kuchars22 Posted March 24, 2008 Share Posted March 24, 2008 Hi, I like to place a covert microphone at the front door of my property (camera 1) and link it to my DM DS2a in the loft (about 15m away). The datasheet quotes the following requirements for a mic: AUDIO The user has the option to record and play back a single channel of audio in real time. Recorded with images from camera one, audio can be played back either directly from the unit via powered external speakers. Recorded audio is automatically copied when images from camera 1 are archived to CD-R or exported across a network. Connections: Mic in: 3.5mm jack socket (requires an electret/condensor microphone with a sensitivity of Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted March 24, 2008 Share Posted March 24, 2008 might be wrong but isnt it illegal now to record audio? Link to comment Share on other sites More sharing options...
kuchars22 Posted March 24, 2008 Author Share Posted March 24, 2008 might be wrong but isnt it illegal now to record audio? I thought that too, but I thought maybe not if DM had the feature on their kit. The guidelines is supposed to prevent recordings between members of the public. In my case (residential), it would be a member of the public and the CCTV operator, or property owner where the mic is situated. Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted March 24, 2008 Share Posted March 24, 2008 I thought that too, but I thought maybe not if DM had the feature on their kit. The guidelines is supposed to prevent recordings between members of the public. In my case (residential), it would be a member of the public and the CCTV operator, or property owner where the mic is situated. hey my car speedo goes upto 160mph so who knows - LOL Ilkie`s the man who will know Link to comment Share on other sites More sharing options...
ICEbear Posted March 24, 2008 Share Posted March 24, 2008 Hi,I like to place a covert microphone at the front door of my property (camera 1) and link it to my DM DS2a in the loft (about 15m away). The datasheet quotes the following requirements for a mic: AUDIO The user has the option to record and play back a single channel of audio in real time. Recorded with images from camera one, audio can be played back either directly from the unit via powered external speakers. Recorded audio is automatically copied when images from camera 1 are archived to CD-R or exported across a network. Connections: Mic in: 3.5mm jack socket (requires an electret/condensor microphone with a sensitivity of –50dBV or better) Line in: 47KΩ input impedance, 1V pk-pk, RCA phono socket Line out: 1V pk-pk, RCA phono socket I'm new to microphones, only use them on Friday nights at my local karaoke bar, but as an idiots guide, what should I be looking for? The description looks as if there are two inputs, one for a traditional karaoke style mic ("Mic in") and a covert style mic ("Line in"). Am I therefore correct in that I plug the covert one into Line in? If yes, then I assume I ignore Mic In? And what about all this "47KOhm" business, is this something that I need to worry about or is just a guideline? Thanks And what about all this "47KOhm" business, is this something that I need to worry about or is just a guideline? its the input impedence, microphones need a preamp, so (for example) some cameras come with audio built in and a RCA phone (audio out) the power inside the camera is also Supplying power to a (op amp) little preamp, and then the audio out is about 775mv to 1v peak to peak "I like to place a covert microphone at the front door of my property" your mic modual should have +/- 12v (red & black) and screened audio out which goes into (line in) electret/condensor not sure what output voltage they are (so many Vairables) but if i was to guestimate then i would say 50 to 150mv out. "line in" is 775mv to 1v and has no pregain "mic in" will have pregain!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!dont try and put 775mv/1v into mic in, it will sound distorted and can do damage. hope this helps Link to comment Share on other sites More sharing options...
kuchars22 Posted March 25, 2008 Author Share Posted March 25, 2008 And what about all this "47KOhm" business, is this something that I need to worry about or is just a guideline?its the input impedence, microphones need a preamp, so (for example) some cameras come with audio built in and a RCA phone (audio out) the power inside the camera is also Supplying power to a (op amp) little preamp, and then the audio out is about 775mv to 1v peak to peak "I like to place a covert microphone at the front door of my property" your mic modual should have +/- 12v (red & black) and screened audio out which goes into (line in) electret/condensor not sure what output voltage they are (so many Vairables) but if i was to guestimate then i would say 50 to 150mv out. "line in" is 775mv to 1v and has no pregain "mic in" will have pregain!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!dont try and put 775mv/1v into mic in, it will sound distorted and can do damage. hope this helps Thanks for that info, I kind of guess what you are saying. The mic I saw on ebay is described below, is this OK for my needs and does this just go into the Line in? "This add-on audio module is perfect for use in conjunction with CCTV camera systems or anywhere you need some serious remote audio monitoring. This miniature board features a high quality electret microphone and high gain amplification. Giving outstanding results in any situation. Sub Miniature-cylinder bullet microphone only 6mm diameter and 18mm long pre-amplifier PCB module, connection is via a mini 3-way connector. Covered in a strong plastic protective sleeving. 2.1mm DC power socket and a RCA phono audio connector for easy connection to your existing CCTV equipment. Specifications: Frequency: 20Hz ~ 16kHz S/N ratio: >58dB Output: standard line level Power: 6-12Vdc, 20mA Audio option for cctv cameras Sub miniature size Extremely sensitive Use with any audio line input" And here looks like the same product from Maplin: http://www.maplin.co.uk/module.aspx?Module...y=25m3#overview Under the FAQ section, it says it is "mic level" and requires a pre amp. Are these two different products? Sorry to sound like an idiot, but the figures here have no reference to the figures that are quoted by DM or by yourself, so I'm lost basically! Link to comment Share on other sites More sharing options...
