Forgive my obtuse question:

Reviewing the JP Pro Manual, it states that the cabinet is a 8", 4 ohm speaker. Silly manual states "speaker" for the backbox, no ohm rating unfortunately. So i opened the backbox, and yep, sure enough, 8 ohms printed right on one of them. That seems SO "wtf???" - why would Stern mix ohm ratings on speakers installs?

I am planning to install 5.25" 4 ohm speakers (the Kicker equivs of the 4" ones) and a Skar 8", 4 ohm cabinet speaker. I would think ohms matching would lead to better quality - mainly the speakers not fighting each other at different impedances.

Thoughts? I value your feedback as I am installing (2) Boss AVA1404 amps (no longer available, used to install these in my Sterns - learned how to do this from @metallik), and I want to make sure I do this right. Back then, I always used matching ohm values for both backbox and cabinet speakers, but maybe Stern did something unique to where 4 ohm cabinet and 8 ohm backbox speakers are necessary...? Can't imagine how that would make sense...

You're right. I forgot about that - I'm used to doing the speaker/amplifier upgrade on the Whitestar games (ACDC, Metallica, Iron Man, etc.)

I also noticed the Spike games have an internal equalize on the display. The Boss AVA1404s are amplified equalizers. Seems like I'd be doing overkill with the 1404s, and that maybe I should explore amp-only options as mentioned in this thread....

Right track? Wrong track?

So appreciate your feedback and insights. So what I am hearing, matching the ohms with both.

FYSA (situational awareness), these are the units I am ordeirng:

KICKER CS Series CSC5's: https://www.amazon.com/gp/product/B07NSCZ27W/ref=ox_sc_act_title_1
(I have the adapters from Space Coast Pinballs on the way)

Skar Audio FSX8-4 8": https://www.amazon.com/gp/product/B00NMJTEC6/ref=ox_sc_act_title_2

The PSW10 external sub underneath the game is plenty of boom. I want the cabinet to bring out more the midranges, hence, well, the "midrange" in the title of the product.

Then, I'll go installing the 1404 amps - one for the backbox 5.25" speakers, and the other for the cabinet speaker and external sub.

Thank you for making this thread. As stated earlier, I learned from Metallik how to do this, and I love reading about other people's DIY projects and the knowledge insights many of you have that I am learning and absorbing.

Time to make this thing sing....

pasted_image (resized).png

Already have a Polk PSW10 underneath. When I'm done, the neighbors are going to think we have dinosaurs IN the house ....!

Was quite fitting as I went to get all the components in for this picture, the "attract mode" music of the John Williams score activated. It's like it knew: "Someone is going to make me sound amazing soon!"

I'm being lazy and just asking here: does the backbox board have a 12v source to power the pre-amp equalizers ? N/M 0 found my answer: CN6 of the power distribution board.

Quick reality check using the Boss AVA-1404 pre-amp equalizers:

pasted_image (resized).png

Back in 2009-2016, Stern hooked their speakers up in series. Using the above diagram of the inputs for the 1404s, I connected L+ and R+ to the Stern factory wiring for the left backbox speaker, and L- and R- to the Stern factory wiring for the right backbox speaker. This is what I did for ACDC, Metallica, and Iron Man.

For Jurassic Park Pro, the speakers are now wired in parallel. Here's the question: would I take L+ and L- wires and use that as the input for the left backbox speaker and use R+ and R- wires as the inputs for the right backbox speaker? Pretty sure that's the case - would like to have someone do a quick "trust but verify" with me here.

Then of course, I will run wiring from the equalizer to the left and right speakers (same as I did when the speakers were wired in series as described earlier...for simplicity sake, I'll be using the green and purple wire sets as outputs in the below diagram):

pasted_image (resized).png

ALSO....I saw CN6 on the power supply board puts out 12V. I'm a bit nervous about using that to power both equalizers as supply issues may limit the availability of a new node board. I'm thinking I'll just use a desktop power supply to source 12V off the supplies harness and plug it into the 120V outlet. While it won't look 100% clean, I'd rather do that than risk blowing a node board. Thoughts?

Excellent, thanks, davegauth ! I'm thinking I'll use a supply that RobF used in his earlier post and then tapping into the power just after the switch like you suggested. Appreciate the insight!

For my own edification , why? Purely wanting to learn here.

Man, I love your posts. While I mimicked metallik 's setup, part of it was "do as he did, don't deviate" - now, I'm starting to understand the "why" and "how" with these kinds of posts. Thank you very much.

I'll be using a PS very similar to what RobF used here: https://www.amazon.com/PHEVOS-Universal-Switching-Transformer-Transceiver/dp/B074YGWDLF/ref=sr_1_3

Using your post, I did the math and determined I only need about 135 to 150Ws to power the backbox speakers and 210W for the cabinet speaker - so about 340Ws total power. All that being said, that is at 60%, and since I only play at about 24 out of 64 on Stern's volume control (38%), I am grossing overestimating what I need to power the backbox and cabinet speakers.

