Is bigger better?

[dexter 0]

I have an RE Audio SX 18. I've heard rumors that this sub can do 2,000 watts RMS fairly easily in the right box. I currently have about 500 watts going to this sub in a 10ft^3 box tuned at around 30 Hz. It's pretty loud. I got pulled over a few days ago for having my music too loud and the officer said "Dude, you were shaking my car, what do you have back there?" Got off without a ticket . I wanted to step it up a notch so I just ordered a Hifonics Brutus BRZ1700.1D. Which does 1700 RMS @ 1 ohm. I designed a box with a net volume of 7.19ft^3 tuned to exactly 34 Hz. Sub up, port back. (My old box was sub back, port back.) For the record, this is going in a 2006 Expedition. The sub is rated for 1000 rms, and I want to push around 1300 to it. I want to this thing to be as loud as possible, will the box I designed impress me or do I need to go bigger? Thanks.

Box uses double 3/4 inch MDF everywhere.

Edited September 9, 2011 by Dexter

[Punkeyboozter 19]

I have an RE Audio SX 18. I've heard rumors that this sub can do 2,000 watts RMS fairly easily in the right box. I currently have about 500 watts going to this sub in a 10ft^3 box tuned at around 30 Hz. It's pretty loud. I got pulled over a few days ago for having my music too loud and the officer said "Dude, you were shaking my car, what do you have back there?" Got off without a ticket . I wanted to step it up a notch so I just ordered a Hifonics Brutus BRZ1700.1D. Which does 1700 RMS @ 1 ohm. I designed a box with a net volume of 7.19ft^3 tuned to exactly 34 Hz. Sub up, port back. (My old box was sub back, port back.) For the record, this is going in a 2006 Expedition. The sub is rated for 1000 rms, and I want to push around 1300 to it. I want to this thing to be as loud as possible, will the box I designed impress me or do I need to go bigger? Thanks.

Box uses double 3/4 inch MDF everywhere.

hard to tell to me honest but it sounds like it might just work.

mind sharing why the port it where it is? Nothing wrong with tuning any higher either but you will lose some bottom end.

[dexter 0]

There's no particular reason for the port being there other than to make this easier to build lol. Should I move it?

[Punkeyboozter 19]

depends on how long it is. Im no pro but I think if its close to the back of the box you might actually create a effect where the box might act like a smaller box. Well that and if you have to put a bend into it...

If you dont have to bend the port turning it sideways might yield better results.

[dexter 0]

The gap between the back wall and the end of the port is equal to the width of the port (5.5 inches)

[Punkeyboozter 19]

The gap between the back wall and the end of the port is equal to the width of the port (5.5 inches)

in that case it should be ok, however Id still rather turn it sideways or move it right to the end. Then again you might find that its the most awesome box ever the way it is.

[dexter 0]

Here's another one I made.

8.94ft^3 @ 35.97 Hz - 105in^2 port area.

[Punkeyboozter 19]

Here's another one I made.

8.94ft^3 @ 35.97 Hz - 105in^2 port area.

I like the second one better to be honest, assuming your sub have enough clearance and the specs are correct and not taking the size into account.

guess what im trying to say the design looks better not taking the numbers into account.

[dexter 0]

I don't care how it looks, just needs to sound good haha.

[Punkeyboozter 19]

I don't care how it looks, just needs to sound good haha.

lol looks to me that option 2 will sound better

build both and let us know.

[dexter 0]

Lol MDF isn't free

[Punkeyboozter 19]

Lol MDF isn't free

off to the woodshop you go... You starting this weekend?

[lithium 358]

maybe someone else can check the box design for you, but i know you need to add bracing to that box, some 1" wooden dow's for example.

[jonbearsmt 919]

i have owned a 18 inch SX

IMO 2000 watts RMS sounds pretty far off.

good luck with your build.

[NB50 206]

The gap between the back wall and the end of the port is equal to the width of the port (5.5 inches)

I wouldnt suggest using this one, the area to the left of the port could act as "dead" area. Meaning the sub wont use it and you'd have a box way different then you originally calculated.

[dexter 0]

Here's yet another idea. 8.08ft^3 tuned to 39.87 Hz. I've never heard an 18 tuned to 40 Hz. I want it to be loud. Is it suitable for daily driving or do you think 40 is too high?

And regarding the bracing, it's going to be double .75 inch MDF all around.

Edited September 9, 2011 by Dexter

[Punkeyboozter 19]

I dont like high tuning. Some do..maybe build it long and then cut it down till u find the sweet spot. If u are not sure aim for 32-35

[Freshh 11]

I've heard with sub up and port back you get better spl numbers, in general. But I don't think it's worth losing some of the music that you listen to, IMO just keep option 1 but put the slot port all the way to the side and keep it around 30-32 hz.

But, that's just me! Good luck!

[bassahaulic 155]

I would defiantly go for more port area, and in doing so a 34Hz tune will get down low while keeping upper end output.

I'd say go for 20^2 of port per cube inside the box. Also, I'd bring the port all the way to one side and run it a long the side and back, as with the larger port area the port will have to be longer.

And BTW, Sub up port back sounds just fine.

[dexter 0]

Is 12 cubes overkill for an 18 when trying to achieve max output?

[Punkeyboozter 19]

Depends on a few things but mostly power. Id do two in that size with rated power

[orlando144 20]

Once you calculate port and sub displacement and suvtract it from the enclosure.. Actual box volume will decrease. So 12 cubes gross wont be overkill i.m.o.

[dexter 0]

how much port area per foot should I be aiming for when designing this thing?

[Duran 387]

how much port area per foot should I be aiming for when designing this thing?

Don't use that rule. The port is for the woofer, not the enclosure. Design the port around what the driver needs.

[dexter 0]

Thank god. Someone said aim for 20inches of port area per foot earlier, so I'm sitting here for like an hour trying to design a box that would meet all of my requirements and i couldn't get it to add up right. lol

I think I'm going shoot for 8-9 cubes at 34 hz

Edited September 10, 2011 by Dexter