PDA

View Full Version : simple porting question

scparrish
01-08-2012, 05:30 PM
when building a ported enclosure can you port 2 subs in a single chamber, as opposed to porting each sub in separate chambers? If so how do you calculate that? I know how to port a single sub in an enclosure just not sure if I can with 2 subs in an enclosure.

to be more specific I am looking at either two sa-10s or type r 10s I just want to make sure I build it right the first time this is my last build for some time and will be a center console enclosure.

ahole-ic
01-08-2012, 05:32 PM
when building a ported enclosure can you port 2 subs in a single chamber, as opposed to porting each sub in separate chambers? If so how do you calculate that? I know how to port a single sub in an enclosure just not sure if I can with 2 subs in an enclosure.
If you think there is a difference, you don't really understand ported enclosures. Google search ported enclosures and study up.

scparrish
01-08-2012, 05:41 PM
I am pretty positive it can be one chamber I just am unsure of calculating a port for it. Sorry if I seem ignorant car audio is not my strong point, yet.

i2ain2thunder
01-08-2012, 05:44 PM
meh.

scparrish
01-08-2012, 05:46 PM
no harm no fowl just need a couple answers is all. I understand the frustration I am on a bunch ford diesel forums and if I read one more question about what exhaust or intake is better I'm going to lose it.

i2ain2thunder
01-08-2012, 05:59 PM
porting is for creating a resonant frequency boost. Therefore the number of subs in a chamber doesn't matter. The port calculations will be the same. Port calculations depend on the box volume and port volume/length so using any calculator will work.
www.the12volt.com has a basic one.
well keep in mind the amount of subs will change the volume of the box through displacement...the subs take up air volume typically between .1 and .5 cu ft

scparrish
01-08-2012, 06:00 PM
thank you

i2ain2thunder
01-08-2012, 06:04 PM
:veryhapp:

scparrish
01-20-2012, 10:52 PM
how do you calculate two ports instead of one?

double 07
01-20-2012, 10:58 PM
Why would you want to do two? That's just more work.......calculate one port with enough port area unless you are putting each sub in a totally separate chamber...

scparrish
01-20-2012, 11:17 PM
as it turns out I am doing a single eclipse sw9122. I really want to do a single 4 inch aero port but am not sure how to incorporate it into the build. it will be a center console and the sub will be firing rearward but the port coming out of the back is out of the question unless I can make to 2 inch ports but am not sure how or if it would sound good or where to have the port exit if I go with a 4 inch.

double 07
01-20-2012, 11:38 PM
Products Menu (http://www.psp-inc.com/tools.html)

go to that site if you know the CF of your box........you can use 2" if that's what your build calls for...........that calculator will help you with length of ports

scparrish
01-20-2012, 11:40 PM
thanks I am just at 2.2 cf after sub displacement. I am concerned about how the smaller port will sound but I also am concerned about a 4 or 3 inch port will sound coming out toward the front passenger seat I don't believe that would be ideal.

double 07
01-20-2012, 11:46 PM
The few console boxes I have built I usually try to do SUBS down and port out the back..........do you have the room to do a small slot port on the rear face of box?

scparrish
01-20-2012, 11:49 PM
I considered down firing with a slotted port rearward but was concerned about losing out on what the sub has to offer by having it firing into the carpet as opposed to my previous thought

double 07
01-20-2012, 11:53 PM
Trust me......the bass will find its way out............I usually try and raise the part where the sub is about 3 inches above floor if mounting depth is still there for sub......This enclosure was pounding in the cab of the F150 it was installed in and BOY would she play the low notes.....

scparrish
01-20-2012, 11:58 PM
thank you for that. I also didn't want to hide the beauty of this sub but am more than willing to sacrifice that for sound

Drummer65
01-21-2012, 12:10 AM
2 2" ports do not equal one 4" port... 2 2" ports are half the port area of a 4" port. Even a 4" port is really not enough port area for a 12" eclipse titanium you really need at least a 6" port if you can.

scparrish
01-21-2012, 12:12 AM
wow alright if I build it down firing it will have a slot port I will just have to calculate the size I need based off of a 6 inch round port.

A 6 inch port seems pretty large

Drummer65
01-21-2012, 12:19 AM
you have 2.2 cubes to work with after sub displacement? if you do a slot port you'll just be eating up precious cubic feet for the sub, id do an external 6" aero.

