(Topic ID: 20541)

Massively improve your AC/DC Premium/LE sound under $80


By markmon

7 years ago



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#1 7 years ago

So I have an AC/DC Premium and it has this huge 12" woofer in it. I agree that stock, it sounds better than other Sterns in the past have stock. But with a 12" woofer, I would expect the bass in this thing to blow away my Ironman, Tron, 24, or any other Stern with an 8" Pro sub. It doesn't. I had to solve that. The result was a more powerful bass than provided by even a $100 external powered sub - and for cheaper. Read on.

Details and theory
If you don't care about any of this, just skip down to "the solution". I'll try to keep this brief.
The Stern SAM systems are driven by two 18w 4 ohm amps. One is used for the backbox hooked up with the red wires, the other is used for the cabinet sub, hooked up with yellow wires. The cabinet sub is running full range. The speakers used in the back cabinet are cheap 4" speakers. These are run in series.

The problem in AC/DC is three fold: 1) There is no crossover on the sub so it doubles up on what is already handled by the backbox. 2) There is no volume control on the sub so you cannot get more bass. 3) This is the big one: The 2030 amp on SAM boards is no where near enough power to drive this 12" speaker. To make matters worse, Stern used an 8 ohm speaker which further lowers the amp's capabilities of driving the sub.

To test the amp theory in #3 above, I pulled out the 12" sub and installed a decent 8" sub I had laying around. I stuck a 100hz crossover on it, and wow, the bass coming from this was way greater than the bass coming from the 12". Why? Because the 18 watt amp is enough to drive this cheap 8" sub but when it comes to a 12", it is not. To make matters worse, Stern used an 8 ohm 12" sub. This reduces the amp's power to it probably closer to 12 watts. You can tell the speaker is under driven as the speaker hardly moves.

I have a polk audio 10" powered external sub laying around. For a while, I had just hooked this up. The bass coming from this was quite good. The 12" provided some decent mids. But I didnt like having the external speaker. It makes moving the pin a hassle. It has to be internal.

So I had this cheap powered amplifier laying around. I decided to try this out. It provides 100 watts. But most importantly, it has a built in crossover and a volume knob. I put the 12" sub in again and this time hooked up the amplifier. And wow, the 12" just came alive. The bass coming from this 12" absolutely blew away the external powered sub. Not only that, but when you're playing the game you can feel the cabinet shaking in your hands as well as massive streams of air shooting up through the glass onto your hands. The external sub does not allow this.

The baffle:
One reason why an internal sub is a good move is because you can get much lower bass due to the baffle. See, subs are designed to be used in an enclosure. The enclosure provides some air resistance so that when the speaker moves, the resistance of air pushes the speaker back out. The cone, therefore, does not move as much as it would without that air resistance. The size of the box helps tune the resonation frequency of the sound. The bigger the box, the more the speaker moves but the deeper the resonation frequency. The cheap FF and PPro subs are rated around 45 hz. But you actually get a bit lower bass out of these due to the fact that they're not installed in an enclosure, but a baffle. The speaker cabinet is the huge pinball cabinet. The air resistance is lower, but the speaker moves a lot more due to this providing lower bass. The downside is you cannot get near the volume you'd get if the speaker was in an enclosure. But this is OK because the cheap pinball 2030 amps only provide 18 watts. You cant get much volume anyway. Because of this, the pro subs work absolutely wonderful in a pinball box. You get deep bass that those cheap 8" would generally not produce, and the pinball volume cant really go that high anyway. (Off topic, but my home theater subs use this theory. I have a massive raised seat platform for a speaker box. Running 4 specially made 12" infinite baffle subs - the infinite baffle allows the speakers to hit 10hz flat!). The 12" Stern sub running in the baffle produced phenomenally low bass. It way out performs the cheaper external subs.

