Port area

[kmb504]

How much port area would you recommend for 3 american bass vfl 8s?

[Triticum Agricolam]

What size box? How much power? What tuning frequency?

[kmb504]

3cuft. Not sure the power. The amp spec sheet says it does 1250w rms @ 1ohm and 625w rms @ 2ohms. The amp should see about 2.67ohms. Tuned to 35hz.

[Triticum Agricolam]

With that amp those subs are only going to see about 500 watts split between them, so you can get away with pretty low port area. 30 sq in should be fine, however I'd recommend giving them 50 sq in so you can run higher power down the road. With 50 sq in you will be good up to the RMS rating of 1200 watts, and would probably be fine with even more power than that.

[kmb504]

Ok, thank you.

[kmb504]

Since I haven't gotten the 3rd sub yet and I don't want to have to get a new amp, I'll rebuild a new box. I've never used aeroports before but I want too. I figure a 6" port should be enough port area but there's no way I can fit a 26" run in my box. The box will be 2cuft. So can I run 2 3" ports, or should I do the 6" port and do a tee to achieve the desired length.

[Triticum Agricolam]

Well first off, two 3" ports does NOT equal one 6". It takes four 3" ports to equal one 6" and they would all have to be about 26" long just like the single 6" port did anyway.

I agree that a single 6" should be great for two subs. To get the needed length you can have some of port external, or you can put a sweep in it, though those are expensive and can be hard to fit too.

[kmb504]

What is a sweep? Thank you for clearing up the multiple port thing. I wasn't sure how that worked.

[Triticum Agricolam]

A sweep is a 90 degree bend, but its more gradual. It has a larger radius of turn than an elbow does.

This is an elbow:

And this is a sweep:

[kmb504]

Ooooohhhh. That makes sense.