PDA

View Full Version : AW1206T Box Help



NavyCTO
01-12-2004, 10:13 PM
I currently don't have my vehicle. I joined the Navy in August, and am at my training school now. I graduate next month and decided I want to build my own box. I'm going all out SPL. It is supposed to be tuned to 31.5Hz. I'm gonna make it 32" x 15" x 15". It will have two 4" Ports that are 12" Long. Where should I place the ports. I plan on putting a Plexiglass Front on the box, because I'm taking out the rear seat and cutting out the wall attaching the back seat and I'm gonna recarpet around it and place the box there. Any help or recommendations would be highly appreciated. Thanks for your time.

Trixter
01-13-2004, 12:01 PM
First off, for an all out SPL box, I would tune it higher, like around mid 40's. Also, if your going with round ports, look at getting precision ports from www.partsexpress.com. Try facing the ports on the same side as the sub is.

bigred78797
01-14-2004, 02:54 AM
Well i just ran a few quick box prospects and here is my conclusion.

If you want all out SPL, You'll need a bigger box, if you want it to sound anything like a speaker and not a unknown tone of brapppppp brap braaaappppp. The box that you are building is 2.6 some odd cubic feet around 2.45 after speaker displacement. With a box this small you will begin to get distortion a long time before you get close to your speakers RMS.

You will need to tune the box higher like the trixter said... but you don't have to worry about that because two 4" ports at 12" long is tuned to 42.36 hz. And with that setup you have a 6 db port gain at 40 some odd hz.

Then there is the problem of port size... when you hit 40hz or so you will begin to hear distortion ( mainly chuffing ) of the ports due to the high air velocities... they reach around 60 m/s.

I think that's it... if i missed anything else guys let me know.

NavyCTO
01-14-2004, 01:55 PM
What is the formula you used to get that Cubic Footage readout. The one I used said that equaled out to slightly over 3.2 ft/3.

bigred78797
01-14-2004, 02:11 PM
Yes, but you still have to account for speaker displacement ( .27 cubes) and port displacement ( .2 cubes ). And i was wrong i added in the speaker displacement in wrong. But you still only have about 2.6 cubic feet. But you will still need larger ports to accomodate all of that port velocity which will know it down to about 2.47 cubic feet. All test were run using Leap 5.. and for the volume calculation i just used 7th grade math.

NavyCTO
01-14-2004, 02:28 PM
Ok. I only have room to make the box deeper. If you don't mind could you how much deeper the box needs to be to give myself 3.2ft/3 airspace?

Trixter
01-15-2004, 11:58 AM
You posted the dimensions but failed to tell which ones were H, W, and D. Here's what you do: multiply H x W x D / 1728 = cu'. Use the inside dimensions. (If you are using 3/4 MDF then subtract a total of 1.5" ( .75+.75=1.5) from the external measurements.) Play with teh numbers until you get the volume you need.

And really, I have used 2 4" Precision ports for a single 15 and they sounded awsome.(got me a 146.2 on linear-x.) They are designed to cut down the turbulance by their flared ends. Also they won't take up as much displacement as a slot port would.