Ok, just had to settle my curiosity too, so I picked up a single MCM 55-2982 12" Driver to test.
http://www.mcmelectronics.com/product/55-2982
I have 4 T39's at 24" Wide each, using the 3012LF Driver. I used 2 of the cabinets to test side by side and compare SPL, using the Radio Shack "Sound Level Meter", and testing the 55-2982 against the 3012LF. Here are my findings:
MCM 55-2982
Outside Diameter = 12.375"
Inside Diameter = 11.062"
BCD Diameter = 11.625
Overall Heigth = 5.75"
Weight = 10 lbs.
I burned in the driver using a 60hz Sine Wave at 10v for 8hrs. I raised the voltage to 40v and found that the 55-2982 had no complaints, I did not exceed 40v until the speaker was in the cabinet, didn't want to waste this driver before I had a chance to get it installed.
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The driver fit into the access opening with no problem, and mounted to the existing mounting holes used for the 3012LF. The BCD for the 3012LF is 11.62". There is only one gasket, face mounted, as you can see in the pic. Also, the gasket will compress in about 30 seconds. I had to make sure to go back over each bolt, and re-tighten. Tightening the driver all the way down to the frame was adequate.
The Wire Connections were Spring Loaded, just push down on the connector, insert wire, spring pop's back up and makes contact. Not bad, easier than the 3012LF, but I always prefer soldering.
Here are the Sound Pressure Levels for each speaker, installed into a T39 24" Wide. I used a 60hz Sine Wave to test each driver installed, digital volt meter, and a XTi 4000 limited -3db.
3012LF
Volts SPL
1.5 = 108
2.6 = 111
3.7 = 113
4.8 = 115
5.9 = 117
7.3 = 119
8.9 = 120
10 = 121
11 = 122
13.2 = 123
16 = 125
19.2 = 126
Above 19.2 volts the Radio Shack Meter Maxed out at 126 db.
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MCM 55-2982
Volts SPL
1.5 = 103
2.6 = 107
3.7 = 110
4.8 = 113
5.9 = 113
7.3 = 115
8.9 = 116
10 = 117
11 = 118
13.2 = 119
16 = 120
19.2 = 121
23 = 122
28 = 124
36.5 = 124
47 = 126
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Over all sound was good, just not as loud, around 5-6db less in volume than the 3012LF. I really don't think there is much that would beat the 3012LF, its a great driver, period. But if someone was on a budget and wanted a less expensive driver to use, the MCM 55-2982 is not a bad choice, it will work for the price, just not as loud. But if someone was to build 4 and V-Plate them, then it would be a great combination, it would turn some heads.
For the price, I might build 4 more, and load the MCM's and just go with it, if ever I find a good deal on a 3012LF in the future I could always swap out drivers, (all 4 that is).
With music, I had the 3012 cabinet and the 2982 cabinet side by side, for sure the 3012 put out more volume. But the 2982 had a smooth bass response as the 3012 but at a lower volume. Overall, I think if someone wanted to use the 2982, it would work, especially if they plan to build 4 and V-Plate, they could reach some good db levels then. I guess it comes down to choice and $$$$.
Here is my current setup, 4 DR200's Pro 8 loaded, and 4 T39 24" wide 3012LF loaded.
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Hope this helps.
Lastcat
