n00b question regarding sound

[akuma4u]

this is a very stupid question to most of u but in a ported box, does most of the sound/bass/volume/sound waves come out from the sub itself or the port? or is it a combination of both?

if its a combination, whats the ratio ? like 20% from sub and 80% port ?

thank you

[frogcase2002]

Whats the reason your wanting to know this?

[Joe X]

Around tuning frequency most of the output comes from the port, elsewhere is almost the sub, it's not a fixed proportion over the sub/enclosure bandwidth.

If you are looking for full box bandwidth going through a single port then a 4th bandpass box is what is needed.

[akuma4u]

Around tuning frequency most of the output comes from the port, elsewhere is almost the sub, it's not a fixed proportion over the sub/enclosure bandwidth.

If you are looking for full box bandwidth going through a single port then a 4th bandpass box is what is needed.

hey

heres what happened, i bought two sa 12s and was going to do a 4th with an installer but the guy is unable to do it for a month or two or longer so what i did was i found a custom box off online classified for a single 12inch , but its NOT custom built for a sa12.. i got it for like 30 bucks

i put the sa 12 in that, and that box BARELY fit in my truck i mean me and my boy took 20 mins trying to stuff it in there cuz the height was a an half - an inch too tall..

anyways we got it in and i have it hooked up running 2 ohms on a crescendo bc2000

the drum n bass and dubstep sounds great! nice loud impact vision blurring etc.. but everything else sounds WHACK.. not only whack and soft and all that but almost makes it sound like the sub is distorting or something.. it just does not sound good at all unless im playing drum n bass or rap / hip hop, etc..i wish i could have all my music , or at least most of it sound great like the dnb and dubstep and rap does.. the trance and slightly higher freq bass just doesnt sound good.. so i guess maybe i need a box that is aimed for a flat response? i dunno..

i have NO idea what the box is tuned to, neither did the guy i bought it off of.

maybe someone could help me find out?

also i need to know this.. i will post the measurements of this box ... i need to know if its worth it to build a custom box for this sub or not.. if the box i have now is close to what it needs then i guess its not really worth it.. but if its off and for sure a custom box can make it sound way way better than i need someone joe x or tri to help me out with that (please and thanks)

here is a note though , if a new box should be made then the height MUST be 13.5 - 13.75 MAX

and the depth no more than 16 max and the width no more than 30 inches

here are the dimensions of the box that is in there now, the sub and port are both aiming back

height : 14.5 inches

width 27.75 inches

depth 1 top: 12 inches

depth 2 bottom: 16 inches

slot port measurements:

height: 13 inches

width 2.5 inches

and finally the reason why im asking if the bass/sound comes from the port or the sub is to figure out if i should have sub and port firing foward or sub forward port up (thru rear deck) etc.. im trying to get the most bass into cabin as possible as my trunk is real bad at trapping in air pressure and bass..

one of my friends has the same car as me and has his 2 10s aiming forward with port up and he swears this is the way to go...

thank for the help

[ShadeTreeMechanic]

Sounds like your sub might be unloading below the port tuning? On a properly designed box, the port would be capable of adding 5db or more. The port can be over twice as loud as the sub itself at the tuning frequency. Below tuning, the sub gets no help from the box as far as cone control goes and the possibility of hitting a voice coil on the motor plate is high.

[akuma4u]

Sounds like your sub might be unloading below the port tuning? On a properly designed box, the port would be capable of adding 5db or more. The port can be over twice as loud as the sub itself at the tuning frequency. Below tuning, the sub gets no help from the box as far as cone control goes and the possibility of hitting a voice coil on the motor plate is high.

the setting for the SSF was tricky for me to figure out so i contacted sundown cust service and he told me to have it set at 20hz which is around 9oclock on the dial.. i did that but i read others say that the SSF should be set to a few hz under port tuning .. when i asked sundown this the guy said its ok to set it to 20hz... not sure which method is the right one.. regardless i dont know the freq of the box so i will never be able to tell what to set it to if i do it the way ive read online.

[frogcase2002]

You set the ssf a little below tuning. . Someone should not have told you 20 hz without knowing the tuning of the enclosure. Subs can really be damaged with the ssf to low

[Soccerballzs]

You bought a box for some other sub then the one you have. Big issue. Build box for sub not a store bought one.

[ShadeTreeMechanic]

Without knowing the box tuning I would say to slowly turn it up until it stops making the funny noise.

[Joe X]

here are the dimensions of the box that is in there now, the sub and port are both aiming back

height : 14.5 inches

width 27.75 inches

depth 1 top: 12 inches

depth 2 bottom: 16 inches

slot port measurements:

height: 13 inches

width 2.5 inches

I wanted to focus on your current box specs, without knowing port length one can't know tuning but just for a guess say it's 40 Hz as it's often the case with prefabs, your box specs would be: 1.4 cubic feet net (with the 2 SA12s installed), port area 32.5 square inches.

If anything that would work for one SA-12 but never two, if you wanted to do a proper box around that size for two SA12s it would need to be sealed or a box a single SA-12 ported.