Extreme Static on 2w 28mm speaker

[kingcobra5352]

I recently completed my first build with a NBv4 in an Epoch saber. Everything was going fine for a few days after I worked out some bugs until the speaker started freaking out this morning.

https://www.youtube.com/watch?v=Ut2qZgrC2D8

[Whosle]

Take this with a grain of salt, as I am amateur saber maker. I am pretty good at diagnosing electronic issues however.

There are a few things that may be causing it. It sounds like a short. Why it happens a while after is unknown. Try shaking the saber to see if it goes away. Check your speaker connections to make sure they cant contact the hilt in any way.

The impedance for the speaker isnt matched. The NBV4 says 2w 4-8 ohm, but makes no mention of what ideal is. If you have 4ohm, maybe try adding another 4 ohm resistor.

The magnet in those bass speakers are powerful. I have had little screws and debris attach to my speakers, I am no audio engineer, but a metal (ferrous) housing in close proximity can create a magnetic field that could cause the speaker to behave strangely. Not sure what a diamagnetic metal would do...

Last issue and hopefully not the cause, is the amp is going...

Ive been watching you develop this saber, lots of roadbumps along the way make for a good saber smith!

[kingcobra5352]

I appreciate your reply. When you say the amp could be going, what would cause that?

Someone else pointed out that my solder points on the board could be too exposed. Though, when I take out the board and turn it on it still has the issue. Thoughts?

http://imgur.com/a/HJx84

[Whosle]

Are the wires touching the little chip in the back? You shouldn't fold over wires onto other metal bits unless they are shrink tubed. Try and pull those wires away and make sure they dont touch anything. If you have to, put some electrical tape on them to diagnose that is the issue. The you may have to rewire. You might be able to just heat the tip until the solder melts , push the wire through until the outside insulation is up against the board. Use little clips to clip off the excess on bottom side. You should also twist the tips of the wires, they should look like tight little spirals.

Or just use shrink tubes. (Everyone forgets and usually its on the nicest solder joint all day)

The amp may be going if you had to fiddle a few times wiring it. But I only mentioned that as last possible issue.

Soldering isn't a trivial skill. It is difficult to teach yourself.
Try skimming a few how to videos. Some guys make it seem easy, others have 100 plus lists of do and do nots.

[kingcobra5352]

Are the wires touching the little chip in the back? You cany fold over wires onto other metal bits unless they are shrink tubed. Try and pull those wires away and make sure they dont touch anything.

The amp may be going if you had to fiddle a few times wiring it. But I only mentioned that as last possible issue.

I pulled the wires away and tried it. Still the same issue.

[Whosle]

Dang. What is speaker impedance? If too low, could be cause.

The speaker also may be blown.

Try and re format the sd card possibly. Good luck.