Click track seems to speed up/slow down

[boove]

odd issue here:

i have been recording a band this weekend (di bass, di guitar, drums) and we all noticed that sometimes it seemed that the click track would seem to slightly speed up and slightly slow down.

it seemed to do this at the start. i let it run for a few bars then it seemed that things were normal so we started recording from there.

it also seems to do it only when they started playing. so i am thinking there is something funny with the computer processing?

like it is taking a few seconds to realise what its doing. its a slight shift in speed, very slight, but still, it meant everyone fell out of time with it. seems odd and we managed to still do good takes but its not something i want at all.

has anyone else had an issue like this?


pro tools 8 by the way.

i checked the tempo rulers etc. nothing had been moved or changed. one solid straight line. no tempo changes in the song what so ever.

its really odd and i am baffled.

[TOM@METRO]

What are you using for a clock source?

[guitar486]

What was your hardware buffer size while recording? I remember an issue in 7.4.2 which caused the click to screw up at high buffer rates while recording...

[boove]

the buffer size while recording was 128.

as for clock source...umm...dunno. how do i find out?