I guess what I'm saying is I'd rather have too much than too little, and I'd be shocked if I ever hit 60% volume (39 of 64) on the machine's volume control.

I certainly appreciate this response. I was planning to tap in directly after the power switch on the backbox. I absolutely do not want to risk blowing a node board as they are temporarily unobtanium. I'm a bit uneducated on voltage inputs. I get 12 and 24 volts are both DC sources (in this case as the power supply converts or "transforms" AC to DC power), and I appreciate davegauth 's explanation that the increase in DC voltage lowers the required current output.

I'm used to 12v sources, so what I'm asking: you can use 24V sources to power the amplifiers with no risk to damaging them? Again, I'm so used to using 12v sources for projects like this in the past, it never occurred to me you could deviate from that voltage level.

If a 24V PS can be used, I'd be considering this unit: https://www.amazon.com/dp/B07RKN7VMV/ref=sspa_dk_detail_1

It sure does. I am using the Boss AVA-1404 amps - one for the backbox speakers and the other for the cabinet and PSW-10 subwoofer. Unfortunately NLA, but man, do they pack a wallop. They are car audio pre-amped equaliezer, so that tells me 12V is the appropriate voltage source in this case.

pasted_image (resized).png

https://www.sonicelectronix.com/item-44121-Boss-AVA1404.html

Here's what I could find at Boss' main website:

pasted_image (resized).png

Click on the silhouette icon next to the time you posted a message. That will narrow it down to JUST your posts or whoever's post you want to narrow it down to.

Got the power supply in for the Boss AVA-1404 pre-amped equalizers today:

pasted_image (resized).pngpasted_image (resized).pngpasted_image (resized).png

Now, I need to go get a 120V plug with wiring and cut the plug off. I'll wire that to the main power switch in the backbox so I don't have to go plugging and unplugging the power supply every time I fire the game up.

I would have this done this weekend, but my significant other is coming to visit 1 week from tomorrow, and she wants to learn how to do stuff like this, so I won't have results until sometime during the week of 04 April.

I'll keep everyone informed once it's all hooked up. Won't be much longer : ).

Will do. My intention is to empower everyone else here who wants to learn how to do this stuff. Like you said, not hard at all - visuals and pictures can go a long way in helping others get over the mental hump and be able to do cool stuff like this!

When I install the Boss AVA-1404s, I plan to turn off the factory set equalizer and tuning specifically with the 1404s. Don't want my settings to overlap or "compound" with the factory equalizer. That'll just be........weird.

The speakers are wired in series, so if you add equalizers or amps that have + and - inputs, you have to hook both +'s to the left input and both -'s to the right input on the amp/equalizer.

Like on the Boss AVA-1404 in the below diagram:

https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/8#post-6833727

Main menu --> Utilities --> Vol --> hit the right arrow until the equalizer comes up as the screenshot you provided.

So, after dealing with a faulty power supply, I began putting together the pre-amped equalizer setup on my JP Pro. This is simply for posterity's sake as a one or two of these components are NLA or very hard to find. Speakers are easy as well as the power supply and the external sub - it is the pre-amped equalizers that may prove to be more difficult for those wanting to use identically what I did.

For backbox speakers: https://www.amazon.com/KICKER-5-25-Inch-Speaker-Woofers-Yellow/dp/B07NSCZ27W/ref=sr_1_3

NOTE - for the backbox speakers, they are 5.25" and NOT plug and play. You will need to get some 3-D printed mounts available here on Pinside. You can buy them here: https://pinside.com/pinball/market/shops/1312-space-coast-pinball/05610-spike-2-diy-525

For cabinet speaker: https://www.amazon.com/Skar-Audio-FSX8-4-Midrange-Loudspeaker/dp/B00NMJTEC6

External subwoofer: https://www.amazon.com/Polk-Audio-PSW10-Powered-Subwoofer/dp/B0002KVQBA/ref=sr_1_1_sspa

Power supply: https://www.amazon.com/WINIT-Switching-Cabinets-Upright-Cocktail/dp/B01C5E8W3K

The pre-amped amplifiers as pictured: Boss AVA-1404s - no longer available. A suitable substitute is the SOUNDXTREME 7 Band Passive Stereo Graphic Equalizer: https://www.amazon.com/gp/product/B00NQJ8N4M/ref=ox_sc_saved_image_4
pasted_image (resized).png

For everything else, I'm not going to tell you every single detail. Good example, the anchoring bolts for the power supply, I'll tell you they are #8 bolts and you use matching #8 T-nuts. I'm not going into length of bolt or EXACTLY where I placed my power supply, or exactly how many crimp connections you'll need, etc. I'll help with overall parts, but I'm not going into the weeds for everything. Happy to take photos, but I'm not writing a novel here.

