That depends, push on the sub cone lightly, if it sounds scratchy, that's probably a voice coil. How high is the volume when this begins to happen, really loud or just getting started? When you just turn on the amp, or after it's been running for a while? If you've got a meter, you can check the voice coil impedance, it should be within 1 ohm of whatever the sub is rated at. If it is, the coils are ok. If the coils are good and the sub performs normally (sounds normal) then you probably have an amp failure, assuming it's not a current delivery problem.
it happens whe the volume is up loud, and when the amp is running for a while. im running shivas in parallel and i aint to sure of what it could be. it mainly happens when a loud and hard hitting part of the song happens. when the bass and the volume are up high. i'll try pushing on the cone to see if it's the subs. thanks
Shouldn't be the subs then if they don't sound weird. I still think it may be a current delivery problem, or thermal protection since it happens when driving the amp hard for a while. You may want to try readjusting your gain, you may be clipping hard. Does it go into protect, then come right back on not long after that, or stay off for a while?
my subs dont sound scratchy when i push on the cone. it does it if i turn the bass up hard, and it don't take long for it to start after i turn it up. yeah, it only will turn on protection for about a second or two. could the amp be drawing to much power and there isnt any to take so then protection comes on?