Why do so many designs have midrange fase reversed ?

[lduarte1973]

just wondering why do so many designs have midrange fase reversed ?

 

[Pano]

Because of phase shift in the crossover.

See also here:
http://www.diyaudio.com/forums/multi-way/234465-drivers-out-phase-2-way.html

 

[lduarte1973]

thanks , now i see why , i dont have passive crossovers on my system anymore , that happens too with a dsp like minidsp ?

 

[Pano]

Yes, all normal filters have phase shift, electronic, passive, active digital, analog, acoustical. There are ways with DSP to flatten the phase, and that has become something of a new approach or a fad. But most filters you'll encounter will have phase shift.

If you have a copy of MicroSoft Excel I highly recommend "Passive Crossover Designer" by Jeff Bagby. Spending time with PCD will teach you a lot about how filter work.

 

[lduarte1973]

thanks i will try it ,i want to learn more about filters , i do prefer the mids reversed , they sound less forward easyer on the ear.

 

[Jay1111]

thanks i will try it ,i want to learn more about filters , i do prefer the mids reversed , they sound less forward easyer on the ear.

Having a mid (or any driver) with opposite polarity is completely dependent on the specific speaker/crossover design. You cant just randomly flip the polarity 😕

 

[balerit]

Having a mid (or any driver) with opposite polarity is completely dependent on the specific speaker/crossover design. You cant just randomly flip the polarity 😕

My Camm Dynatone 2-way speakers have the same polarity by manipulating the values in the crossover calculation.

 

[Jay]

i do prefer the mids reversed , they sound less forward easyer on the ear.

Having a mid (or any driver) with opposite polarity is completely dependent on the specific speaker/crossover design. You cant just randomly flip the polarity 😕

Anyhow, it was an interesting observation regarding absolute phase.

Assuming that absolute phase is not audible, then
Woof(+) Mid(-) Tweet(+) is equal to
Woof(-) Mid(+) Tweet(-)

But often/usually/ime Woof(+) sounds better/louder than Woof(-).

In many 3-way cases, the midrange driver is too sensitive and cannot easily be padded down like tweeter to match the woofer insensitivity. This brings harsh or too forward sound so Mid(-) might be preferable than Mid(+) (may be audible only to batman )

But if the design requires the same polarity between woofer and midrange (for example Woof+/Mid+/Tweet- or Woof-/Mid-/Tweet+), may be I will prefer to prioritize the woofer to have the favorable phase.

 

[lduarte1973]

Having a mid (or any driver) with opposite polarity is completely dependent on the specific speaker/crossover design. You cant just randomly flip the polarity 😕

i was just trying the minidsp 🙂 but you are right the original design has midrange reversed