Ok i am building a ported box for 2 12" bazooka RSW1224DVC subs and i am confused about the enclosure size. The instruction manual says : BOx volume 2.0 cubic feet* *Box given as internal air volume including port and driver displacement. THen the box says Rec. Vent. Enclosure volume 3.2 cubic feet. Is this 3.2 cubic feet including the displacement of the driver and the port? I am confused on what size my box should be. THe Manual for the subs is located here
https://bazooka.com/pdf/current/rsw.pdf . ANy help would be greatley appreciated.
We don't see the box your sub came in, just the manual. First, how are you wiring those subs...they are dual 4 ohm DVC. Like option 2 below for a 4 ohm load on the amp?
Option 2-Coils in series, subs in parallel:
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Chances are that this will include the driver and the port.
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Top Secret, I can tell you but then my wife will kill me.
I looked at the manual and it shows a Qes value of .51 if coils are series-wired. Trying to see what works in a design program for those subs. The EBP comes out to 62, which is okay for either sealed or ported, but a large enclosure needed for ported. The best sound and lowest bass extension for the two subs is in a box 9.5 cubic ft (!!!) with a round port 4" x 2.27". Box is tuned to 26 Hz. Other than that, you could get by with a box 5 cu. ft., tuned to 32 Hz, with one round port 4" x 3.67". I used WinISD for those numbers, with the parameters lifted from the manual.
The second one, with the smaller enclosure, gives a bump to frequencies in the 50 Hz area. So it you use that size, don't add any bass boost (if you were going to). The volumes do not include driver displacement or port area, which have to be added.
If space is a big issue, you can build the enclosure to 4 ft^3 (and add drivers displacement and port area) as they show in the manual, with one port as shown 4"X 8.35", with the trade-off being in the low frequency response. The lows will drop off quickly below about 50 Hz.
Use what you have space for, and look into some of the box designing programs to help you do it. Nobody should ever build a ported enclosure on anyone's recommendation alone, including the manufacturer's (as you can see, sometimes it's conflicting), unless you also look at possibilities by using a design program.
You might want to look at using a larger port opening than I showed here, too. The length would be longer if the opening is bigger.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Your subs will perform best in a sealed enclosure. You should look into that. Start with
this. And
this.-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
wow stevdart that is very thorough information. However i listen to blues rock rap metal rave techno etc. THe box has been started with a fiberglass mould that forms to my trunk. All of the sides etc will be made from 3/4 mdf. THe shape now is about 2 cubic feet per chamber. Do you think it is worth for me to finish the box ported, or finish it sealed and fill it with 1 cubic feet of wood blocks? I know the you said it will "perform best" But i want the boomy bass for rap etc. Thanks for ur oopenion!!!
Involved here in my Eagles game... you have a total of 4 cubic feet gross, not counting space that the woofers and the port will take up? I'll check with you at game's end....
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
The only thing I can say at this point is go with what you started. I'll just recommend that you make it one chamber instead of two for ported, because your port sizes will take up much more space in the chambers if you have to use two ports. I think it will sound better and be more manageable sealed with the size you have now. No need to fill it to make it smaller, but if you go sealed go ahead and put in the center divider for a two-chamber box. If you've got enough good power going to those subs, you'll get the bass you want for all types of music.
Bottom line is: 1. Ported box building takes careful homework before beginning construction. 2. The specs for those subs tend more to sealed, mainly because they need a large enclosure for ported, with large porting. 3. The space you have to work with is too small to work out the best sound if you go ported.
Some tools and info links: https://www.carstereo.com/help2/Articles.cfm?id=31
https://www.carstereo.com/help2/Articles.cfm
https://www.linearteam.dk/default.aspx?pageid=newdriver
https://www.linearteam.dk/default.aspx?download=winisdpro
https://www.bcae1.com/
https://www.the12volt.com/installbay/search.asp?KW=ported&SM=1&SI=TC&FM=2&OB=1&Submit=Start+Search
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.