BigRedGuy

iTrader: (11)

You will be better off if you encourage your passengers to suck it up a bit....

1 or 2" further forward for the passenger seat and you have tons of space to build the right size ported box for one driver....rear vent space will no longer be an issue and with decent power you will get better bass than 2 speakers in cramped quarters.....

If they complain reminding them the alternative is walking usually quiets them right down.....

HTH

Hardwrkr

iTrader: (5)

The driver only needs a bit of space behind it if it is vented on the rear. Some drivers have moved to new designs that have the vents on the side. So depending on which driver you choose if it doesn't have a vent on the back then you won't need to allow the extra space.

Also, I'll throw in a suggestion for the new Polk MM series. They can be had quite cheap online, sound great, work well in small enclosures, and are fairly light as well.

bnevets27

iTrader: (1)

Well here's the cardboard mock up (man is it ugly)

Long vertical rectangles would be were I would put the port tubes. Square blocks would be for bracing.


The wall that the box sits on in the car is angled like the back of the box.


The box will have these dimensions, plus or minus 1/4 or 1/2 an inch.

W: 19
H: 30
D: 4.250
Thickness of MDF would be: 1/2 in
Vol = 0.98177

Volume of triangle pieces that are missing because the shape of the back = 0.226
MB Quart sub displacement = 0.06
Bracing (wild guess, probably a bit small) = 0.03

0.982
-0.316
--------
0.666 cu. ft.

So that is the correct volume I need according the the Kenwood and MB Quart. So I shouldn't have any need for a larger box. Unless I'm missing something?

Two subs have the side venting in that list, the Dayton and the MB Quart.

I'll check out the Polk MM and see if they fit the bill.

EDIT: Checked out the Polk MM, spec wise they look good, linear excursion = 1 inch and light which is nice but they need a mounting depth of 4 1/2 and they are rear vented unfortunately.

Dukk

As mentioned, you only need space if the pole is vented. Even so, if the baffle is angled with reference to the back wall, 1" is lots.

Area being a squared figure, you need 4 vents of one diameter to equal one vent of twice the diameter.

BigRedGuy

iTrader: (11)

I would suggest 3/4" for the baffle.......it's a large area and even braced the 1/2" is too thin....

Also the bracing doesn't need to be square blocks...using a piece of the 1/2" about 2 or 3" long at each spot you have indicated will keep the box from flexing and cost you less internal volume....

HTH

Haunz

iTrader: (3)

As dukk said you need to go by area not diameter.. two smaller ports at the same length and tuning would each need to be 2.12" dia..

With that said I'd be hesitant to port any woofer (let alone a shallow mount) using manufacturer's recommendations...


Post the T/S parameters...


Edit: .67 is too small for a ported box.. also you did not subtract the area the ports would take up in your calc. for box volume...

bnevets27

iTrader: (1)

Thank you, now I know that I can safely use a rear vented sub.

Thanks for the advice on the bracing. I thought if I used strips of MDF for bracing I would effect the air flow on a ported box, but I guess if they are only 2 or 3 inches long its fine. And if its a sealed box I assume its less of an issue.

I don't really want to do 3/4, I know it is probably more correct to use 3/4 because of such a large area. But it makes the box much bigger and heavier. Do you think its possible to have enough bracing to ensure there is no flex in the box? I'll have to see how much volume all the bracing would take up and if it ends up being a lot, then its possible that 3/4 think pieces might make more sense.



Well I had originally planed on doing a sealed box, according to what I had "seen" and read it seemed most common for small boxes. And I figured it is "safer" in the sense that it is harder to damage the sub, no idea it that's true or not.

But it was suggested here that a ported box would be better. Since the kenwood was the most suggested and it had specs for a 0.65 ported box I decided to start going down that road.

Since I don't have any idea how to use the specs of a sub to ensure its being used efficiently and tuned correctly to the music I listen to, I just used the manufactures specs.

I assumed that when they gave the spec of 0.65 that included the port and sub displacement, since it was calculated by them, I could be wrong. That's why I didn't include it.

I still haven't completely decided on a sub yet. I was only going to use the kenwood because it was suggested and it was the only one that listed a recommendation for a ported box.

Which ever sub best suits the box I'll go with.

Ok so I got all the T/S parameters and put them in a chart, then used the calculator to get the Qtc, Fc and F3. Don't really know what the numbers mean. According to a link with some info on the calculator page, "Most people like the sound of boxes designed with Qtc values ranging from 0.9-1.1" so according to that the kenwood is the right pick....? The MB Quart does have a lower F3 so does it produce better low notes?

Also kinda curious how MB Quart came up with the Qtc/F3 values in there spec sheet, definitely not anywhere close to what I got.

Chart attached bellow.

I really appreciate everyone's help, I'm slowly learning a lot.

zoomer

iTrader: (3)

lol what good is a shallow mount sub if you need another 3 inches behind it ?

danyman

iTrader: (1)

u know this is dated in march eh lol

mommjomma

Put it in the passenger side footwell, have heard this done this many times in Porsche, Benz, Solstace etc and worked extremely well