The solution:
Get a cheap sub amp such as one of these:
$60 - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-784
I used one of these, but it's probably over kill. I used this because I happened to have it just laying around:
$90 - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-802

Installation:
1) Plug the power cable into your service port. The amp turns off when there's no audio signal to it, so this works fine. Stick the amp in the back part of the cabinet. It can just set there. If you want you can velcro or tie strap it down, but it's not needed unless you're going to put your pin on its back.
2) Remove the yellow and white speaker wires from the 12" positive and put it on "High input" or "from amp" red on left speaker input on the amp.
3) Remove the yellow and black speaker wires from the 12" negative terminal and put it on "high input" or "from amp" black on left speaker input on the amp.
4) Wire the red wire from the amp to the + terminal on the 12" speaker (where the yellow white was)
5) Wire the black wire from the amp to the - terminal on the 12" speaker (where the yellow black was).
6) Test and adjust. The amp has a knob for gain. This is the sub volume. Adjust it to where you want it. There is a freq knob. This is your crossover. I put mine somewhere near 100hz. You want to cut all the ugly higher vibration sounds out of the sub and have it only producing bass. That's what this knob will do for you.
7) Your 12" speaker is now going to move so much that it will pound on the metal grate that stern provided. You have two options: 1) Remove that metal plate or 2) Space the speaker up slightly. This is easy. I got a cardboard box. The one that the amp came in works. Cut it up and fold the cardboard into small squares 4 layers thick (just cut like 1" wide x 4 inch long strip and fold it 4 times into a square). Loosen the 8 5/16th nuts that hold the speaker down just enough to be able to shove in the cardboard, and insert these cardboard spacers around the edge of the speaker between the nuts. Insert 4-8 of these cardboard spacers. Try to keep them around the edge as you don't want the speaker cone to pound these instead. Then tighten the speaker nuts down. Dont crank them. Just make sure that the bolts are tight enough so that the speaker doesn't move.
8. Last, the speaker will be so aggressive that your glass is going to massively rattle on bass notes such as pop bumpers. Remove your glass and line the edges with electric tape. This will tighten the glass preventing it from rattling.

When I'm playing my AC/DC with the vol up, the 12" is moving so much that I feel streams of air shooting up through the lockdown bar onto my hands when the bass hits. It's absolutely awesome!

Optional (under $20): Now for the highs - AC/DC is music based. Unlike most other pins, it requires decent treble to replicate cymbals. Therefore, replace the backbox speakers to get some decent highs. You need a coax speaker. Anything on this page will do. Pick something around $18 if you want to go cheap. I actually used these clarions for about $28. They're great speakers for the price: amazon.com link »

If you replace these, remove the little blue cap on the right speaker from the circuit. It's not needed and only serves to remove some of the mids. It was needed on sterns' speakers that had no real tweeters. But on coax, you don't want it. Just desolder it, unscrew it, and throw it away. Connect the wire that connected to this directly to your speaker.

Comparisons:
$100 external powered sub - The external sub is blown away by this 12" internal sub with a $60 amp. The amp is cheaper, just as easy to install as the external sub. And, everything is internal in the machine.

Stock: there's no comparison between this set up and the stock set up. You'll be blown away.

Pinball Pro or FF kit: They haven't come out with anything yet, but I can't see how it would be better.

#2 7 years ago

NICE.

#3 7 years ago

Great post Markmon! I have used the Dayton amp on 2 of my machines with great results. The only slight fault with the Dayton is the efficiency of its built-in crossover. After playing around with a few passive crossovers I decided to go electric with this simple unit amazon.com link » and it made a huge difference. These pics are from A Gottlieb Genesis (restored) and a DR. Who (in progress). The Genesis has dual 8 inch subs http://www.mcmelectronics.com/product/MCM-AUDIO-SELECT-55-2971-/55-2971 wired in parallel to get the full wattage from the amplifier. My Dr. Who has a 12 inch subwoofer http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=292-132 They both sound awesome. Makes the game 10 times more exciting. I also upgraded the back box speakers as well. The factory speakers are always less quality than aftermarket...Just as in a car from the dealer.

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#5 7 years ago

Yes very nice

#7 7 years ago

Awesome may have to do this. Are all the speakers just plug and play or do the wires need to be soldered? Not the its a big deal anyhow. Any potential negative impact?

#8 7 years ago

Don't believe Stern has released any games programmed for stereo. If they had, you could externally hook up two mid / high range speakers and one subwoofer to get some really good sound.

For that matter they could have installed standard speaker setup, but added three external speakers to override what is in the cabinet for a few hundred dollars more. A simple switch would allow Op to decide whether to use internal or external system. Stern should have spent some effort figuring out how to allow the songs to play in stereo. For their premier music pin release, I expected no less and it would have helped establish Stern as being on the cutting edge. Oh well, opportunity lost.

#9 7 years ago

Thanks Mark I just ordered 2 amps and speakers for my AC/DC pro and my Tron.
I did something like this with a car amp before and it turned out well.
But if I put out too much bass it would blow the 12v fuse.

