Looking for suggestions for a good tuning freq for a SI18 in a 7ft3 net box. I did some modeling in winisd and found 18hz with two 3 inch ports about 14 inches long looked pretty good. I could build a minimarty but I need a different shape. I also would prefer to stick with round ports unless the slot ports would allow me to achieve something the round ports couldn't.
I could go up to 8 ft3 but that didn't appear to offer a lot of gain over 7.
You're going to have some serious port noise if you approach anything near xmax. Which is about 1kwatt. You could underpower it, but that seems pointless. Consider 4x3" ports that are 60cm long for a 20hz tune, or some a way to get that port working. That's still not really ideal either. I'd be thinking 4" ports. That's where slot ports are nice, you can extend them along the side of the box and get lots of mouth area. You might need elbows in your PVC.
Thanks. How do you calculate first port resonance? I don't see any mention of it in winisd. If the port velocity is real low is that wasting something? If i can get the same tuning with two different port diameters and they are both under the acceptable limit for velocity is one better than the other?
How about three 3 inch ports at 22.5 inches. That gets me .05mach which should equal 17ms. That is alot of port though. The slot port is looking better now! How hard would it be to convert the minimarty design into a box that has a 22inch max width or depth for the bottom panel? I need it to fit between a wall and a floor register.
I put 600 watts in the driver specs. But if you're asking about how much I will actually be using, I'm not sure yet. An inuke probably or another pro amp with about 1000 watts. I need as much output out of this as I can get since I wont be able to add another. Large room. Already have a ported 12 to back it up. But it needs to fit around an air vent. I can't move the wall or the air vent. Otherwise I would just build the minimarty, or even the martycube. I probably listen to more music than movies,