4 fi bl 12's in a 7.46cube box

[83chevyflexxin]

Ok so I'm planning on build a box for my 4 fi bl 12's, I've got a rough measurement and it comes out to be 7.46 cubes before displacement and bracing, it will be my daily and comp set up. My question is about port area. I was planning on 4 8" aero ports tuned to around 34hz..but is there such a thing as to much port area? And what would be a good port size for both daily and competition?

[DustinBolt]

i would think you would be fine with 4 6" ports. this way you would also have more volume.

[CleanSierra]

Ok so I'm planning on build a box for my 4 fi bl 12's, I've got a rough measurement and it comes out to be 7.46 cubes before displacement and bracing, it will be my daily and comp set up. My question is about port area. I was planning on 4 8" aero ports tuned to around 34hz..but is there such a thing as to much port area? And what would be a good port size for both daily and competition?

Have you given ANY shot hard hard it'll be to tune low with the airspace you have, and the port size?

It's literally impossible to get a tune that low with 8" ports times 4. 2 6" ports, or 5 4" ports is where I'd go with it.

With the airspace you're working with, my personal preference, would be 5 4" full length aeros. So 5 ports at 4" in diameter at 17" long. That's gonna give you a pretty ideal setup.

[CleanSierra]

i would think you would be fine with 4 6" ports. this way you would also have more volume.

4 6" ports gives him almost 20 square inches of port per foot(way too high) and it also puts his tuning around 45Hz...bad suggestion

[CleanSierra]

P.S. this is a blowthrough build right?

[83chevyflexxin]

Nah it's for my other vehicle, extended cab s10, so 5 4" full length areo's? What exactly determines good port area, I've built boxes and know mostly what I'm doing but I've never built a 7.46 cube box

[CleanSierra]

Typically HOW the sub is built to perform determines how much port area you wanna throw at it. A sub that has a lot of XMAX would want more port area per foot than a sub with less, things like that. Usually the lower you tune, you won't need as many square inches of port per foot. So basically each sub in your box would LIKE a 4" port. To bump port area per foot up into a more suitable range(in MY personal opinion) I added a 5th to even out the load and bring port area up into a range if prefer myself.

[CleanSierra]

I also like the idea of 5 4" ports in that space because there will be no cutting required of the ports. Run them full length and you've got your tuning RIGHT where you want it.

If you're gonna run numbers through Torres or something similar, try 5 4" ports at 17" in length. Don't forget sub displacements when you run your numbers.

[DustinBolt]

i would think you would be fine with 4 6" ports. this way you would also have more volume.

4 6" ports gives him almost 20 square inches of port per foot(way too high) and it also puts his tuning around 45Hz...bad suggestion

i would think you would be fine with 4 6" ports. this way you would also have more volume.

4 6" ports gives him almost 20 square inches of port per foot(way too high) and it also puts his tuning around 45Hz...bad suggestion

yes..,. what i should have done is ask first if this is the volume before ports... cause if it is the volume after ports with the 8" ports the switching to 6" ports would drastically increase the volume at the same tuning.

I also think that 2 6" ports is not enough port for 4 bl 12s... i run more port than 1 6" on my single ssd 12.

In the end OP we need more info to really help you out.

[CleanSierra]

I agree that 2 6" ports is not enough area. It was your suggestion though, not mine. 5 4" ports are my suggestion and the numbers look good for the drivers being used, PLUS the airspace.