#10 7 years ago
Quoted from jeffspinballpalace:

Don't believe Stern has released any games programmed for stereo. If they had, you could externally hook up two mid / high range speakers and one subwoofer to get some really good sound.

For that matter they could have installed standard speaker setup, but added three external speakers to override what is in the cabinet for a few hundred dollars more. A simple switch would allow Op to decide whether to use internal or external system. Stern should have spent some effort figuring out how to allow the songs to play in stereo. For their premier music pin release, I expected no less and it would have helped establish Stern as being on the cutting edge. Oh well, opportunity lost.

JJP is all over that!

#11 7 years ago
Quoted from pinballlooking:

Thanks Mark I just ordered 2 amps and speakers for my AC/DC pro and my Tron.
I did something like this with a car amp before and it turned out well.
But if I put out too much bass it would blow the 12v fuse.

Let me know what you do with the tron. The 18 watt amp seems plenty to drive an 8" sub at 4 ohms.

#12 7 years ago
Quoted from markmon:

Let me know what you do with the tron. The 18 watt amp seems plenty to drive an 8" sub at 4 ohms.

I usually do not have my games very loud. Without cranking them up you don’t get any bass.
The amps I have installed in the past were used so I could have good sound at a lower volume.

I know this is not why most people get amps.

#13 7 years ago

Ha,

I ordered 4 sets of speakers and an amp. Plan on upgraded all my back box speakers that I had not already put in FF speakers.

I will upgrade just speakers as I have hooked up external subs on 3 of my games.

Its cool to upgrade the sub but not needed on every game. The speakers I feel different about. Basically just take off the capacitor and hook em up. Best $15.00 upgrade ever!!! I cannot wait to try it

Any thoughts on doing the same thing on Bally/Williams games? Do I need different speakers or mounting equipment. I assume the 4" for the Stern games are basically plug and play with just unsoldering removing CAP and resoldering new speakers and screwing them in.

-1
#14 7 years ago

Thx for the details on the sound system, which I did not know before. AN 18W 4-ohm amp circuit hooked up to an 8-ohm 12" woofer? For shame! I expect better given the price of the premiums/LEs. Sad that you have to spend even more $$ and effort to get really good sound out of a "premium" pin. (And yes, I've listened to the LE and Premium, and the sound is 'meh' at best--not a great high end, bass is vague.)

#15 7 years ago

Great idea Markmon. Treat it like a stereo system. I have made amps and volume controls on bread boards for arcade stuff many times but buying cheap works too.

I bet it rummbles the neighbors now =-)

have fun rockin out

#16 7 years ago

Would this be too little juice? My pins are in a small room with low volume

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-782

Also is there any chance of this thing drawing too much power and blowing a fuse or anything of that nature?

Post edited by mandelbloom

#17 7 years ago
Quoted from mandelbloom:

Would this be too little juice? My pins are in a small room with low volume []

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-782

Also is there any chance of this thing drawing too much power and blowing a fuse or anything of that nature?

Hi. Mandelbloom I have this model amp on an 8 inch subwoofer in my den surround sound system and it is barely hanging on. I would not recommended it. It does not have enough juice even for low volume. With amplifiers you want to have more than enough power even if you don't plan on using it. This extra power gives you what they call "head room" and is basically "buffer" power but it definitely equates to much cleaner sound even at low volume. Amplifier demand changes depending on the type of sound it is receiving so when a deep note or intense multiple tones are required...you want to have the juice needed to make it all come together. If not you will end up with clipped audio signals (distortion) which can damage speakers even at low volume. These amps are individually fused and only draw about 35 to 37 volts after their internal transformers per my actual DMM readings. No worries for power draw. I simply cut the plug and direct wired it at the rear power receptacle of each machine. Go with the next model up it has good power.

#18 7 years ago
Quoted from mandelbloom:

Awesome may have to do this. Are all the speakers just plug and play or do the wires need to be soldered? Not the its a big deal anyhow. Any potential negative impact?

Soldering gives the best connections. You can however use female connectors if you have a crimping tool. I prefer soldering.

#19 7 years ago
Quoted from hank527:

Any thoughts on doing the same thing on Bally/Williams games? Do I need different speakers or mounting equipment. I assume the 4" for the Stern games are basically plug and play with just unsoldering removing CAP and resoldering new speakers and screwing them in.

