it's possible.

You can get the Polks onsale from time to time for $49... But you would not want to use a splitter to add multiple machines, you would be tying the audio amps together and that is not good for the machines. What you can do however is use an old ABC type audio switch and push button select between machines.

http://www.walmart.com/ip/RCA-4-Way-AV-Switcher-With-S-Video/3312963?action=product_interest&action_type=image&placement_id=irs_middle&strategy=PWVUB&visitor_id=74046077956&category=0%3A3944%3A1060825%3A133270%3A4537&client_guid=2e69d0f6-a32a-4bbe-832e-233e642b4821&config_id=2&parent_item_id=3312963&guid=6db3cbfc-c927-4e71-9261-419da4d357ed&bucket_id=irsbucketdefault&findingMethod=p13n

That is how I wired my machines. (I should take pics)

Take one short 1 meter F/F RCA audio cable, cut it in half and then cut the two halves down to about 1 foot.
Take the cut end, separate out the shield from the center conductor and solder on two small alligator clips.
Loosen the screws holding down the cab speaker enough to lift the speaker and the grill off the bottom of the cab.
Thread the female end about 6 inches through the bottom of the cab and re-tighten the speaker.
Install the two alligator clips onto the cab speaker.

Et voila!

You now have a short pigtail under the machine you can plug your sub into using a M/M RCA cable.
The reason you leave the pigtail short is it stays in the void of the speaker hole should you use a lifter to move your machines.

Can you put diodes in the wires to keep the signal from feeding back, like in games? Or doesn't it work that way for sound signals?

You can try this thread
https://pinside.com/pinball/forum/topic/anyone-use-a-line-level-mixer-with-their-polk-subs

We will have this ready for sale at Allentown. Plug up to 4 stern games into on subwoofer. Play all four at the same time or one at a time.
Thanks,
Lorenzo
Pinnovators.comimage-519.jpg

You can use it on your Wms/Bally games. Just take a 3.5mm cord cut one end off and tie into the speaker terminals. The other end plugs into this box. If u have stern games we have the adapter to go from the sound board directly not the speaker

Looks like a bit more than just diodes, but seems to install a lot easier!

Yes if u want the quality of the sound to not be compromised its more involved

And each game will have the white potentiometer knob so u can adjust the bass signal from each game for more or less bass out of the sub. Complete control of each games output on the sub. Set it and walk away

So, the diodes would work, but compromises the sound? In other words, they (diodes) act as a filter also?

Exceptionally Brilliant, Lorenzo!

Ill let mark explain that

Hi Guys,
The Pin-SMX completely isolates the inputs from each other. We used small isolation transformers so there wouldn't be any interaction between games. You can now mix up to 4 games into one subwoofer. Each of the four input levels can be adjusted and balanced too! We just received the prototype boards in yesterday and built our first demo. I tested it out on my STNG and it works great!
Pin-SMX is compatible with our mute button on our Stern Sam headphone kits. When you mute the system speakers, it also mutes that machines audio in the subwoofer.

Thanks,
Mark

I was thinking of using a mixer to have all my pins connected to one subwoofer as well....thoughts? I have a mackie 1202-vlzpro laying around, it should do the trick for 8 pins

http://www.sweetwater.com/store/detail/1202VLZ4?device=c&network=g&matchtype=&gclid=CK-BprHM4r0CFTMV7AodYi0ATA

Adding Diodes in the path of an audio signal will probably cause distortion.
The diode would rectify the audio...only half of the audio would make it through the diode. A typical diode has a 0.7 V droop across it. If the audio level was less than 0.7V, nothing would make it past the diode.

I tried a few methods for mixing the audio while developing Pin-SMX. Using resistors to mix the audio almost worked but I needed to keep the grounds isolated so our headphone kit would mute properly. The final solution was to use a small isolation transformer to get the job done. The transformers add cost but it keeps everything completely isolated! Aka: No Ground loops!

price?

One more thing.. This is a completely passive mixer. It does not need any power supply to make it work.

How would this sound with 4 games playing at one time. I cannot imagine very good.

