What happens to amp sounds at low vol vs high vol?

  • Out of curiosity, when you have say a crunch type sound and you play at lower volumes I find that it sounds it may appear have a good bit of distortion going on. If you wind up the volumes I hear that the distortion seems to be less? I know this happens with amps as well as the KPA. But I don't understand why? Can anyone explain what is happening?

  • I wonder whether the OP meant fader level as he perceives the frequency content of the printed track? If so then the 'distortion' could be the higher proportion of higher frequency perceived at lower volumes per Fletcher Munson curve?

  • Thanks for the replies - I mean the sound as I hear it in the room (not recorded) . I know the only difference should be the sound being louder but it does always seem less distorted the louder you go. In theory I suppose if my hearing is reacting differently at higher db's then a recorded sound at high vols should be the same? If the difference is down to the Fletcher Munson issue then is how do I compensate (and make it sound more like the lower vol sound)?

  • In my limited experience what you are seeking is not really workable. Our hearing is most sensitive to sound in the 1khz -5khz range with 3.5khz being the point where the least sound pressure is needed to be audible.

    If you look at the Fletcher Munson curve you will see the bottom end and over 5khz is least well perceived at lower volumes, the effect becoming more exaggerated the lower the measured SPL.

    Ignoring the issue with headphones which will not of course be affected by the resonances you create in a room (both nulls and peaks) Hi-Fi amps use the 'Loudness' button which bumps the bottom end and the high frequencies. Something similar using the KPA is about the only option I see.

    However bear in mind the difference between say 60db and 70db is a perceived (i.e not measured) doubling in volume and you are still along way off the 90db point where our hearing is most linear and trying to fix that with the crude method above is never going to be that convincing. When I first started using a hand held SPL meter it was something of an eye opener to see just how much that 10db actually means from a listening experience. I'm pretty sure some of that was due to the fact that certain room modes were being excited or nulled out in a non linear fashion as volume changes were made.

    Hope it is of some limited help