Stereo Microphones and ATT822

[Pete Cofrancesco]

I inherited an Audio Technica ATT 822 stereo condenser microphone which I'm told is a quality mic but it seems to be on the quite side. I've check the battery but compared to phantom power mics such as the oktava mk12, the internal mics on my camera or digital recorder the levels are substantially lower. Are all battery powered condenser mics less sensitive?

My other question is about stereo mics, what benefit is there over a mono mic?

All of my equipment can't utilize the ATT822 stereo capability and only see it as a mono, that includes my Sony Z1u, Fx1, and Zoom H4 digital recorder. Most of my work is filming live events. I set up an off camera mic to record the ambient sound, I want to use the ATT822 for this purpose but I find my octava 12 has greater sensitivity. So should I sell the ATT822 because I don't see a purpose for the mic (at least for my situation). Would it be a mistake to get a large diaphragm omni mic to record dance recitals/plays/other live events, or should I stick with my oktava mk12, or get another oktava for a stereo pair?

[Mike Peter Reed]

The AT822 has an output sensitivity of 5.6mV/Pa - cold!
http://www.microphone-data.com/microphone.asp?mic=149

The Oktava MK12 outputs 10mV/Pa - kind of tepid (I have two of these mics, non matched)
http://www.microphone-data.com/microphone.asp?mic=606

I like M/S recording with the AT BP4029, nice and hot at 31.6mV/Pa
http://www.microphone-data.com/microphone.asp?mic=154

Of course this says nothing in particular about the mic self-noise, I just like it when I don't have to crank the gain so much.

If the AT822 doesn't do it for you, sell it.

[Pete Cofrancesco]

Since I'm a not an audio expert, I wanted to ask before selling it, to make sure it wasn't user error, or an inherit characteristic of that type of mic. In the past I used what ever equipment was made available or buy a mic with the most positive reviews/stars without fully understanding how to use it. Now that I'm gaining more experience, I can see a lot of negative comments are made by people who are using it improperly or for an application that it wasn't intended for.

I have a hard time making sense of the sensitivity specs because each manufacture lists them at different db/voltage, so I've given up trying to compare them. Looks like I have to register to read the links you posted, but the specs you listed support my personal experience.

It isn't always clear that a mic won't be good for a certain application until you try it or can understand how the specs/type of mic will impact your desired use. I now can see that ATT822 is designed to be used close up, capturing a person's voice and the lower sensitivity combined with the built in wind screen makes it an advantage, reducing the pops of speaking, but those characteristics don't lend themselves to recording at a fixed location that isn't close to the source.

Btw, I'm not saying its a bad or noisy mic, its just too cold for what I need it to do, recording live events at a distance. In a perfect world, the person on stage would be properly miced or know how project their voice, but that's often not the case so its better for me to have a mic that has to extra sensitivity in reserve to use at those moments not one that is maxed out with no where to go.

[Steve House]

Originally Posted by Pete Cofrancesco

.... I now can see that ATT822 is designed to be used close up, capturing a person's voice and the lower sensitivity combined with the built in wind screen makes it an advantage, reducing the pops of speaking, but those characteristics don't lend themselves to recording at a fixed location that isn't close to the source.

Btw, I'm not saying its a bad or noisy mic, its just too cold for what I need it to do, recording live events at a distance. In a perfect world, the person on stage would be properly miced or know how project their voice, but that's often not the case so its better for me to have a mic that has to extra sensitivity in reserve to use at those moments not one that is maxed out with no where to go.

Actually ALL mics are designed to be used close up, with the exception of parabolic "spy mics." Even a top-shelf long shotgun like the $2600 Neumann KMR82, even when used on a quiet soundstage, starts to suffer when the mic-to-subject distance gets out to 6 to 8 feet or so. If your quest is for a mic you can have with the camera at the back of the audience while shooting a person speaking in a normal voice on stage 20 or 30 feet away, that will record his speech in usable clarity, I'm sorry to tell you it just ain't gonna happen - the fundamental laws of the physics of acoustics dictate that such a microphone simply cannot exist. You would be better off concentrating on how to insure the stage is properly mic'ed - either put a wireless on the speaker, place a mic on the podium, put a PZM on the speaker's table if one is being used, something that lets you close-mic the speaker as much as possible.

Remember that a mic with a reserve of sensitivity will have increased pickup of the audience shuffling their feet, sound reflections from the walls and ceiling, etc, as well as the speaker's voice - you're boosting the bad with the good, canceling out the benefits of the increased sensitivity.

I have a hard time making sense of the sensitivity specs because each manufacture lists them at different db/voltage, so I've given up trying to compare them.

