Avalanche 18 Sonosub help, please

[hardg]

So I've decided to go with an 18" Avalanche in a sealed 4.6 cube sonotube, powered with a 500 watt plate amp. Does the tube need any internal bracing?

I was also thinking of trying to flush mount my plate amp onto the tube, like SVS does with their tubes. Is this advisable? If so, does anyone have any suggestions on how I should go about doing this, or will it compromise the strenght of the tube? Thanks guys.

[RobP]

When you say sonotube, are you talking about the sonotubes used to form concrete?

[ThomasW]

Tube subs do not need internal bracing. Actually bracing would create asymetrical pressure on the walls of the tube.

I would not subject an amp to the vibrations from a high excursion 18" driver

You'll need a 8" diameter port to prevent chuffing.

[hardg]

When you say sonotube, are you talking about the sonotubes used to form concrete?

Yup. I'm pretty sure those are the only tubes that are used for this, actually.

[hardg]

Tube subs do not need internal bracing. Actually bracing would create asymetrical pressure on the walls of the tube.

I would not subject an amp to the vibrations from a high excursion 18" driver

You'll need a 8" diameter port to prevent chuffing.

Thanks, Thomas. I didn't think they needed any bracing, but I had to ask, as I've seen a couple of people use bracing in their build pics. This makes it a lot easier now, which i like!

Now I just need to figure out where I'm gonna put the plate amp. Does anyone have any suggestions or pics of their own sonosubs with a plate amp? Please post if you do.

I was thinking of painting the whole thing with some sort of textured paint. The stuff that gives it the texture of stone. And then paint some runes on it. Kind of like a stonehenge theme. I know, it's geeky, but I love that stuff.
:B

[Dustin B]

Here is my solution to the problem of mounting a plate amp to the tube.

http://dustin.bunnyhug.net/construction.php#Plate%20Amp%20Mount

and here is another solution.

http://members.optushome.com.au/wcallen/Construction.htm

[hardg]

Hey, can anyone tell me if there is any advantage to mounting the driver on the top or bottom of the tube? It's gonna be sealed, by the way. thanks

[ThomasW]

No sonic advantage either way. Downfiring of course tends to protect the driver.

[JonMarsh]

It occurs to me it might not be nearly as easy to tip over a sonotube sub with the woofer at the bottom than at the top....