Box Questions for (3) SA x-8 v.4

[Joe X]

Really you don't want a ratio higher than 6:1 (say 6 inches wide and 1 inch tall or 6 inches tall and 1 wide for example)  going from 20:1 to a 10:1  is not going to help a thing and also using two (or more) ports by itself is less efficient than using one so that divider idea would just make things worse. I am probably a bit annoying now but it's better to know this things, rebuilding a failed enclosure is very frustrating not to mention the ruined wood and effort.

 

 

[Ecohostile]

Hey Guys, I appreciate everyone sending me Subbox pro Designs using the specs from the website. That's essentially where I started and the Box was taking up too much space in my rig. 

By adding a wedged back to for to the seats, I gain 2-3inches of trunk space, and add .13cuft (the displacement of one driver) back to the box.

 

So I've made a few compromises!

 

I'm only going with 2 subs. My buddy wants the third for his truck, and a 2ohm load of 2000w is a more Ideal match for my amp. So here are my newest renders.

 

At the Bottom is a 32hz option with all factors the same excepts size and a couple disclaimers. Any Pro's and cons of 39hz vs 32hz would be appreciated.

 

1.88CuFt Gross (1.62cu Net ) or .81cuFt per sub

3/4in MDF With Kerfed Port

Tuning - 39Hz

Port Length - 28.02"

Port Area - 24sqIn

Port Width - 2.52"

Kerf Fold Length - 4"

Kerf Fold Width - 2.50"

 

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Thinking I will round the hard edge of the port on the right as well as the opposite corner, since kerfing on an angle is impossible, at least I think it is.

 

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And this last image shows a 32hz Option but it's 1 3/4" wider, 2" deeper, and gets in the way of that 3rd seat folding down. I know that seems like a small change but it makes the difference of me being able to drive my brother, bassplayer, and their ampscabs to shows without taking out the sub box (I'm in a band) or taking two cars.

 

 

One More Pic just for fun. This is the Boneyard of failed box designs lol!

[Joe X]

Whatever happens with your car audio project you will end up a sketchup expert!

 

As for the question, high tuning makes you louder but less able to play properly certain types of music like rap and such, more so with small woofers which usually struggle a bit more with the lower notes BUT if you play madonna or classic rock you are not affected by higher tuning.

 

If you listen to all types of music you want a tuning in the lower 30s, when space is concern I always suggest 34Hz, it plays very much like 32Hz but saves a lot of box volume due to the shorter port length.

 

You should also factor in what is the proper port area for the power you are using which seems to be above rated now that you left one sub out, Maybe 12 square inches per sub will be enough or maybe not, one needs to see with modeling software, sure enough with that kerf you will avoid most port noise but overall port efficiency gets impacted by port area.

 

Really when you are trying to do a small box is when a design becomes challenging, One needs to pick the right compromises, sometimes it's better to lose some space, I say a wider box doesn't hurt the usability of the trunk. As always this is just food for the thought.

[Ecohostile]

Well I bought one of these...

 

(It's the one I modeled @ 39hz in the last post)

 

I know it's a prefab but it's on sale because of black friday so I figured I'd try it out.

 

I bought a bunch of other stuff too, and i'll post it all when it gets here.

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Edited November 23, 2023 by Ecohostile

[Ecohostile]

Another Idea I had involving Aero ports

 

I honestly have no Idea how to calculate aero ports, so I copied this box from ebay and modified it into a wedge.

 

The only Issue I have it that the ports are too close to the bottom of the box.

 

I'm thinking about either throwing some 45deg adapters in or running the ports out the right side

 

The other issue is that I am trusting an ebay seller, hoping that dual 3" ports @ 13" each tunes the box to 32hz. 

 

Enclosure Details:

- 3/4" MDF Cnstruction

- Black carpet (charcoal or light grey carpet may be substituted upon request)

- Port Tubes - 3" flared x 13"

- Tuned to 32 Hz. (frequency is adjustable upon request)

- Exterior Dimensions - 26" (wide) x 14" (tall) x 16.75" (deep)

- 2.0 Cubic ft - Net Volume

 

 

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[Joe X]

The problem with that is that two 3" ports have 14.1 square inches of port area, not nearly enough for two subs so you will likely get port noise when pushing more power.

[Ecohostile]

looks like I would need 2- 4" ports then. Thank you everyone for your input and help. I think my next post will be a new thread in the project log section. I'm still a long way from installing anything into the car, but I'll be doing the

Big- 3  (possibly 4)

hidden amp rack

Upgraded AGM up front

148ah lithium in the back

8ch Dsp, Active Crossovers

2-way in the front (3-way later with some custom a-pillars)

Full Sound Deadening Treatment

And an SQL Tune using a Dayton Audio Umm-6

 

Most of the gear I have installed in my 2006 Scion TC. I still need to rip out all of my gear and get that car sold before I start working too much on this one.