Hi, Can I use the Eminence Kappalite 3012LF in the MTH-30?
And with RCF-LF12G301 (http://www.rcf.it/it_IT/products/precision-transducers/low-frequency-transducers/lf12g301)?

Please answer me quickly...

Thanks, Giacomo.

I took the Hornresp input parameters for the MTH 30 from the construction thread. and run the sim for the Eminence Kappalite 3012LF.
There is good news and bad news...
The response has more ripple.
The power that it will take is increased

The Precision Devices 12sb30 driver hits Xmax (7mm) at about 45V (250W / 8 Ohm load)
The Eminence driver hits Xmax (9.1mm) at about 52V (340W /8 Ohm load
Attachment shows the Hornresp sim for the Eminence in black and the PD driver in grey.
How many cabs were you planning to build?
Note that either driver will require a High pass filter at about 40hz!

The RCF LF12g301 Driver sims up almost exactly like the PD 12SB30.
There is not a lot of difference in the response It may be a slightly smoother frequency response if the quoted LE of 2mH @ 1khz is more than the PD ( for which the LE figure is not given)
Xmax (6.8mm) is still reached at 250W

about Xmax: Hornresp sim excursion on a sine wave, but music is not a sine wave and never in music you will hear a sine wave at full level.

If you cut at 120Hz, you can easily take a margin of 3dB, so the Xmax will not reach the limit at 250 watts, but 500 watts in reality.

Ok thanks at all! I will use the RCF