The Bally/Williams games have a 5 1/4 inch full range speaker on one side and about a 2 inch tweeter on the other. These drop right in http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=267-080. The tweeter has a crossover cap on it to help filter the high frequencies. The 5 1/4 speaker I observed on my ES and Dr. Who were actually quite beefy in terms of construction but still not aftermarket sound quality. Also I prefer to remove the tweeter and cap, enlarge that opening to match the other, and have matching size coaxial speakers on each side. It definitely improves the sound projection even if it is not stereo. Now-a-days clock radios even have dual speakers

#20 7 years ago

I will give it a try with my AC/DC LE. the external sub was a big improvment but an internal solution would be better so I ordered from a german shop:
http://www.conrad.de/ce/de/product/301043/Aktiv-Einbau-Verstaerkermodul-80-W/SHOP_AREA_22499&promotionareaSearchDetail=005
Hope that is good enough, I will put it in when I have the time for it. And willl report here about it.

For the backbox speaker I wasn't sure which one to get here in germany.
I ordered these but don't know if they are the right ones:
http://www.conrad.de/ce/de/product/373438/SINUSTEC-ST-100C-2-WEGE-KOAXSYSTEM/SHOP_AREA_17281&promotionareaSearchDetail=005

I don't know when I have the time to put them in but I will report here when I am finished.

#21 7 years ago
Quoted from Asael:

I will give it a try with my AC/DC LE. the external sub was a big improvment but an internal solution would be better so I ordered from a german shop:
http://www.conrad.de/ce/de/product/301043/Aktiv-Einbau-Verstaerkermodul-80-W/SHOP_AREA_22499&promotionareaSearchDetail=005
Hope that is good enough, I will put it in when I have the time for it. And willl report here about it.

I'm interested in the report, when I get my AC / DC Premium I might upgrade the sound system, but for me ordering from the US is not really an option compared to this item shipping from Europe.

Thanks in advance!

#22 7 years ago

The pyle blues are not drop in. they stick out quite a bit. You will need spacers and longer screws. Just put them in AC/DC with power amp for sub and sound is better

Also wired on one side only for mono as the game is only mono

#23 7 years ago
Quoted from pinballlooking:

I usually do not have my games very loud. Without cranking them up you don’t get any bass.
The amps I have installed in the past were used so I could have good sound at a lower volume.
I know this is not why most people get amps.

Yea, you can put a vol control on your backbox speakers and do the same thing for way less. Then you up your volume, lower your backbox and you get more bass without more volume. Another option is to just solder a 16 ohm resistor inline to the + terminal on the first backbox speaker. This may lower the volume on them enough.

#24 7 years ago
Quoted from Asael:

I will give it a try with my AC/DC LE. the external sub was a big improvment but an internal solution would be better so I ordered from a german shop:
http://www.conrad.de/ce/de/product/301043/Aktiv-Einbau-Verstaerkermodul-80-W/SHOP_AREA_22499&promotionareaSearchDetail=005
Hope that is good enough, I will put it in when I have the time for it. And willl report here about it.
For the backbox speaker I wasn't sure which one to get here in germany.
I ordered these but don't know if they are the right ones:
http://www.conrad.de/ce/de/product/373438/SINUSTEC-ST-100C-2-WEGE-KOAXSYSTEM/SHOP_AREA_17281&promotionareaSearchDetail=005
I don't know when I have the time to put them in but I will report here when I am finished.

These look very good. The amp is for sure right a good choice and will work. The speakers will work if they are 4 inch. I see them in millimeters. I assume you already did the conversion.

#25 7 years ago
Quoted from Asael:

For the backbox speaker I wasn't sure which one to get here in germany.
I ordered these but don't know if they are the right ones:
http://www.conrad.de/ce/de/product/373438/SINUSTEC-ST-100C-2-WEGE-KOAXSYSTEM/SHOP_AREA_17281&promotionareaSearchDetail=005

Those look like really good quality! Keep us updated : )

#26 7 years ago
Quoted from hank527:

The pyle blues are not drop in. they stick out quite a bit. You will need spacers and longer screws. Just put them in AC/DC with power amp for sub and sound is better
Also wired on one side only for mono as the game is only mono

Anyone know some that are plug and play? Almost ordered those

#27 7 years ago

So I installed my selected amp to the cabinet speaker. I put in the speaker wires and conected the wires that come from the back of the amp to the speaker. the whole pinball field vibrated but I didn't liked the sound. I don't know what went wrong but there suddenly weren't mids anymore. The bell sound wasn't right too. I tried to calibrate the amp but got no success. My external amp solution was way better. I think the amp that I used wasn't good enough. But I also don't know if this was the right way to do it. I don't know if I did something wrong or if my amp just isn't good enough. So I took it out again hooked the external sub again on it and wait for a better internal solution with components we can easly get here in europe.

