Timeline for Further to my question about wiring my music room...wiring finished, now I have a noise question!
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 31, 2021 at 9:31 | comment | added | Tetsujin | It might be mitigated by using metal conduit for both sets of cabling. tbh, balanced cable ought to be pretty tolerant of induced hum, as the induction should be positive in one side & negative in the other, cancelling out as it unbalances. You've reached the stage now where I'd be tracking round the room with a single-coil pickup guitar, trying to figure out where it's worst & what needs switching off to kill it the best. | |
| Jan 31, 2021 at 1:32 | comment | added | Dusty0b9 | I did not know that I needed to be 2 feet away from any power lines, and on all 4 circuits I am within one foot of the vertical power lines on one wall, and about the same running along the floor below the outlets on the outside wall. Can I lower the impact of the induction by soldering the copper shield to the ground clip on both ends of the cable, so that when the xlr is plugged into the mixer, the mixer will act as a common ground for all the cabling? I tried using aluminum foil to shield the wires from the overhead LED lights, but without effect. | |
| Jan 28, 2021 at 17:25 | comment | added | Tetsujin | I can't tell. "Power cleaners" are usually just snake oil for hi-fi buffs who don't know what they need, so can be sold anything. The ad contains no description of what it actually does. | |
| Jan 28, 2021 at 13:12 | comment | added | Dusty0b9 | Would this help me reduce the noise in the circuit? amazon.ca/APC-C2-C-Type-2-Outlet-Filter/dp/B000OF4R8C/… or do I need to find something else? | |
| Jan 27, 2021 at 11:45 | comment | added | Tetsujin | You've reached the stage where I'd still think it induction, but my next test would be to change which ring main I was running power from (then pull other fuses one at a time until you find the culprit) & also test with an isolating transformer in circuit (but that's because I have one already;) | |
| Jan 25, 2021 at 16:11 | comment | added | Dusty0b9 | The noise builds on itself with every XLR cable I plug into the mixer. And when I plug in one cable the level light always come on no matter what input I use on the mixer with that cable... does that shed any light on the problem? | |
| Jan 25, 2021 at 16:11 | comment | added | Dusty0b9 | I even plugged a 50 foot extension cord into a power outlet adjacent to my main panel, and this made no difference to the noise, the noise still was present. When I disconnected everything, I did notice that if I put my ear next to the mixer, the noise appears to be in the mixer, and not just the cables... is this what induction would do? I just went downstairs and disconnected all the XLR cables from the mixer, and the noise disappeared. There is no noise present when only the guitar 1/4 inch jacks on the same cable type are left in the mixer. | |
| Jan 25, 2021 at 16:11 | comment | added | Dusty0b9 | So that leaves induction... I noticed that turning the LED ceiling lights on and off did impact the amount of noise as did the connection of microphones to the XLR plugs in the wall. The noise dropped significantly. | |
| Jan 25, 2021 at 15:53 | comment | added | Dusty0b9 | You are probably right about ground loop, if I understand it correctly after read ing an article on the net. My system is as follows. My mixer is plugged into ONE outlet, and my speakers are slave to the mixer via speakon cables, and all of the wiring is home run from an outlet in the wall to a dedicated input on the mixer. No other equipment is plugged into an outlet, or connected to the mixer. So I am thinking that would rule out a ground loop. Am I correct? | |
| Jan 24, 2021 at 14:13 | comment | added | Tetsujin | It's either induction or a ground loop. if it affects a single cable going to one of many preamps all connected to the same mains power, ground loop is less likely than induction. The only cure for induction is distance. | |
| Jan 24, 2021 at 14:00 | comment | added | Dusty0b9 | is there any kind of filter or ground I can install that will fix this one run??? Or do you have any other ideas for me to try, I am at a loss to figure this out! | |
| Jan 24, 2021 at 13:58 | comment | added | Tetsujin | It's certainly a possibility. Just to eliminate your preamp, though, swap to another one. Make sure it's not the unbalancer that's not doing it's job properly - as I say, balanced line ought to be pretty good at rejecting induced hum | |
| Jan 24, 2021 at 13:57 | comment | added | Dusty0b9 | I just tried something, I put an XLR connector on a 20 foot piece of XLR cable, and ran it across the floor in the center of the room away from all the power outlets, and that new cable has the same noise. I started turning things on and off, and noticed that the led lighting in the ceiling changes the amount of interference when switched on and off, but did not eliminate it entirely. is is possible that the sum of all the wire runs, 200 feet over 8 connections could be the problem? | |
| Jan 24, 2021 at 13:34 | comment | added | Tetsujin | Mains voltage, depending on country - 240v 50Hz or 120v 60Hz. If you put a tuner near the audio interference, 50Hz comes out a bit sharp of G, 60Hz is slightly flat of B. You kind of get to recognise the pitch after a few years (or decades) of chasing it down at a myriad gigs & cheap studios ;) | |
| Jan 24, 2021 at 13:28 | comment | added | Dusty0b9 | When you say mains, do you mean the speaker cable runs? My speakers are on speakon connectors, and the speakon cable runs across the ceiling and the mic cable is behind the baseboard, so they are far enough away from each other. And I am not sure what you mean by" switch off that ring"???? | |
| Jan 24, 2021 at 10:35 | history | answered | Tetsujin | CC BY-SA 4.0 |