Stereodude
Per chance does anyone have a the T/S parameters for the 8" powered woofer in the RS1000?

I had an amp die and I'm trying to figure out how much power the woofer can safely handle to help pick a replacement.  I did discover the driver is only 8 ohms so the "350W" amp that came with the RS1k couldn't have putting out more than ~200W into the driver and it was capable of getting unsettling mechanical noises from the driver.
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Mark_Seaton
I think I came across one of these amplifiers here.  I know it's the same general amplifier, just not certain if it's the same plate size.  Can you e-mail me a picture and dimensions?
Mark Seaton
Seaton Sound, Inc.
sales@seatonsound.net
773-290-8436
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Stereodude
Mark, I e-mailed a picture and the dimensions of the amp to you.

In related news my DATS will be here tomorrow so I can measure the 8" driver (and other drivers I'm playing with).  I'm rather interested to see exactly how poorly designed this driver / amp / enclosure combo is.
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Stereodude
Here are the T/S parameters I measured:

 #1#2Ave. 
R(e)7.497.517.50ohms
F(s)49.1249.849.46Hz
Q(ts)0.7050.710.7075 
Q(es)0.8430.8550.849 
Q(ms)4.3114.1874.249 
L(e)3.213.183.20mH
M(ms)93.1590.0491.595g
V(as)7.257.307.28L
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Stereodude
Also, based on a fairly careful measurement with a ruler I calculate Sd to be 186.4 cm^2.

Xmax is unknown so far.  I am thinking to use the method shown in this thread to indirectly measure it based on power input at 10% distortion at a given frequency in a box of known volume.  Once a power level is determined, a software simulation of the driver in that box design is used to determine how much the cone travels at the test frequency at the measured power level and you've got xmax.  Or, at least that's the theory.
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Stereodude
Well, I managed to put a little more than 300W RMS into the driver at 20Hz (free air) without blowing anything up or hitting any mechanical stops.  I decided to stop there instead of pushing on and risking the driver.  At 20Hz the driver starts to make audible harmonics / distortion somewhere around 100W.  Unfortunately, the scope I was using doesn't have useful FFT capability at low audio frequencies, so I couldn't find the 10% distortion point.

Here's the 300+W capture:


Channel 1 is voltage across the driver
Channel 2 is the voltage across a .1ohm shunt resistor in series with the driver (multiply by 10 to get Amps)

This confuses me a bit since I've heard not so nice "mechanical" noises from the powered woofers in the RS1k's if they're run large for HT (like during the plane crash in Flight of the Phoenix) and the original amp isn't pushing 300+W into the driver (probably 150-175W).  I guess the "mechanical" noises were the amp clipping, not the driver bottoming out.

Another interesting I found is that the QSC PLX2402 amp doesn't roll off at 8Hz like the specs say.  I found the -3dB point of the amp together with my USB DAC to be ~2.5Hz.
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Stereodude
My coworker helped me get the FFT working on the scope so I could get useful data.  Assuming I did the calculations right at 20Hz 10% THD is right around 55W and 20% THD is right around 180W (analyzing the current waveform).  Putting the measured power into the driver model that's correlates to 7.6mm "xmax" and 13.8mm of "xmax" respectively.
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