Feedback through speakers from motor shield

I'm working on a project using the motor control shield and sparkfun mp3 trigger. Both work perfectly on their own but now I'm combining the two into one.

When I connect the mp3 trigger to the arduino via the motor shield I'm getting a lot of feedback through the speakers, especially when the motor starts to run.

Any ideas what I can do?

Thanks
Dan

You can try to move them away from each other. the motors create an electro magnetic field when they are active, and this field tends to affect other devices that have magnets in them, such as speakers.

Have you ever use a fan next to a radio? when the fan is on, the radio has some interference, that is the electro magnets being too close to the radio.

Another thing you can try is to shield the speaker wires to ground.

How are you powering the motors? Do they have there own power supply? Are they fitted with suppressors?

Post your circuit diagram.

This link may help http://www.fightingrobots.co.uk/documents/EMIGuidelines.pdf

Mark