The specs say the QRX218 is rated at 1200 watts rms, with 4800 watt peaks.
I'm still not following your rationale on why the continuous rated power is going to damage the driver.
Bo,
The cabinet is not rated at 1200 watts "RMS", it is rated at 1200 watts using the AES2-1984/ANSI S4-1984 signal using a 6 dB crest factor.
RMS , or root-mean-square, is a measure of the average power level of a signal. The RMS level is representative of the heating capacity of the signal.
Peak is a measure of the maximum level that a signal attains.
For a sine wave, the peak level is 3 dB above the RMS level. For music, the peak level can easily be in the range of 10 to 15 dB above the RMS level, or as low as a sine wave for low frequencies in EDM (electronic dance music).
The pink-noise output of AES2-1984/ANSI S4-1984 has a peak to RMS ratio of voltages of 2:1, or 6 dB, half the average power of a sine wave.
Look at the current draw of your PLX 380 amplifier at various output levels, 1/8 power is 12 dB crest factor pink noise, about the equivalent of fairly compressed music, 1/3 power is 6 dB crest factor, Full Power Sine Wave is 3 dB crest factor, like we see in some LF EDM. Note the BTUs and current, around 80% of that power is being dissipated through the speaker, only 3% or so actually makes sound, the vast majority just makes heat.
New speaker designs have improved heat management and excursion by a factor of three or more compared to the EVX 180B, designed in a kinder, gentler era (late 1980's), when the most compressed EDM you could find had more than double the crest factor of today's droning stuff.
Sold the last of the EVXs off years back, I no longer can get behind my EV ad from 1990. There have been a lot of changes in 24 years, EV has not kept up
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Art