These are just "band-aids" for engine noise. They usually just suppress the noise which also quiets the regular signal. Best thing to do is check to make sure you have a solid ground connection, make sure no power cables are near signal cables, and a small ground connection on the battery can also cause it. But this is still a decent product.
I am a returning customer. My past experience with SonicElectronix was a very good one. So after researching pricing on the web I came back. Shipping was less than I expected and it all arrived in 1/2 the time predicted by UPS. If I need upgrades or future projects I know exactly where to go.