The more sensitive the mic, the higher the output signal voltage in response to a sound at some particular level. It's possible to compare specs if you remember that the sensitivity is represented as output signal strength, in either mV or -dBV, when the mic is exposed to a standard reference sound pressure level of 1 Pascal (Pa). That corresponds to a "loudness" of approximately 94dB SPL. The more millivolts output or the less negative the dBV, the more sensitive is the mic. Translating the voltages on the mics Mike listed to dBV, the 822's 5.6mV translates to -45dBV, the Oktava's 10mV is -40dBV, and the BP4029's 31.6mV is -30dBV. The industry favourite interior boom mic, a Schoeps CMC641, is rated at 14mV/Pa which is the same thing as -37dBV/Pa. Hope this helps, they're not as arcane as they may appear at first glance. There's a handy converter page online at Microphone Sensitivity.

[Pete Cofrancesco]

Originally Posted by Steve House

Actually ALL mics are designed to be used close up, with the exception of parabolic "spy mics." Even a top-shelf long shotgun like the $2600 Neumann KMR82, even when used on a quiet soundstage, starts to suffer when the mic-to-subject distance gets out to 6 to 8 feet or so. If your quest is for a mic you can have with the camera at the back of the audience while shooting a person speaking in a normal voice on stage 20 or 30 feet away, that will record his speech in usable clarity, I'm sorry to tell you it just ain't gonna happen - the fundamental laws of the physics of acoustics dictate that such a microphone simply cannot exist. You would be better off concentrating on how to insure the stage is properly mic'ed - either put a wireless on the speaker, place a mic on the podium, put a PZM on the speaker's table if one is being used, something that lets you close-mic the speaker as much as possible.

Remember that a mic with a reserve of sensitivity will have increased pickup of the audience shuffling their feet, sound reflections from the walls and ceiling, etc, as well as the speaker's voice - you're boosting the bad with the good, canceling out the benefits of the increased sensitivity.

Most live events I rarely know what's coming. So in an auditorium I have one mic at the back pointed above the stage where the speakers generally are located, and the other mic up by the stage. For example, I recently filmed a dance number where each of the performers stands up and says something. They had only set up one mic in the center of the stage so it was hard to hear the majority of them. In this case, I crank up the stage and or camera mic gain. does it magnify all the other noise? It sure does but the parents will be able to hear their son or daughter. Another situation the MC was standing to far from the mic. I can't stop the performance and tell them to speak up or move closer to the mic. These things happen all the time with non professional productions, so I have learned to make the best of the situation I'm given and in my experience a more sensitive mic gives me the ability to get something rather than nothing. I would love to be able to plug into their board and get direct feed for the music and mic'ed people but I had too many problems with that.

The more sensitive the mic, the higher the output signal voltage in response to a sound at some particular level. It's possible to compare specs if you remember that the sensitivity is represented as output signal strength, in either mV or -dBV, when the mic is exposed to a standard reference sound pressure level of 1 Pascal (Pa). That corresponds to a "loudness" of approximately 94dB SPL. The more millivolts output or the less negative the dBV, the more sensitive is the mic. Translating the voltages on the mics Mike listed to dBV, the 822's 5.6mV translates to -45dBV, the Oktava's 10mV is -40dBV, and the BP4029's 31.6mV is -30dBV. The industry favourite interior boom mic, a Schoeps CMC641, is rated at 14mV/Pa which is the same thing as -37dBV/Pa. Hope this helps, they're not as arcane as they may appear at first glance. There's a handy converter page online at Microphone Sensitivity.

Yes, this is what I need to know. Thx.

[Steve House]

Originally Posted by Pete Cofrancesco

Most live events I rarely know what's coming. So in an auditorium I have one mic at the back pointed above the stage where the speakers generally are located, and the other mic up by the stage. For example, I recently filmed a dance number where each of the performers stands up and says something. They had only set up one mic in the center of the stage so it was hard to hear the majority of them. In this case, I crank up the stage and or camera mic gain. does it magnify all the other noise? It sure does but the parents will be able to hear their son or daughter. Another situation the MC was standing to far from the mic. I can't stop the performance and tell them to speak up or move closer to the mic. These things happen all the time with non professional productions, so I have learned to make the best of the situation I'm given and in my experience a more sensitive mic gives me the ability to get something rather than nothing. I would love to be able to plug into their board and get direct feed for the music and mic'ed people but I had too many problems with that...

