Constant Latency, How many samples?

    Hello,
    I think I understand what constant latency does and why it is crucial for reamping,
    After reamping I assume I have to compensate for this latency in my DAW


    The KPA operates at 44.1 kHz, so I wonder how many samples is it exactly?


    Cheers,
    Salvo.


    EDIT: Alright, I try to answer myself, seems to be 162 samples (3,673 ms) from what I can measure in Reaper so after reamping one should nudge items right of this amount assuming 44.1kHz sampling rate (that is, unless you have sample rate converter in between)

    Edited once, last by everasia ().

    This sounds very useful. I have been wondering this myself when reamping, and although I use constant latency, I am not quite sure what it does. Would you mind explaining a bit more what you're talking about?

    Quote from MCVA444

    This sounds very useful. I have been wondering this myself when reamping, and although I use constant latency, I am not quite sure what it does. Would you mind explaining a bit more what you're talking about?

    Each rig has it's own latency depending on it's complexity. When you reamp, you want the latency to be fixed in order to avoid phasing issues.
    So constant latency will make every rig "slow" as the slowest possible, so they are all "slow" but all same.

    Quote from tommyguitar

    Constant latency is 5ms AFAIK.

    mmh weird, I recorded something with constant latency OFF, then I reamped that track with constant latency ON and I aligned those two tracks until they were perfectly in phase, that's how I got that 162 samples.


    But I am thinking maybe this way I am just measuring the difference between those 5ms and the rig instrinsic latency. ?(


    BTW, does anyone actually nudge items after reamping or you guys just live with those few more ms due to reamping?

    Quote from sambrox

    Constant Latency is about 4.9 ms, according to @'ckemper'

    Is that for a rig with just the stack engaged maybe?


    Engaging other stomps definately influences the latency, even when constant latency is engaged: I noticed a bigger latency when I turned on a Transpose stomp before the stack section, although constant latency was still engaged. I didn't do any measurements but just noticed the latency when playing.

    Quote from DaanJM

    Is that for a rig with just the stack engaged maybe?
    Engaging other stomps definately influences the latency, even when constant latency is engaged: I noticed a bigger latency when I turned on a Transpose stomp before the stack section, although constant latency was still engaged. I didn't do any measurements but just noticed the latency when playing.

    It's supposed to be fixed, but I see that it was introduced before the pitch shifting effects existed, so maybe they do impact on the latency. @ckemper ?

    Good question. We know it's supposed to relegate all Rigs to the slowest common denominator(!), which has always, AFAICR, been between 4 and 5ms.


    However, adding HQ pitch shifting into the equation is IMHO a bad idea. The latency introduced by such processes is in a different league and is felt by all. This would impact on the playability of the KPA for those who like to keep CL switched on for consistency across playing and reamping. Perhaps a caveat could be added to the manual, such as:


    * Constant latency applies to all Rigs except where pitch-shifting algorithms are active.

    Quote from Trazan

    It's not crucial for reamping. At least not for me :) I have no interest in reamping the same recording more than once though.

    Ok then maybe I am missing something.
    Let's say you record your playing with rig A. rig A will have it's own latency that you basically compensate while playing and SW monitoring in your DAW. So you play it back and it sounds perfectly in time with your click track.


    Then you want to reamp that track with rig B. let's say the rig B latency is more than rig A latency. The result will be then a bit off, so you need to nudge items of a certain amount.


    Then you repeat this with rig C and the nudge amount will be different and so on...


    With constant latency the amount you have to nudge is bigger but always same, regardless the rig you are reamping to. So I can create a beautiful custom action in Reaper that fixes the reamped tracks alignment with one click.


    Is this correct or I am talking nosense? ?(?(?(

    No, you're correct, everasia, but the latency shouldn't even be a consideration unless you're doubling tracks and are trying to achieve perfect phase alignment.


    Even then, folks tend to modulate pitch and time in order to create the illusion that multiple tracks are discrete takes, in which case perfect phase alignment is irrelevant anyway.


    If it's purely for perfect-timing purposes, nudging the tracks by ear in, say, 5 or 10ms intervals to fit the groove can't be beat (get it? Beat? Uugghh...).

    Alright I got it. I was overthinking this latency thing.
    So if I have to reamp two separate played tracks there is no value in using the constant latency, at the end I'll have to nudge anyway if I really feel I need to.


    It makes sense only when I am reamping two times the same track with two different rigs and I want those to reamped tracks to be in phase.

    I wouldn't worry about latency too much unless you reap the same di with 2 different rigs. Surely your playing is likely to be more than 5ms off the beat anyway.

    Karl


    Kemper Rack OS 9.0.5 - Mac OS X 12.6.7