1 flyneye 3 years ago Odd, no posts here and I thought I was going to see a tech-tip. O.K. I'll leave one, the wife is trying to get me to be polite and sharing and stuff. If I understand the premise of the header, from my perspective it is a cry to cut feedback in a hollow body guitar,without compromising the looks. 1 Know the depth of your guitar. 2 Obtain a chunk of foam rubber, thicker than the depth of your guitar. New foam can usually be obtained from Sewing Shops/WartMart/Upholstery shops.Beware cutting up old furniture/beds/other fartcatchers. especially if the foam is deteriorating and crusty/crunchy. 3 Cut two bricks from the foam using a hacksaw blade (Bread knives will work, but make your cook irate) . Make these bricks twice the width of your f-hole and about two inches longer. 5 Spray-paint the tops of the foam bricks flat black. Don't lay it on too thick. Do it in several light coats. Let dry. 4 What happened to 4? Doesn't matter, I'll just have another drink and move on to 6. 6 Pinch the unpainted bottom of the brick together and work into the F-hole. Using pencils w/erasers, Popsicle sticks, a borrowed drumstick, your fingers, work the brick all the way into the f-hole and spread it to either side and end of the hole. Repeat for other f-hole.The pressure of the foam pressing on the top and back of your instrument should eliminate some howl. The covered entrance for air should eliminate the rest. The flat black makes it pass for a natural looking f-hole at a casual distance.If that doesn't solve your problem, re-pot your pickups, they're micro-phonic. 8 If these should ever become annoying, just hook them out with a piece of wire.