Speaker phase observation and question?


Hi everyone,

After months of playing around with positive phase and reverse phase connections to my Monitor Audio Silver 8 speakers, I have made a couple of observations. When connected in positive phase (red - red, black - black), the speakers put out pretty substantial bass, but the mids and treble are somewhat subdued. Upon reversing the phase, the mids and treble open up substantially, and the bass becomes somewhat subdued. To my ears, I actually prefer the reversed phased.

Moving forward to the current day, I purchased an app that tests phase using a generated tone. In testing my speakers, both bass drivers test positive phase, but the mid and treble test negative. I had read somewhere that some manufactures wire the drivers like this intentionally, but am confused as to whether or not this is the case with my speakers, or if it's a manufacturing flaw?

Any thoughts? 
chewie70
Hi  @almarg 

Looking at my answer, I see that I tip toed around your question, this still isn't a complete answer, but contributing...
We look at phase angles varying by impedance, so yes,  if we change crossover points or slopes,  we can affect phase angles to some degree. Anytime that voltage and current cannot travel together, they are no longer in phase themselves... A speakers impedance along with each drivers own characteristics, ie load variations, qes, voice coil induction etc causes these variations.  I hope this makes sense, 
Tim
Sorry, for those of us that are a bit slow, the phase angle of a speaker obviously changes with frequency and so does the impedance. Furthermore, it appears that a combination of a low phase angle and low impedance puts "stress" on the partnering amplifier. So, this begs the question why would a "good " speaker designer design a speaker that would create such condition. In other words, how does sound quality - whatever that means in objective terms, benefit from such design.
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

Hi Almarg,

I am definitely on team "easy to drive speakers." Get easy to drive speakers and a lot of amps will sound really great.

Get demanding speakers, and your amp costs may go up considerably.

So make sure if your speaker is demanding that it's really worth the cost of ownership. Being able to tell amps apart is not why I buy speakers anymore. :)

Best,

E
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