less latency (i compared the Kemper, the Axe FX and the Line6 Helix)

  • When I have my Line6 G70 wireless in front of the Kemper and my Eventide H9 in Loop I get 8,79 milliseconds. That feels definitely unpleasant. When the loop is switched off, everything feels nice again.


    The Loop doubles the latency because the sound is converted twice. Therefore, I have the H9 now in front off the Kemper.

  • When I have my Line6 G70 wireless in front of the Kemper and my Eventide H9 in Loop I get 8,79 milliseconds. That feels definitely unpleasant. When the loop is switched off, everything feels nice again.


    The Loop doubles the latency because the sound is converted twice. Therefore, I have the H9 now in front off the Kemper.


    But the H9 in front adds another AD/DA as well. ?

  • Latency issue will be discussed as long as there is DSP present. A/D, D/A, DSP operations, all take time = latency. Question is, what is the real value of latency? Comparing latency by ear is IMO not the best option. As it was mentioned before, compression and other factors can shift our perception of latency. @Bommel If you could measure the latency for Axe, Helix and Kemper and post results here, it will shed more objective light on the issue. great tool for measuring latency (if you are on Windows) can be downloaded here: https://centrance.com/downloads/ltu/


    cool! thanks i'll try it!


    my question is just is it possible to speed up the kemper amp by reducing the dsp operations then ? i mean just in case ...
    like mentioned before it isn't a dealbreaker, but i mean it fits into the feature request, so why not. if it is possible it would be cool and maybe i'm wrong
    and it was just because of the more compressed axe fx sound ... :D i'm not an expert, that is why i'm in the forum :D

  • I find it amusing that the whole latency issue wasn't an issue before we all had DAWs and reducing latency became a sport similar to squeezing an extra 1/4HP out of a car engine. You never heard guys complaining that they couldn't stand more than 7 feet away from their amp on stage (7ms latency) because the lag became noticeable.


    My thoughts exactly.


    In addition to the 1mSec per foot that sound takes to travel, there is also a mechanical delay associated with speakers (at least there is with the woofer).


    When I play through my basement speakers from my computer area (which is about 15 feet from the speakers), I do notice a delay. When I play with headphones, I can't hear any delay at all.


    These informal results make some sense to me. Lets assume that the measurements done with the y cable are correct and that a Kemper has latency of 3.5-4.6mSec. That registers as "instant" in my head. Add another 15mSec for my speakers being placed some distance from me and we have around 20mSec. Most of us would be able to easily hear this I believe.


    Some people can hear IEM delay of 5mSec.... but this is different since you actually "hear" what you say through your bones vibrating before the IEM actually reproduces the sound. When playing a guitar, you only have the mechanical act of picking to time the latency with.


    I defy anyone to be able to "feel" a timing of 5mSec from one pick to the sound hitting your ear ;)

  • A SPDIF loop would be a nice addition for looping in other digital gear :D I have the KPA in the SPDIF loop of the Helix currently.

    MJT Strats / PRS Guitars / Many DIY Guitars -- Kemper Profiler Rack / Kemper Remote / InEar

  • I don't think comparing digital latency to a distance between the listener and a sound source tells the whole story tho. As we are seeing also from discussions in other threads, the brain is more complex that just a measurement device\computer. We for example already know that the brain adjusts frequencies function the level of the sound, in order to make us hear better the weakest sounds.
    I'll start from the notion that we do not only hear the direct sound but also the indirect sounds coming from reflections. The perception of "where" the sound source is with respect to us is the result of a complex computational and emotional effort.
    I think that when the sound source (say a cab) is far from us we have a way to adjust to this distance that is quite different than if a "delay" unit is placed before the loudspeaker (like in the case of latency due to digital processing). Thinking for example of a singer, a guitar player or a percussionist playing 30 meters from us: we register that their gestures anticipate the sound we hear, but we just accommodate for this. But imagine the player is close to us, and we perceive the same delay (also include reflections in the scenario): this would probably be "unnatural" to us.


    Summing up, I don't think we can reduce the whole story to a matter of feet and milliseconds.

  • A SPDIF loop would be a nice addition for looping in other digital gear :D I have the KPA in the SPDIF loop of the Helix currently.


    How is the SPDIF loop thing with Helix working for you?


    Today, when there is so much great digital gear, it would be great if all boxes could be connected with digital I/O to reduce the amount of cumulating latency. Even though latency of a single piece of gear is low, there is so much conversion going on, starting from digital guitar wireless and all the rest guitar gear, digital monitor mixers and even digital in-ears.

  • The best way to measure the kemper latency is:
    - on your sound card, loop an output with an input
    - connect the 2nd output of the sound card to the input of the kemper, and the output of the kemper to the 2nd input of your sound card.
    - play a DI on both outputs and record both inputs.
    - the delay between both inputs are the kemper latency without any other latencies due to drivers, USB, sound card DAC/ADC, whatever.


    But I'm too lazy to change all my setup :)

  • Isn't it that every D/A or A/D conversion takes about 1 to 1,6 ms at 44.1KHz depending on the converters?
    So that would be like 3,2 ms latency without any signal processing.
    If the KPA has a maximum latency of 4,9 ms it's just pretty damn fast, especially for all the goodness it creates.


    Compare this to the figures of someone using the BIAS App on an IPad, with an external audio Interface. Has anybody at their forums ever complained about too much latency?


    To rule out unnecessary DA conversions in the signal chain, IMHO all manufacturers should adopt more digital I/O capabilities.


    I mean what's the point in using a digital wireless system, then using its analog converted output to go into another digital device with an A/D right at its Input???


    Using a digital wireless, a KPA, 1, 2 or 3 digital pedals in the loop, a digital mixing console, digital IEM wireless system can easily add up to 10-15 ms just because all the signal conversions are so time consuming.


    If most musicians would come to the point of understanding these technological difficulties the industry would sooner or later react to the demands for a faster "single domain" signal chain.


    But most musicians are more into "buying stuff that just works" and for as long as the majority is thinking like that, nothing will change, because it's way simpler to plug in a couple 1/4 jacks than to carefully plan the master/slave signal chain for clocking...


    And let's face it, our brain fortunately compensates quite high amounts of latency on the fly without actively thinking about it - even for the most paranoia driven audiophile nerds out there. :)