Limiter


  • It's impossible to make the KPA digitally distort, it can handle much higher numbers. I had made some maths time ago, now I've forgotten the results but believe me, the only things that can distort in the KPA are the analogic sections (i.e. before the A\D conversion and after the D\A conversion).


    I'm guessing the Kemper is floating point within? Which makes it impossible to internally clip, but when going to 24 bit fixed you can easily clip. Converters and the spdif pipeline are 24 bit fixed. So, depending on the analog headroom at the DA stage, both digital and analog clipping can occur. Spdif will also clip.

  • For sure it can clip, select a clean rig with a lot of output even at normal output and now crank the volume of that rig all the way up and strum hard. You get some nasty clips. Solution: Don't crank it up like that. Unfortunaly there are no optical leveling meters and the coloured output LED is often enough useless on stage when coloured lightcans are on. The OP sould have better asked for a display of the volume of some stages of the soundchain IMHO.

  • The OP sould have better asked for a display of the volume of some stages of the soundchain IMHO.


    I would really have liked some simple dBFS peak metering for the outputs! The only way I can do that now is metering the spdif output on the receiving end.


    Makes it possible to easily gain stage to avoid blowing my cab with this much too powerful Matrix amp! 8)

  • For sure it can clip, select a clean rig with a lot of output even at normal output and now crank the volume of that rig all the way up and strum hard. You get some nasty clips. Solution: Don't crank it up like that. Unfortunaly there are no optical leveling meters and the coloured output LED is often enough useless on stage when coloured lightcans are on. The OP sould have better asked for a display of the volume of some stages of the soundchain IMHO.


    It certainly can clip. The point is whether it's clipping in the digital domain. In any case it's solid state, so even the analog distortion can be "nasty" :wacko:
    :)

  • I wondered the same thing, of course. I measured the Behringer once and its latency was extremely short, on the order of samples with all FX off IIRC - but that was a long time ago. The unit has other (non lookahead) limiters built in, but I haven't measured those.


    In practice, I have the digital output of my KPA running into a Crane Song HEDD 192 (and sometimes, the Behringer but not often) which has a very large LED bar graph for me to keep my eye on. The HEDD is often thought of as a mastering device (almost a tape sim), but it's fantastic on distorted guitars and works wonderfully with the KPA. Anyway, being a saturation device I try to feed it with a fairly stable RMS that's in the device's sweet spot. But occasionally, weird transients squeak through that force me to feed the HEDD with a lower signal than I might otherwise do in order to keep the HEDD's DSP from clipping. Frankly, if I've got a guitar performance that's fairly smooth in level aside from the occasional transient (pickup switch select, guitar cable oxidation, chest thump, whatever) I'd be Very Happy to see those things get limited at the very end of the KPA signal chain rather than on the mixing board or DAW end. It's one less thing for me to worry about, and I'm sure other mix engineers would feel the same way.


    Anyway, I understand that there are several different types of Kemper users; the live guys who only need a mono out to feed their cab may never be worrying about these issues. My Kemper may never see a live stage, ever! It's in the studio strictly for recording/reamping purposes and since it's ideal for this that's how I use it. (It also shows off the amp to its best effect, BTW.)


    -djh

  • I agree that a real mastering style brickwall limiter which would add some msecs of look ahead latency will not be such a good choice. For high gain guitar stuff you don´t need any limiting at all. However, for bass and clean guitars, a non coloring limiter with hard knee can be awesome, to give you some loudness increase without too much coloration.


    Perhaps, instead of limiter, there could be something like a studio compressor with more traditional controls like threshold, ratio, attack, release and makeup gain. With ratios over 10:1 or 20:1 you would have a limiter.

  • Quote

    For sure it can clip, select a clean rig with a lot of output even at normal output and now crank the volume of that rig all the way up and strum hard. You get some nasty clips. Solution: Don't crank it up like that. Unfortunaly there are no optical leveling meters and the coloured output LED is often enough useless on stage when coloured lightcans are on. The OP sould have better asked for a display of the volume of some stages of the soundchain IMHO.


    You sure you're clipping the KPA internally? An internal limiter would not stop the output signal from clipping later devices, that would all still have to be gain staged correctly.


    Quote

    I agree that a real mastering style brickwall limiter which would add some msecs of look ahead latency will not be such a good choice. For high gain guitar stuff you don´t need any limiting at all. However, for bass and clean guitars, a non coloring limiter with hard knee can be awesome, to give you some loudness increase without too much coloration.


    Perhaps, instead of limiter, there could be something like a studio compressor with more traditional controls like threshold, ratio, attack, release and makeup gain. With ratios over 10:1 or 20:1 you would have a limiter.


    Been a while since I messed with the on board compressor, but don't we already have that?

  • I think this is quite a useless gear-geek discussion.
    Limiters are great in a live environment, when you cannot fully predict signal levels from microphones etc.
    The Profiler is very predictable in a live situation, because it's a guitar amp.


    In a studio situation it is not a good advice to prevent clipping with a limiter, unless it's not the last element of the signal chain.
    Here clipping should be avoided by setting the right levels, rather than smartly masking it by a limiter.
    In a recording situation I want to hear and see local clipping n a device, so I can avoid it the next time or take by bringing down the level.