Sundown X 15 Port??

[Kyle O'Quinn]

So I bought this bohemoth of a subwoofer, the X 15 from sundown. I got a box already built with 5.4 ft^3 after sub displacement, just waiting for an aero port. I'm probably going to tune it to ~29-30 Hz. I'll be putting about 1800 - 2000 watts on it.

My true question is about some recommendations on the port area, port diameter, and port length you guys have. Which would be best?

I have two 4" aero ports, and I could use those, but I was thinking either a single 6" or 8". Just let me know.

Thanks in advance,

Kyle

[Cj Kumz]

Two 4'' is way too little port area. You can either do two 6'' or one 8''. Two 6'' (area: 56 sq inches) ports will have to be around 35 inches long to tune to round 30 Hz and you will remain with about 4 cubes after all displacements. And for the single 8'' (area: 50 sq inches) the port will be 29 inches long for 30 Hz tuning leaving you with 4.3 cubes after all displacements. Though personally I would make the box slightly smaller due to the power you putting.

[Weigel21]

Yeah, smaller enclosure's allow the sub to handle a bit more power more easily. so I'd recommend either going smaller with the enclosure (perhaps add some blocks of wood to reduce the internal volume since it's already constructed, or not feed the sub more than say 1500RMS with the enclosure you have. I'd probably opt for the dual 6" ports to get the internal volume down a bit more, but even then, I'm not so sure the sub would want to take so much power.

[CleanSierra]

Why are you planning to put that much power to that sub if you don't mind me asking?

The airspace you have(in my opinion)is too much for even rated power, let alone overpowering. You should really be more in the 3-4 cubic for range. Probably closer to 3 cubes if you really plan on sending close to 2K to a sub rated at 1250W.

As far as port area, the single 8" round port would be my choice. Make sure both inner and outer are flared out to avoid unpleasant noise. Granted, the 8" is plenty of port area, but you still should user the practice of flaring the inside and outside opening. If you need tips on how to make that happen, I'd be happy to help.

This box was rushed as hell and was started and finished in 2 days between sleep and work. You can see the inside piece slightly. That piece is double layered MDF. The one layer is cut to the outer diameter of the PVC pipe do it slides through. The other piece is the inner diameter of the PVC. The outer piece is flared with a roundover bit on a router. The outside baffle(where the subs mount) was done in the same manner. The inner baffle was cut the outside diameter of the PVC and the outer baffle was cut the inner diameter of the PVC and then rounded over with the router. If I would have had time, I would have use body filler to cover my seam perfectly, sanded it down and it would had a random transition from wood to PVC that you never would have known was there.

[timc31610]

I did the same thing on my last pvc ported box and it turned out really well. Here are a couple of pics to show the process.

[Kyle O'Quinn]

Well I meant more like I'll have about 2k available, I'll proably have to tune the amp down to keep it, but I'm not chasing numbers or anything and that X is built for the low end, so I figured a little oversized would aid its strongsuit. I'd probably just buy an 8'' aero if I can find it, I just hate how thin that plastic is. I've also got a square port thats 8.25" X 8.25" tuned to 30 Hz that could be an option, I could just as easily round over the inside of that port. Also, the square port would take up more airspace and bring it down to maybe 4.5 ft^3 or so. I dont't know, just throwin around ideas.

[CleanSierra]

The sub will play low in the box that Sundown suggests on their site. Last time I checked that design, I think it was 3-3.5 cubes tuned at like 30-32 Hz. You don't need to throw 5 cubes at it to get it to play low. Thermal handling is what you need to keep an eye on, that sub can handle itself well mechanically in the right amount of airspace.

[Kyle O'Quinn]

I see what you mean. The box was built already for two welves, I'm just butting another baffle on it to swap it for the 15 so yea itll be too. The only reason I'm not rebuilding is because Birch ain't cheap and it already fits perfectly. After I add 45's, bracing, and port, it should be closer down to being right. I think I'm gonna do the square port and position in like a diamond (kinda like turned 45 degrees) because I love the asthetics, It'll take up the most space, give me a little over 14 in^2 per ft^3, and almost 70 in^2 over all. I'll do what I can to lower he air space, thanks for advice on that. If I do anaero port, I'll probably buy a 9" psycoport!