Me too - but there is a huge leap being taken from the 1950s paper cone full range speakers and the little Stern amp that could - gave a little more.

I would be willing to bet many people could/would stop here and be really happy with the results.

Next up - some 5.25" speakers arrived to test out and compare.

I didn't purchase any adapter plates or rings as I want to climb the DIY ladder. We can see if a DIY route is even a good idea versus just purchasing a ready made mounting solution.

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If you can post a picture or two of how you did it. It will be a good reference for anyone coming accross this post.

Here is what I am set at as a reference. Tweak to your liking.

4ohm for backbox, 8ohm for cabinet. Fade about +5

The gap you are hearing is probably in the frequencies in-between the sub and backbox speakers. They should be overlapping smoothly and complimenting each other. But instead the gap is a bit bigger and you probably are hearing this as everything probably sounds good and clear - but just seems to be a bit hollow in the low mid area. Just a guess.

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Food for thought.

It's pretty intuitive that upgrading speaker size from the 4" stock speakers to the 5.25" speakers will deliver more sound. This is going to come from the larger cone surface area available to move more air.

So just how much of an increase is this going to be?

I broke out the calipers and mad math skills of Google.

Not counting for the coax/tweeter opening of either speaker as it appears constant accross these speakers.

The 4" Kicker comes in with a surface area of 7.07 square inches.

While the 5.25" Kicker comes in at 10.32 square inches.

That's an increase of 46%. That's huge and should translate into a nice increase in the lower midrange. This should also be relatively the same accross brands like Kenwood, Pyle etc.

But let's throw a curve ball into this. JBL uses what they call their Plus One design. They squeeze in a much larger cone by attaching the suspension of the cone to the outside of the basket. This means the diameter of the cone is 5/8" larger than the similar sized 5.25" Kicker.

If we are after more sound and more low midrange - how much more can we potentially get by using JBL Plus One style speakers.

Revisiting the math....
5.25" Kickers = 10.32 Sq Inches
5.25 JBLs = 14.19 Sq Inches
A 38% increase from the similar size Kickers.
and it's a 101% Increase from the 4" speakers.

I can't wait to compare these and see how this actually plays out.

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Pinballmonkey

#1 - Print an adapter yourself, there are 2 on thingiverse.
#2 - Cut the studs off the stock mounting plate and drill new holes - get some #6 screws and nuts and bolt in your flush mount 5.25" speakers.

Out of curiosity what is Stern using for the LE subwoofers?

Hmm I may need to add the LE setup as well as the Pyle/Skar setups to my testing later for comparison sake.

DIY Round 4...

Fitting 5.25" speakers in the backbox.

There are 2 off the shelf solutions for this.

1 - New steel mounting plates are offered from a few vendors for about $50 a set + shipping.
CONs - Best for use with flush/surface mount speakers. However, selection of speakers is limited that are truly surface mountable. If the tweeter protrudes or if the cone movement needs some space, then you will need spacers to create some room between the plate and mounting surface of the speaker.
PROs - Convenience, buy it, install it. This option also creates the most space behind the speaker for additional clearance. This helps with room for speaker light kits and/or larger speakers etc.

2 - 3D printed plastic adapters. These are available from a couple of vendors as standalone items and are often included with aftermarket speaker upgrade solutions. Generally, they can be found for $30-$50
CONs - Many of these adapters take up close to .5" of space just for the adapter itself. This could reduce the speaker choices available due to size constraints. Adding speaker lights could complicate the situation and take up even more space. Air infiltration (See next post I make)
PRO's - Convenience; price. Given these are spacers they naturally create room between the front of the speaker and speaker plate, allowing for speakers with protruding tweeters.

NOTE: JBL and Infinity style speakers with the Plus One woofer design cannot be used with either solution above. These speakers are difficult to flush mount due to their design.

Conclusion: I honestly think that buying either of these solutions maybe money worth spending. There is something to be said for the amount of effort it takes to do something yourself versus how much money you will be saving. Time is money, dollar waiting on a dime, stepping over dollars to pick up pennies etc. If you love to tinker, then by all means go the DIY route, just know that your time may not be worth the effort on this one.

