Is this a problem when she's playing the game, or when others are playing the game and she's just hearing it from another room?

Soundproofing inside the game would trap heat. Excess heat could cause issues.

If she's playing, maybe recommend ear protection, headphones, or ear plugs?

If she's not, maybe add soundproofing to the room it's in?

A thicker cut wood back door would probably solve the problem without soundproofing it.

l take you're not married or soon to be devorced?!

You could try a sound reduction mat stuck to the inside of the back door, it's about 1/2" thick but l would take note of Forceflow point about heat build up inside the head. Check the vent slots are not full of dust and rubbish.

You'd be wrong on both accounts.
Besides I picked Ultra-Soft and Comfy Cush

My wife would be happy. I'm not so sure Tammy Wynette would be.

...Someone will get that.

When I lived in an apartment I just turned the chimes off. That still didn’t satisfy my lower neighbor because she could still hear me having fun. Oh well, she’s probably a Karen on the prowl now.

Is this a real post?

The score motor is as much a contributor to noise as the score reels and that’s in the base cabinet.

Maybe an early SS game is for you?

The playfield and flippers make as much or more noise than the scoring part of the game

Or is it just fantasy?

maxresdefault.jpg

I think having an EM style game is a poor choice in your house. Pick a solid state on up game in my opinion.

That’s exactly what I do when I’m trying to keep the noise level down when the wife is trying to relax. It helps out considerably.

A chime switch cut switch can be installed under the front of the cabinet for easy access and unnocticeable.

To me it’s the pop bumpers that make the games loud, especially if they’re juiced a little or are DC Williams. The pops on my Lucky Hand are especially loud. So much so that I won’t play it late at night unless my wife is awake.

I agree with some that most of the loud sounds come from the cabinet and playfield not the backbox.
But is sounds to me that the reset sounds of the score reels seem to be the trigger that causes the issue.
Not sure if the mat in back would work but that's probably the best option to try.
Or if maybe rubber under the leg levelers would insulate the sound from travelling through the floor and help more than insulating the back box
Or a thick rug or sound insulating mat under the machine that covers a few feet around it.

Tell her to go shopping and then play...I know this doesn't really address the issue..but it really does work...although your bank acct may get smaller when she is not home while you play.

Sound is travels either airbourne or via a solid object. Either decoupling or absorbing are two ways to reduce sound travel and retansmission. Now you have stated where the machine is to where your wife is, l would stand the machine on a heavy rubber mat, (decoupling). To reduce airbourne sound l look at a sound absorbing material like whats used in car interiors and fit this the the underside of the machine, the thin plywood on the underside of the machine acts like a drum skin. The same material could be used on the inside of the rear metal door, l don't recomend wood panel as this will only soak certain frequencies but allow transmission of others.