phase alignment procedure of the subwoofer with the main

[surreal89]

good evening, I need someone to explain to me the procedure for phasing the sub with the main...
I have both separate measurements, but I don't know the procedure.

Click to read more...

 

[RobGMN 5,000+ posts]

Are you using REW and a DSP?

 

[spokey9]

Not again

 

[YourNameHere 10+ year member]

......waiting for this also

 

[RobGMN 5,000+ posts]

Not again

Probably best to know what he has before making a suggestion on how to do it.

If you have a problem, keep in the 'dome where it belongs.

 

[surreal89]

Are you using REW and a DSP?

Yes..I've already done all the measurements and corrections, I just need to correct the phase between sub and main

 

[surreal89]

Probably best to know what he has before making a suggestion on how to do it.

If you have a problem, keep in the 'dome where it belongs.

I can send my measurements if you prefer.
I was interested in the process of how to tell when it's aligned

 

[winkychevelle 10+ year member]

I mean if you have the phase plots you should be able to overlay the phase of your sub with the midbass drivers and adjust multiple things ie: phase, crossover type and/order order, time alignment, to get the phase to be as close as possible between drivers at crossover points.

Typically I would time align all drivers then set phase and then set eq. Then verify proper summation of all like drivers to see if like drivers need a phase adjustment or allpass filter to fix problem areas. Not all nulls can be fixed and narrow nulls are rarely even heard.

 

[RobGMN 5,000+ posts]

I can send my measurements if you prefer.
I was interested in the process of how to tell when it's aligned

What equipment are you using? It can be done physically (placement of sub), electrically (reversing wiring), electronically (DSP).
If your amp has a phase "switch", you only have two options. In that case, select a piece of music you are VERY familiar with from hearing it on a good system, play it at a reasonable level. Literally switch phase back and forth. One of them with sound more "right" than the other, even if not perfect.

If you have DSP, then you can use REW plus your DSP to find the right setting by doing sweeps of mains, then subs (one at 0, the other at 180 degrees), then look at the overlap of the two sweeps.
When you see cancellation instead of summation at common frequencies, that is your sub working out of absolute phase with the mains.

You could actually just test the mains and the sub separately, then simply reverse the phase of the sub in REW to create the second "test", and compare the three sweeps.

I like to do actual sweeps just in case an electrical change causes changes other than simply reversing cone motion.