Microseven M7WP-MIC microphone with Dahua42212TNI - buzzing noise

[marklyn]

OK, will make another attempt tomorrow, I put it up today because it looks like rain.
Will update results on next attempt. Thanks everyone.

 

[looney2ns]

sorry milliamps, basically 1 amp, right?

Try a PS that is something like 250mah. The mic doesn't need much at all.

 

[DsineR]

Use only the White and the Black wires. The audio (red) out is for adding a speaker outdoors so you could "talk" to a perp.
For the mic, White and Black are the wires.

Mic -> Cam -> Spkr

 

[marklyn]

DsineR, what are you referring to: Mic->Cam->Spkr

 

[DsineR]

Audio from the Mic goes into the Cam (use Aud In connections).
Audio from the Cam goes out to a Speaker (use Aud Out connections).

 

[marklyn]

Audio from the Mic goes into the Cam (use Aud In connections).
Audio from the Cam goes out to a Speaker (use Aud Out connections).

ahh, got it. Thanks!

 

[tigerwillow1]

Is the camera properly grounded as it should be?

This question caught me by surprise. Am I the only one not running a grounding wire to my cameras? If the camera has a plastic case, how could it connect to a grounding wire?

 

[DsineR]

Grounding the camera is really a misnomer. The object is to protect the network equipment & camera via surge protectors on the CAT cable. See attached recommendations from Anixter, goto UL-497 for twisted pair protection standards.

 

[tigerwillow1]

Grounding the camera is really a misnomer. The object is to protect the network equipment & camera via surge protectors on the CAT cable.

OK on that, but I can't see how this would have anything to do with an audio hum and/or ground loop.

 

[DsineR]

Correct, 2 separate topics.

 

[Mark_M]

I guess ground loop or power supply is terrible.

 

[Cameraguy]

I used a lower amp wall plug that solved my hum

 

[marklyn]

I've deduced from comments here I should use the black and white wire, does it matter which color is on positive/negative on terminal block?

 

[marklyn]

WOw, you guys are amazing for helping me with this. All this time I was focusing on using the red/white wires, never the black. I think it was because I stumbled on some very loose instructions someone posted last year on another type of camera so I stuck with the wiring diagram they spoke of. There was never much at all about the specifics on how to hard wire a mic onto a Dahua camera that I was ever to find.
For future reference I used the black wire to the negative terminal and the white wire to the positive terminal. Works like a charm, no buzzing and almost too much sound.
Might now need to find one of those things you put over a mic (whatever they're called) to help block wind. THANK YOU GUYS!!!

 

[DsineR]

Windscreen. Good to know you got it working!

 

[Cameraguy]

WOw, you guys are amazing for helping me with this. All this time I was focusing on using the red/white wires, never the black. I think it was because I stumbled on some very loose instructions someone posted last year on another type of camera so I stuck with the wiring diagram they spoke of. There was never much at all about the specifics on how to hard wire a mic onto a Dahua camera that I was ever to find.
For future reference I used the black wire to the negative terminal and the white wire to the positive terminal. Works like a charm, no buzzing and almost too much sound.
Might now need to find one of those things you put over a mic (whatever they're called) to help block wind. THANK YOU GUYS!!!

Yes that mic is amazing

 

[Ratfink11]

Hi All,

I have 32 of these mics. Regarding use on Dahua Cams.

1. The Dahua Camera Pigtail wires for the Audio in/out, Alarm I/O, are EXTREMELY small gauge wire. All of my cameras I have patiently soldered wire connectors along with heat shrink tubing for both Audio in/out.
2. Black is common ground for BOTH the In and Out sides of the Audio. This is the Minus - side of the power supply wire to connect to.
3. These mics have to be powered. They require 12vdc @ 17ma. I have always used a separate 12vdc 500ma power supply. I never share or use a splitter from the cameras power supply mainly due to the cheap garbage splitter pigtails as they can cause these exact same problems.
4. If you have a long dc power supply cord and you have it neatly wrapped or wound it will cause noise. The shorter the dc power cord the better.
5. If your home/business AC power mains, or any outlets are not properly grounded or any improperly shielded A/C Wiring will also cause noise as mentioned from others above.

These mics are very sensitive to surrounding or background noise. I have attached audio settings. Prefer not to use the noise filters as these mics will (I kid you not) pick up the sound of a nickel dropping on a train track 700 feet away. If you add an acrylic dome, Clear Acrylic Plastic Display Domes. or use a clear vinyl umbrella with a wind screen you can increase the sensitivity over a mile with a clear line of sight, no trees, etc...

 

[marklyn]

I spoke too soon. After I got it working (very well I might say) in a few hours the buzzing was back. Now that I know I have wires connected correctly I will start trouble shooting again by trying a different power plug. I do have a 14' extension from the power brick to the location where the camera is, so I'll also try just temporarily connecting power with just the power adapter to the mic and omitting the extension. I so thought I had this issue licked.

 

[tigerwillow1]

After I got it working (very well I might say) in a few hours the buzzing was back.

I find that to be weird, which I realize doesn't help you. I'd start by trying to figure out what changed after a few hours.

 

[marklyn]

I find that to be weird, which I realize doesn't help you. I'd start by trying to figure out what changed after a few hours.

Weird is right. I had thought I fixed it and when satisfied I 'walked away' for 3+ hours, then came back to check some video clips and the blasted buzzing was back. Will work on it today more.