I will be covering some DIY methods, and a new adapter I am working on in the next post.

WizzardRob

Using mounting plates is sufficient in many cases by themselves. Providing you are using flush mount speakers. The color ring and foam are if you are trying to change the appearance of your back box. These items allow your speakers to show through the front grille of the backbox. The color ring is just to add a little color/flare to your machine.

Pinball Life and Speaker Light Kits both sell a version of plates. I'm sure there are a couple more floating around.

Right now I can only test on Sterns and an AFMr. But a ton of this information is still a foundation that can be applied to other machines as well.

There have been a few real good posts with information and Amazon links to items that can be used on other machines as well.

DIY Round 4.1..

5.25" speaker adapters.

In the last post we spoke about some available options that could be readily purchased. This post concentrates only on DIY options and some tips.

1 - Modify the Stern stock speaker plates. All you have to do is remove the plates, cut off the 2 studs that held the 4" speaker on. Then drill new holes for the 5.25" mounting. Install some 6-32 machine screws, reinstall the plates and you are ready to mount up some flush mount speakers. You'll need a dremmel, drill and some drill bits.
Tips: You will need a 9/64 drill bit to drill the holes for the 6-32 screws. Once you drill the holes in the plate install the 4 screws and run a nylock nuts down to the plate to lock them in(you will not need washers). You do not need to worry about the bolt heads on the front of the plate as they will push into the speaker foam. Use black machine screws if you can find them, if not use a sharpie on the bolt heads so you will not see them through the foam.
If you really want to be precise, then make a small 1 to 1 drill template that you can print out and align using the current two studs before cutting them off.

2 - You can design and make your own adapters. This will take way more time than it maybe worth. But if you want to tinker and have the skills then it's not so bad. You can 3D print it, make it out of wood, machine it out of aluminum, use foam core like shown in a previous post. How you make it depends on the methods you have access to and feel comfortable using.
Tips: Try to use 6-32 machine screws in your design. This will keep everything consistent with everything else on the machine and be easily servicable by the same size nut driver used on everything else.

3 - If you have a 3D printer you can print your own using 1 of the 2 designs on Thingiverse. Which design may depend on the speakers you want to use.
Tips: Be ready to drill out the bolt holes with a 9/64 drill bit for 6-32 screws. Every printer prints a little different and odds are high the holes will be undersized. Make a trip to the hardware store after you print the adapters not before. This will save you from having to go to the hardware store twice(like I did). Have some silicone handy or even hot glue to close up air gaps. (see below)

I started by printing one of the adapters on thingiverse as I thought it would be the most common choice. However; it didn't take long to see there was a fundemental flaw with the design. Then with some googling and looking at other vendors selling adapters and full.speaker kits, I was like holy crap they are all making the most basic design errors.

Let me explain - speakers make noise by creating air pressure waves. As the speaker cone moves forward the air infront of the cone creates a high pressure zone, while the air behind the cone creates a low pressure zone. When those two zones are allowed to mix the result is noise cancelation. This is why a speaker sounds so much different when it's in an enclosure versus just sitting commando on a desk. You lose almost all low end, it becomes very muffled and you lose tons of sound volume/decibals too. In order to get the most out of your speakers you don't want these two air pressure zones mixing with each other.

All the adapters I have seen, all have big gaps allowing the front and back air pressure zones to mingle and create noise cancelation.(See Pictures) To resolve this be ready to use silicone or hot glue to close up these gaps.

So what am I going to do? I don't like the idea of sealing my speakers up with goop. Mainly because it's not conducive to swapping in and out speakers for testing. Instead I'm going to bang my head against the wall and design a better adapter. One that will stop the air mixing and also be able to mount the JBL/Infinity Plus-One speaker designs.

I'll post what I come up with next.

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Certainly, both are very good ideas.

Black_Knight By all means ask away, it's a good question.

I'll be trying something like this out in a few weeks, it'll be good info to have if something is out there.

You could just go the wired route for now. Cheap, easy, and foolproof which maybe a good thing for your launch party.

You can get plug and play line out adapters from Pinsound or Pinnovators(there are a couple others) then take it straight into your arcade amp. If you want to hook up multiple games - Put line outs on all of them, and run them all to a mixer and then to your arcade amp.

