measurement answers [message #42281 is a reply to message #42280] |
Tue, 26 August 2003 13:00 |
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Wayne Parham
Messages: 18786 Registered: January 2001
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Illuminati (33rd Degree) |
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What we're looking for are impedance values at specific frequencies. So, for example, DC resistance is impedance at 0Hz and Zmax is impedance at the resonant frequency. Zmax is described by a frequency and an impedance. If you measure voltage with a scope, you'll see peak values and can find RMS by multiplying by 0.707. If you measure with a DVM, you'll read RMS values and can calculate peak by dividing by 0.707. As for SPL, sure, you can put a microphone 1 meter away and supply a 2.83v test signal to find the 2.83v/M level, or whatever levels you wish. But below 100Hz, the cabinet will have a lot of influence so keep that in mind. For that matter, so will the room unless you do the acoustic measurements outdoors.
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