weird bass cancellations - sealed vs. ported

[fredberg]

i've been testing out a single ported vs single sealed box in my trunk, using the same amp. each box has an Alpine 10" sub, same model. obviously, the ported box plays a little louder. but here's the weird thing.

i made sure the subs are wired correctly inside each box.

when i play the ported box, i have to hook it up in reverse polarity on the amp. otherwise, there's a lot of bass cancellation going on with the interior speakers (which are just running off the HU).

but when i use the sealed box, it sounds best when wired in correct polarity on the amp. again, if i don't there will be phase cancellations.

theoretically, either box shuld work best using the same wiring polarity, right?

my guess is that the sound energy coming from the port may be affecting bass waves from the interior speakers. any other theories?

[Corollacrazy42]

if those waves effected how the rest of the speakers sounded... then no one, in theory, would be able to have subs and have them playing....

you should still be wiring it the same way when going ported... in all honesty there shouldnt be much difference ported if you switched the phase.

All it sounds like to me is that your interior stock speakers cant keep up... not to mention if the back speakers are exposed to the trunk... then yes, the speakers will be effected by air movement within the trunk.

[fredberg]

yes, the rear 6X9's are exposed to the bass energy in the trunk.

wut im saying is, when i wire the sub a certain way, the whole system seems out of phase, with less bass. but the bass from the sub should overpower them anyways, right?

[CamrySExxx]

what do you mean by bass cancelation.. :S im new to this stuff

[[SMAN]]

the wave comming out of the port is oposite phase from the wave comming off the sub itself. depending on where in the trunk you put you box will effect how the waves line up, try moving the ported box to different sides of the trunk, also play with weather the port is facing forward, or up, or to the side, or out the back, all of this will effect the sound. I was able to squeeze 2DB higher outa my old setup just by turning the box around 180 degrees.

[fredberg]

Originally Posted by CamrySExxx

what do you mean by bass cancelation.. :S im new to this stuff

the ultimate form of bass cancellation is hooking up a dual-sub box out of phase. meaning, hook up one sub normally, then reverse the wiring for the other sub. watch them move like crazy, but virtually no bass will come out. the subs would be out of phase with each other. when 1 sub moves out, the other will move backwards, canceling the sound waves.