#28 7 years ago
Quoted from mandelbloom:

Anyone know some that are plug and play? Almost ordered those []

Regarding the 5 1/4th Pyle blue speakers from Parts Express for Williams and Bally machines... I did not have to alter the original 5 1/4 factory back box speaker mounting locations or the front grill assemblies. Now as I said before I do choose to alter the William/Bally tweeter locations because I like matching left & right speakers. I believe Stern uses 4 inch speakers but I would doubt very seriously they use speakers that have abnormal bracket mounting locations as I am sure they source their speakers from a standard speaker manufacture. The picture below is from my Earthshaker that I upgraded years ago and I just realize I installed 6 1/4th inch speakers which are even larger than the original factory size with no major modifications as you can see. Again my Dr. Who picture as well that I did recently. As you can see the speakers mount from the rear and I did not need spacers or longer screws however I did use "BETTER" screws because I don't like the cheap screws that come with most speaker sets as they tend to strip out very easily when tightening down. Once you remove the factory speaker you basically have a flat piece of wood so there is nothing to do but place the new speaker in place and connect the wires however you choose. Just click and enlarge the pictures, its a very simple installation for Williams / Bally machines especially if you are not changing out the other speaker (tweeter) location.

IMG_20120720_132931.jpg IMG_20120624_200744.jpg

#29 7 years ago
Quoted from Asael:

So I installed my selected amp to the cabinet speaker. I put in the speaker wires and conected the wires that come from the back of the amp to the speaker. the whole pinball field vibrated but I didn't liked the sound. I don't know what went wrong but there suddenly weren't mids anymore. The bell sound wasn't right too. I tried to calibrate the amp but got no success. My external amp solution was way better. I think the amp that I used wasn't good enough. But I also don't know if this was the right way to do it. I don't know if I did something wrong or if my amp just isn't good enough. So I took it out again hooked the external sub again on it and wait for a better internal solution with components we can easly get here in europe.

Ok. You need to remove that cap they soldered in on the back board speakers. That will allow them to produce some decent mids. You could also put some better backboard speakers in that can reproduce decent midrange sound. In your current set up, the 12" is providing all your midrange sound.

#30 7 years ago

Great thread Mark. You seem to know quite a bit on this. You should update a new how to for all types of machines as all of the old ones out there point to parts and links that are obsolete.

#31 7 years ago

Ok I took Marks advice and bought two amps
$60 - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-784
I had an old pinballpro sub that was in my Tron so I added the amp. I am happy with it.
It really helps the bass and adds to the game play.

Next up will be AC/DC Pro I have a 8” sub the amp and pyle blues.
I will report back once I receive it and install it all.
Thanks Mark for the wirte up!

#32 7 years ago

Another idea here is to grab a dual voice coil capable subwoofer and hook up each amp to one of the voice coils in series with one of the mid speakers. This should result in a huge gain of power provided to the sub by the internal amps since two amps would be driving the sub rather than one. If anyone has one of these types of speakers laying around and wants to try it, let me know and I'll try to draw up a wiring schematic to help the test.

#33 7 years ago

There are a couple of other approaches to take.

The volume a speaker puts out is defined by its efficiency, not its resistance.

The stock speaker is quite inefficient for a 12" at 87.2dB. I replaced it with one from MCM Electronics with an efficiency of 97dB - that means that it produces almost 10 times the sound level from the existing amp. So if you were getting 5W, this speaker makes it sound like 45W.

http://tinyurl.com/cov2wdf

This one has similar specs, but is cheaper right now.
http://tinyurl.com/c4tz7rw

The Fs (low frequency resonance) is good enough.

On the backbox, we made spacers and replaced the existing speakers with car units. This was way too loud, so I put the cap back in. It really needs a ceramic resistor in there, I need to set up a pot and test it.

