cell phone + speaker buzz = twitchbrain

Choke Cores, available for about $3 at Radio Shack, can help cut back on that annoying buzz (EMI, or electromagnetic interference) caused by some cell phones when they are close to speakers.They are easily attached to your speaker cables (slide them right up to the back of each speaker). Some GSM-type cell phones have extremely strong signals– try two on each speaker if necessary, or move them around to different places on the wire (CDMA phones generally do not cause this buzz).