I noticed this with my Star Wars about a month ago and thought it was a problem with the CPU board. The sound from the cabinet speaker on the bottom of the game was slightly distorted compared to the audio coming from the backbox speakers. We ran the audio to a different speaker to verify that it wasn't just a case of crappy stock speaker, but the distortion was still there. When we routed the backbox sound to the cabinet speaker it was crisp and clear, so no issues with the speakers. I was sent a replacement CPU board on warranty and swapped it out, but the distorted sound problem still persisted. I ended up going back to a really early version of the code (0.91) and the distortion was gone!! I then upgraded back to 1.03 and as I expected the sound problem returned.

We verified with another collector who tested his Star Wars and he also had the distortion from the bottom cabinet speaker. It's not really noticeable standing up playing normally, but if you crouch down to the bottom of the game and listen to the music and callouts, you can tell its fuzzy. I had another person check their Batman 66, Star Wars, and Aerosmith and they all had similar distortion coming from the bottom cabinet speaker. I think when Stern redid the plumbing on the Spike II sound system earlier this year with the ability to adjust speaker bass/treble independently, they may have inadvertently messed something up here.

I think they are mixing the Stereo sound to mono for the cabinet speaker, but they are not applying Pan Law when they do this (reduce each channel gain by -3dB before mixing to mono) so the audio is ending up distorted or clipping.

I'm curious if anyone else here has noticed this. I did mention this on the Star Wars thread, but it got missed in the sea of posts about hyper loops and escape gates not working, or was written off as a speaker issue by folks who didn't fully read my posts on the issue.

As far as I am aware, this could potentially be an issue on all Spike II games that have the underlying system updates for the audio adjustments from around the Feb-April 2018 time frame.

Edit: Also, I have emailed Stern about this observation a week ago, but hadn't gotten any sort of confirmation or response they have read and understood it.

I sent to the "software" address and it didn't bounce back, but it appears that the proper one to send to is "bug.report", so I have just resent it and we'll see what happens.

The bug report folks responded right away and they are aware of the issue and currently investigating.

[email protected]

Just an update, but Stern has started releasing code updates that fix the sound issue on a few Spike II games in the last week. Star Wars sounds good again on my end with 1.05 code.