Audi4780

I would like to create a ported subwoofer box for one Sony 12" sub.

The recommended specs of enclosures (from Sony) are:
Sealed Enclosure Volume : 1.15 cu.feet
Ported Enclosure Volume : 0.82 cu.feet

I always thought that a ported box volume should be greater than a sealed box volume. What do you guys think I should aim for with volume size for a ported? I should also mention, this will be used for my home theater application. =)

ek mike

in ported applications, the box itself will generally be bigger, but that doesn't mean that the actual internal volume of the subwoofer enclosure is bigger. btw, for not much more money, better subs can be found... just my two pennies

Audi4780

This way I can compensate for the volume the wooofer takes up in the box and to be able to build a port that is long enough.

I got the subwoofer for $50 so I dont think I did too bad on price...

avincar

The smaller a box volume, the longer the port to tune the enclosure for the same frequency.

There is almost no way to fit a 4" port into a 1CF enclosure tuned below 50 Hz. The port either has to be smaller in diameter than 4", or stick out, or be tuned fairly high for obnoxion rather than good sound.

Smaller ports compress the air on the way through as the speaker moves farther and farther. This causes port noise, or whistling, and also causes dynamic compression.

So I would suggest against it. Better with a sealed box.

Audi4780

I am really scratching my head trying to figure out what dimensions would sound the best as a ported. What volume size would you recommend for a ported??<ul><li><a href="http://www.crutchfield.com/S-51t54W5Vy9O/cgi-bin/ProdView.asp?g=520&amp;tab=features_and_specs&amp; i=158XSL123#Tab">Sub Specs</a></li></ul>

joeyrf

With these free programs you can determine how your sub will sound based on box volume and port lenght. Do note that you'll still need to add the sub's displacment and the volume of whatever bracing you use to the suggested box volume. Try to get within 10% of the suggested volume for the response curve you want.<ul><li><a href="http://www.linearteam.dk/">http://www.linearteam.dk/</a</li></ul>