ICEbear Posted March 25, 2008 Share Posted March 25, 2008 Thanks for that info, I kind of guess what you are saying. The mic I saw on ebay is described below, is this OK for my needs and does this just go into the Line in?"This add-on audio module is perfect for use in conjunction with CCTV camera systems or anywhere you need some serious remote audio monitoring. This miniature board features a high quality electret microphone and high gain amplification. Giving outstanding results in any situation. Sub Miniature-cylinder bullet microphone only 6mm diameter and 18mm long pre-amplifier PCB module, connection is via a mini 3-way connector. Covered in a strong plastic protective sleeving. 2.1mm DC power socket and a RCA phono audio connector for easy connection to your existing CCTV equipment. Specifications: Frequency: 20Hz ~ 16kHz S/N ratio: >58dB Output: standard line level.............................................775mv to 1v............................(mv) means milli volts (1000mv is 1volt) so 775 is 3/4 of a volt Power: 6-12Vdc, 20mA..................................................12v dc to power the PreAmp Audio option for cctv cameras Sub miniature size Extremely sensitive Use with any audio line input" And here looks like the same product from Maplin: http://www.maplin.co.uk/module.aspx?Module...y=25m3#overview Under the FAQ section, it says it is "mic level" and requires a pre amp. Are these two different products? Sorry to sound like an idiot, but the figures here have no reference to the figures that are quoted by DM or by yourself, so I'm lost basically! perfect choice my friend just make sure the mic needs 12v AND YOU KNOW THEN ITS GOT A PREAMP "Under the FAQ section, it says it is "mic level" and requires a pre amp. Are these two different products" ---Yes simple thing to remember and you wont go wrong: line level is a standard input and the standard is 775mv to 1v mic level is approx 50mv to 150mv and needs a preamp to get it up to 775mv. let me try to drill this standard (line in) also called (line level) remember 775 ok another example, on "standard hifi equiptment" cd input 775mv/1v tuner input 775mv/1v tape input 775mv/1v aux input 775mv/1v phono 300mv MM or 150mv MC................so as you can see, phono needs a preamp (its normaly built-in) line in on a pc 775mv/1v your Dedicated Micros, if it says (line in) on the audio inputs then its 775mv/1v figures here have no reference to the figures that are quoted by DM or by yourself, so I'm lost basically! it can be blinding hope this helped if you get stuck, just come back. joe Link to comment Share on other sites More sharing options...
kuchars22 Posted March 25, 2008 Author Share Posted March 25, 2008 perfect choice my friend just make sure the mic needs 12v AND YOU KNOW THEN ITS GOT A PREAMP"Under the FAQ section, it says it is "mic level" and requires a pre amp. Are these two different products" ---Yes simple thing to remember and you wont go wrong: line level is a standard input and the standard is 775mv to 1v mic level is approx 50mv to 150mv and needs a preamp to get it up to 775mv. let me try to drill this standard (line in) also called (line level) remember 775 ok another example, on "standard hifi equiptment" cd input 775mv/1v tuner input 775mv/1v tape input 775mv/1v aux input 775mv/1v phono 300mv MM or 150mv MC................so as you can see, phono needs a preamp (its normaly built-in) line in on a pc 775mv/1v your Dedicated Micros, if it says (line in) on the audio inputs then its 775mv/1v figures here have no reference to the figures that are quoted by DM or by yourself, so I'm lost basically! it can be blinding hope this helped if you get stuck, just come back. joe Yes, it sounds clearer! My brother gave the example of a headphone with microphone, as there is no power for this, it is provided by my computer when connected to the soundcard, whereas one with a power output obviously means that it is self-powered? Link to comment Share on other sites More sharing options...
kuchars22 Posted April 17, 2008 Author Share Posted April 17, 2008 Yes, it sounds clearer! My brother gave the example of a headphone with microphone, as there is no power for this, it is provided by my computer when connected to the soundcard, whereas one with a power output obviously means that it is self-powered? Help! I bought both the Maplins and the other one off ebay and I can't get either the mic to work. I've bought a 15m phono cable (originally for any mono device like a subwoofer) to extend the mic to the DVR, connected it to the mic in, do hear humming noise but that's it. I've tested it on the Line in too, same results exept the humming was at a lower volume. It worked without any extension in the mic in. Is the cable type incorrect, if so, what type of cable do I need? Thanks Link to comment Share on other sites More sharing options...
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