Topic: Helppp!! Electric-Acoustic getting feedback

Hi All!

I recently got a 12 string electric-acoustic guitar (BReedlove) and plugged it into my Spider II amp. But at ANY kind of Volume at all I get feedback as soon as I take my hand off the strings.

Moving either in front of or 15 feet away from the amp does not help.

Do I need a special "ACOUSTIC" amp for this guitar??

BTW - the guitar sounds great without plugged in, but I did want to annoy the neighbors just a little.

Stanley James

2 (edited by hazenk 2007-09-06 16:52:29)

Re: Helppp!! Electric-Acoustic getting feedback

Here ya go...try this...its only $ 8 Bucks!

http://www.wwbw.com/Kaman-Feedback-buster-i10792.music

These typically help prevent feedback from a facing monitor but I was listenting to guy the other night who had one in his guitar and did not have a monitor. And he was using to help ward off feedback.  Basically, its a plastic insert for the body.

H

Re: Helppp!! Electric-Acoustic getting feedback

OK, I know next to nothing about this, but from what I understand, electric amps are open, or partially open in the back for....I don't know why.  And Acoustic amps are closed in on all sides--something about how much the guitar vibrates...causing feedback something along those lines, how a closed in amp helps--I don't know.  I've also heard that an acoustic amp sort of acts as a PA, just increasing the signal the same across the spectrum, and an electric amp treats different parts of the signal differently.  All I know is I have the same problem when I plug my acoustic into my Hartke, and I don't when I plug it into my Crate Acoustic amp.
Told you I know nothing about this topic...why I'm writing....beats me.

Re: Helppp!! Electric-Acoustic getting feedback

25Frankster wrote:

OK, I know next to nothing about this, but from what I understand, electric amps are open, or partially open in the back for....I don't know why.  And Acoustic amps are closed in on all sides--something about how much the guitar vibrates...causing feedback something along those lines, how a closed in amp helps--I don't know.  I've also heard that an acoustic amp sort of acts as a PA, just increasing the signal the same across the spectrum, and an electric amp treats different parts of the signal differently.  All I know is I have the same problem when I plug my acoustic into my Hartke, and I don't when I plug it into my Crate Acoustic amp.
Told you I know nothing about this topic...why I'm writing....beats me.

Your on the right tract in your train of thought. The pickups on a acoustic/electric guitar are usually piezio type pickups and they act as a microphone. They pick up the excessive vibration of the sound box which helps project the sound of a non amplified acoustic guitar.

Bootlegger.
Bootlegger guitars.

Re: Helppp!! Electric-Acoustic getting feedback

Thanks for the comments on this issue. Helps explain things a little ... Makes sense that the acoustic will be projecting a lot more sound fromt he cavity ... and likely the 12 strings even more so, with twice as many strings to vibrate.

I will perhaps head over to my music outlet in the next few weeks and ask them also ...

Strangely enough, I have a digitech 100 amp modeler that I can hook up to a set of computer speakers .. on some channels/models I get the feedback problem and others not. Clean channels seem to be less sensitive to the feedback issue.

Also, I have been surfing craigslist looking for a small acoustic amp ...

thanks again, all!

Stanley James

6 (edited by david blair 2007-10-03 23:20:29)

Re: Helppp!! Electric-Acoustic getting feedback

If there is a volume control of the guitar it's best to keep it at low setting and get more volume at the amplifier. Feedback is caused by a loop of a particular frequency and can be controlled to some degree by lowering the boost of that tone. High, shrill tone? Treble control. Low, building hum? Bass. Most guitars need a reduction of the bass, "roll off". This can best be accomplished with a DI box or an inline buffer  that offers a 10-20db reduction of the signal. Piezo type pickups a notorious for this. Your acoustic amp likely has buffer built in and the other is designed for magnetic/coil pickups. Magnetic pickups sometimes work better plugged into a mic or line input when using an acoustic amp. Soundhole covers can help. Of course don't face the amp with lots of volume...

If you made recordings of the feedback, and played really loud DJ music at the same time you could leave them on all night while you sleep elsewhere, and really annoy the neighbors!

Re: Helppp!! Electric-Acoustic getting feedback

That amp isn't one with an acoustic emulation setting is it? If so and you've switched to it you're boosting the treble on an already treble rich signal. Look for a clean channel or dry setting on the Spider...

'The sound of the city seems to disappear'