Delays out of phase

    Hi have the powered kemper but find the delays through mono cabs sound out of phase? Sound excellent through headphones but delays and reverbs through single cab not great. Any thoughts.
    I am going through a matrix fr212. I was going through my old Marshall 4x12
    The matrix is more detailed but the Marshall is warmer?

    Quote from Trazan

    Only Master Mono will give him both L and R delays. But this may sound phasey when L/R delays have identical timing and modulation is applied.

    This.


    But its generally a good advice to double-check any stereo effect for its mono-compatibility.

    Ne travaillez jamais.

    Kind of wish it had stereo outs on the powered kemper. I did have an unpowered with a stereo camplifier amp which does work.

    Quote from Trazan

    Only Master Mono will give him both L and R delays. But this may sound phasey when L/R delays have identical timing and modulation is applied.

    Can confirm - I also get weird phase issues when running some stereo delay profiles through Master Mono.


    One thing to keep in mind is that "stomps" are mono so will not have phase issues as compared to the "effects" section, which CAN be stereo.

    I've often wondered if I was just hearing things or if the delays were really having phase issues when I run master mono out. I just thought I was hearing things. Maybe there are some issues. Not really enough to complain about, but it is something.

    Quote from timdabel

    I've often wondered if I was just hearing things or if the delays were really having phase issues when I run master mono out. I just thought I was hearing things. Maybe there are some issues. Not really enough to complain about, but it is something.

    What is a "phase issue"?


    DIfferent phases of one and the same audio source comes from, well, a *delay* between both. Its just the nature of the beast. I.e. two microphones, with one standing further away.


    Depending on the length (and modulation) of the delay it will - and *must* - change phases. Thats what it is all about. You decide (by tweaking it) how it will sound.


    Very small delay times, say below 50 ms will change the combined sound, i.e. by combfiltering. That means our ears still hear one guitar, but altered in sound. Slightly above 50 or 70 ms our ears will tend to hear still one sound, but with a kindof room reflaction (which comes from the delayd sound). When the delay times get longer our ears will "suddenly" hear 2 distinct guitars, with one just playing "later".


    If you want to reduce those "issues" with smaller delay times you might want to reduce the high frequency content of delayed part. If you still dont like the outcome: switch it off.

    Ne travaillez jamais.

    Like 1
    Quote from SpinnerDeluxe

    DIfferent phases of one and the same audio source comes from, well, a *delay* between both. Its just the nature of the beast. I.e. two microphones, with one standing further away.

    There's a fundamental difference to how this is perceived depending on whether you listen to a stereo signal in 3D space or if the signals are blended and emitted through a single speaker. Inverted/opposite sine-waves in a 3D space may appear to vary in volume depending on the listening position. Inverted waves that are electronically superimposed on each other will result in a flat-line (silence) before the signal even hits the poweramp.


    Whatever the Kemper does in its conversion from stereo to mono doesn't always work well, so there must be opportunities for improvements in that algorithm. At times it sounds better for me to have just one side in the monitor instead of the synthetic mono signal it produces. I prefer to either use two monitors or stereo IEM to avoid the issue.

    could this be the 'issue'?


    "Stereo ModulationInduces a delay time modulation to create a lush and chorus-like sound. The delay taps are modulated in differentphases to produce a wide stereo image similar to the Air Chorus, even when the delay times are set to equal values.If you want to create a delay modulation, without creating a stereo effect, use the Flutter parameters instead."

    - Reference Manual 5.0
    https://www.kemper-amps.com/downloads

    I just wish the power amp was stereo. When on headphones the profiles with delays
    and reverbs are awsome. Mono cab is not as good. I might have to try 2 powered cabs in stereo at some point. But why spend the extra on the powered version?

    Don - that could be, but to the best of my recollection this was an issue since I purchased my KPA in 2013. I believe what you are quoting from reference manual 5.0 is for the latest delay parameters. It seems to be better to my ears now, but sometimes I still hear it. I haven't really done a very scientific analysis though, so I may just be crazy. :)