Hey guys,

I bought some E8s a long time ago and haven't had time to install them in a vehicle yet. I'm looking to build a ported box for two of them and was using a calculator online to help me figure out how big to make the port.

The box is for two E8s (they displace .03 ft3 each right?) and I'm trying to build it so each sub gets .6 ft3 of airspace and the port is tuned to 30 hz (like the sundown website recommends). I can get the internal dimensions right at 1.2 ft3 (a little more actually to accommodate the displacement of the sub) but the port is only a 2"x2" square 8" long. Does that seem right? Could I make it 1"x4" rectangle or even .5"x8"? Or would that cause too much turbulence having the port that narrow? It just seems odd that the port needs to be so small....but I've never built a ported box before...only sealed.

Thanks for the newb help.

The port is indeed too small... you need more like 12-16 in^2

Hey guys,

I bought some E8s a long time ago and haven't had time to install them in a vehicle yet. I'm looking to build a ported box for two of them and was using a calculator online to help me figure out how big to make the port.

The box is for two E8s (they displace .03 ft3 each right?) and I'm trying to build it so each sub gets .6 ft3 of airspace and the port is tuned to 30 hz (like the sundown website recommends). I can get the internal dimensions right at 1.2 ft3 (a little more actually to accommodate the displacement of the sub) but the port is only a 2"x2" square 8" long. Does that seem right? Could I make it 1"x4" rectangle or even .5"x8"? Or would that cause too much turbulence having the port that narrow? It just seems odd that the port needs to be so small....but I've never built a ported box before...only sealed.

Thanks for the newb help.

Sounds like the work of RE Calc?

Make it bigger and it will get longer. Amusingly so much so that if you were running just one 8 the box may be bigger on the outside than if you run 2 considering how much longer the port will need to be.

I would try and at least use a 3" ID port for a pair of those 8s, as a minimum. A 4" ID port or larger would be best.

It really depends on your power though, the area of the vent has nothing to do with the box size.... That is a stupid rule of thumb...

I have installed tons of 8s. Hundreds really. With mosts drivers that have around an inch of throw, a 3" ID port for the pair is usually adaquate and is about as long as you can go unless your box is an extremely thin design.... For the Tangband (both neo and ceremic motors) and the RE and Parts Express Reference 8s, I almost always end up at .7-1ft3 per pair of 8s with a 3" ID PVC vent tuned at 30Hz... That always has seemed to work very well and not introduce a noticable amount of compression....

For all out efficiency at full stroke, I have used larger vents, like the ones in My Avatar, that is 3 x 4" ID Aeros for each set of (4) 8s.....