Feedback control with your cab/monitor, good and bad interaction

    I often get problems when i play too near a FOH stack with my single coil pickups picking up the FOH signal and getting some nasty high freq squealing as the signal chain of guitar-->kpa-->desk-->FOH loops. Similarly i sometimes experience this when standing too near my monitor, which is just for my kpa, as there is no longer a need for a guitar amp/cab.
    Previously i had a 4x12 behind me and it was never an issue. Used to be nice to get extra sustain when stood near the cab as there was some "good"guitar-->cab interaction.
    i wonder if the "old" setup of a standard amp+cab acts as enough of a filter that it reduces the bad feedback but allows the "good" feedback.
    I figure that there must be some hi freq signal creeping through the signal chain, or more specifically, less of a LP filter with a kpa and full-range monitor.


    any strategies for achieveing the right amount of good/bad feedback with a FUll-range monitor
    other than use humbuckers? (Or the obvious move further away or turn down-theres a noisy drummer close by im trying overcome)
    Incidentally since i replaced them with lace sensor noiseless pickups it has helped but still an issue.
    theatre venues that employ a induction loop for hearing-aids are enemies of pickups too.
    thanks

    Like i mentioned earlier, theyre lace sensor, so very quiet compared to standard single coils. I've addedextra screening to the guitar internal too.
    theyre not microphonic in the sense that they are influened by audio, which i have experienced in poor quality pickups, but do pickup EMF.
    Obviously theyre doing theyre job and picking up changes in the magnetic field, of which there is a strong influence being emmitted from the afore mentioned speakers. Its often a compromise between where i end up on stage and how much gain i can apply.

    You mentioned your Lace were better - I thought you might be talking primarily about some other pickups. I have a strat with Lace Sensors and a Clapton Boost - too much gain with it makes it feedback in the low midrange.


    It is likely, like you said, the amount of gain and how close you are to the speaker.


    If you need that much gain in the sound, you'll either need to turn the cabinet volume down, or move it slightly farther away from you.


    But, sometimes a sound with too much gain is harder to hear onstage, and much harder to hear in the FOH mix.

    Im a fairly low gain person in terms of dirt and overdrive. Think softer rock than metal :)
    its more of the overall gain from guitar to amp. Obviously the overdriven sounds are more likely to be susceptible to the unwanted squeals. I wonder if applying some additional LPF to the signal chain might assist. After all, the top end of the guitar audio spectrum is relatively low compared to the overall range of a complete band. The biggest factor seems to be at what angle the guitar is at relative to the output speaker, usually the FOH unit that i stand behind and to the side of.

    Well, i play a lot of heavier stuff - metal included - and i'm actually having trouble getting feedback from my FRFR setup when i need to make some serious noise. Kemper's gain for my heavier tones is around 6.2 and my FRFR is a 15" active cheapo wedge. Guitar has a humbucker in the bridge and a single coil in the neck. Noise gate is set to 1.0 when i play live, which is often.


    Have you tried messing with the ground lift switches in the rear?.. What you're describing doesn't sound right to me...

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

    Slateboy, do you have the same issue when the strings are muted?


    If you do not, then feedback comes from the strings: it's that the "wide response" cabs excites frequencies that the guitar cab could not. So I believe with a touch of parametric EQ you'll master the issue.


    If you do, then as Paul was suggestion you PUs' coils are too loose and they resonate (like strings do) you need to have them properly waxed.
    Not that a ParEQ would not help, if there's one base resonating frequency and it's within the EQ range.


    :)

    Muting the strings does not help. Pickups in "out of phase" config does.
    my experince of microphonic "badly waxed" pickups has been that with a bit of gain you can hear every tap and bang on the guitar body and even your voice if you shout into the pickups. This is not present.
    it is the emf emmited by the foh stack (and monitor) that is getting picked up by the guitar.
    incidentally i hate metal pickup mounts/surrounds as these can sometimes "vibrate/resonate" like a metal string does and transform into unwanted noise. So I prefer plastic pickup mounts.


    as i think i mnetioned before, its high power ouput units that give me grief, obviously creating the larger amounts of emf. If im far enough away or the foh rig is not delivering "loud" ouputs im safe. A compromise for those gigs when stage space is limited and the volume gets whacked up. Another reason to aim for the bigger stages :)

    I'm not familiar with excessive feedback with lower gain sounds, as I don't get any feedback even at higher volumes. High frequency squealing seems like undesirable feedback and if you didn't have this problem with a cab, my guess is that there is gain being added to your signal at the FOH.


    I think the idea of using a filter will only work to some extent, since you'll be changing your tone as well.


    I think the best solution is to to turn the monitor off axis when you're playing and stand a safe distance away for good measure. This is, of course, after looking into what is going on FOH, I don't think your cab will be filtering out bad feedback. This seems to be a symptom of additional gain in the signal, probably at the FOH end.


    Ask the soundman to lower the gain so you don't get feedback. Raise the volume on your Kemper to be loud enough to be heard.