Record 1 Mono Audio input to 2 tracks at Different Levels
- Thread starter andynick
- Start date
basspig
Veteran
Why not just do what I do and set the levels for the loudest anticipated level?
Also, do not rely on the external trim controls--they do not prevent overload, as they are downstream from the preamps. Use the attenuator menu to set levels.
Example, with -37dB rated condenser mic:
Fireworks: -8dB attenuator
Loud rock concert -17dB attenuator
Rock concert at OSHA-approved levels: -23dB attenuator
Outdoor events, including tractor pulls, equestrian, etc.: -32dB
Indoor, soft levels, conversation, no applause: -38dB attenuator
The above are guidelines. The rule that works for this camera is to leave the external levels at "5" and use the attenuators to set the gain. During the loudest sound pressure levels, the on-screen VU meters should not exceed 4 segments below the red segment. Anything higher will trigger the awful-sounding on-board limiters and believe me, you don't want to hear what they sound like.
Also, do not rely on the external trim controls--they do not prevent overload, as they are downstream from the preamps. Use the attenuator menu to set levels.
Example, with -37dB rated condenser mic:
Fireworks: -8dB attenuator
Loud rock concert -17dB attenuator
Rock concert at OSHA-approved levels: -23dB attenuator
Outdoor events, including tractor pulls, equestrian, etc.: -32dB
Indoor, soft levels, conversation, no applause: -38dB attenuator
The above are guidelines. The rule that works for this camera is to leave the external levels at "5" and use the attenuators to set the gain. During the loudest sound pressure levels, the on-screen VU meters should not exceed 4 segments below the red segment. Anything higher will trigger the awful-sounding on-board limiters and believe me, you don't want to hear what they sound like.
This works perfectly!
The reason I want two levels of recording the same source is because there's a huge variation in level and pitch of the audio I want to record.
We're training sheepdogs and sometimes, the trainer is literally whispering and at others, he's shouting at the top of his voice or (worse) whistling with a very loud, high-pitched sheepdog whistle.
I feel safer using this method (which I've used for years on other cameras) but I'll certainly play around with Basspig's suggestion too.
adamr316
Well-known member
And indeed the "two levels with the same input" trick works wonders. I first read about it in Jay Rose's awesome book "Producing Great Sound for Digital Video" and will continue using it when I am recording a mono source (which I am more than half the time).
A college professor of mine made a documentary and did not know about this technique. A lot of his interview subjects varied in speaking volume...from whispers to yelling, just like andynick is going to deal with. The camera they used didn't have any limiter circuit and they spent probably hundreds of hours in Pro Tools redrawing their digitally distorted audio. If only they knew this trick...because I'm pretty sure the camera they were using could do it.
A college professor of mine made a documentary and did not know about this technique. A lot of his interview subjects varied in speaking volume...from whispers to yelling, just like andynick is going to deal with. The camera they used didn't have any limiter circuit and they spent probably hundreds of hours in Pro Tools redrawing their digitally distorted audio. If only they knew this trick...because I'm pretty sure the camera they were using could do it.
basspig
Veteran
This info was necessary back in the days when cameras had 40 dB s/n ratio. However, the EX1 has over 90dB s/n ratio, and can easily handle everything from a whisper to a shout. The most extreme situation is a fireworks display. Not clipping the explosions, but still being able to hear the crowd and softer ambient sounds. Of course this requires thousands of watts of playback audio power, lest the amplifiers will clip badly on the explosions, but the full dynamic range is in the recording. You can run a compressor filter in post that will reduce this dynamic range so that mere mortal sound playback equipment can handle it though.
davidcheok
Member
Brilliant thread...
individual microphone attenuator settings?
individual microphone attenuator settings?
Where can I find the rating for each individual microphone? Just curious to know what the manufacturer recommends. I check the pdf's but it was not obvious to me. just trying to get a ballpark setting on the attenuator.
individual microphone attenuator settings?
Why not just do what I do and set the levels for the loudest anticipated level?
Also, do not rely on the external trim controls--they do not prevent overload, as they are downstream from the preamps. Use the attenuator menu to set levels.
