Latency With Bussing

[midnightsun]

I thought I understood latency, guess I don't. I have PT11 HDX. I was doing a complex mix and wanted to verify that there would be no latency or misalignment of a bussed track. Track 1 with audio file, without any plugins instantiated was SENT to Bus 1. Track 2 was setup to record with input from Bus 1. Track 1 and Track 2 had the same Output. I/O setup delay compensation box was checked. I did a recording pass pass and compared the wave forms from Track 1 and Track 2. They were not perfectly identical and Track 2 lagged by a bit. This entire experiment was entirely ITB, i.e. no DA or AD conversions. I was thinking and hoping that bussed wave information would be perfectly in alignment other than perhaps gain change or wave form characteristics imparted by plugins.

Where is my assumption flawed and/or what am I doing wrong?

[Ryan Young]

Is delay compensation on? Otherwise, it should be delayed by whatever your buffer setting is at.

[Darryl Ramm]

Its hard to follow your writing. What *was* done, what plugins were instantiated? DSP or native? *how* were the waveforms different? What exact latency do you measure (in samples, at what sample rate?).

If no plugins were instantiated anywhere then the only differences should be signal level and possibly latency.

If there are any plugins anywhere then what exact ones? Native or DSP? And in either case what latency is expected for those plugins? If native what is your playback buffer size? If delay comp was enabled what was showing for each track?

Complex mixes may not be the place to check stuff, try starting with a empty session and play and then go looking for possible problems in you session if you suspect that... sounds like you may be doing that but I'm still lost if plugins were instantiated anywhere.

[Rich Breen]

Originally Posted by midnightsun

... I/O setup delay compensation box was checked....

OK, I/O DC is turned on, but is ADC enabled in the "Options" menu?

[Dan IceWood]

what version PT?

give track one and 2 different output - ie bus - hardware.
but stilll at 64/128 you should be fine