How to read speaker sensitivity rating?

Will someone please explain "phase angle"?

FWIW, when a speaker's specs include both its sensitivity and its power handling capability, it allows the user with a similarly capable amp to estimate how loud the speaker will play safely and continuously. For example, ratings of 87dB and 150 Watts translate to a maximum volume of just over 108 dB, earth shaking but not shattering.

Just my two cents, Mitch, but at 40k for the Dominance, shouldn't an audition trip to Utah be part of you plan? Or does Zu's generous return policy apply to the flagship as well?

John

Will someone please explain "phase angle"?

It refers to the phase relation between voltage and current, at a given frequency.

Speaker impedance, or any impedance, will be some combination of resistance, inductance, and capacitance. For a pure resistance, voltage and current are in phase with each other at all frequencies. In the case of a pure inductance, voltage leads current by 90 degrees (1/4 cycle of the signal frequency, denoted as +90 degrees). In the case of a pure capacitance, voltage lags current by 90 degrees (denoted as -90 degrees).

Pure resistances, pure inductances, and pure capacitances only exist in theory, although depending on the device, the application, and the frequency it is often reasonable to neglect two of the three terms as insignificant. That is not generally true for speakers, though.

Derivation of the net phase angle corresponding to a given combination of resistance, inductance, and capacitance, at a given frequency, involves some mathematical complexity, and is described in my post here in a thread on the difference between resistance and impedance.

Phase angles that are significantly capacitive, say -40 degrees, more or less depending on impedance magnitude, make life more difficult for the amplifier because they increase current draw. If significantly capacitive phase angles coincide with frequencies at which impedance magnitude is low, current requirements are increased further.

The speaker reviews in Stereophile generally include a plot and a discussion of impedance magnitude and phase angle, in John Atkinson's measurements which usually appear at the end of the review.

Regards,
-- Al

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Jdoris, an auditon trip to Utah is certainly under consideration. There are several speakers that I am considering. All of them require a plane ticket for me to audition them at their location. The freight to get them to me in Los Angeles will be ungodly. That's why I'm asking so many questions on this forum....to eliminate any unnecessary travel. Of course SOME travel will be required. I'd like to narrow it down to two finalists. I am also considering a set of Genesis 201 speakers, VMPS V60/VLA combo, Magnepan 201 with a separate subwoofer.
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