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oldschoolboomer
05-28-2009, 02:42 PM
building a 4th order for 8 concept css-10's. using the carstereo.com 4th order calculator, I know the ported section needs to be 3.24 cubes tuned to 58hz. it doesn't do port calculations, so i am using re's calculator for that. my question is about the port area. whats the rule of thumb? is it @1/3 of cone area?

oldschoolboomer
05-28-2009, 05:58 PM
nobody knows?

oldschoolboomer
05-28-2009, 07:45 PM
bump surely somebody has some knowledge. Isn't this caraudio.com?

oldschoolboomer
05-28-2009, 07:57 PM
did i accidentally stumble into nambla.com?

fearof85
05-28-2009, 08:01 PM
I would run 4-5 cubes sealed and 10 cubes ported w/ as much port as you can get away with.

EDIT-lower tuning to around 46-50 hertz as well.

Drew

Cabin_Pressure
05-28-2009, 08:01 PM
How much Xmax do the tens have?

80INCHES
05-28-2009, 11:32 PM
building a 4th order for 8 concept css-10's. using the carstereo.com 4th order calculator, I know the ported section needs to be 3.24 cubes tuned to 58hz. it doesn't do port calculations, so i am using re's calculator for that. my question is about the port area. whats the rule of thumb? is it @1/3 of cone area?

no
use the biggest port u can possibly fit in ur ride
i hope that 3.24 is for 2 subs

80

galacticmonkey
05-28-2009, 11:36 PM
Definately needs to be bigger. Go with around .6-.7 sealed per sub and then 1.2ish ported per sub, with around 20-24in^ of port per cubic foot of ported airspace. Tune to around 45-50ish hz.

oldschoolboomer
05-29-2009, 07:43 AM
How much Xmax do the tens have?

a half inch

oldschoolboomer
05-29-2009, 09:19 AM
Definately needs to be bigger. Go with around .6-.7 sealed per sub and then 1.2ish ported per sub, with around 20-24in^ of port per cubic foot of ported airspace. Tune to around 45-50ish hz.

gln305 says these subs get sloppy in more than .5 sealed. concept recommends only 1 cube ported, so I would assume these sizes would be too big. Or am I missing something? Here are the ts parameters:
Fs = 26.1 Hz
Qms = 4.34
Vas = 1.678 cu.ft
Xmax = 0.472 in
Qes = 0.377
Re = 3.2 ohms
Z = 4 ohms
Pe = 250 watts
Qts = 0.347
1-W SPL = 85.38

oldschoolboomer
05-29-2009, 09:35 AM
when I use an f3 of 36Hz, I get the following numbers for one sub:
sealed 0.445
ported 0.396
tune to 56.98
boost 2.36 dB
passband 36-90.2Hz
Qbp 0.76

when I try lower f3's it tells me my boost is negative 1.xxx dB.

Try a different calculator? Please enlighten...

oldschoolboomer
05-29-2009, 10:11 AM
did some more research. carstereo.com's port area calculator says a minimum of 320 sq. inches of port for 8 10's with 12 mm xmax in a 4th order.

galacticmonkey
05-29-2009, 01:07 PM
You dont need a calculator to design a bandpass.

oldschoolboomer
05-29-2009, 01:22 PM
I built one around 12 years ago for 2 jbl gtx 15's. I just guessed on everything. @ 4 cubes sealed into @10-12 cubes ported in a blowthrough. The port was the blowthrough. @ 6" x 22" 6" deep. Didn't know the tuning I just made the port as big as I could. The bass flexed my windshield, shook the doors and steering wheel to the point the striker plate was starting to rip. Windows of stores would flex when I got within 15 feet. All on 500 watts. Only problem was it would only play between @10 and 35 hz. I want the volume and efficiency in a more usable range. The goal is tons of 40-45 hz. Can you help me out?

oldschoolboomer
05-29-2009, 02:39 PM
bandpass bump

iamamp3pimp
05-29-2009, 02:43 PM
heres what im doing for 2 level 5 10's

.8 sealed and 3.3ish ported tuned to 44 HZ

and a port as big as i can fit.

most people dont have the room to go with 20+ squares per cube of port area chuck.......lol

iamamp3pimp
05-29-2009, 02:43 PM
i meant per cube of airspace in the ported chamber

oldschoolboomer
05-29-2009, 03:10 PM
heres what im doing for 2 level 5 10's

.8 sealed and 3.3ish ported tuned to 44 HZ

and a port as big as i can fit.

most people dont have the room to go with 20+ squares per cube of port area chuck.......lol

wow so the 3.3 is net or gross?

oldschoolboomer
05-29-2009, 04:28 PM
bumpity bump bump

oldschoolboomer
05-29-2009, 05:43 PM
may be building for 12 10's now. More opinions would be great....

galacticmonkey
05-30-2009, 03:31 PM
Just try to stick with the guidelines I have you.

oldschoolboomer
06-01-2009, 03:38 PM
how does 4.8 sealed, 8.1 net ported with 227.25 inches tuned to 48hz sound for 8 subs?

galacticmonkey
06-01-2009, 03:43 PM
Shrink it down to around 200in^ of port. Tuning is fine.