EDIT: oh wow this is going in the center console? You'll be fine with a 4" port then a 6" would be way too long. If you did a 4" you wouldn't need to do an external port

scparrish
01-21-2012, 12:24 AM
an external port is not an option if I do a slot port I will build it on top of the existing design

Drummer65
01-21-2012, 12:25 AM
yeah i just saw this is going in the center console. Do a 4" port and id tune low 30-34hz depending on your preference

scparrish
01-21-2012, 12:46 AM
honestly I am unsure of tuning I was thinking 32 or 33 hertz

Drummer65
01-21-2012, 12:53 AM
32hz is good, how much power you running? If your only going to do 1 4" port make sure you face the port away from you. With only 12" of port area you will probably get port noise. Make sure you use aero ports as well don't just use pvc, aero ports will help with port noise.

If you can make the box a little bigger you could pull off a slot port. It may be easier and you'll be able to gain a lot of port area. Id shoot for at least 28". The port displacement will be around half a cube so you really need to make your box bigger if you want to do a slot port.

scparrish
01-21-2012, 12:59 AM
For a slot port I can build on the top of the box and style it into the console so it wouldn't take away from the cf of my box design. I am looking at a slot port about 9 inch wide 2.5 inch tall and 23 inch long which would be 32hz sound about right

Drummer65
01-21-2012, 01:02 AM
yeah that would be better then the 1 4", Id go with that. And yeah 23 inches long is right for a 32hz tunning

scparrish
01-21-2012, 01:05 AM
awesome I can finish drawing up this design it should look killer I just hope it sounds as good as it looks

double 07
01-21-2012, 01:11 AM
We want pics when its done!!!!!!!!!!!!!!!

scparrish
01-21-2012, 01:15 AM
I will be starting the build tomorrow I am excited

pro-rabbit
01-21-2012, 01:16 AM
If you have the room for it, sub down with a slot port down as well. If done correctly will work out nicely, but with a 12" you may be a bit limited.

I didn't look to see what year/make/model you have, but I have done this several times with great success. I have also done several sealed down firing enclosures that work great.

The issue you will find yourself in with the eclipse is ensure you have clearance. Those will move a lot if you are giving them enough power.

As for other ideas I have read/seen in this thread. Meh, they will work as well as I have done a few of them. Just not my choice.

If you want when I get back on Tuesday I can do some modeling and gauge the response of a few options in your actual application. Takes out a large part of the guess work.

---------- Post added at 11:16 PM ---------- Previous post was at 11:16 PM ----------

I will be starting the build tomorrow I am excited

Guess no waiting haha...

Good luck man, I'm sure it will turn out just fine.

scparrish
01-21-2012, 01:31 AM
I plan on a 3.5 inch space between the sub and the floor I can easily give it 1000 rms at 2 ohms. I never considered porting down I was unsure about that. It's an 04 f250 crew cab harley and I am trying to design something as nice as the rest of the truck. truck is in sig. I would be more than happy to push some ideas around this is one of my first space constrained builds with a ported box most of the rest of the builds had more space than I had money to fill it. I only plan on building this once so I really really want to get it right the first time around.

pro-rabbit
01-21-2012, 11:17 AM
I would suggest doing a little fiberglassing and wrapping it in a matching vinyl. Should give you the look you are going with. Depending on the amount and type of sound a sealed enclosure can work very well for those drivers.

scparrish
01-21-2012, 12:32 PM
coming from four tens sealed I want decent output but quality is important. there may be some fiber glassing but I want to keep it to a minimal since I don't have much experience with it. I plan on wrapping it with black vinyl. I am wondering what the best output would come from downfiring with downfiring port, rear firing with rear firing port, rear firing with downfiring port, or downfiring with rear firing port. all are possible but my designs will change with each option. the rough specs of my box for downfiring sub is 40" long 14.5" wide 10.5" tall the sub would be as rearward as possible.

the rain here has pushed back the build so I have more time to put into different designs

scparrish
01-21-2012, 09:41 PM
alright after pushing around all my ideas I am going have the sub downfiring at the very back of the console with the port rear ward and will be tuned to 33hz and it will be 2.2 cf after displacement. thanks for all the input I will post pics when I can finish it

scparrish
02-09-2012, 11:40 PM
so this is what I have so far but I have some more questions at this point. Any recommendations for wrapping this thing it's far from a simple rectangle? I still have quite a bit of sanding ahead of me but it is coming along pretty well I spent a lot of time trying to make corners and edges smooth inside and now I am trying to smooth out the outside. feel free for input

http://i578.photobucket.com/albums/ss229/scparrish/IMAG0130.jpg
http://i578.photobucket.com/albums/ss229/scparrish/IMAG0131.jpg