Here’s a good sound add-on for a classic solid state Williams game. This will work for any game that has one speaker in the bottom and an open grille area under the back box. I did this upgrade on Gorgar.
The problem with one speaker in the bottom is the sound can be muffled or hard to hear since it is pointed at the floor. The fix for this is to put a speaker in the grille area under the back box. It could be just a tweater, but I happen to have a rectangular wide range speaker that came out of a gutted TV that I used for a MAME project that fits perfectly.
I wired it in series with the bottom speaker. It could be done is series or parallel depending on the sound balance your looking for. I tapped into the wiring that goes straight to the bottom speaker so it doesn’t interfere with back box removal. With a smaller wide range speaker up top, you could also put a subwoofer in the bottom for even better sound. The best part about this is it’s completely hidden once the back box is mounted and it sounds great.
I took this sound upgrade one step further yesterday. I put a 12″ sub woofer in the bottom of Gorgar and the top speaker sounded pretty flat. After digging through my box of speakers, I found a Bose cube speaker that also fits in the grate area. That speaker combined with the subwoofer, plus a crossover unit that allows for adjustment of the db setting for the top speaker, sounds completely awesome. The heart beat of the game has a loud thump and those classic Williams sounds are better than ever. I guarantee this sounds better than ANY aftermarket pinball speaker option available. I can find no better place to put a Bose speaker than in a Gorgar, the first talking pinball machine.