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Posted: Fri Jan 01, 2010 1:42 pm
by cool mr grinch
how long does it need to be? i can also make it smaller in diameter.

and when you say to big, you mean it has too much air space?

Posted: Fri Jan 01, 2010 2:27 pm
by Ryan from Ohio
Your subs are called out "optimal" at 1.25 cubes per sub tuned to 34 Hz.

Right now you got well over that and tuned higher.

Basically your going to have a nice peak but not alot of low end. Making the port longer will give you more low end, less peak.

Its a trade off.

Give it a try as it sits and let us know what you think. Just remember to set your subsonic filter to the F3 I listed so you dont unload them.

Posted: Fri Jan 01, 2010 3:07 pm
by cool mr grinch
how are you calculating airspace? i'm getting a different measurement, but i may be doing it wrong. i'm calculating by the size of the box minus the port. which gives me 3.11 cuft. before the subs. is the port added in as airspace?

Posted: Fri Jan 01, 2010 3:25 pm
by Ryan from Ohio
I took the overall outside dimensions you gave, calculated the actual interior volume up to the port board inside, should be 32.25"

14.5 x 32.5 x 12.75 tall = 3.45 cubic feet before displacement

Each sub is .12 cubic feet displacement.

Posted: Fri Jan 01, 2010 3:44 pm
by cool mr grinch
i re-did measurements inside the box which came out to 14.5 deep, 28.75 wide, 12.875 tall. 3.11 cuft which is still to big, but better. the book that came with my subs shows displacement at .14 and re audio website shows it at .12. so im looking at 2.87 cuft. so i need to take out.37 cuft and adjust port from there? i'm not second guessing you, i'm just overly technical.

Posted: Fri Jan 01, 2010 5:42 pm
by Ryan from Ohio
Well if you got better measurements then thats better.

I will rerun it with the measurements you just gave.

.02 cubic feet wont make crap of difference

Posted: Sun Jan 03, 2010 6:59 am
by Ryan from Ohio
Ok, given the new measurements:

2.87 after displacement

47 Hz tuning

9 dB gain @ 51 Hz

F3 @ 36 Hz

Image

Posted: Sun Jan 03, 2010 10:24 am
by MobileAudio219
Wow, that's tuned high!

Posted: Sun Jan 03, 2010 10:47 am
by cool mr grinch
i'm going to make the port longer, i have some spare pieces and i'm going to make a "u" shaped port, and i'm going to lose a little air space.

Posted: Sun Jan 03, 2010 11:08 am
by Bwcad1
MobileAudio219 wrote:Wow, that's tuned high!
Oye...