments on the TD12H which they used in this speaker. Notice his comments about how it has likely the lowest non-linear distortion of any driver. The TD12M has the same motor but shorter coil so inductance and distortion will be even lower.
http://www.htguide.com/forum/showthread.php4?t=29988

Originally posted by BHTX
Ah yes. I've looked at these recently. They look very nice indeed. Only thing that's kept me from getting too hyped up about them is the lack of info (graphs, etc). I've seen some preliminary T/S data on his forum, which actually differs slightly from what's on the product pages, and entered all those drivers into WinISD a while back. But I have yet to see a response graph or even a price for any of these. And from what I remember about Lambda/AE/Stryke/etc (I dunno how all that works, I thought Stryke had their own site at one time?), they come and go fairly often, never to be seen for years at a time. I've never understood that. But anyhoo, he does make some nice drivers, that's for sure. Thanks for the reminder.

I have been in business since 1997 as Stryke Audio. In 2001 I had to change the name as another company claimed to have trademarked the name Strike, which made Stryke be a violation. Their attorneys were stuck on me and I changed the name. I had originally sold drivers made by Lambda and had drivers made by TC. As Nick closed up Lambda and TC ran off with a bunch of my money I ended up having to start building drivers in house back in 2003. I then bought out remaining inventory from Lambda. I have been in business since 1997. In the same location since November 2000 and have had the same phone number active since then. I've never really gone anywhere, just didn't have product at times due to suppliers taking money and never delivering parts.

Regarding the parameters, the parameters on the forum are from the old Lambda site. Everything is built now with the same parts so things don't change much. You'll see the main difference is that we now measure Sd using 1/3 of the surround vs 1/2 the surround. The majority of the industry uses 1/2 the surround, but the technically correct method is to use 1/3 the surround as per the original Theil and Small formulas. As a result the Vas measurements and efficiency measurements you see from our drivers now will be slightly different. Essentially efficiency is under-rated slightly as well. Xmax we do now spec based on the Bl curve of the driver and .707 x the rest BL value. This has become somewhat the standard. In the past Lambda just spec'd the physical overhang, but based on the BL curve there is quite a bit more Xmax.

As far as measurements go, I just don't have the time to do everything. We've been so busy building and shipping drivers that we just don't have the time available. To get all data people seem to want would take a full day for nearly every driver. We have a pair of TD12M's going in a system today with pair of BMS 4550 compression drivers on 18sound XT1086 horns, so I will try to get some close mic response curves and post the impedance curves.

The other issue with measuring curves, etc is that you still can't really compare it to anything. Most companies publish curves with heavy smoothing that don't tell you much of anything going on. People ask for distortion measurements, but other companies either don't publish this data or they tell nothing about the conditions in which the data was taken. People ask for power compression numbers but again how do you compare to other info out there? We've relied primarily on the word of mouth from those who have used the drivers to spread the word and the response has been very good.

John

[ucla88]

Originally posted by John_E_Janowitz

The other issue with measuring curves, etc is that you still can't really compare it to anything. Most companies publish curves with heavy smoothing that don't tell you much of anything going on. People ask for distortion measurements, but other companies either don't publish this data or they tell nothing about the conditions in which the data was taken. People ask for power compression numbers but again how do you compare to other info out there? We've relied primarily on the word of mouth from those who have used the drivers to spread the word and the response has been very good.

John

Ahhh,
sooner or later krutke or I will end up testing a Lambda...it's inevitable.

[audiokinesis]

Having some experience with Nick McKinney's excellent drivers from his Lambda Acoustics days, I voted with my wallet and recently ordered some TD12M's with the Apollo motor upgrade.

Thank you John for bringing back the Lambdas!

Duke

[nickmckinney]

Originally posted by ucla88


Ahhh,
sooner or later krutke or I will end up testing a Lambda...it's inevitable.

Working on getting more into knowledgeable hands.

Originally posted by audiokinesis
Having some experience with Nick McKinney's excellent drivers from his Lambda Acoustics days, I voted with my wallet and recently ordered some TD12M's with the Apollo motor upgrade.

Thank you John for bringing back the Lambdas!

Duke

Is this the Duke from NO?

BTW - expect to see more data on Lambda's shortly, once I figure out this Dreamweaver crap.

[LineSource]

Originally posted by nickmckinney
BTW - expect to see more data on Lambda's shortly, once I figure out this Dreamweaver crap.

Hi Nick,

Do you plan to prototype and measure a few new "ultimate midrange" speaker designs? Putting your underhung motor on a TD10M or TD12M would be interesting data.

Very low Mms, like 30g for a 10", a flat flux underhung motor, 8mm Xmax, and ~94db/watt SPL seem necessary for an ultimate midrange. Pre-magnetized NdFeB might be managable for a couple prototypes. The tapered outer pole steel like that used by TC Sounds in their underhung motors to get linear flux over the full gap length and a solid steel center pole cylinder might be able to handle NdFeB higher flux without saturation.