Some questions regarding measuring speaker parameters:

1. "So simply measure the DC resistance of the driver with an ohmmeter, and use the impedance found when measuring the driver's resonant frequency for Zmax." I'm missing something here. All the tests until this point seem to give frequencies, not impedances. How do I determine the impedances Zmax and Zmin?

2. It seems that the scope is used to determine highest voltage and .707 times that. Can I just use a voltmeter instead?

3. When taking these measurements, is there a way to determine the speaker sensitivity? Should I just use an SPL while running the 1 volt RMS with the resistor? Will sensitivity change unequally for the drivers due to their different ensclosure volumes?

TIA

"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."

OK, I can determine the frequency but how do I find the impedance?

"Impedance can be found by measuring the voltage across the speaker motor and calculating the current through the circuit."

X = 2πFL for inductive circuits. I assume I find resonance (and from this paper I understand that resonance is where inductive reactance and capacitive reactance are equal), then plug the values into that formula. But I don't know the inductance. Furthermore, from I=E/Z, we can derive Z=E/I. Fine. The signal generator I ordered puts out 1.2V RMS. I don't know the current it puts out.

I'm to put a 10 ohm resistor in series with the speaker coil. Am I to break the circuit at Zmax and Zmin and measure current draw with a milliameter?

Do I then measure voltage drop across the coil once I reconnect the circuit?

"This reactive circuit (inductance and resistance) forms a voltage divider, so you can use Ohms law and reactive circuit formulas to determine the impedance of the motor."

We put the resistor in series with the coil. I don't understand how this is a voltage divider. Where are we dropping the divider to ground?

These questions certainly must seem naive to you, but again, I'm a hobbyist who just wants to build a speaker.

I'll take it a step at a time.

Thanks.

somehow the DPL looks better than shiva i think..

are these tests good enough to warrant calling the DPL12 lower distortion?

at moment im designing my front chamber /horn expansion twist-change in dimension.>

if the DPL12 is less distortion,is it worth choosing it instead of shiva? if i could even order it.
_Mike

• http://www.mfk-projects.com/woofer_data.htm#shiva

Regards,
Gabriel