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  #1  
Old 03-19-2018, 08:43 PM
islander53 islander53 is offline
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Default Low end feedback on A string

Hi everyone, it's literally been years since I posted around here, and now I have a problem that just won't go away.

I use a Baggs M1 Active, which I love, but many times I get an extremely bad low end feedback off the A string, or any low A note I play (for instance when playing a barred A chord and such). Even with a capo, if I play a low A, the feedback jumps in.

I've tried changing position, playing with the EQ, yada yada yada, but nothing seems to work. And moving the FOH speakers around is pretty much never an option.

Any ideas what causes this to happen, and how to prevent it? I even adjusted the pickup pole to its lowest setting to keep it as far from the string as possible, but no luck.

Help!
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Old 03-20-2018, 12:33 AM
Gordon Currie Gordon Currie is offline
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Since the M1 active includes a mag coil to capture body resonance, I wonder if you haven't found that guitar's resonant frequency?

Good test would be to swap it out into another guitar and see if it feeds back the same way.
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Old 03-20-2018, 03:42 AM
YamahaGuy YamahaGuy is offline
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I'm not sure what causes it, but I believe some kind of notch filter, like the one on the L.R. Baggs Para D.I. would get rid of it.
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Old 03-20-2018, 05:34 AM
Nymuso Nymuso is offline
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Quote:
Originally Posted by YamahaGuy View Post
I'm not sure what causes it, but I believe some kind of notch filter, like the one on the L.R. Baggs Para D.I. would get rid of it.
I've encountered this problem with this pickup and addressed it with this solution.
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Old 03-20-2018, 05:46 AM
martingitdave martingitdave is offline
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Any guitar EQ preamp with feedback control, or a notch filter will work. The low A is 110 Hz. Look for the offending frequency there. You can also purchase some preamps that will “auto kill” active feedback. That will work well too.
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Old 03-20-2018, 06:43 AM
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Methos1979 Methos1979 is offline
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I have the same issue with my Emerald X20 with a K&K in it. The only way I found to tame it is with a Baggs PARA DI. Excellent notch filtering, not to mention excellent EQ abilities. You can pick them up used everywhere for $100 (got mine for $90 used but in mint condition here on AGF). Built like a tank. Takes a little time to get used to - read the very short manual and you're good to go.
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Old 03-20-2018, 07:39 AM
varmonter varmonter is offline
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yes what everyone says here.
i think most acoustic guitars have this issue.
you just need to find the offending freq.
I think an acoustic guitars A string tuned to
440 is 110 hz so it should be somewhere close
to that . and notch it out.you may need to
widen your Q . or use a hpf or low cut above that freq.
not sure what you have for equipment.
Sometimes it's the B note on the second
fret that causes this . Sometimes it's the interaction
of another guitar or a bass that cause your
top to vibrate but it's usually in that freq range.
it depends on what you have for equipment, to do the notching.
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Old 03-20-2018, 08:15 AM
lschwart lschwart is offline
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As per what others have said about a notch filter. Note that the pole height isn't making a difference because the pole is probably not the source of the resonance. It's probably coming from the body resonance picked up by the other coil in the pickup. I use a passive M1 and it has the same resonance on my Taylor, although its prominence varies from venue to venue. When it's a problem, the notch filter on my preamp takes care of it. When things are really bad, I can set my HPF to 200 Hz, too.

Another thing you can do, although it does take away some of the characteristic sound of the M1, is to use some padding where the pickup clamps onto the top in the soundhole to reduce the responsiveness of the pickup to the vibrations of the guitar top. This will give you a signal based more purely on what the main coil picks up from the magnetic fields of the strings, and it will make the pickup more feedback resistant.

Louis
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Old 03-20-2018, 09:35 AM
islander53 islander53 is offline
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Thanks, everyone, for the great suggestions. I came back to live performing in August 2015, after 18 years away from it, and have been doing more solo acoustic gigs in recent months, so the problem is coming up more often since I go for a full-bodied sound as opposed to a thinner sound when playing with a band. In the old days I used a Feedback Buster in the sound hole, so it wasn't an issue.

I'll look into all suggestions. Much appreciated!
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Old 03-20-2018, 09:52 AM
varmonter varmonter is offline
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When you played in a band did you thin your
sound for the same reason? you may find
you can't get all that nice acoustic low end
when you play live in some clubs and will
have to compromise. if you get some time
read this article . I found it interesting.
https://ehomerecordingstudio.com/fletcher-munson-curve/
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Old 03-20-2018, 09:55 AM
MrErikJ MrErikJ is offline
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Not sure what preamp/DI you use but all of the Baggs units have an easy notch filter to address that. One of my dreads likes to resonate on the A string as well and just a tiny cut on the notch brings it in line.
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