Any point to gain matching identical subs before REW

[siggie]

I am getting ready to set up two matching subs using miniDSP and REW. Is there any benefit to gain matching them? It seems that if I set the gain on the sub amps the same, then they should already be gain matched. However, my research has not provided any guidance on this question.

Thanks in advance,

siggie

[megash0n]

Jul 16, 2020 14:00:00 GMT -5 siggie said:

I am getting ready to set up two matching subs using miniDSP and REW. Is there any benefit to gain matching them? It seems that if I set the gain on the sub amps the same, then they should already be gain matched. However, my research has not provided any guidance on this question.

Thanks in advance,

siggie

From the research I've done, this is critical.. So, yes. Gain match with an SPL meter.

[kahodges1721]

Jul 16, 2020 14:21:26 GMT -5 megash0n said:

Jul 16, 2020 14:00:00 GMT -5 siggie said:

I am getting ready to set up two matching subs using miniDSP and REW. Is there any benefit to gain matching them? It seems that if I set the gain on the sub amps the same, then they should already be gain matched. However, my research has not provided any guidance on this question.

Thanks in advance,

siggie

From the research I've done, this is critical.. So, yes. Gain match with an SPL meter.

I believe you are confusing gain matching and spl matching possibly. If the sub are at different locations in the room then the best thing to do is measure both sub brought to the same exact point in the room 1 foot from driver. With that said if you have two identical subs playing from different channels on the same amp then setting the gains the same on the amp is all that you will need to do. No additional worry about gain matching. The idea of gain matching is that all subs run out of head room at the same time rather than spl matching which may force one sub to work much harder than the rest.

[Boomzilla]

I think 2kahodges1721 is right (despite the fact that he's an Alabama fan - LOL). Before you run REW or MiniDSP, set the gain pots of BOTH subs to somewhere between 50 and 75%. The gain pots should have identical settings - THEN run the room correction. Why do you want to do it this way instead with a SPL match? Simple - the room may add or subtract up to 20dB at any specific frequency, and the speakers or subs (being in different locations) may not give the same SPL even at the same gain setting. So match the gains snd then let DSP adjust for the room.

[kahodges1721]

Jul 16, 2020 15:14:36 GMT -5 Boomzilla said:

I think 2kahodges1721 is right (despite the fact that he's an Alabama fan - LOL). Before you run REW or MiniDSP, set the gain pots of BOTH subs to somewhere between 50 and 75%. The gain pots should have identical settings - THEN run the room correction. Why do you want to do it this way instead with a SPL match? Simple - the room may add or subtract up to 20dB at any specific frequency, and the speakers or subs (being in different locations) may not give the same SPL even at the same gain setting. So match the gains snd then let DSP adjust for the room.

Yup exactly!

Ps. I was raised that way spent my life and my undergraduate money there. At least you recognized the double mullet and didn’t mistake it for braves! Most people say braves.

[siggie]

Thanks, Boomzilla  megash0n and kahodges1721 . I am asking about gain matching. According to my research, you do this by putting each sub in the same location relative to the mic, sending the same signal to each, and changing the gain on the second so you get the same SPL without accounting for the room or distance from the listening position.

What I'm taking away is that this process is not necessary with identical subs with identical amplification. Correct?

siggie

[kahodges1721]

Jul 16, 2020 16:38:46 GMT -5 siggie said:

Thanks, Boomzilla  megash0n and kahodges1721 . I am asking about gain matching. According to my research, you do this by putting each sub in the same location relative to the mic, sending the same signal to each, and changing the gain on the second so you get the same SPL without accounting for the room or distance from the listening position.

What I'm taking away is that this process is not necessary with identical subs with identical amplification. Correct?

siggie

That is correct

[megash0n]

How would one go about confirming the gain match?

[foggy1956]

Jul 16, 2020 19:54:54 GMT -5 megash0n said:

How would one go about confirming the gain match?

REW with the mic placed directly in front of each sub at about 1' I believe

[Boomzilla]

But the dials on the subwoofers' plate amplifiers are generally close enough (same brand of sub + same version of plate amp) that you need not acoustically verify. Why? Because REW / MiniDSP will take care of any small discrepancy for you.

[siggie]

Jul 16, 2020 21:07:42 GMT -5 Boomzilla said:

But the dials on the subwoofers' plate amplifiers are generally close enough (same brand of sub + same version of plate amp) that you need not acoustically verify. Why? Because REW / MiniDSP will take care of any small discrepancy for you.

The amps are Dayton Audio SA1000s. Going by the look and feel, this is the nicest sub amp I’ve ever laid my hands on. Hopefully that means they’ll have consistent performance and accurate controls.