Nathan P Posted December 9, 2006 Report Share Posted December 9, 2006 Okay, I finally got my wiring figured out, but now my mics make a horrible hum, it's very annoying, especially on a system with a sub. It is present in silence too. What could be causing this? It's not my camera. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 10, 2006 Author Report Share Posted December 10, 2006 I found it, it was my cables, I replaced the cables and rebuilt my adaptors and everything worked fine. Maybe I had a short in the wiring somewhere. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 10, 2006 Author Report Share Posted December 10, 2006 AHHHHHH IT'S BACK! Grrr. This is fricken pissing me off now. It recorded sounding fine in one scene of the play, then it hummed, then it was fine, I changed tapes it was fine, It would hum when it was silent but not when something was happening, and then it would hum all the time. Give me a break, why is this so difficult! It would sound great if it weren't for the fricken hum! How could it sound perfect, I even recorded a song, played it back on my stereo, and it sounded great, and now it's humming, exact same equipment, same battery, (Tested good, only used 3 hours or so), same cables as when it recorded good, and it hums like a maniac. I'll have to use a sound scrubber just to get decent sound out of it, and who knows what kind of problems that'll introduce. Quote Link to comment Share on other sites More sharing options...
King Ghidora Posted December 10, 2006 Report Share Posted December 10, 2006 It sure sounds like a grounding issue somewhere. Check where your cable connects to the camera. Jiggle it around to see if you can introduce the noise by changing the position of the connector. I've heard of other people having problems with hum in their recordings using certain mics where it was pretty obvious that it was a grounding issue. The fact that it happens sometimes and not others would indicate that a connection just isn't seating right. It almost has to be a grounding issue. Are you using the mic that you built? Maybe a connection didn't get soldered just right. If all else fails you might try to use this ground loop isolater from Radio Shack. I'm guessing there are others that are designed with miniplugs if you want to look around. But I'd think you can probably track it down since it works sometimes and doesn't at other times. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 10, 2006 Author Report Share Posted December 10, 2006 Okay, I switched out the stereo cable that ran from the battery box to my camera for a RCA to miniplug cable with a miniplug adaptor on the rca end, and it worked fine. Could it be that I had 2 crummy cables? My recording from the first performance, which was made with the rca cable, had no noise, even though it was wired incorrectly. My noise issues started after I found out about the wiring issue and started using the stereo cables with the 3.5mm connectors. These were both ones I had had from various computer things I have gotten, soundcards, speakers etc. Maybe the camera was making some electronic noise and the way they were wired was picking it up? Quote Link to comment Share on other sites More sharing options...
King Ghidora Posted December 11, 2006 Report Share Posted December 11, 2006 Possibly it was a problem with interference affecting the 3.5mm cables. Many of them have no shielding at all and even on a short run you can pick up noise. Possibly a cell phone operating nearby could have caused the problem. The phone wouldn't need to be during a call to cause problems. Those cell phones communicate with the towers even when there isn't any phone call in progress. I get intereference in almost every electrical system I have because of cell phones and I live in an area where I can barely pick up a signal from a tower. The RCA cable would have some shielding but not a lot. I'm just guessing here of course but try turning on your cell phone right next to yoru cable and see if you pick up noise at that point. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 11, 2006 Author Report Share Posted December 11, 2006 I'm not sure, but I've built a new battery box with correct connections. I soldered the cable from the box out directly to the box. RS didn't have any 2.2 uF caps, but I found two in an old Harmon Kardon amp from a set of computer speakers I took apart, they are polarized (The last ones weren't), but they are also much smaller, and my battery box is a much nicer form factor. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 11, 2006 Author Report Share Posted December 11, 2006 Woooo! All test so far show little to no noise, although, my bedroom has a million fans in it, and these mics pick up things louder than I hear them! The click wheel on my mouse was very noisy on the recording, while it is just kind of medium to my ears. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 11, 2006 Author Report Share Posted December 11, 2006 (edited) Okay, here's a clip of my mics recording music from my computer speakers. The funny thing is that these speakers sound terrible through the mics, although my regular stereo/home theatre speakers sound great. Wierd. Maybe it's because of the tiny drivers or something. As you can see, it picks up my computer's humming rather loudly. The good thing though, is that that noise isn't the noise that was in my recordings, and it isn't loud and obnoxious like the one before, plus, it's not coming from the mics.Extracted_Audio_01.mp3 Edited December 11, 2006 by Nathan P Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 11, 2006 Author Report Share Posted December 11, 2006 Heres some pics, the new one is on the right (If you couldn't tell by the massive improvement in form factor/size. Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 11, 2006 Author Report Share Posted December 11, 2006 Heres a recording I made of a song I wrote for the piano. I named it Solace, it is played in C-major. I'll post up one that was recorded straight to my computer, and one that I did through my camera. Note that during the camera one I was rudely interupted I am quite pleased with it, and although you haven't heard my recordings with the other battery box, you really don't want to. I'll have to get a soundtrack from the play from the sound guys, or use some kind of audio cleaner to remove the noise. I'm quite happy with what an hour or so of work and some recycled/left over components did to improve the sound of my mics.Solace_No_Accompaniment.mp3Extracted_Audio_02.mp3 Quote Link to comment Share on other sites More sharing options...
Nathan P Posted December 16, 2006 Author Report Share Posted December 16, 2006 Okay, I found out that the noise was caused by the plug in power, I had the camera hooked up to the charger so the batt wouldn't die during both of the performances where I got the noise. I tested this theory with my new box, and it's the problem. I guess it is a ground loop or something. Why is the 60hz (Which seems about right actually from listening to it) frequency going to my mics or to the mic in jack or whatever? what would cause this? Quote Link to comment Share on other sites More sharing options...
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