Geometry in the Humming

"There is geometry in the humming of the strings, there is music in the spacing of the spheres." Pythagoras

Well Pythagoras, at least you never had to deal with the humming of the speakers...

Roughly three or four years ago I purchased what I believed to be an awesome 5.1 surround sound speaker set - Philips SPA 2600/00 - in reality, nothing special. I love it all the same.

The first thing I didn't like was how long it took the sub woofer to warm up and kick in (10 - 15 mins). I guess this is normal. I figured to remedy that, I'd keep it switched on 100% of the time. Problem solved!

The second thing I didn't like was how the sub and satellites started to make a humming noise from time to time, but when I tapped the side of  the sub unit, it went away... for a while.

After three years of this, I finally cracked tonight, and opened the sub unit up to see what could be done. My first instinct was to look for bulging or leaking capacitors, of which there were none. Mind you, what would I have done with them if I had found any? I don't think I could have been bothered getting the soldering iron out.

My second instinct was... well.. I didn't have one, because let's face it - I didn't know what I was doing. It's all transistors here and resistors there, capacitors this and conductors that...

Then, a stroke of pure luck. As I cast my eyes across the lower circuit board, I spotted a bit of wire which seemed to be protruding a bit too far out from the connector. I pushed the wire in to make a better connection, and the humming stopped!

I can only assume that this was some kind of earth wire, because I know that humming can be caused by a lack of an earth connection.

So there you are, a very strange ongoing problem easily solved. Though I am left kicking myself that I didn't think of trying this sooner...