I hear ya, I fully understand the compromises necessary, the reality that something is better than nothing. Still, when I hear sound that's distant, hollow sounding and echo'y, full of distracting room noises, etc, I cringe. Did you see the recent audition programs for the new season of "So You Think You Can Dance?" The lobby interviews with the contestants and especially the on-stage post-audition interviews of the contestants by the judges demonstrates the sound quality that I keep hoping to hear in event videos. For better or worse, theatrical film and broadcast radio and TV have set the bar as to what an audience expects to hear when they watch any video, regardless of its source. If you're shooting for pleasure, shooting your own kid's school performances, for example, it's not so critical - if it's not perfect, the only one you disappoint is yourself and the technical production values probably aren't so important anyway, compared to the memories you're recording. And there's nothing wrong with that. But if you're shooting for money you've got to keep aiming at that higher bar and try to figure out how not to have to live with compromise. It's certainly a unenviable position for a freelance videographer.

[Jonathan Plotkin]

Originally Posted by Pete Cofrancesco

All of my equipment can't utilize the ATT822 stereo capability and only see it as a mono, that includes my Sony Z1u, Fx1, and Zoom H4 digital recorder.

I bought an AT822 off of Ebay and it also only seems to record mono. Anyone have any ideas about this? Thanks!

[Paul R Johnson]

Don't forget the output on the AT822 is non-standard. It uses the normal 3 pin xlr, but has an unbalanced output, with the left and right outputs on pins 2 and 3, ground as usual on 1.

When you use a standard xlr-xlr cable then what you actually record is the output of the two capsules BUT with reverse polarity, so it does very odd things to the output. It orginally came with an xlr to two 3.5mm plugs and an xlr to one 3.5mm three circuit 'stereo' type plug. I have seen people who have lost the cable use these mics, not even knowing they are stereo!

Also worth noting that what you have is a compact quite decent sounding stereo mic - but it isn't remotely designed to be a shotgun style - record at a greater distance mic. Stuck on a stand in front of a choir, it works really well - it's designed for big, loudish sound sources. If you want to record what is in front of the camera, I'd probably use the one in the camera, rather than one of these.

[Pete Cofrancesco]

Originally Posted by Steve House

I hear ya, I fully understand the compromises necessary, the reality that something is better than nothing. Still, when I hear sound that's distant, hollow sounding and echo'y, full of distracting room noises, etc, I cringe. Did you see the recent audition programs for the new season of "So You Think You Can Dance?" The lobby interviews with the contestants and especially the on-stage post-audition interviews of the contestants by the judges demonstrates the sound quality that I keep hoping to hear in event videos. For better or worse, theatrical film and broadcast radio and TV have set the bar as to what an audience expects to hear when they watch any video, regardless of its source. If you're shooting for pleasure, shooting your own kid's school performances, for example, it's not so critical - if it's not perfect, the only one you disappoint is yourself and the technical production values probably aren't so important anyway, compared to the memories you're recording. And there's nothing wrong with that. But if you're shooting for money you've got to keep aiming at that higher bar and try to figure out how not to have to live with compromise. It's certainly a unenviable position for a freelance videographer.

I hear where you are coming from and for what's worth, I know the proper technique and use it when I'm payed to do my documentary work or weddings. In those situations I have more control and can properly position mics and use lavaliere mics. Again I agree when these live performances don't properly mic or light their performance it ends up reflecting poorly on me, and I don't use them in my demo reels.

Originally Posted by Paul R Johnson

Don't forget the output on the AT822 is non-standard. It uses the normal 3 pin xlr, but has an unbalanced output, with the left and right outputs on pins 2 and 3, ground as usual on 1.

When you use a standard xlr-xlr cable then what you actually record is the output of the two capsules BUT with reverse polarity, so it does very odd things to the output. It orginally came with an xlr to two 3.5mm plugs and an xlr to one 3.5mm three circuit 'stereo' type plug. I have seen people who have lost the cable use these mics, not even knowing they are stereo!

Also worth noting that what you have is a compact quite decent sounding stereo mic - but it isn't remotely designed to be a shotgun style - record at a greater distance mic. Stuck on a stand in front of a choir, it works really well - it's designed for big, loudish sound sources. If you want to record what is in front of the camera, I'd probably use the one in the camera, rather than one of these.

I'd imagine paired mono mics would be a better solution for video cameras with 2 xrl inputs. Although I'm not really clear what the difference is between mono, paired mono, and true stereo. I'd imagine stereo give more dimension but does paired mono do the same? I saw some talking about it in another thread.

Going back to what I said earlier its often not made clear to the buyer these important details. For a long time I thought stereo mic ok plug in and get stereo. hmmm its not working???? better use my good old stardard mono mic because I can't figure out why its not working.

[Jonathan Plotkin]

Originally Posted by Paul R Johnson

Don't forget the output on the AT822 is non-standard. It uses the normal 3 pin xlr, but has an unbalanced output, with the left and right outputs on pins 2 and 3, ground as usual on 1.

Hmmm, I bet that's the problem. I need to go back and check what cable I'm using... Thanks!
-JP