Speaker phase observation and question?

Likewise, Erik. Putting it another way, I prefer the dollars I choose to invest in an amplifier to go as much as possible toward sound quality and build quality, rather than a lot of that investment simply going toward watts and amperes.

Best regards,
-- Al  

Tim & Erik, thanks for the excellent info and the informative link, which I’m still going through.

Kalali, first, although the term "impedance" is commonly used to simply refer to a number of ohms, to be precise a speaker’s impedance is a vector quantity, meaning that it is comprised of both a magnitude (the quantity that is measured in ohms) and a phase angle (measured in degrees). If the impedance is purely resistive at a given frequency the phase angle will be 0 degrees at that frequency; if it is purely inductive (hypothetically speaking; no speaker will have an impedance that is even close to being purely inductive at any audible frequency, or it would not be able to consume any power at that frequency) the phase angle will be +90 degrees; if it is purely capacitive (again, hypothetically speaking) the phase angle will be -90 degrees.

Also, as has been mentioned above, the phase angle of the impedance describes the amount by which voltage leads current (in the case of a positive/inductive phase angle) or voltage lags current (in the case of a negative/capacitive phase angle), at a particular frequency.

But to address your question, I suggest that you take a look at this thread. The entire thread is well worth reading, but note especially the latter part of Atmasphere’s post dated 1-9-2017 (beginning with "I feel like several points need clarification ..."). The short answer is that sound quality **does not** benefit from low impedance design, but other factors such as cost and marketability may. With those factors deriving in part from the fact that solid state amps can supply more power into low impedances (up to a point, of course) than into high impedances. The background and previous experience of the particular designer, and the kinds of designs he or she is most familiar with, also seem likely to be factors in many cases.

Best regards,
-- Al

Tim, thanks for another of your always valuable inputs about speaker design.  Regarding:

In theory when designing a crossover, 6db per octave gives you 90 degrees out of phase, 12db produces 180 degrees out of phase, 18db per octave produces 270 degrees out of phase and 24db per octave produces 360 degrees or full circle back in phase.

I believe this theoretical model assumes that the impedances of the drivers themselves are purely resistive, and of course they are not.  Is that the basic reason why the phase angles of a speaker's impedance, as shown for example in John Atkinson's measurements in Stereophile, typically vary up and down over the frequency range by several tens of degrees, and swing between negative (capacitive) phase angles and positive (inductive) phase angles at various frequencies?

Thanks again.  Best regards,
-- Al
 

From the measurements section of Stereophile's review of your speakers:

The Silver 8's step response on its tweeter axis (fig.7) shows that the tweeter and midrange unit are connected in inverted acoustic polarity, the woofers in positive polarity. More important than the polarities (see "Letters," November 2014, p.11) is the fact that the decay of each unit's step smoothly blends with the start of the decay of the next step lower in frequency, which suggests optimal crossover design.

Enjoy!  Regards,
-- Al