Out2 latency?

edo

edo

Power User
Vendor
I'm in the middle of a soundcheck and the sound guy says my amp (out2) is not in phase with out1 (foh), and reversing the phase on the out2 doesn't solve it... He says he applied 0.037ms delay on the amp to get a decent result.. Any clues? Could the 3rd party IR's (taf) add latency to the main out?
 
What amp? Power amp feeding FR monitors? Or power amp feeding a traditional cab?
 
Apart from what has been said, watch the EQs because many dont know that they can alter phase in a great way... for example, if you duplicate a track and in the copy put a non linear EQ and boost the bass, the sum of both signals can result in a loss of bass frecs.
 
Doesn't the motor drive in the cab block add additional latency? do you have motor drive in the cab sim on?
 
FractalAudio said:
Perhaps the speed of sound from the speaker to the mic.
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Actually .037ms is 12 inches in distance from source to mic. Any distance between mic and speaker will alter the phase and add some delay. Add any processing at all and it only gets worse.
 
Patzag said:
Actually .037ms is 12 inches in distance from source to mic. Any distance between mic and speaker will alter the phase and add some delay. Add any processing at all and it only gets worse.
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It's about 1/2 inch.

350 m/s * .000037 s = 12.9 mm => 0.5 inches
 
The thing is, if we had to apply 0.037ms delay to the amp to correct the phase with the axe sims, the latency is not on the amp, but it's on out 1.. No motor drive applied, no eq, just 2 ac30tb's going into 2 taf cabs.. Could that just be dsp latency as i have amps to out1 and nothing to out2?
 
edo said:
The thing is, if we had to apply 0.037ms delay to the amp to correct the phase with the axe sims, the latency is not on the amp, but it's on out 1.. No motor drive applied, no eq, just 2 ac30tb's going into 2 taf cabs.. Could that just be dsp latency as i have amps to out1 and nothing to out2?
Click to expand...

Did you apply latency to the Axe fx foh out1 signal or to out2(the real amp)?
 
I added delay to the amp (out2) to compensate with out 1. Sorry, I got it wrong and misleading in the title
 
edo said:
I added delay to the amp (out2) to compensate with out 1. Sorry, I got it wrong and misleading in the title
Click to expand...

A way to compensate for whatever this is w/o using a delay block is to use a compressor set to 1:1 ratio. Use the look ahead parameter as a micro delay.
 
Good call! Yeah, i wasnt using the delay block as the latency is a micro delay.. Will check by recording an impulse from the 3 outputs and see if they align as soon as i get the chance
 
Karl Houseknecht said:
Not only that...but who has a delay unit that can add 3/100 ms of delay???
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You do. Cab block and the compressor block will achieve those. Some PA EQs or digital boards also have micro delays for adjusting speakers a different distances.

you can check if you can hear it yourself. Set 2 cab blocks in parallel. Adjust the delay of one to .035. I seem to hear a extremely small bit of a difference when I compare various delay times between 0 and .05, but nothing that would remotely make one sound bad.
that is with the same cab sim. Using a real cab with a cab sim, there would be way more things (mic position, distance, room nodes, preamp/eq circuitry) that would make a much bigger difference. I'm thinking it had to be a greater amount of delay.
 
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