rear tray woofer - free air or.....

[1sikride]

Hey there,

1971 chevelle.... nice clarion 6x9 and 6.5's and a nice alpine nav deck and plan on getting a 5 channel amp.

i want a subwoofer, but refuse to stick a box in my trunk and have the rattle...

so... my daily driver lexus has a woofer in the rear tray.. i have the room in the chevelle to do it...would it be easy? sound good?
questions comments concerns please...

another idea/method I've came across is guys building a box and attaching it to the rear tray from inside the trunk and having the
woofer face poke out in between the 6x9's... basically suspending the woofer box under the rear tray but from inside the trunk..



hmmmmm help!

[ilikeike]

I have not seen or heard a free air sub that would be worth my time or money to install,vs a normal enclosed or ported box sub setup.
Find a shop with some talent to build a nice unobtrusive sub box for maybe a 10" sub. when done right you shouldn't have a rattle issue.

I built a nice ported box for my 70 chevelle firing into the back of the seat with crossover and 3 amps mounted back in the 90s, I could have easily made a false cover to make a cleaner look.

Right now I have a 12" JL w-6 sitting on a shelf waiting to go in my camaro,I'll want a clean look to blend with a stock looking trunk as much as possible.

[CampbellshotrodsAZ]

Curious to see what people say. I've been wondering pretty much the exact same things. I don't need to rattle the windows out, but I want to road trip my 71 Firebird... and with limited trunk space, I kind of like the idea of a package tray mounted sub. It's more about space for me, over hitting hard. Plus, my package tray was hacked out, so that's a blank slate for me.

[csouth]

There was one done hear a little while back. As stated above, it would be more beneficial to have a box built than try free air setup. Newer cars are sealed better than any 70's car which is why you see subs in decks performing well.

https://www.pro-touring.com/threads/...ot-sub-install

[Jerems]

I would agree with having a box, free to air subs can be done but you need to make sure you get one that's made specifically for that. Like above, I would go the route of putting the sub in your tray and building a small sealed box below. You can get Some 10" / 12" subs that are made for sealed boxed that require very small cu.ft of air required.

Examples of subs needing small cu.ft sealed boxes:

http://www.dcsoundlab.com/level2 - or level 3 depending on how much power you plan on having for the sub. 0.5 to 0.65 cu.ft for a 10"
http://www.ficaraudio.com/product/ssd-series-ssd10/ - only needs 0.2 to 0.4 cu.ft box - usually referred to the High QTS option.

You would have to the speaker displacement to those numbers or course but the box can be very compact.

[Interceptor5588]

The package tray tin is not strong enough to support the pounding of a sub, unless you braced it up considerably. Especially with 2 6x9's mounted in it as well, they will pick up each other's vibrations.

[WFFW]

Might want to consider a ported Band Pass box. Multiple design possibilities including, Duel Reflex housing 1 sub(8" or 10")with dual ports running thru rear package tray.

[ilikeike]

Band pass boxes a normally pretty huge,
compared to a sealed or ported box.

[CampbellshotrodsAZ]

My package tray currently isn't even there enough to hold the 6x9's... so yeah, I'm starting with a blank slate and making a sub mount.

[ilikeike]

Holy hell !



Yeah,you can get creative with that blank canvas.

[WFFW]

I realize there are size requirements. I'm simply offering another option. The box can be securely mounted to the floor and the ports can be ran external rather than internal (box volume and port tune size still critical) therefor the only thing attaching to the package tray are the ports. Added benefit is the sub is enclosed and protected and done properly can produce some outstanding tight sub output using a small sub. Isobaric Band pass is also an option.

[cpd004]

My package tray currently isn't even there enough to hold the 6x9's... so yeah, I'm starting with a blank slate and making a sub mount.

This looks like a crime scene!

[CampbellshotrodsAZ]

This looks like a crime scene!

Yep, looks like someone took a machete to it. I was quite surprised to take out the wrapped wood package tray to see that. One of numerous "WTF" moments with this car. At least I know the car top to bottom now, and it'll be better than it ever could have. My favorite was stuffing the quarter panels with about 6 plastic bags worth of pink household fiberglass insulation.

