180 degree phase shifts

[stevetennant]

Hi I have Spectra 22's and when doing my room EQ found that both the left and right units exhibited 180 phase shifts at certain frequencies. How can this be corrected?

 

[tyu]

Here what we got.....I have the Specstra 3s......I run them fullrang..I don't care for the Spectra sound.......cant wate for more input on this.....
look like...sounds like....well to me.....there is some shift....
here the setup of the panels.....pic 3 is one panel....so you have 2 in ea speaker.....so that's setup to like 4 panels ea...with..4 front 4 back...but only 2 mylars.............nut right

 

[bolserst]

Hi I have Spectra 22's and when doing my room EQ found that both the left and right units exhibited 180 phase shifts at certain frequencies.

Can you post the measurement and/or give some more details?
1) How were the speaker and mic positioned in the room?
2) From your description the phase shift was localized at a few narrow frequency bands, not several octaves, correct?
3) High frequency? Low frequency?
4) Did the phase reversal coincide with a dip or peak in the response?
5) Same or different between the speakers?

Remember since they are dipole speakers, the sound coming from the backside of the diaphragm is 180deg out of phase with the front, so depending on proximity to rear and sidewalls can get some localized cancelling and phase reversals. It may also be related to room modes being excited in a different manner than with a monopole box speaker.

 

[bentoronto]

Other than some low freq coordination, I never found absolute or even relative phase to matter much or matter consistently.

But the relative phasing of various drivers can matter a bit, if unpredictably and inconsistently. Trick is to measure freq response with and without reversal and see what works best (or works better more of the time, sort of).

Ben