Bullet Mic Review

Discussion in 'Accessories' started by nayr, Oct 3, 2016.

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  1. tangent

    tangent Known around here

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    So we're on the same page: the camera and mic psu are both located in your basement and the mic is powered via Ethernet cable?

    How far are the camera and microphone from one another? What type of cable did you run between them for the audio signal?

    Changes in the atmosphere effect radio signal propagation. Assuming that's a SUNY station, I could see more variation in their broadcast than your average radio station... I suspect it might also be broadcast on AM.
     
  2. tangent

    tangent Known around here

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    I would still like to know what type of cable runs between the camera and mic and how long it is.

    Assuming I understood how you're powering things correctly, here are 2 things you can try:
    -Ground the unused wires in the UTP cable that's being used to power the mic
    -Move the power for the mic to a single twisted pair. This mic is a very small load 17mA. For most things the approach you took doubling up and running + on a pair and - on a pair would be the right way to do this, but the load of the mic is so small it should work fine to do it this way and the twists will help filter it a little. 75' is a long run and I don't do math after 8... so no guarantees.

    Start by grounding the unused wires since that doesn't require a ladder.

    As for the cable between the cam & mic:
    plain shielded cable, stp, or even coax are all good chioces. If you used UTP again, this should be a twisted pair.
     
    Last edited: Mar 27, 2018
  3. Kil

    Kil n3wb

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    I tried it with a 12v 0,5A adapter i found laying around. It does seem to have fixed the humming issue. I still get a bit of static on high volumes, but it's pretty nice and silent on normal volumes.


    Thanks! i didn't think of these connectors. Worth a try. I only have 1 cat6 cable at the location of the cam/mic, getting PoE to the cam. I don't like the splitting PoE from the cable and attaching the powerocnnectors to the cam and mic from there on-story, so for now, this lower-amp solution you guys pointed me to seems to do the trick of fixing the hum without starting to pick up radio stations :p
    I was thinking of replacing the cam soon to get a better angle. I'll keep the utp power idea in mind for then.
    Thanks again!
     
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  4. looney2ns

    looney2ns Known around here

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    For the static, I'd try turning down the volume in the cam a little, and also if there is a "noise filter" setting in the cam, turn it off.
     
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  5. EMPIRETECANDY

    EMPIRETECANDY IPCT Vendor

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    i will get some new mic, maybe looney can help make a testing with the dahua cams.
     
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  6. Solar Deity

    Solar Deity Getting comfortable

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    So we're on the same page: the camera and mic psu are both located in your basement and the mic is powered via Ethernet cable?

    @tangent That is correct, both power supplies plugged in to 2 individual basement 15A circuits. For 12V mic power, I used a 75' length of 24 AWG solid copper Cat5e UTP (my mistake, didn't read enough) alongside a 23AWG Cat6 UTP for the camera's data and power. The 2 unused twisted pair are just pulled back and wrapped around the cable, at both ends of the run.

    How far are the camera and microphone from one another? What type of cable did you run between them for the audio signal?

    Camera and mic are less than 12" from one another. The SD59 has audio in wire, approx. 18-20 gauge, that I attached screw down RCA connector to, then plugged it in to the mic signal wire. This has been my standard practice for the 5 I've installed. They are all custom and different of course, but two others reside in the basement as well, right next to this mic/cam, and they have zero interference issues.
    20170612_202902.jpg IMG_5616.JPG IMG_5287.JPG


    Changes in the atmosphere effect radio signal propagation. Assuming that's a SUNY station, I could see more variation in their broadcast than your average radio station... I suspect it might also be broadcast on AM.

    You may be right. I listen to it enough to know their call frequencies are FM, buy they rattle off 3 numbers so they are transmitting on multiple frequencies, and one may be AM.

    I would still like to know what type of cable runs between the camera and mic and how long it is.

