Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Hi All,

I just recently upgraded from PTHD 2018.3 to PT Ultimate 2019.5. I'm on Mac 10.12.6 Trashcan.

I've noticed a change in how PT sums a stereo track that is bussed to a mono Aux.

In 2018.3 (and before) if you bussed a Stereo track to a mono Aux, it would yield a +3db signal (due to the summing).

In 2019.5, the same process yields a +6db signal.

I am seeing this across multiple suites on HDX and Native.

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Wow.really? Oh no. Messes up recalls then from pre 2019.5

Sent from my SM-G975U using Tapatalk

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Could it be the pan law setting?

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Possibly but the pan depth is set the same in both instances. So, they shouldn't be different.

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Just saw your post and happened to be in in a studio with pt11.3.1. and also pt2018.12.0

So did the following check. Both have same result.

If I put 1k tone (Created via audio suite signal generator which would make it a coherent source) on a stereo track at -20dB and then route that to a mono aux the result is -14dB on the mono aux.

anyway hope the info helps

Cheers

Bruno

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

I think everyone needs to be clear if they are testing coherent or non-coherent/incoherent sources.

A coherent source will sum to +6. This has nothing to do with pan law but everything to do with audio physics.

An incoherent source should sum to +3.

Basic calculator and explanation

http://www.sengpielaudio.com/calculator-leveladding.htm

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Hi Guys,

Thanks for this.

Here are two screen shots of the same session. I am using a file for the tone made by the Audiosuite Signal Generator @-20. It is the same file for the left and right.

2018.3 Mono= -17 Stereo= -20
2019.5 Mono= -14 Stereo= -20

Given Bruno's results, maybe 2018.3 is the problem?

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

Are the tones time aligned? Audiosuite tones are notorious for not starting the waveform exactly at the same point in time, so i would double check phase alignment

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

This is why I used the same file for both left and right. Only way to be sure.

Regardless, I should get the same result in both versions of PT.

Re: Bussing a Stereo Track to Mono Aux: Summing change from 2018.3 to 2019.5
 

From Avid Support:

The issue you reported is by a known issue with PT12.0 - 2018.3,
which was fixed in PT2018.7.
The current version is working properly and the previous versions (12.0 - 2018.3) did not...