need help building a ported box

Post by **Bfowler** » Wed Nov 11, 2009 1:46 pm

i have a 10" hertz sub i intend to make into a home theater sub.

i don't even know the part number, let alone specs for it. (other then its a 10, svc 4ohm sub. that came in a hertz pre fab box that was in a chamber about .8 sealed

so can i just take a box design from the PG manual for say a rsd? which is 2cf, with a 2inch diameter by 7inch long port? (maybe make it longer to tune it lower

Post by **Bfowler** » Wed Nov 11, 2009 1:53 pm

from bogart via pm

bogart wrote:High energy series 10 4...450rms 900 peak per...I havnt seen anything about em ported...go 2.25 per tube port and design the box to run stupid low...trim the tubes back till you like it...run the design backward. I have a generator...build a big ass box that can be baffled back in units with tube ports. Then play with it and run it on the gennie till she is running as desired...the gennie will tell you the tuning frequency

[/quote]

Post by **Eric D** » Wed Nov 11, 2009 1:54 pm

You need a bigger port diameter for home theater. Otherwise you will end up listening to port "chuffing" which sucks.

Get one of these it is worth every penny...

http://www.parts-express.com/pe/showdet ... er=268-352

I think you should build a 2 to 3 cu ft box for it. With home theater bigger works better. Tune it for around 45Hz.

Try some of this to get your tuning nailed down...

http://www.carstereo.com/help/Articles.cfm?id=31

Post by **Bfowler** » Wed Nov 11, 2009 2:23 pm

to further clarify. this box is going under a couch that USED to recline. i dont want to tune it lower then 45hz?

the biggest box that i can make work is 2.064

which is (h7" x w22.25 x l32.75)

so according to that calculator, i should go with a 4" port 5.18 inches long for 45hz

bogart · Post by **bogart** » Wed Nov 11, 2009 2:56 pm

45 hertz is quite high for a theater sub....after re reading the pm I see that wasn't real clear....should have been split...

Build the box as big as will fit and port it out behind the chair....with the sub firing into the top of the seat...then tune it appropriately in application. I would think that you'll like the sub running lower....like below 30 hertz for a theater....

running it lower enables you to use just about any bass boost which would generally occur centered around 45hz to run it more acoustically. I think that porting a sub for a theater at that tuning frequecy you would just hammer the sub below 30 hz and most low frequecy response for theater application is generated below 30 hz or around there.....

2.5 to 3 ft is a huge box for that sub....they were running .6ft sq in an sq sealed enclosure...maybe less...

I meant run it backwards thru a box calculator to find the peaks center per the port.....

bogart · Post by **bogart** » Wed Nov 11, 2009 2:58 pm

I totally agree with eric on the port too...they make it easy and look and work great

Post by **Eric D** » Wed Nov 11, 2009 3:11 pm

I was thinking 45Hz would be good for a 10. Maybe lower would be better. If it were a 12 or better yet a 15 I would go much lower. (actually I would just use a few woofers in sealed boxes)

Post by **Bfowler** » Wed Nov 11, 2009 3:29 pm

its a pretty serious 10. based on what i know about the PG rsd, rsdc, and xenon subs. i would't think twice about dropping it to 26-30 range

Post by **stipud** » Wed Nov 11, 2009 6:38 pm

Yeah I like to port HT subs as low as feasible. HT doesn't have the "cabin gain" that cars do, or at least not as much, so I like to make the response as flat as possible in BassBox when I try to calculate the port size.

brenzbmr@sb · Post by **brenzbmr@sb** » Sat Nov 14, 2009 3:45 am

i just did an 8 inch DD 1508 in a transmission line at 31 hz,, holy hell batman that thing get low.. sounds so smooth to.

try a tl for that sub

Post by **Bfowler** » Tue Dec 01, 2009 5:05 pm

ok...so this is what i got....

2.179 TOTAL airspace

3inch internal - 9.5inch long port

port area displaces .0538

by the calculator above, that should put me right at about 28hz

this sound right to you guys?

i haven't put the back on the box so i can make adjustments

Post by **Bfowler** » Thu Dec 03, 2009 3:40 pm

bump!

Post by **Bfowler** » Mon Dec 07, 2009 12:24 pm

BUMP!

Post by **stipud** » Mon Dec 07, 2009 2:40 pm

Nice box B... too bad I dont have Bassbox anymore or i'd look it up for ya.

Edit: wow only took 2 mins to download
http://thepiratebay.org/torrent/3229123 ... program%29

CarAudioGuru · Post by **CarAudioGuru** » Wed Dec 09, 2009 3:56 pm

Shorten the vent about 3 inches and it will tune about 32HZ and be MUCH flatter in response. Just go get WinISD Pro. Its FREE and what I teach to all HERTZ retialers to use. Super easy , and FREE!!!!!!