multiple ports

[Jspawn80]

Explain why you "can't run them sealed"
We've advised you to not use multiple ports several times now.

If you want to get really technical with it, yes. You only add half the distance of the flare as port length iirc. If you added flares to the existing 4" port though, I see that as a way for you to possibly still run ported.

Also i tried putting in a 5 inch diamiter port into winisd and it says that at 38hz my port would be 17.5 inches long and would be about 2 inches away from the transmission hump wall. But where could i get a 5" port??? i've looked for 5" pvc but it doesn't seem to exist.

 

[adulbrich 5,000+ posts]

I've looked on alot a places online that say its not a good idea to run the sa8's ported and sundown doesn't even have a recommended box for the subwoofer sealed.
Also i dont really understand the way flared ports work. When i put my box info into winisd with a 4" port thats 10 inches long, my tuning is at 38hz and my vent mach (which from what i understand has to do with the speed of the air traveling through the port) is a 0.21. And from what i've read it has to be below 0.16.

Now if i put in a flared port thats the same length will it reduce the vent mach or will it just keep the port from making noise?

Also while messing around in winisd and using the same 4"diameter port, the only way for me to reduce the vent mach is to raise the tuning. Which reduces my vent length and brings it down to a port thats 4" long but my tuning is ridiculously high a 52hz

You can run anything sealed.

Also i tried putting in a 5 inch diamiter port into winisd and it says that at 38hz my port would be 17.5 inches long and would be about 2 inches away from the transmission hump wall. But where could i get a 5" port??? i've looked for 5" pvc but it doesn't seem to exist.

Look around on the internet. You can get any kind of plastic pipe diameter custom made. That being said, I still recommend you just go sealed because you don't have a ton of room.

 

[blazian87 10+ year member]

From what I've seen online, most people run their SA-8's ported rather than sealed. That space is rly tight so going sealed might be the only way to salvage that box. Going flared helps a ton when going ported. I run a 4" flared precision port on my 4 10's. My port area is too small for my box too but I pretty much got away with it by going with flared. The way they calculate it is just adding like another 1" to the whole port length. The problem is the overall diameter is much larger so it still might not fit in your application. Don't rely completely on winisd. If you can't get the tune you want, you might as well seal it or go with a different setup all together. Here's the calculator for the flared precision ports to get a better idea.. http://www.psp-inc.com/tools2.html

Sent from my iPhone using Tapatalk

 

[adulbrich 5,000+ posts]

Yes, most people run them ported, but you don't have to. Mine was in about 3/4 of a cube with a 4 foot 2" flared aeroport