Four Polk MOMO 8's ported. need tuning help

[thur5d4yf4n 10+ year member]

well i just need to know what size aeros I should use for the best tuning.. i want these 8's to get low and loud. or any tips on the total cubic ft for all 4. fry's electronics had a deal on these where they are half off to start with then if you buy one you get the second half off so i paid $182 for four 8's that came with 3 year full replacement warranties on each sub. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif oh yeah i'm wiring all 4 onto a diamond audio d3 800.1 @ 1 ohm. 200 rms per sub //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

any help is great.

here's specs

Driver Complement

Woofer 1 - 8" Diameter (20.32cm)

Metalized (aluminum) Polypropylene Dynamic Balance cone

Electrical

Overall Frequency Response 26Hz-200Hz

Nominal Impedance 4 ohms

Minimum Impedance 3.3 ohms

Power Handling (continuous) 200 w

Power Handling (peak) 400 w

Efficiency 85 dB

Voice Coil Diameter: Driver 1-1/2" (3.81cm)

Magnet Weight 25.00 oz.

Driver Mounting Depth

Top Mount 4-1/4" (10.79cm)

Bottom Mount 4-9/16" (11.59cm)

Cut-out

Driver Cut-out Diameter 7-1/16" (17.94cm)

Theile/Small Parameters

Recommended Enclosure Sealed / Ported / Bandpass

Resonant Frequency 43 Hz

Qms 15.13

Qes .68

Qts .65

Vas 0.562 cu.ft./15.9 L

Bl 10.2 Tesla Meters

Sd 34.72 sq.in. / 224 sq. cm.

Xmax (linear) .709 in. / 18 mm.

Le 1.84 mH

Other

Product Weight 9.00 lbs.

Click to read more...

 

[J31Rob 5,000+ posts]

around 4 cubes total.. after displacements sounds about right.

tune around 33-35 hz.. you'll be set.

 

[IamDeMan 5,000+ posts]

2.5-3 cuft sealed.

 

[thur5d4yf4n 10+ year member]

can someone explain why i should go sealed?

and if i do ported, how do i figure out what exact size ports i should use to achieve a 33hz tuning

 

[DBfan187 5,000+ posts]

2.5-3 cuft sealed.

Correct, these subs specs scream for a 3cF sealed box.

 

[thur5d4yf4n 10+ year member]

alright then i guess sealed it is. what sort of numbers do you guys think ill be near. i know its a retarted question but maybe someone might know.

 

[IamDeMan 5,000+ posts]

can someone explain why i should go sealed?and if i do ported, how do i figure out what exact size ports i should use to achieve a 33hz tuning

Well it kind of rests in the jack of all, but leans more toward sealed for SQ. I think it will get boomy if ported. It's EBP is sitting at 63.2 I go for SQ over output, so I would seal this driver.

Of course this is all theoretical modeling and has no absolute dictation on in vehicle response. Only true way to find this out is to build 1 of each enclosure and play around with them until, you find exactly what YOU are after.

 

[thur5d4yf4n 10+ year member]

d@mnit i wanna go ported. i get so sick of hearing sealed. someone please give me some help on tuning these b!tches. after measuring and calculating i have 4.26 cubic feet of space for my box not including port, and sub displacement.

 

[IamDeMan 5,000+ posts]

d@mnit i wanna go ported. i get so sick of hearing sealed. someone please give me some help on tuning these b!tches. after measuring and calculating i have 4.26 cubic feet of space for my box not including port, and sub displacement.

Then do it. They are still within the realm of either or.

I would ideally want like 5 cuft though for them ported myself. 4 cu ft @ 36hz should be fine though.