Ok, got it. That answered my question perfectly. Thanks Mark.
And nice work on the smx.

With the adjustment pots it allows u to set them up well. I did two games at once that seemed fine to me. I like that I don't have to buy more subs, I have one $500 sub to run three games.. Generally only two are being played at once in my house.

+1 .... price?

Pricing ill have shortly

why is it bad to run 2 machines on one polk sub?? whats the big deal ??

The big deal is that you are not buying more Polk subs!

But it has to do with connecting 2 machines audio amps together. If you have any grounding issues in one or both machines, the new path created by connecting 2 machines to one sub could cause problems.

Our mixer doesn't need a power source. And u won't have to worry about blowing up your shit lol

Sounds like a great solution, I'll have to give one a try.

Yeah the fact that they used isolation transformers means that the machines are in no way connected to each other or to the sub directly.

https://www.facebook.com/Pinnovators/posts/820152017999070:0

$60 is the price.

Thanks,
Lorenzo
Pinnovators.com

1 sub per machine is the way to go....

and its WAY cheaper than pinball speaker kit...

doesn't make your PF glass rattle, and is controlled by your game volume, just like normal

10 minute install, and it easily goes from game to game...

its a no brainer

U could go that route, but its $80 x 4 subs = $320 plus tax and shipping to do what this does.... Or $60 from me and one sub... If your playing all four subs at the same time maybe it's a issue maybe not.

personally, i'd buy your product and get a better sub.

You don't have to worry about "too many sources" playing through the sub at once, a modern movie could have 128 channels of sounds mixed into the LFE (low frequency effect) channel.

You DO need a mixer if you are going to have more than 2 machines hooked up to one sub.

Ground loops only happen when there is more than one ground path, like a game is pressed up against a cold water pipe, or plugged into a different circuit breaker across the basement. If all the games, mixer and sub are connected to the same electrical breaker, you will probably be just fine.

Our kit has isolation transformers which does protect the ground path.

Ya, I bought a $500 sub, I have three games wired to it with my prototype pictured above. Cheaper then spending $1500 on three subs.. But I wanted the expensive one!

Spending $500 on a sub for a home theater? Totally get that. For pinball? Seems like total overkill for the fidelity and frequencies no?

Deff over kill!!!

That's how I roll some times lol

Told myself it would be louder and cleaner at higher levels. Shakes the room type of levels lol

i've been unhappy with the sub testing I've done over the last week. While 95% of the game is improved, some sounds are very poor and outweigh the benefits, IMHO.

I started with TZ. It was great, except when the ball drains. The game makes "crashing/slamming" sounds when the various bonuses are displayed. They crack like crazy with a sub.

So I tried IJ, thinking the DCS quality might remove this... Sadly, no. A few samples in there also make the sub crack and sound really bad.

Are you guys hearing this? Perhaps the "it sounds better 95% of the time" is ok for most.

I'm not hearing this.

Look on your sub for a little LED that lights up when the incoming signal overloads the preamp stage.

It sounds like you are WAY overloaded during the loud passages.

Also, make sure that you are running into the SPEAKER inputs, and not the LINE inputs.

Powered subwoofers on stern games are much much better then Wms/Bally games. Iron man, tron, acdc are killer powered sub games.

Ground loops can be an issue for moderately sized arcades that span several circuits.
Honestly; I was thinking a mixing opamp would do the job of this isolation transformered solution llvjr came up with.
BUT; there isn't anything wrong with llvjrs solution ... I image it works nicely. Something I'll think about when/if I ever get around to installing a sub on my Star Trek lineup.

I guess I should mention something that as of Allentown is part of my stern headphone kits. We built a audio out direct from the amplifier to a powered sub or to my mix box. There is two version, one with my headphone kit, the other is one for people who just want to add a powered sub and not my headphone kit.

Thanks,
Lorenzo
Pinnovators.com

image-414.jpg

Sometimes as low as $49 shipped.

http://pinside.com/pinball/forum/topic/polk-audio-psw10-subwoofer-for-4999-use-code-naftechmas46-newegg