[mc84_zz4]

Dang! they really hacked the rear deck.
I hope you are able to re-weld something back in there, the structural integrity of the panel is gone with that huge gap.
Even if you add some XX bracing and bolt it in.

Now getting back to the subwoofer install:
- sealed box enclosures are normally 1/2 the size than a ported box, they sound very different, one is tight, focused bass, accurate and fast, the ported has a sweet note that hits like a sledgehammer, but they tend to sound 'boomy'.
- as far as rattles, a 36 sq ft box of Dynamat Xtreme should cover the entire trunk and rear deck, I would suggest another box for the entire interior floor and rear wells, if you want the car completely solid, buy a 3rd box, and use most of it for the entire roof, and inner door panels.
- the quieter the car is, the better sound you will have on the road, it really does work even with 30-40% of large surfaces covered it makes a BIG difference.
- the Sub boxes I have installed all sound best when aimed toward the rear of the car, the low notes will go right thru the rear seat, with or without a bulkhead jute pad, once the trunk is closed, the difference is very, very noticeable, at the same volume level the sound seems like 50% more.
- if you opt to port a box directly into the cabin, make sure the box surface is very close to being inside, to not cause an extended port, as the tuning of those boxes is very specific even a 1" different is noticeable.
- I use a single 12" woofer in a 1 cu ft sealed box, my non-square boxes (cube w 2 slanted sides) seem to hit much harder, as there are no resonant waves cancelling each other inside, I always stuff the box w polyfill, and the last 2 were also reinforced with deck screws, a bead of silicone on every seam, and Dynamat Xtreme inside, the difference in the same box & same woofer was a huge gain, try it, you will see.
- The Dynamat Xtreme inside the sub box was a HUGE addition even after all the reinforcing.

Rock On ! and don't blame me if you rearview mirror becomes useless.

HTH

[nekkidhillbilly]

6x9s aren't idea first off. stay with a 6.5 unless its already cut for them from the factory. second a box will not rattle if its built right and secured. a tube or box to enclose it is idea. the box doesn't have to be big just enough cf to support it. free air never work out well. you could enclose the sub and the other woofers too and increase base.

[CampbellshotrodsAZ]

Dang! they really hacked the rear deck.
I hope you are able to re-weld something back in there, the structural integrity of the panel is gone with that huge gap.
Even if you add some XX bracing and bolt it in.

I've got a bead roller, and plan to make a nicer looking shelf anyways... not that you'd see it. But the way I see it... it'll make my rollbar install easier. I'll build any additional supports for any sub mount while I'm at it, if I decide to go that route.

[chuckd71]

Whether in a box or hanging from the deck the things that would rattle will rattle regardless. Any decent sub is going to be heavy; adding extra supports would only be heavier still. If you're building a cage I'm guessing you're going to track it? In that case just get a tube/sealed box and set it on the rear shelf behind the seat, that way you can pull it out easily.

[CampbellshotrodsAZ]

Whether in a box or hanging from the deck the things that would rattle will rattle regardless. Any decent sub is going to be heavy; adding extra supports would only be heavier still. If you're building a cage I'm guessing you're going to track it? In that case just get a tube/sealed box and set it on the rear shelf behind the seat, that way you can pull it out easily.

I'm not looking for serious bass, I don't need anything massive, just a 10". I'd probably be fine with just 4 speakers, but I figure just a little more bass wouldn't hurt. A box isn't an option, there is no upper shelf in a 2nd gen F-body, so it would just be... the trunk floor, which is severely limited on these cars, I need every inch possible. I'd run no sub before I'd put a box on the floor. I also want something integrated that I don't have to pull out for varying conditions. I can design something to hold an 8" sub securely, I engineer crazier things every day at work. I don't really mind a little added weight at back either, my Firebird will always be nose heavy, a little rear ballast to balance things out probably wouldn't hurt.

[minendrews68]

This looks like a crime scene!

Man, I don't think that'l buff out!

[1sikride]

All real good advice But frig, confuses me more n more on what to do.

Maybe I start with a small box with a 10" done the way I've been advised.
And if it rattles then plan b then c etc...

wish me luck lol.

And ya I already have real nice 6x9s set up. Clarions