Soundproofing a pinball machine

When I first got into pinball I lived in an apartment. I actually moved into a house because of pinball. Apartments are far from ideal places to have a machine. You think pinball machines are loud until you move it into a small quiet room surrounded by neighbors. Then you discover pinball machines, specifically solenoids, are very loud. Naturally, being a respectful neighbor, I went on a quest to soundproof my machines at the time using Terminator 2 as a test subject.

If you want the short answer:

Nothing I did dampened the sound to a level I was comfortable with playing my machines at 3am short of building a fort of acoustic blankets around them.

At the time I worked until 9pm or so and would frequently play after midnight, so dealing with sleeping neighbors was important. If you found this blog post, I assume you've already found the other bits of Usenet information, this flippers.be article, this fliput.net article, and years old forum posts as I have. Here's my experience.


Putting things on coil stops

I honestly think this has a chance of working if I had thought about it more. I tried putting felt (yes, plain old felt) and cutting up those rubber cabinet things into the coil stops. This was useless. Nothing I used would adhere permanently to the coil stop after beating on it, so I gave up quickly. I think perhaps a proper material (rubber foam as recommended by fliput.net), cut and adhered carefully (with what?) might work. You can probably do a whole game for $1 using a beer seal in your next PBL order. If you succeed with coil dampening, please let me know.

I can't imagine doing this for every coil in every game I purchased, then maintaining them when they fall off, even if I had found a way to make it work.

Putting rubbers on the plungers of VUKs seems to be more common, and is probably effective, but the main noisemakers in your game are flippers, slingshots, and pops.


Dynamat / Vibration dampening mat inside the cabinet

DO NOT DO THIS! I laid Dynamat down on the sides and bottom of the cabinet and it made an absolutely minor difference. Not only was this pretty expensive, but it's absolute hell to try to remove. It's not a little bit of hell, it's pure melty, tar-like, rubber adhesive hell. I ended up having to sell the game without being able to remove it. I have no idea who recommended this in the first place. It's perhaps worth noting that the back of dynamat is conductive foil, so if you're stupid and do this, keep it away from wires, etc. Also make sure not to put any where it would be visible above the playfield after you lower it. Also, don't do this.

Here is a picture of the interior of the cabinet all Dynamatted up, which is how it will stay for eternity.

Fiberglass insulation slab inside the cabinet

Again, taking a page from one of the above blogs, I tried to dump some fiberglass insulation in the cabinet. This was marginally effective at best. I can tell it made a difference, but that difference wasn't enough to make 3am pinball a possibility. I can't find the exact brand I bought but it was 4" thick.

Once you have insulation in the cabinet, it definitely stops the hallow echo of all the mechanical sounds in the game and makes it more muted. It does remove some of the cabinet noise, but there is still a lot of noise that comes up through the glass.


Eggshell acoustic foam tiles in the cabinet

This worked about as well as the insulation but at least looked nicer than having a slab of insulation in my cabinet. I bought some used tiles like this off of Ebay

and covered every inch of the cabinet interior. Again, cabinet definitely dampened, but overall sound was still loud enough that 3am pinball was not going to happen.


Bob's Ultimate Pinball Glass

At this point, I want to prevent noise from coming up through the glass. With the glass off, the game is insanely loud (as pinball tends to be). With the glass on, it's much quieter. I found Bob's Ultimate Pinball Glass which is maybe twice as thick as normal glass. Like most of the things I tried, it has a slight effect (Maybe 10% reduction in noise).

At about $150 a sheet it isn't cheap. I do have 6 sheets of it right now though which I'm happy with. My one paragraph review: It's a very nice, very clear sheet of glass. I like the look of the beveled edges. I like the slight sound dampening. The supposed anti-glare properties are nothing like Invisiglass/PDI. If your goal is anti-glare, save 2 sheets of Bob's and get one sheet of PDI.


Let's do this thing. Acoustic Blanket Fort. Seriously.

There is no simple mod to make a machine silent. Maybe if you really focused on some of the above strategies and spent a lot of time and effort you might get better results. I decided to build a blanket fort around my machines. I grabbed a comforter off my bed, threw it over the machine and my head, and played. The lifeless, dull thuds were exactly the results I was hoping to achieve with all the time (and money) I was wasting. It's so simple. Blanket fort.

I personally used six VocalBoothToGo Producer's Choice Sound Blankets zip tied to a PVC structure for 2 games. I'm sure some moving blankets or something cheaper would probably work too, but not only did these look nicer, I'm looking for that sweet ticket to late pinball and I've failed over and over again at this point. I needed the best there is.

You don't exactly need a garage and tools to build a crappy PVC structure for your apartment. Get a pipe cutter, some connectors, and some schedule 40 PVC pipe at Home Depot. Wonderful stuff.

If you're seriously doing this (and you should be because it's awesome), plan your structure and connectors out beforehand. Home improvement don't carry some of the 4-way connectors that are more useful for building than plumbing so you'll have to order them online (I used Formufit). It's better to figure that out before half of your 600sqft apartment is covered in your insane PVC project. Definitely get pipe that's thicker than 1". I used the thick 1" kind and the structure was a little wobbly with the heavy blankets on it.

I can say without hesitation that if you do this dumb thing you will not be disappointed. Whether inside or outside the fort, all of the solenoids make nothing but the dullest of thuds. It really was the ultimate solution for me. Well, maybe the ultimate solution is buying a house out in the sticks with an outbuilding where you can't bother anyone. After building this I seriously considered whether I was going to do this again for each game I bought. If I hadn't decided it was time for a house, I would have.