I recently aqquired a 1990 civic Sedan and am going to be installing an SQ oriented system that I can enjoy day to day and compete in IASCA's SQ division on weekends. Im going to be running an IDMAX12D2V.2 and powering it with an MTX 225 H.O bridged to 1 OHM. Im currently trying to come up with the best possible position for the sub to fire to optimize SQ, Imaging, and SPL. The idea I had was this: since the rear seat folds down I was thinking about doing a sealed enclosure with the sub firing against the back of the seat and in turn directly into the interior. Now what I would like to know is how will the effect my imaging, SPL, and SQ? Would it be better to fire the sub the standard way towards the back of the car? Any help is greatly appreciated!

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2002 Honda Civic Coupe

-Canton Component speakers
-12" Image Dynamic IDMAX D2 v.1
-Alpine CDA9887 deck
-MTX Thunder 225h.o (sub)
-MTX Thunder 275x (fronts)
-Alpine 12 disc changer
-Alpine XM satellite radio
-Alpine Blackbird Navagation

well I have tried possibly every single option you mentioned for positioning and then some.. I have a 92 civic sedan and I found the best setup to be a ported enclosure with the woofer facing up and the port pretty much right against the side of the trunk

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| Trunk ____ |
| |SUB| | Port Facing Side Of Trunk
| |___| |
|_________________|

However this is the best setup for having the rear seats not folded and up.. if you wanna drive like a wanker with your rear seats folded down then I found it doesn't really matter.. The above setup is pretty much the loudest I have found for having the sub closed off from the cabin.

I think you misunderstood me here, firstly im not looking to run a ported enclosure, secondly im not looking for all out SPL all the time so therefore having the backseat up during normal listening is not really an issue. And plus when it comes time to do SPL judging during shows I can simply fold the seat down for maximum gain.

Actually one a side note will I be allowed to fold my seat down during the SPL portion of the testing if im in the rookie class?

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2002 Honda Civic Coupe

-Canton Component speakers
-12" Image Dynamic IDMAX D2 v.1
-Alpine CDA9887 deck
-MTX Thunder 225h.o (sub)
-MTX Thunder 275x (fronts)
-Alpine 12 disc changer
-Alpine XM satellite radio
-Alpine Blackbird Navagation

Every single car I've owned had folding rear seats.....

Coincidence ? I think not...

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SIC Audio

This part confuses me.. Since you are looking for SQ with occasional SPL I would think you the perfect candidate for a vented enclosure. Doubly true considering the woofer and amp you have chosen.

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Paul Niwranski
1966 Cadillac Superior Crown Royale Limousine Hearse

If you're mirrors ain't shakin...you got taken...
RIP Member #8
Be careful what you wish for...

if you have the room port that baby. if you need we can help ou with a design

The more I think about it the more I think I want to port it! And yeah if you could help me design a ported box to fit within my orginal design idea then that would be awesome!

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2002 Honda Civic Coupe

-Canton Component speakers
-12" Image Dynamic IDMAX D2 v.1
-Alpine CDA9887 deck
-MTX Thunder 225h.o (sub)
-MTX Thunder 275x (fronts)
-Alpine 12 disc changer
-Alpine XM satellite radio
-Alpine Blackbird Navagation

ya, ports arn't just for the SPL, i have my focal system ported haha. smaller the ported box the better for SQ, withing the limits of the sub of course. thats just my opinion, it creates a deeper and not the loudest of sound which is perfect. tune the port around 34, at least thats what i would do.

So how do determine what will be the optimal enclosure volume and port tuning frequency for my application? Also what are the advantages of slot porting versus circular ports?

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2002 Honda Civic Coupe

-Canton Component speakers
-12" Image Dynamic IDMAX D2 v.1
-Alpine CDA9887 deck
-MTX Thunder 225h.o (sub)
-MTX Thunder 275x (fronts)
-Alpine 12 disc changer
-Alpine XM satellite radio
-Alpine Blackbird Navagation

i dont have time to look into what size/tuneing right now but if you do find out send me a pm and ill draw something up for you