Here's my pictorial on the backbox:
http://mrtn.smugmug.com/Other/2012-07-06/24018064_vJNDHk

#34 7 years ago
Quoted from PamPinbits:

On the backbox, we made spacers and replaced the existing speakers with car units. This was way too loud, so I put the cap back in. It really needs a ceramic resistor in there, I need to set up a pot and test it.

Pam thanks for posting this. Let us know how the resistor works out.

#35 7 years ago

Thanks PAM that sounds like a good option! Where did you get the spacers or where they home made?

Also if I read correctly you just did a direct swap of the wiring to the back panel speakers not modification to that, same for the sub?

#36 7 years ago
Quoted from markmon:

Ok. You need to remove that cap they soldered in on the back board speakers. That will allow them to produce some decent mids. You could also put some better backboard speakers in that can reproduce decent midrange sound. In your current set up, the 12" is providing all your midrange sound.

Thanks! That was the solution. After I took the cap out and the better backboard speaker in the mids were there, now it sounds good.

I still believe that my external sub had a slightly better sound but overall the internal mod is way better. Now everything is in the cabinet and like you told the vibrations and the stream of air that blows out of the cabinet feels great.

I have to make better spacers for my backboard speakers and also I put tape on the glas it sometimes rattles.

But thumbs up and thanks for your mod marmoon!

#37 7 years ago

I am going to order the Sub that pin bits used sounds like a really easy drop-in solution. I am also thinking about ordering some pyle-blues along with it as they are only $15 and shipping is the same. Seems like those aren't drop-in though as the volume will be too loud if I put them in place of the current speakers?

#38 7 years ago
Quoted from PamPinbits:

There are a couple of other approaches to take.
The volume a speaker puts out is defined by its efficiency, not its resistance.
The stock speaker is quite inefficient for a 12" at 87.2dB. I replaced it with one from MCM Electronics with an efficiency of 97dB - that means that it produces almost 10 times the sound level from the existing amp. So if you were getting 5W, this speaker makes it sound like 45W.
http://tinyurl.com/cov2wdf
This one has similar specs, but is cheaper right now.
http://tinyurl.com/c4tz7rw
The Fs (low frequency resonance) is good enough.
On the backbox, we made spacers and replaced the existing speakers with car units. This was way too loud, so I put the cap back in. It really needs a ceramic resistor in there, I need to set up a pot and test it.
Here's my pictorial on the backbox:
http://mrtn.smugmug.com/Other/2012-07-06/24018064_vJNDHk

Pam: try a 40 ohm resistor and removing the cap in the backbox. Also, if you're going to swap out that sub in the cabinet and not get an amp, you need an inductor to cut the ugly mid bass from the cabinet. I suggest at least a 6mH to handle that 8 ohm speaker at around 200 hz and down. You may even want to go bigger. Too bad you can't find an efficient paper cone 12" sub that's 4 ohms or 8 ohm dual voice coil. Efficient or not, 12w max just isn't going to produce decent bass And while you're right that lower impedance doesn't mean louder speaker, lower impedance does mean more power wattage to the speaker. My experience with some of these cheaper subs is also that while they may be louder, their resonation frequencies are higher resulting in no additional decibels after you have installed the low pass inductor. I might buy one of these just for the fun of testing it.

#39 7 years ago
Quoted from markmon:

Yea, you can put a vol control on your backbox speakers and do the same thing for way less. Then you up your volume, lower your backbox and you get more bass without more volume. Another option is to just solder a 16 ohm resistor inline to the + terminal on the first backbox speaker. This may lower the volume on them enough.

I like the idea of the vol control, never thought of that!

#40 7 years ago

AC/DC pro
I put in a 8” sub and the amp
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-784
back box speakers. pyle blues
The base is great but the high and mids are so so. I bypassed the capacitor out in the backbox.
I am thinking I need different back box speakers. Any suggestions?
It sounds better but not the way I want it to just yet.

#41 7 years ago

What do you not like about the backbox? Mids are missing? Being a music pin you may want to splurge a bit on the quality of the back box coaxes. Maybe get something nice at your car audio shop...

#42 7 years ago

The high are missing mids are ok. I do not mind splurging on the backbos speakers at all I just want it to sound good. If someone has already tried a set of a brand and thinks they sound great I will try to listen to a set of those. I just want music sound as good as it can.

#43 7 years ago

Check the woofer for mids and highs bleeding through to the woofer. If you read the review of the 70W amp, there have been multiple reports of the crossover not working properly. Based on those reviews, I purchased the 100W amp which should be here Thursday. That could cause your sound to be off.

