(Topic ID: 39529)

Williams system 11: Cabinet and Backbox speaker upgrading

By nosro

6 years ago

Topic Stats

  • 67 posts
  • 12 Pinsiders participating
  • Latest reply 5 years ago by Curbfeeler
  • Topic is favorited by 53 Pinsiders


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There are 67 posts in this topic. You are on page 2 of 2.
#51 6 years ago
Quoted from Jeff_PHX_AZ:

So you all running 4 ohms in the panel/backbox and the cab. speaker is 4 ohms. Now the old cab. speaker I pulled out was rated at 8 ohms, what gives?

Sounds like someone replaced it before you got it, maybe? If I remember right, I did research and listened to the guys here for the ohms, because my T2 has 8 ohms, so I had to order different speakers for each pin.

#52 6 years ago

More than you needed, and biased toward WPC era machines, but Tony D did a really nice write up on wiring in an L-Pad here....


#53 6 years ago
Quoted from nosro:

I used that L-pad

Do you not use it anymore?

Also you say 20 gauge wire, this is better then 18 gauge?

Sorry for all the questions, just want to have everything I need for when I start the install. If I have more then I will come back and ask, thanks for the time you taken to break it down. When you do a google search for "high speed replacement speakers" this is at the top of the search, no other info on replacing high speed speakers is found on google.

#54 6 years ago

20 gauge is thinner than 18 gauge. It's not a problem for such low wattage and short runs.

Sorry about the bad grammar. I continue to use an L pad on all my machines to crank up the bass!

#55 6 years ago
Quoted from nosro:

20 gauge is thinner than 18 gauge. It's not a problem for such low wattage and short runs.
Sorry about the bad grammar. I continue to use an L pad on all my machines to crank up the bass!

Hows the sound quality using thinner wires? Should I get the individual strand of wire or the type that split down the middle? I don't need the red or black colored wire right?
Also the L-pad is a 15 watt mono, thinking I should have gotten the 25 or 50 watt. Can you tell me how the 15 watt L-padis holding up? Thanks

#56 6 years ago

The 15W L-pad is fine. I think you would be lucky to peak out at 1W at ear-splitting volume. The amp is probably pushing something more like 0.1W at typical volume levels.

I wouldn't worry too much about the wire. I think the wire coming out of the connector on the machine is probably 20 gauge. Buy whatever is at your local hardware store.

#57 6 years ago

thanks man, will report back. L-pad will be delivered on monday

1 week later
#58 6 years ago
Quoted from nosro:

I highly recommend a volume control (really an attenuator) for the backbox speaker. Because most people like more bass, reducing the volume on the backbox speaker is a good way to increase the relative volume of the cabinet speaker that has been presumably upgraded to a bass-capable speaker. Key words are "L pad attenuator". I purchased this one: amazon.com link »
Use the following wiring diagram (taken from http://techtalk.parts-express.com/showthread.php?205712-L-pad-wiring ). Don't worry too much about the polarity. As long as 1 and 3 go to the amplifier somehow and 1 and 2 go to the speaker somehow, you are fine.

Well I finally received the L-pad and got her installed. First, speaker panel removal

#59 6 years ago

2 phillip head screws, 2 on each side. 4 screws and and the speaker panel comes easily out.

#60 6 years ago

right side screws

#61 6 years ago

removing the screws

#62 6 years ago


#63 6 years ago

Now you can get at the speaker. Easy and the panel removes quite effortless.

#64 6 years ago

After the wiring and soldering you get this

#65 6 years ago

Now mounted against the backboard of head. Just using Velcro for now until a better solution. I also did not replace the back box speaker. I will eventually though. I do I have question for those who use L-pad's, look at the picture see how the volume level is like low at the min. This setting gives me just enough sound from the top backbox speaker to not drawn out the cab. speaker. But why is it like almost off? If I put the volume lever at mid point on the dial its way to loud. Just curious is all. Game sounds a lot better now.


#66 6 years ago

Yes, I also have the volume dialed almost completely to min. If you set the attenuation to max and put a sound level meter right next to each speaker, you will find them to be quite comparable. The fact that the cabinet speaker doesn't point at your ears requires that it be much louder in comparison to the backbox speaker in order to be audible. It is the same way with a Judge Dredd machine I have where I also upgraded the speakers and installed an L pad.

2 months later
#67 5 years ago

Great thread! I'm going to do this exact thing with my F-14 and Pinbot for sure.

Have a DE question if it's okay. I'm also looking to upgrade my Robocop, which is a 3 channel amp (stereo + center). If I want to dial down my backbox speakers there, I will need to two L-pads for that, correct? One for each speaker in the box? I've also seen stereo L-pads. This is also an option, yes? Total cost is about the same for two L-pads or one stereo version, so just confirming.

Thanks in advance,

Edit: I'm impatient! Just went ahead and bought 2 mono L-pads.

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