2000SPL Box Design

SSS 18734
5,000+ posts

Dollar Menu Millionaire
I posted a thread about this a while back, but turns out I entered the wrong T-S parameters //content.invisioncic.com/y282845/emoticons/blush.gif.99bc659ee2012b7d826165e26fb5eebe.gif , and thanks to member PowerNAudio i've been making a lot of progress.

Heres a new graph. The response is relatively flat, and has a nice little peak around 32hz. I'm going less for flat response and more for low end here. Basically, I want it to rattle the sh*t out of the car. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Box will be ~1.5 cu.ft. per sub, tuned @33hz

Slot ported: 3" wide port, 10" tall, 40" length.

Response curve is like so:



Im trying to make this box as shallow as possible, with a divider in the center so both subs have seperate airspace, with both ports firing out of the middle of the box so it will be easier to make indented sides. Plenty of bracing also.

I've got a few questions.

1. Would the port I am planning on using be large enough to avoid port noise? Is port area calculated by figuring the entire area of the port througout its length, or just the area of the opening? also, during the design process, I may end up increasing the height of the port, giving me even more port area.

2. If possible, I'd like to have the subs firing upwards. However, making the port fire upwards would be completely unpractical, as I'd need one hell of a long port. Would I be likely to experience any cancellation having the subs fire upward, while having the port fire to the rear? anyone ever had any experience with this type of setup?

3. This box will likely weigh well over 100 lbs. My current one is pretty small and I can barely move it around as it is. Might I be better off making two seperate boxes? I take them in and out pretty often.

 
ok I probobally gave way too much info to have anyone interested in helping. so ill sum it up.

1. will a port that is ~3" wide, 10" tall, and 40" long be adequate to avoid port noise?

2. what is the chance of experiencing cancellation by firing the subs upward and the port to the rear in a station wagon?

 
if I increase box volume to 2 cu.ft., and raise the tuning to 35hz, I only need a port 27" long.

However, at maximum power the subs will reach full excursion before 30hz, which i'd like to avoid. The other box wont reach full excursion untill around 25.

 
how about this, using round ports?

2 cu.ft. //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

tuned to 35hz

two 4" tube ports, 25" in length.

or two 3.5" wide ports... 19" in length

Think that would have any port noise? i'm getting port noise right now with a single 4" by 6.5" tube port... not all that much though.

 
use the rear port air velocity window, when changing port width and length and try to stay as close to the 17m/s or below as you can, since any thing above that speed makes port noise and also keep an eye at the freq that the peak of the curve is on, since that the freq when youre actually going to hear the port noise. if the freq is high then dont worry about it and if its below a freq youre sure youre never going to play on like 25hz or for sure 20hz and below then dont worry about it ether.

also, on the signal tab make sure you put on there the rms power youre going to be giving the particular sub or subs youre designing the box for since that will change how fast the air goes in and out off the port.

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

About this thread

SSS 18734

5,000+ posts
Dollar Menu Millionaire
Thread starter
SSS 18734
Joined
Location
Kansas City, MO
Start date
Participants
Who Replied
Replies
21
Views
1,153
Last reply date
Last reply from
FOSGATE JOE
IMG_20260516_193114554_HDR.jpg

sherbanater

    May 16, 2026
  • 0
  • 0
IMG_20260516_192955471_HDR.jpg

sherbanater

    May 16, 2026
  • 0
  • 0

New threads

Top