problem with subwoofers

atanner

i have 2 12 inch mtx thunder. and i have a 2000 watt amp. i have them plugged in right and everything but when i turn on my head unit they move to music but no bass is coming out. and if i only have one plugged in it sounds great.

reason for this anyone ?

Greg Peters

Check the polarity of each sub, to ensure positive is connected to positive, negative connected to negative on each voice coil...if one sub is wired reverse from the other you'll see cancellation.

You can check polarity with a 9V battery- touch speaker positive to battery positive, then briefly touch speaker negative to battery negative...if the woofer cone jumps outwards, polarity for the voice coil terminals you are testing is correct. If it moves inwards, polarity is reversed. Check both to make sure each coil is wired the same according to how it responds to the battery test- polarity of a pair of subs isn't as important as making sure each is wired the same as it's partner. Miswiring isn't all that hard to do, and even if everything is wired correctly as per the labels on speaker terminals, it's not unheard of to find these mislabelled at the factory.