Also, take what I did with a grain of salt. You break your stuff following and trying to replicate what I did, that's your personal problem. I anticipate anyone who attempts this install has a basic understanding of electronics and mechanical know-how. Now, with all that out of the way, let's begin!

1. Find a source to pull 120V from whenever the game is turned on or off and connect to your external power supply.

When doing an install like this, you don't want to have to plug and unplug the amps every time you start or end a game. That's just annoying. You need to find a place to draw 110V-120V from. In this case, Stern actually provided a plug to do this, and it is pictured here:

pasted_image (resized).png

On the factory side of the wiring, the black wire is your hot lead (110V), and the white wire is your neutral return. The wiring I used is 14 gauge wire in black and red (I didn't have white to match the factory white wire). The female crimp connectors are as pictured below and available readily from Great Plain Electronics:

pasted_image (resized).png

You'll need a special crimping tool for this to crimp the metal legs around the insulation and bare wire. That tool is available here:

https://www.greatplainselectronics.com/proddetail.asp?prod=W-HT-1921

Once done, I did not know what matching molex connector was needed for this factory molex connector, so I used heat shrink, cut it to where it fit completely over the metal crimp connector, and eliminates the worry of an accidental short. This heat shrink is evident as white on the black wire and black on the red wire in the first photo on this post.

Now, we have power and neutral, but we still need a ground. I fabricated my own ground wire using a ring crimp connector on one end and a fork terminal on the other. I purposefully made it longer than necessary as I'd rather have some slack than the wire be too tight and restrict my movement.

pasted_image (resized).png

I slid the ring terminal on the cabinet speaker threaded post where the ground braid run. For those that don't know, the ground braid is exactly that - a mesh braid that runs throughout the cabinet and gives a readily available ground. I simple loosened all the nuts holding the cabinet speaker down, raised the speaker off the lugs, slid the ring terminal in place, and reinstalled the speaker.

pasted_image (resized).png

Now, we connect the ground to the power supply on the FG (with ground symbol) on the power supply. We connect the black wire (live 110V feed) to the "AC/L" (alternating current/live) terminal, and we connect the white wire (neutral) to the "AC/N" (alternating current/neutral) terminal. I used fork crimp connectors for all of these so they could be easily installed and removed.

pasted_image (resized).png

Once you've done that, as the picture indicates above, you flip the game's power on, and the green light turns on, indicative that you have power to the unit. Never hurts to do a quick double check with your DMM and verify you're getting 12V. You do that by setting your DMM to 20V DC as seen in this picture:

pasted_image (resized).png

You want to put the dial at "20". This will allow you to read voltages equal to or lower than 20V.

You will then put one probe on the 12V terminal and the other on either of the labeled "GND" terminals. If you are not at 12-13V, you can turn the adjustment screw (near the green light on this unit) to raise or lower the converted 110V AC to 12V DC voltage. Didn't take a picture of this but glad to upon request.

2. Connect your pre-amped equalizers to the external power supply.

We need to start prepping the equalizers for power input. If you go the Boss AVA-1404 or equivalent units, you'll get really good at crimping connections. In this case, you'll want to crimp both the orange wire and red wire to a single fork crimp. These wires will feed 12V to the equalizer. You'll want to connect this fork to the 12V source on the power supply. Then you'll want to crimp both grounds (brown and black wires) to their own fork connector. You'll want to connect this fork to the "GND" source on the power supply.When you're done, they should look like this:

Ready for install
pasted_image (resized).png

Installed on the power supply
pasted_image (resized).png

Now, fire the game up, and you should see the equalizer turn on - indicative by the fader knob green light turning on as seen below:

pasted_image (resized).png

3. Anchor the external power supply to the cabinet.

Now, we have not anchored the power supply down, and you'll want to do that in case you ever move the game. First, pick a location where the playfield WILL NOT interfere when in its natural lowered position. I picked to the right of the cabinet speaker as the power and ground wires of the equalizers reached the power supply terminals with no issues. I used #8 bolts and matching T-nuts as available from these links:

#8 T-nuts: https://www.pinballlife.com/8-32-tee-nuts.html
#8 bolts: https://www.pinballlife.com/8-32-x-1-unslotted-hex-head-screw.html

The drill bit size for the holes was 3/16". I placed the power supply where I wanted it and then used an awl to make a small divet in the wood for the drill bit to catch. I only used two holes to secure the power supply (there are 4 mounting holes available on the unit, 2 should be sufficient). Pictures as shown below:

Using an awl for the divets:
pasted_image (resized).png
pasted_image (resized).png

Mounting holes drilled:
pasted_image (resized).png

Bolts protruding through lower cabinet:
pasted_image (resized).png

T-nuts installed:
pasted_image (resized).png

For the T-nuts, I gently tapped them into place with a hammer to get them started, and then I used a hammer to press them fully into the wood. As you drilled your bolts into them, the teeth on the T-nuts will catch and dig deeper into the cabinet.

