This sounds good. Is there any reason not to phase shift my subs?

[2Sunny]

So playing around with my subs today. I assume that minimizing nulls is a good thing so that was the goal. I used REW to take readings of L,R,L+R (no PEQ),L+R (w/ PEQ), and then here's the interesting one, L+R with PEQ but the left set 90 degrees out of phase. Oddly enough I found shifting the phase 90 degrees smoothed out the subwoofer response considerably. So then I listened to some scenes and music, both in phase and out, and I could tell a slight difference between the two especially in kick drums in music.

Have others tried this?
It's hard for me to imagine a downside because it sounds good to my ear, but are there reasons this might be a bad idea?

I only tested 20-80 Hz because I'm only interested in optimizing my subs and I have the crossover set on all my speakers at 80 Hz and the subs are only rated to 20 Hz at the low end.

 

[kemmler3D]

Tweaking the phase is often considered an important part of sub integration, and your blue line does look better to me, so I'd say you're on the right track here. I'd still do something about that 55hz peak though.

 

[morphemes]

only downside to me with phase is directionality of the vibrations... asking the sub to reverse phase is like asking it to vacuum up the earthquakes... not gonna happen. in phase it is epicenter, reverse phase it should open a portal to hades. black hole sub... wont you come... really just makes it less a bit efficient at hitting the tones. doesn't propagate as efficiently.

0/180 phase switch is really for the cardioid array. you can use two subs to create a quiet zone that isn't full of earthquakes. discrete directionality in the phase requires more control than that. it's not so critical because the room is acting like a waveguide on all of it, but 80-150 down typically summed to mono in both tracks, so... bass source is logically front center in phase. still joke about how the sub rear center 180 out of phase is the poor man's dolby surround.

From the measurements i think running it in reverse likely dodging the mode just as much as turning the sub down a dB. purely from the lack of efficiency, you can see the gap gets bigger and bigger and then *click no more mode.. and then it's right back at it again, you need a damper... could open a ski resort on that.. just a little damping, done right, you knock that valley up to where you're getting it with the calibration and then calibrate it.

 

[GXAlan]

Phase Alignment of Subs – Why I don’t use the impulse response

OK. The saga continues down below………………………. What is the best way to phase align our subwoofers to the mains? There is a hint in the way the que…

bobmccarthy.com

Very interesting article but short answer is that yes, aligning your phase is a good idea.

 

[kemmler3D]

like the actual general modal issue hasnt changed at all the speaker is just having a harder time getting as loud because you're running it in reverse...

This is not how speakers work. Motors don't work any less efficiently going in than out, at least not noticeably, otherwise there would be crazy distortion.

Losing 5dB when inverting phase would just be from turning partially constructive interference to partially destructive.

 

[Keith_W]

Remember that all peaks and dips you observe in the bass region are not a frequency domain problem. It's a time domain problem manifesting in the frequency domain - for e.g. subs interacting with woofers that are out of phase, subs interacting with reflections that are out of phase, etc. Therefore the solution is to tackle the time domain problems first, and then address the remaining issues with frequency domain EQ. Time and phase align, and then try all-pass filters. If dips remain after this, you either need to find better sub positioning, or you need more subs. If peaks remain after this, lop them off.