#44 7 years ago
Quoted from tktlwyr:

Check the woofer for mids and highs bleeding through to the woofer. If you read the review of the 70W amp, there have been multiple reports of the crossover not working properly. Based on those reviews, I purchased the 100W amp which should be here Thursday. That could cause your sound to be off.

I have a hard time understanding how this amp hooked up to only the woofer could cause the highs to sound bad. He said he likes the bass sound. That tells me the amp is probably ok. If what you were saying we're the cause, I think the mid bass would be resonating in the cabinet.

The Pyle blues are pretty cheap and good for probably every stern machine that doesn't have the cymbal sounds of acdc. You maybe should just go to your car stereo shop and audition 4" coax speakers. Bring some acdc to test it . That's my advice.

Also, the internal amp was probably enough to handle the 8". But I'm sure it sounds better with the powered amp.

#45 7 years ago
Quoted from tktlwyr:

Check the woofer for mids and highs bleeding through to the woofer.

That is a good point I have a 100 Hz Low Pass from parts express that I will add to it tonight.
Maybe that will help some. I almost bought the 100w amp let me know how you like it.

#46 7 years ago

Would this mod work on 80s Bally pins with the existing speaker?

#47 7 years ago

I put a pair of aftermarket 4" speakers in my Xenon and it did brighten up the sound. I also have the pyle pro woofer in my Fathom and it sounds amazing.

#48 7 years ago

Pam: try a 40 ohm resistor and removing the cap in the backbox. Also, if you're going to swap out that sub in the cabinet and not get an amp, you need an inductor to cut the ugly mid bass from the cabinet. I suggest at least a 6mH to handle that 8 ohm speaker at around 200 hz and down. You may even want to go bigger. Too bad you can't find an efficient paper cone 12" sub that's 4 ohms or 8 ohm dual voice coil. Efficient or not, 12w max just isn't going to produce decent bass And while you're right that lower impedance doesn't mean louder speaker, lower impedance does mean more power wattage to the speaker. My experience with some of these cheaper subs is also that while they may be louder, their resonation frequencies are higher resulting in no additional decibels after you have installed the low pass inductor. I might buy one of these just for the fun of testing it.

Actually - it does produce really good bass. More turns = more impedance = more magnetic force for the same current. As you note, you do have to watch for an overly high Fs. You can check all this out by finding a speaker simulator. Model it as a 300L leaky box.

Here's an analysis of a relatively efficient 8" speaker (94dB). A typical 8" speaker would produce maybe 1/4 of the output. The more sophisticated tools also let you model in corssover parts.

prlss.gif

#49 7 years ago

I just picked up a home subwoofer on the local classified site for $50. Wired it in to PotC and Tron (gave each one a right or left input) and connected it directly to the woofer in each cabinet.

Wow.... absolutely night and day. I can see the appeal of putting one in each game but honestly, I don't know if it's worth the money or the hassle when it was so easy to add the external (and especially shared betweent the two machines as someone else suggested was possible on the site).

#50 7 years ago

OK, I did all the mods this week and, because the parts came from different sources, I upgraded in stages. Here are the order of upgrades and my thoughts:

The woofer recommended by PinBits: http://tinyurl.com/cov2wdf

This did increase the bass significantly. IMHO, it was too much without an L-Pad to work out a nice balance between the woofer and backbox speakers, even after removing the capacitor on the backbox speaker.

Pyle Blue Label in the backbox: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=267-078

Sounds was better, but the bass still dominated the sound. You will need to remove the grills on the panel to fit these unless you have the ability to make a spacer. I removed the grills. The only downside to this is the blue color if you have anything other than a BIBLE. It's not bad, though. I'll probably try a different set in the backbox since I need to place an additional order and move the Blues over to S-M.

The amplifier recommended by markmon: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-802

I used the more powerful of the two amplifiers markmon recommended. The reason I chose the more expensive of the two is after reading the reviews of the lower end model, a few people had problems with the crossover not working properly. For placement, I simply put it where the coin box goes, which allowed me to wire it all up without clipping zip ties on the cabinet harness and pulling the wires from the main bundle should I ever (doubtful) choose to remove it.

All I can say is WOW! This really brought the audio to life and with both the volume and crossover adjustments, it allows you to dial the sound to your personal taste. I am very pleased with the results! Thank you, markmon!

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