Buzzing speakers in cab

[jtkauff]

One of these days I'll buy a machine that works great the first time that I plug it in. In the mean time...

I've got a machine with buzzing speakers. It's a dedicated Guitar Freaks (which uses the same board and setup as DDR), which has 4 speakers and sound-activated lights. Two of the four speakers buzz constantly. I've checked connections and unplugged/replugged everything. I've swapped the two non-buzzing speakers with the buzzing ones, and it didn't help. I made sure that the speaker wires were far from the monitor and power supply so there isn't any interference. Whenever the machine has any power running through it the speakers buzz and the inner section vibrates rapidly. Is it likely that the speakers are getting too much power? Or might it be something else?

I will note that the machine actually has two power supplies hooked up (which concerns me), one of which powers the main board while the other seems to only power the audio boards and speakers. At least one supply is a 220/110 (though everything is set to 110, me being in the States), since the machine was originally sold for use in Korea/Asia. Might someone have overkilled setting it up for 110 (though it operated for 12 hours a day in an arcade without issue), and that's where the speaker issue actually lies?

Any help would be appreciated - I'd love to kill that buzz (and make sure my cab is safe).

[Barry Barcrest]

Have you tried it with the neons disconnected? I only ask as somebody else posted something the other day about neons creating interference.

[jtkauff]

Unlike DDR, Guitar Freaks doesn't have any neons - there are two spotlights and the marquee light, and then two small lights in the two start buttons. I've not tried it with those disconnected, but I totally removed the two buzzing speakers from the cab to see if it was something within the cab, and it wasn't - they still buzzed when sitting a few feet away from the cab (as far as the wire would stretch).

[MonMotha]

Those cabinets have nasty ground issues (as do DDR and DMX cabinets, presumably it's the power supply as that is the same amongst the three, as is the monitor).  Apparently, tieing all the grounds (various frame, logic, DC power common, audio, and the incoming AC safety ground line) together fixes that problem.  Apparently the monitor frame itself is also not grounded, and supposedly grounding that can help as well.  Most of the metal pieces of the cabinet are painstakingly wired together with some hefty ground (green/yellow) cabling, but I'm not sure that it actually goes anywhere!

As a warning, my friend's DDR machine has such nasty leakage from DC power common to the earth ground on the AC line plug when connected that the breaker on the power supply trips!  I discovered this when I clipped a scope ground lead on once - very happy ground loop.  However, I know someone else who did this exact thing with his Guitar Freaks machine and it is apparently much happier now.  YMMV, I guess.

As a nice bonus, it should also fix the coin door (or DDR stage, in our case) zapping you issue

[jtkauff]

I'll have to try that out. From a quick look inside the machine there aren't any ground cabling at all, so that very well may be the problem. I'll see what I can do to ground everything (which probably should be done regardless of whether it's the problem) and hope that it does fix the problem. Thanks!

[Taborious]

I had this exact issue in my cab as well and it took me forever to figure it out and it was a stupid setting. I tried, as you to keep the calbes away from the monitor, put a choke on the cable and nothing helped, it was really pissing me off. Building to climax.....One day I tried to look at the settings for my speakers which I have a basic PC speakers with sub and it turned out I had the bass set too high. Once I turned it down the buzzing went away. I felt like a fool but at least I got rid of my buzzing. Give that a try and hopefully this will clear up your issue as well; it sounds the same. Just to clarify I had to turn the bass down but I was then able to turn the volume up so a littel trade off...good luck...

[dougman]

make sure everything in your cab is grounded properly.
I had Horrible buzzing out of my speakers, and i couldnt figure it out.
I had taken the entire cab apart trying to figure out what the hell was going on, and it was one of the arcadevga lines that werent grounded. :O
Or something like that.