Amp Cover Carvin

Quick question about guitar/amps?
I play acoustic guitar for my school’s show choir/cover band thing and I play on a Carvin SX200 amp. But every time I turn the bass up just some to give it a little ‘umph’ the sound from the amp makes a huge ‘roarrr’ sound that’s extremely loud and disturbing. How do I keep it from doing this?

Yes, that’s low frequency feedback all right. Two things: First of all the amp here is designed for electric guitars – not acoustic ones.

Electric guitars are focused more in the mid frequency, while the acoustic ones are more “broad frequency” or spread more evenly over the frequency spectrum, if you like.

An amp designed for acoustic use is able to play squeaky clean where a regular amp usually is meant to be able to go into over-drive/saturation. Also, acoustic amps have different speakers, usually incorporating a treble horn or tweeter for the higher frequencies. A regular guitar amp tend to sound best with 10″ or 12″ speakers (focusing on those mid frequencies).

Acoustic guitars are typically being routed directly through the sound system/PA and the player will hear what’s going on through monitors – just as it is done with vocals.

You can also use a dedicated acoustic guitar amp. One of the benefits is that they have a direct out – meant to be hooked directly to an input on the main mixer (in other words no need to have a microphone for the acoustic amp).

There are three culprits for acoustic guitar feedback. One is the type of amp and its settings. There are EQ settings on the amp which you can use to roll off some of the offending frequencies. But like I said, your amp is no good for acoustic use…

Then you have the position of yourself and the speakers (guitar amp, monitors or PA). If you get to close and at certain angles, then there will be problems with feedback.

Then, there’s the guitar. There are special dampers made to fit into the sound hole of the guitar, which helps cut down on potential feedback. Also, most acoustic guitars have a built in preamp with EQ to help cut down some frequencies. In your case, if you have a preamp built in, you would probably need to cut in the lower mid or bass end of the spectrum.

If you don’t use a PA, then an acoustic amp would be the way to go. If you have a decent PA, then get a DA box and hook your guitar up through the PA. That’s what most stage performers do. And do use a damper for the guitar…

Professional and/or experienced performers and sound engineers may also use dedicated feedback eliminators and special multi band EQs to better control any frequencies causing problems. Plus, they will always attempt to keep drums and electric instrument volume down on stage to make it easier to get a good live sound with acoustic instruments.