On Mon, 22 Apr 2019 09:53:05 -0400, Mike Rivers
wrote:
On 4/22/2019 7:01 AM, Don Pearce wrote:
A true RMS current meter doesn't help, unfortunately. A speaker's
impedance is very reactive so multiplying RMS current and voltage
doesn't give you power. That would need some sort of measurement
system that could provide vector products. As for doing that with a
noise source, forget it. You need single frequency sine waves for that
calculation.
So no, you can't measure pink noise power into a speaker. Just supply
it a known voltage is the best you can do.
While this is way off the subject of a guitar amplifier speaker, Meyer
Sound has created a new test signal that more accurately represents
music, one with a crest factor that increases with frequency. While
their goal using this test signal is ultimately to determine the maximum
system SPL, and hence the system dynamic range and available headroom,
it can be used for telling us what we can expect to hear from a given
loudspeaker.
https://m-noise.org/
OK, I see the crest factor - it makes it kind of crackly. But that
pink noise covers 20Hz to 20k, which is not what you need for speaker
sensitivity testing.
d