Subs in Rear Parcel Shelf?

[Arythael 10+ year member]

Hi all! So I'm in the middle of my first build ever, going in my 03 maxima; my front soundstage is installed and I'm preliminarily beginning to look into the substage. I'm focusing on SQ or maybe SQL, and will most likely buy an MB Quart ONX1.1500D to power the subs (haven't begun deciding which yet).

I've searched a little but haven't found much on the subject: what are the implications of mounting subs in the rear parcel shelf? Mine lays flat with the trunk below the entirety of the parcel shelf - would such an install basically turn the trunk into an enclosure, is it some sort of infinite baffle, or what? Also, I've heard of people mounting tweeters firing up into the front windshield to reflect the sound waves to the listeners... would this apply to the subs firing into the rear windshield too, and produce better/louder sound than if the subs were in the trunk? I would assume that because the subs' front waves are being produced in the cabin, there is some increase in sound quality... but I have no knowledge to back this up, only intuition.

If that's a bad idea, what if I built a box that would sit in my trunk and the baffle would essentially replace my rear parcel shelf? If it would be ported, I would assume the port would fire up into the cabin as well.

I want to use the spot because there's a lot of mounting space using the shelf as the baffle, and it would save me trunk space compared to just putting a sub box anywhere in my trunk. There's also the added benefit of showing off the subs through the rear windshield //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

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[DoesDad 10+ year member]

Hope you park in a garage if planning on "showing off" the subs.

 

[Arythael 10+ year member]

Hope you park in a garage if planning on "showing off" the subs.

I knew that comment would get some hate haha... I live in a very rural area with extremely low crime rates, but in any case I don't plan to be high-school stupid about "showing off". I just meant that I would enjoy being able to watch the subs myself, or show them to my friends, without having to open the trunk.

 

[keep_hope_alive Premium Member]

you can do it, but it requires a shitton of work, roughly 100 hours of skilled labor to pull it off. and the car will NEVER be the same. also, any openings between the rear seat and trunk will need to be sealed air-tight.

properly implemented, it can help you win you world championships in any series (Andy Jones proved that with his Altima)

 

[maylar 10+ year member]

It's called an infinite baffle (IB) install and it has both good and bad points.

Good -

You need much less power than any box install. Direct coupling to the cabin allows you to hear your subs even at low volume. Some subs can play ~very~ low IB.

Bad -

Difficult install, especially for a noob. Your rear deck needs to be rock solid, a plastic or fiber parcel shelf would just buzz uncontrollably. Gotta seal the trunk from the cabin, which means you need to deal with the car's ventilation system.

I have an IB with 2 8's in my 85 Olds, but the rear deck is heavy sheetmetal and they only get 70 watts each. Sounds excellent for a daily driver.

Also, I've heard of people mounting tweeters firing up into the front windshield to reflect the sound waves to the listeners...

.. which is a bad idea for SQ.

 

[hispls 5,000+ posts]

The secret to doing this with any level of success is having the trunk comletely sealed off from the cabin, which as has been pointed out is quite a bit of work and will be quite permanent.

 

[keep_hope_alive Premium Member]

and technically isn't IB. that would require several wavelengths of surface area - which would be over a hundred feet.

it's a TB or trunk baffle. the volume is greater than the air-spring compliance of the woofer. so the woofer isn't loaded by the enclosure.

i did toss a few 8's in the rear parcel shelf of a civic for a buddy one night. powered off an amp. it buzzes like crazy if he turns it up, so it's for low level listening only. he didn't want to modify the vehicle.

 

[wenn_du_weinst 10+ year member]

it would be much less work to use an enclosure.

 

[Arythael 10+ year member]

Well, I had hoped otherwise, but I didn't really expect it to be as easy as it sounds... still, what about my idea of building a box under it? I'm envisioning a vertical enclosure that would sit on the floor of my trunk but, after removing the rear parcel shelf, the baffle of the enclosure would basically replace the shelf. Sure, it'd take a little extra work to make it look nice, but this way the subs are still in the cabin and I still get to save some trunk space while the sub enclosure remains traditional. I don't see why I would need to seal off anything more than it already is, considering that it's a somewhat typical install except the box is placed in a very specific spot. I'm sure someone has to have thought of this before; does it work? As long as its not ridiculously difficult, I would be interested in attempting it both for the learning experience and the uniqueness factor.

 

[Arythael 10+ year member]

bump