Got my tempest up and going, or at least for the most part (1 Viewer)

[Scott Parker]

I've been slowly pieceing together my sub over the past couple weeks and here's the stats
24" 4' sonotube
15" Tempest (on top, until I get legs)
3/4" MDF caps
2 4" Aeroport's
250W Plate Amp
The 4" Aeroport's haven't arrived yet but I wanted to hear this thing this weekend so we cut 2 endcaps and a 14" hole in one. Right now I have the tempest laying on the top in the hole because I don't have legs or anything yet. So basically its a sealed tempest now, but its already starting to show some nice potential. One thing I have noticed is the tempest starts flapping a little when I turn the gain too high on the plate amp. I know for sure its not bottoming out, cause I've experienced that on my Dharman and its not pretty. The only thing I can think of is when its sealed like that its getting messed up cause the enclosure's so big. Do you think when I get the ports in it'll fix the problem? It doesn't really matter if I put 'em on top instead of the bottom right? I've played around with room positioning and I've got in a pretty good spot right now. Oh yeah, and should I get some of that speaker sealing caulk to make sure I get a good air tight seal when I screw down the tempest, or is there something better I can use. Thanks in advance

 

[Jack Gilvey]

Oh yeah, and should I get some of that speaker sealing caulk to make sure I get a good air tight seal when I screw down the tempest, or is there something better I can use.

I use closed-cell weather-stripping from Home Depot. A less-than-airtight seal will also cause premature overexcursion. I've used caulk and it's a pain when removing the driver to putz around, which I do often.

 

[Scott Parker]

I've been playing around with port sizes and here's my options. I figure a 16hz tune will be optimal. I'm using the Adire Simulator with 125watts into 8 ohms. Is this going to be similar to the 250w plate amp?

Air Speed

2 4" 17" Aeroport (10 m/s at 20hz) (peak: 22 m/s 12.5hz)

1 6" PVC 48.4cm (11 m/s at 20hz) (peak: 20 m/s 14hz)

1 8" PVC 92cm (6 m/s at 20hz) (peak: 11 m/s 14hz)

Actually the Aeroport one would tune it to 14.9hz because I can't adjust the size. Is there any pros and cons to each of these. And how exactly can you enter the Aeroport into the simulator. It says something like the flare radius should be half of the port length, is that right?

 

[Jack Gilvey]

And how exactly can you enter the Aeroport into the simulator. It says something like the flare radius should be half of the port length, is that right?

I don't think you can sim the Aeroport-type end-flares in the program, it's usually left at the default "Inf."

What's the Vb you're shooting for? Either the dual-4's or the 6" should be great, no need for the 8", really.

 

[Scott Parker]

I'm shooting for around 311L with an 8" 3' port, 340L with a 4" 16" flare. When I subtract the size of the port do I subtract everything the port encompasses. So a 8" 3' port would take away 1.04 cubic feet right. My caps are 3/4" each, so did I do that right. I guess what I meant was is it more accurate to put in 5" or 6" for the 4" flare. Cause if its similar to a 5.5" that would tune it to 15.8hz. And is the 8" PVC going to be stable enough if I glue it inside the MDF, cut a hole and mount it flush.