QuestionI'm currently having issues with rattling in my truck after
installing a new 12" Alpine Type X subwoofer. I have an
MRP-M1000 Alpine amp powering it and I currently have the
gain turned up almost 90% on the knob and the bass boost is
at +7. I was informed today that the gain and bass boost
need to be lowered, but how will I know if this will fix the
problem? The sound happens when it hits high frequencies on
certain songs. It only rattles on certain songs and I
notice that if I reposition the box, the noise stops. The
noise sounds like it's coming from the area where the
speaker is but I don't think it's coming FROM the speaker
itslef. Is this an issue with the speaker, the amp pushing
too much power, or just something rattling inside my cab?
AnswerHi Chad,
When you say "high frequencies", do you mean "high volume levels"? Or is it happening when the sub is playing upper bass tones? If so, you might be able to control the issue by reducing the crossover frequency.
Unfortunately, it's hard to say what's causing the rattling without listening in person. I can give you a couple ideas you might not have considered, though.
I've seen rattling originate from a defect in the subwoofer box itself; one of the box panels can become loose from its seams, resulting in the panel itself resonating at high volumes. In this case, pressing on the box panel with your hand would temporarily stop the noise, and I can see where re-positioning the box might have a temporary effect as well. Another possibility is a poor seal between the subwoofer and the box surface. If air is escaping around the edge of the subwoofer basket, it can often result in a rattling noise. You can test for this by pressing gently on the subwoofer, moving it back and forth, while listening for the hiss of air around the edge of the sub. If air is escaping, you can try re-mounting the sub with a gasket material between the box and the sub basket.
Hope this helps!
Brian
