Car doors vibrating horribly. Is 150hz high pass crossover an ok fix?


Headunit: Sony XAV 5000

Speakers: Alpine X 6.5 C

Subwoofer: Alpine Swt-12S4

Amp: Alpine X 5 Channel Amp 4 Order Sub Crossover/2 Order Highpass Speaker Crossover

Installed above setup in car. There was so much rattling and whining noises from the car doors that the system was horrible and completely unenjoyable. The shop I took my car to tried covering the panels with dynamat, as well as even building custom enclosures for the speakers, and it took the system from unlistenable, to much better, with occasional awful noises on frequencies around 130hz and below with the high pass crossover set to 60hz. Also it did NOT sound like it was reproducing 120hz and below at an acceptable volume, even though the frequency response measurement claims these speakers supposedly play clean down to 80hz.

We tested 120hz crossover quickly today and the panel rattle was ALMOST completely gone. I could only find 1 song it appeared on which was: Felt Tip by Love Is All


But I figure if I set the crossover a liiiiittle higher, I can get rid of all of the panel rattle. We have tried pretty damn hard to get rid of the last of the rattle to no success. Setting the crossover a little higher would fix this - but I’m worried about giving so much work to this lower end sub. However, I tried the more expensive Alpine Type R sub in a sealed enclosure and the entry level ported sub I’m using from the same manufacturer was actually outperforming it in terms of overall sound, so I wonder if paying even more for the flagship Type X subwoofer would be wasted effort. Is this insane? Is it gonna sound awful? What do you recommend? What are my other options?


Right now I’m thinking setting lowpass filter to 150 on sub and highpass to 150 on speakers. But are there other options? Maybe setting the lowpass on the sub to 80 and just having a dip from 80 to 150? I don’t know, I am a noob.


Please come at my with your expertise!

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The 150/150 solution sounds like the only cure apart from getting a car that doesn't rattle so much. 
Thanks for the response. Something I'm wondering, is if it'd be more ideal to set them the high pass and low pass slightly different, since one is a two order, and the other is a four order.
You don't need to mess with the crossovers.  You need an EQ. miniDSP sells these explicitly for cars.
There’s a "10-band Graphic Equalizer" in your Sony head. Try adjusting that and/or the Xovers.
Cut holes on the outside of the the door where there are rattling panels in order to make an infinite baffle set-up, a la the great “The Kenjitt”.  Next up, how to convert your auto into an anechoic chamber...
its nothing to do with the crossover. Fix your panels.