Here is a post I did in the ACNC thread. Works mint. I’ll be doing it again on my HW.
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Ok … ages ago I said I would build up a sub box and port the cabinet on my Spooky games, to stop the glass rattling.
Last night I finally got around to it.
Stage 1 - Port the cabinet!
~ The glass rattling is because the sub is creating waves of air in the cabinet, and the air has nowhere to go. A lot of bass comes off the BACK of bass speakers. That’s why pro PA bass cabinets are ported in some way - half the sound comes out the ports, not the front of the speaker as you’d think.
So - drill some holes! I chose a 2 1/4” hole saw and went to work. I drilled the holes at the rear of the speaker - reasonably close, so the sides of a sub box would cover them. (You want the holes inside the sub box, of course …)
Here is the result!
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The result of these holes - all bass rattle has gone.
I turned the amp bass up full. Still no rattle.
You know at the start of each ACNC ball - if you leave the ball in the shooter lane the background music has a pulsing bass … this usually shakes the machine like crazy. Now - nothing. Sounds cool. No added mechanical noises that we can notice.
Cosmetically, it just needs some mesh stapled over the holes (if you care about such things)
Cost of this mod …. $0.
A free mod in pinball! WTF!
Priceless.
Now to me, I’m happy with the result and I may leave it as is.
However - one day I may be bored and whip up a sub box to see what happens. My prediction would be that the bass output would increase, and the bass would be tighter, as the box hastens the exit of the sound from the cabinet (rather than it swirling around inside the cabinet). Maybe I’ll make one. One day.
So - go drill some holes!
Enjoy.
rd