Speaker Damage When Profiling?

    I have an old late 60's Marshall cab with 25W greenbacks. I tried to do some profiles today with a modified blackface Bassman 50W head. It has a master volume that was on about 4-5.


    The level of the profilng noise was un-nerving. What do you guys think about profiling high-dollar vintage speakers? Your thoughts, please


    This cab has survived 45 years of beatings and the amp doesn't sound good until it is pretty loud.

    The KPA most certainly produces higher levels than a passive guitar, at the very least, but these are mostly burst noises.
    The rating on your speakers is a max continuous rating and is a measure of their ability to disperse heat - it's nothing to do with a 50 second noise.


    It should be very, very difficult to break a speaker by playing a sharp sound through it. You can't even tear the cone - you'd have to make the voice coil break free and i've actually never heard of that happening - but maybe someone else has had a different experience.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

    Cool. Thanks Quitty. Appreciate the input.


    I'd still like to stir up some more discussion on this if possible. Would it mess with the profile quality to attenuate the signal from the Kemper a bit?


    The search pulled up an older thread that mentioned an attenuator called "the pot". Something like that should be easy to build.


    That same thread had some amp damage reports. Zappledan's Blankenship fried a screen grid resistor. I wonder what the wattage rating on that one was. I know the build quality on Blankenship's are top notch. That one is a little concerning. Makes me wonder about not being able to use an attenuator between the amp and speakers. On the other hand, Armin's filter caps in that Tweed Fender were living on borrowed time.


    http://kemper-amps.com/forum/i…ad&threadID=7040&pageNo=1

    Hello, with older amps it's very usefull to use the 'return level' knob while profiling to keep profiling waves from the KPA as low as possible. Your KPA will tell you if the level is too low, so you can process several iterations before finding the right level, start with -30 db or something like this.


    I profiled a my 70's amp this way with no damage, and the last cranked profiles (with volume at max on the original amp) where done this way.

    Quote from waraba

    Hello, with older amps it's very usefull to use the 'return level' knob while profiling to keep profiling waves from the KPA as low as possible. Your KPA will tell you if the level is too low, so you can process several iterations before finding the right level, start with -30 db or something like this.


    I profiled a my 70's amp this way with no damage, and the last cranked profiles (with volume at max on the original amp) where done this way.

    I think this will not lower the level of the profiling signal that is entering your amp. It will only adjust the signal level that is entering the KPA return after you miked it. If you are really concerned that you could damage and old amp or your speakers, just set your amp volume to a lower setting.

    " I think this will not lower the level of the profiling signal that is
    entering your amp. It will only adjust the signal level that is entering
    the KPA return after you miked it."


    Ok, I thought it was the opposite, so forget my advice....


    There still is the option to quote distorded/clean option in order the reduce the signal strengh.