[Tuna_Sammich]

I have a box that looks like this, a pair of Orion HCCA's came in it..

the orange area is the port...

a cutaway would look like this...

what is a box like this good for??


thanks..

 

[Supernaut]

:dunno:

but your avatar is not funny man :angry:

 

[Tuna_Sammich]

why not?

 

[Mac2118]

it's a ported box... what it does is gives you more output at different frequencies..

if you want, you can give me the box dimensions, port length, and the size of the port opening and I'll tell you what frequency it's ported at

I've had 3 ported boxes.. technically 2... one was 4cu ft with 2 RF HX2's in it ported at 40hz, then 2 RE HC12's in the same box, and that gave me a boost at 40hz... the other box is 2 cu ft ported at 30hz... if you look at a graph of the response curve, you'll notice a peak at a certain frequencies...

ported boxes will give you a larger output too. most SPL competitors find out what the resonant frequency is in their car (car's natural boost,.... the car has a certain frequency that is louder than all others in it) and they use that to their advantage by tuning their box to that frequency and burping that note...

it's not good for you to play below the tuning frequency, if you do, the subs think they're in freeair, and that will hurt your subs...

 

[Tuna_Sammich]

i dont really need the box, I just had never seen a design quite like that before..

 

[Mac2118]

it's quite common actually...

 

[JeremyD]

Originally posted by Mac2118@Oct 8 2003, 07:29 PM
it's a ported box... what it does is gives you more output at different frequencies..

if you want, you can give me the box dimensions, port length, and the size of the port opening and I'll tell you what frequency it's ported at

I've had 3 ported boxes.. technically 2... one was 4cu ft with 2 RF HX2's in it ported at 40hz, then 2 RE HC12's in the same box, and that gave me a boost at 40hz... the other box is 2 cu ft ported at 30hz... if you look at a graph of the response curve, you'll notice a peak at a certain frequencies...

ported boxes will give you a larger output too. most SPL competitors find out what the resonant frequency is in their car (car's natural boost,.... the car has a certain frequency that is louder than all others in it) and they use that to their advantage by tuning their box to that frequency and burping that note...

it's not good for you to play below the tuning frequency, if you do, the subs think they're in freeair, and that will hurt your subs...

Some misconceptions to clear up here. The tuning frequecy is actually not where the ouput peak is. The tuning frequency is like the F3 frequency of a sealed enclosure, the -3db rolloff point. The actual peak in response is usually anywhere from 3-5 db higher than the tuning frequency.

Ported enclosures generally can give you more output, but they can be designed to yeild a flat resposne as well.

 

[h-town caddy king]

Hear in Houston we can buy those exact boxes for about $35-55 all day. I’ve tried them & I like them. But I have had more luck putting the port in the corner then make it turn towards the side of the box about another 6-10in. the port will look like a “L”

 

[Mac2118]

h-town.. that's the way my box was with the dual HC's.. it was alot easier to build using the wall of the box as a side of the port...


Jeremy... how so? with my ported box, I had it tuned to 40hz, I ran a sweep from 50-35hz and my peak was at 40hz.

 

[JeremyD]

Originally posted by Mac2118@Oct 9 2003, 02:24 PM
Jeremy... how so? with my ported box, I had it tuned to 40hz, I ran a sweep from 50-35hz and my peak was at 40hz.

Lots more plays into it than that....

vehicle resonance is the most likely cause...

 

[BuThatsaCHRYSLER]

what size subs is that box for?

 

[Mac2118]

Originally posted by JeremyD+Oct 9 2003, 09:08 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (JeremyD @ Oct 9 2003, 09:08 PM)</td></tr><tr><td id='QUOTE'><!--QuoteBegin--Mac2118@Oct 9 2003, 02:24 PM
Jeremy... how so?  with my ported box, I had it tuned to 40hz, I ran a sweep from 50-35hz and my peak was at 40hz.

Lots more plays into it than that....

vehicle resonance is the most likely cause...[/b][/quote]
my res freq is 51hz

 

[JeremyD]

Here's a perfectly good example.....

Look at this plot....

45 hz tuning frequency, peaking at nearly 50....

Last edited by JeremyD at Oct 10 2003, 06:42 AM

 

[Mac2118]

what are the port specs on there?

and I do n't look in the SPL graph... I look more into the transferre function