    It is Microseven's standard insulated cable with a female RCA plug on the end. I attach the mic in from the camera to a screw down male RCA I grabbed on Amazon. The total length of the two attached is approx. 24".
    dh-sd59225u-hni_img4_d.jpg


    Assuming I understood how you're powering things correctly, here are 2 things you can try:
    -Ground the unused wires in the UTP cable that's being used to power the mic
    This will be fairly easy and a quick troubleshooting step.
    -Move the power for the mic to a single twisted pair. This mic is a very small load 17mA. For most things the approach you took doubling up and running + on a pair and - on a pair would be the right way to do this, but the load of the mic is so small it should work fine to do it this way and the twists will help filter it a little. 75' is a long run and I don't do math after 8... so no guarantees.
    This is an easy mechanical step, but logistically a little more difficult. Have to get the lift up there, which is parked on the side of the house. Understand the no math after 8. I'm more of a "needs to be warmer than 40 degrees" to work outside! The warmer weather is approaching soon.

    Start by grounding the unused wires since that doesn't require a ladder.

    As for the cable between the cam & mic:
    plain shielded cable, stp, or even coax are all good chioces. If you used UTP again, this should be a twisted pair.
    I really appreciate your time taken to assist. I've attached a couple pics of the hardware posted above.

    SD
     
    Last edited: Mar 28, 2018
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  7. Kil

    Kil n3wb

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    Thanks! i had seen the noise filter option, but it made the hum increase. Now with the hum gone, turning it off makes it so much better. Everything in the direct surrounding of the mic sounded great, but passing cars sounded more like alien spaceships. With it turned off everything is great. And again, thank you!


    So, i've been happy with my mic for 14 seconds. Now i'm curious about the new one you talk about. Great, haha.
     
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  8. tangent

    tangent Known around here

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    Ok, that wasn't clear earlier. You shouldn't need to do anything to the signal wires.

    Switching the camera to 24VAC and using a 24VAC to 12VDC converter as described earlier in the thread is also an option for powering the mic.
    You could also try running a wire between the housing of the mic and the housing of the camera and try connecting that to earth or not (keep this wire close to the others).
     
  9. Firefighter

    Firefighter Getting the hang of it

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    Couple years later, is this still the go to mic in the link?

    Gonna buy a few, appreciate the link and review
     
  10. Al*_*

    Al*_* Young grasshopper

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    Recently there was a post about new released microphones
    I believe there was a plan to review one or two. Don't know. Not sure if the quality/cost Dahua's would justify but from what I've read the M7WP-MIC is good.

    I ordered a couple from Microseven myself.
     
  11. ingeborgdot

    ingeborgdot Getting the hang of it

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    Okay, I need a little help here. I thought I had what I needed but then I see that the SD59225U-HNI does not have connectors on the wires.

    If I start with the power and use one of these https://www.amazon.com/dp/B00FEOB4E...olid=1KQFQ8GV400GW&psc=0&ref_=lv_ov_lig_dp_it


    Then go to this extension cable https://www.amazon.com/dp/B00FEOB4E...olid=1KQFQ8GV400GW&psc=0&ref_=lv_ov_lig_dp_it

    I can get the power into this mic. How do I now get it from the mic to the bare cable when the mic has an rca on the end of it? Is there a diagram I missed someplace that can help me?
     
  12. ingeborgdot

    ingeborgdot Getting the hang of it

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    Last edited: Jun 3, 2018
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  13. tangent

    tangent Known around here

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    That will work. The thing you will have to watch / experiment with is how you're powering it and if you introduce audible noise in the process. There are a lot of different options.
    One option I like is to power the camera off of 24VAC and to use a small 24VAC to 12VDC adapter near the camera to power the mic.
     
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  14. ingeborgdot

    ingeborgdot Getting the hang of it

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    So where does the red wire go in that setup?
     
  15. tangent

    tangent Known around here

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    nowhere unless you're using audio out. Audio in and out share a ground. Audio out is unamplified.