2018.7 low latency Recording question

[RobertDorn]

Hi!

I almost never used low latency recording mode before on my HD native setup, but since I have an UAD Arrow interface it’s quite handy to use this.

I was recording a guitar today in a 96K 32 bit session, automatic delay compensation turned on.(always have that on) And The recorded audio was not time aligned correctly. When in low latency mode plugins on the record armed track are automatically bypassed, this track had some plugins on it, giving 64 samples of delay for the 3 plugins when the track was not record armed, but when hitting the record button the delay listed jumped to above 4000 samples. The only way to get my recorded take time aligned like when played was by making the plugins inactive. The session consists of just a print stereo track guide to play on (no plugins on the inserts) and a mono guitar track. It didn’t matter if I made just some or all plugins on the guitar track inactive, also only the fabfilter Pro-Q2 being active (but bypassed in LLM) made the track delay going up to above 4000 samples when hitting record , with a take printed back out of time.

Am I overlooking something or shouldn’t I use low latency recording with plugins instantiated already, or is it the 96k sample rate?

If anyone perhaps knows I’d be glad to hear:) ps im on 2018.7 ultimate on a Mac with High Sierra. Sample buffer was 512 samples .

[Darryl Ramm]

I'm not following what you are doing.

What are you doing in general? e.g. Tracking guitar? what type of guitar? e.g. an electric guitar miced off an amp?? Or a DI signal through an amp sim plugin? Or what? What amp sim plugin... etc.

If your IO buffer is so big (512 samples) why are you worrying about low latency mode?

How large (in samples) are the tracks offset/out of time?

I am not sure what track the fabfilterPro-Q2 is on. What are all the plugins you ave inserted anywhere? A screenshot of mix window showing plugins and reported latencies of a absolute minimal session showing this problem might help.

What mode is the fabfilter Pro-Q2 in? It's got several k worse case sample latency. What does it do in zero latency mode? What is it reporting to Pro Tools how you are trying to use it? What is it actually doing (do a clap test compating a mic signal going through e filter and direct.

What happens with no plugins inserted *anywhere*?

If things still don't make sense try starting with a new session and trash preferences.

What are you doing in the UAD Console with any plugins?

Since you gave a UAD interface and why not monitor thought the Console/plugins on that instead of Pro Tools?

[RobertDorn]

Hey Darryl,

Thanks for the quick reply!! I was recording an electric guitar through the DI input on the arrow, with a unison guitar amp (Friedmann Buxtom Betty) loaded on the unison slot in Console, and a bx_tuner in an insert slot.

Without any plugins inserted on the track in ProTools (or when plugins made inactive, not bypassed but greyed out) everything goes perfectly fine. Even if only the Pro-Q2 is instantiated (not in lineair phase mode which is huge sample delay, just the default setting causing almost no latency) the sample delay displayed at ADC at the bottom of the track jumps up to over 4000 samples delay, when in LLM as soon as I press record on the track. (when rec Unarmed it gets back to 64 samples delay for all 3 plugins active) Other 2 plugins were Tape from Sofube and Echoboy from Soundtoys.

I guess it's also around that 4000 samples early when playing back the recorded take, Since I'm a human not playing sample accurate on the grid:) I can't tell for sure how many samples it is delayed exactly. I indeed could check this with a 2 - mic clap test, one on a PT track with plugins on insert slots (bypassed in LLM) and one track without any plugs loaded in the inserts.

I will try making a new session and also a 48k session, which I record at most of the times, to see if there's any difference. I could return PT output to a virtual channel in console, do you think it'll make a difference? When routing the PT track outputs to MON L/R it's already 'getting back' in console on the mixbus, only not through a virtual input then.

[Darryl Ramm]

Hi Robert

Mmm I am not sure what is going on. But I would want to exclude the Pro-Q2 as a culprit here. Trash prefs, simplify as much as possible, say create a session using aggregate built in input/output and stick that plugin on a track and play with what delays it reports to Pro Tools under different, session sample rates etc.

I would close/open the Pro Tools session when testing between different Pro-Q2 latency modes to force it to pick up any latency changes.

I am also not following how you are monitoring... you are trying to monitor via the UAD console?