That's where I got for tonight. We still have to send the sound inputs to the equalizer and then run wiring from the equalizer to the speakers. We also still have to replicate this process for a second equalizer for the cabinet and external subwoofer. My plan is to continue the install tomorrow. I'll provide the next update when I hit a good stopping point to further the documentation. Happy to take a video as well once it is completed.

NO way, man. Don't go Pyles. If we're paying $7000+ for a flipping PRO now, just spend $80 and get speakers that are actually work it.

Installation of the pre-amped equalizers is coming along. Got the first one hooked up, tested, and works great.

pasted_image (resized).png

The first one pictured is for the cabinet speaker and PSW10 subwoofer. The RCA cables feed signal from the sub to the amp. So far, wow. On volume setting 5, it is pretty full. Volume 8 is loud, and volume 12 is a full on blast. May have to swap the settings back to 4 ohms in the diagnostics and bring the max volume range down some. I'm interested to see how it sounds with both equalizer hooked up.

Working on the second one now...

pasted_image (resized).png

Well, I am all done with the install. Took a solid weekend (took my time, had meals, watched a movie here and there), but it got done! I have the equalizer on the left running the backbox speakers, and the equalizer on the right running the cabinet speaker and RCA input/outputs for the Polk PSW-10 subwoofer.

I removed the coin door anchoring bracket and installed the equalizers side by side with the mounts that came with each unit. I also cleaned up all the excess wiring. I'll be using blue painter's tape to create taped labels for each wire so I can clearly discern which wire is responsible for what input/output/speaker.

Only boo-boo I made was installing the external power supply too close to the installation location of the equalizers. To disconnect the ground wires from the power supply, I have to move the right equalizer out of the way first. Whoops. Other than that, pretty simple but methodical install!

Happy to answer any questions. After the first book I wrote earlier in this thread, I'll hold off explaining everything this time.

Video link is below. It was taken before I "tidied up" the finished install, so please don't infer the video showcases the completed install state - I cleaned up the wiring and made it much cleaner upon completion.

pasted_image (resized).png

pasted_image (resized).png

Everyone's level of willingness to modify their game here is different - from plug and plays to setups like mine and others in this thread that splice wires, cut factory connectors out, and get more nitty-gritty/enjoy the sense of mad scientist/tinkering/making their own sound system.

That being said, if you want to make your game boom and have selective channel control, add pre-amped equalizers like I did (along with upgrading to 5.25" speakers, a good mid-range cabinet speaker, and an external subwoofer).

While the Boss equalizers metallik and I used are no longer available, SoundExtreme has a unit nearly identical and available:

https://www.amazon.com/SOUNDXTREME-Passive-Graphic-Equalizer-ST-EQ-180/dp/B00NQJ8N4M/

Super simple to do in terms of introducing to the audio circuit:

1. Cut wires off left speaker
2. Take + back box speaker wire and tie to yellow wire of equalizer; take - wire and tie to yellow w/black stripe wire of equalizer
3. Repeat step 2 for right back box speaker to orange and orange w/black stripe wire
4. Get some car audio speaker wire and locate the "speaker output" wires on the equalizer
5. Connect green wire to + terminal of left back box speaker. Connect green w/black stripe wire and connect to - terminal of left back box speaker
6. Repeat step 5 for right back speaker and use violet and violet w/black stripe wires

The equalizer has now been added to the audio circuit. All you need now is to determine how you want to supply power to it (see my post earlier in this thread on this). Repeat steps above for the cabinet speaker being hooked up to its own equalizer.

The longest and hardest part is picking where to install, what wire gauge to use, how much wire you'll need, all the appropriate crimp connections, tools to complete the job, and most importantly - the fortitude to complete the job.

It's worth it though. My girl told me the game sounds like it has a home theater system installed in it now. The ability to tune 7 different channels for the back box speakers and another 7 separate channels (remember, the back box speakers get their own equalizer as well as the cabinet speaker. You can really dial in a full and wide spectrum of sounds going this route.

Completed on my JP, and as long as the speaker setup is the same in Spike I (speakers wired in parallel [meaning EACH speaker gets their own dedicated + and - wires]), any Spike I and II game can perform this upgrade (I can't imagine what Iron Maiden would sounds like!!!).

You should use the bookmark function to save posts you consider key. Bottom left of every post by every person on the forums.

Welcome to the mad scientist level of fun : ).