This would get you a very usable solution you can get running today while you research Bluetooth possibilities.

The wired in method, is something I'm hoping to test in the coming weeks and report on.

If you try it please post it hear for everyone to see it with your thoughts and results etc.

Quick update - Been working on new speaker adapters.

Been really busy at work and haven't had much time to design these and do a writeup. I should be able to post more in depth tonight or tomorrow.

Here is a look where I'm currently at.
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Bax1 Right now none of what I have done has required amplification.

I'll test out some amplification options in future posts.

DIY Round 4.2...

Designing a better 5.25 speaker adapter.

I spent some time designing a better 5.25 adapter. The 2 things that needed to be solved were:
1 - Being able to seal off the back of the speaker from the front to maximize sound output and avoid unnecessary noise cancellation.
Why? See my DIY 4.1 post above showing some of the downsides of many of the adapters available for print or purchase that have big gaps allowing the air pressure zones from in front and behind the speaker to quickly mix and noise cancel.
2 - Having the ability to mount different types of speakers like the JBL and Infinity Plus one designs that do not allow for flush speaker mounting.
Why? Most aftermarket speakers are designed to be top mounted e.g., to be dropped into a hole and then bolted down from the front/top. Mounting a speaker flush or against its face and bolting it down from behind is less common and presents some challenges. Things like protruding tweeters and cone suspensions need room in front of the speaker to function. There are far fewer flush mount style speakers to choose from because of this.

And since we are on the DIY kick, out comes the CAD while watching shows like Peacemaker, and Book of Bobba Fett etc.... and several nights of listening to the 3D printer whirr whirr it's way around for hours on end. And the test fitting and more test fitting.. and the.... well, you get the idea. As I said before I'm not certain this is a cost-effective method versus buying a readymade solution. I'm going to have to rewatch those shows because I definitely missed 50% or more of what was going on.

The design I came up with allows the speakers to be mounted as drop in speakers. This allows for all kinds of speakers to be used. Tweeters sticking out, all cone and suspensions designs (Like JBL/Infinity) can also be mounted. There are no air large air gaps and the front of the speaker is now sealed off from the back.

I thought they turned out pretty good. But take a look for yourself and let me know your thoughts.

There are a couple things that need tweaking, and a couple of really interesting future improvements have also come to light. But more about those in a later post.

They did require some modification to the stock speaker plates. But this wasn't terrible and only took a few minutes. First I used the spacer as a template and centered it up on the plate using the studs that held the stock 4" speakers in place. I then drilled two new mounting holes. Next I cut off the stock studs with a dremmel. Then I put two new 6/-32 bolts through the new holes and ran a nylock nut down the bolt to lock it to the plate. A little black sharpie action and the plates get reinstalled.

Now you just mount the speakers into the adapters and bolt the speakers to plate.

Next on the agenda is to go through all the different speakers I purchased to test things like, sound quality, loudness etc. The couple brands I will be comparing are Kicker, JBL, MBQuart, and Alpine. If anyone would like to see another tossed in there let me know, but do know my wallet is getting a little stretched so there are limits to what I can do. Maybe someone can send me something they have laying around?

After that we will move onto sub woofers, external sub woofers, home stereos, and probably some amplification options as well.

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Just a quick side post... Glass Rattle

Even with the stock Stern amp, I am able to get my bass kicking with improvements thus far. With this comes the inevitable glass rattle.

Now there are some aftermarket tapes you can buy, and they do the job well. But reading some of these manufacturers descriptions like - Proprietary Technology, Anti rattle technology, Patented.... You'd think this was designed by teams of rocket scientists to be used on space missions. hmmmmm....

Either way, at some point you will need to deal with glass rattle as your sound system comes up to speed. You can buy some of these ready to go tape solutions or you can DIY it.

For me the solution is as easy as a 5cent O-ring I found amongst my plumbing repair tools I had in my garage. I just picked out a thin O-Ring from a kit and place it between the glass and trim at the top of the machine and rattle be gone.

You have to remember to remove them when taking the glass out. But it's provides an easy enough solution for now.

Has anyone else come up with anything interesting to quite glass rattle?

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