Stereophile - Sabrina 5

In a 3 way speaker, having the polarity of the midrange reversed is a well known speaker design technique. JBL pioneered that in the 1970s. 

Yep!

Mike

@audphile1   Glad you have found bliss with your Sabrina loudspeakers. Please be open minded enough to understand that not all of us find Wilson Audio speakers as the "Holy Grail". Yes, some negative posts can be over the top berating Wilson Audio that are unjustified. The bottom line is IMO there are loudspeakers that portray music in a more natural/realistic/organic presentation even at a lower price point.

@dayglow please be open minded but not delusional. I’ve heard and owned enough speakers in my life. I can make the most natural and organic sounding speaker like the Audio Note for example, sound either dull and boring or extremely clinical and analytical and send you running out of the room  

So please don’t patronize me.

https://youtu.be/G_kaYKVpENI

ask AI…

Why It’s Done

Crossover networks use capacitors and inductors to create "slopes" that roll off frequencies. These components shift the timing (phase) of the electrical signal: 

• 2nd-Order Filters (12 dB/octave): These are the most common reason for reversing polarity. A 2nd-order low-pass filter (for the woofer) shifts the signal by +90°, while a 2nd-order high-pass filter (for the midrange) shifts it by -90°. 

• The Result: At the crossover frequency, the woofer and midrange are 180° out of phase with each other. If you wire them both with "normal" polarity, they will cancel each other out, creating a massive "dip" or "hole" in the sound at that frequency. 

• The Fix: By physically reversing the wiring on the midrange, you flip it another 180°, bringing it back into alignment with the woofer and tweeter so they "push" and "pull" together.

@machif  - Any multiway speaker may need to invert the polarity due to phase matching issues with the other drivers.   The issue isn't whether it's positive or negative, it's whether the polarity has been chosen to minimize cancellation due to phase alignment. 

Sometimes this means you put the midrange in positve polarity, sometimes not. 

To be clear, positive polarity means that a positive voltage at the inputs pushes the driver towards the listener. 

In other words, sometimes inverted polarity is the correct polarity.  Depends.  In the Sabrina V ... well, sigh.