Example, with -37dB rated condenser mic:
Fireworks: -8dB attenuator
Loud rock concert -17dB attenuator
Rock concert at OSHA-approved levels: -23dB attenuator
Outdoor events, including tractor pulls, equestrian, etc.: -32dB
Indoor, soft levels, conversation, no applause: -38dB attenuator
The above are guidelines. The rule that works for this camera is to leave the external levels at "5" and use the attenuators to set the gain. During the loudest sound pressure levels, the on-screen VU meters should not exceed 4 segments below the red segment. Anything higher will trigger the awful-sounding on-board limiters and believe me, you don't want to hear what they sound like.
Where can I find the rating for each individual microphone? Just curious to know what the manufacturer recommends. I check the pdf's but it was not obvious to me. just trying to get a ballpark setting on the attenuator.
The Sennheiser MKH-416 is rated "Sensitivity (free field, no load) (1 kHz) 25 mV/Pa ± 1 dB". Any idea how that translates?
EDIT
http://www.sengpielaudio.com/calculator-transferfactor.htm has a calculator for this. Looks like -32dB for the MKH-416 then. Does that sounds right?
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basspig
Veteran
This web site has a calculator that will enable you to do just that:
http://www.sengpielaudio.com/calculator-transferfactor.htm
It looks like your mic is rated at -32dB sensitivity, but that high figure is probably due to it being an "open" (no load) measurement.
A microphone sensitivity specification tells how much electrical output (in thousandths of a volt or \"millivolts\") a microphone produces for a certain sound pressure input (in dB SPL). If two microphones are subject to the same sound pressure level and one puts out a stronger signal (higher voltage), that microphone is said to have higher sensitivity. However, keep in mind that a higher sensitivity rating does not necessarily make a microphone better than another microphone with a lower sensitivity rating.
http://www.sengpielaudio.com/calculator-transferfactor.htm
It looks like your mic is rated at -32dB sensitivity, but that high figure is probably due to it being an "open" (no load) measurement.
A microphone sensitivity specification tells how much electrical output (in thousandths of a volt or \"millivolts\") a microphone produces for a certain sound pressure input (in dB SPL). If two microphones are subject to the same sound pressure level and one puts out a stronger signal (higher voltage), that microphone is said to have higher sensitivity. However, keep in mind that a higher sensitivity rating does not necessarily make a microphone better than another microphone with a lower sensitivity rating.
Something that confuses me in all this talk about the attenuators and where to set them is that this doesn't take into account the other methods of audio ENG configurations that many of us employ in the field.
For instance, I will often have a sound recordist using a Wendt X5 mixer sending mic level to the EX1. There is no way to alter the output level of the X5, nor would you want to, and although I record many different levels of audio, in order to get tone to register at -20db on the EX1 with the record level set to the requisite '5' I must set the internal attenuators to -41, which according to basspig's configurations, would be only for very quiet situations.
I am not arguing these findings, but I also use Lectrosonics wireless directly to camera and have found that to get an adequate level with the transmitter dial set to around 11 O'clock, and a Sanken COS-11 attached, and the receiver set to a more than generous -30, I must still set the camera to -41 or -47 to get the proper level I need for Final Cut and my ears...
I wish there was some easier way, because audio on betacams is much more cut and dry- output a level from one device, set input level on the other device. Simple... not so with the EX1.
For instance, I will often have a sound recordist using a Wendt X5 mixer sending mic level to the EX1. There is no way to alter the output level of the X5, nor would you want to, and although I record many different levels of audio, in order to get tone to register at -20db on the EX1 with the record level set to the requisite '5' I must set the internal attenuators to -41, which according to basspig's configurations, would be only for very quiet situations.
I am not arguing these findings, but I also use Lectrosonics wireless directly to camera and have found that to get an adequate level with the transmitter dial set to around 11 O'clock, and a Sanken COS-11 attached, and the receiver set to a more than generous -30, I must still set the camera to -41 or -47 to get the proper level I need for Final Cut and my ears...
I wish there was some easier way, because audio on betacams is much more cut and dry- output a level from one device, set input level on the other device. Simple... not so with the EX1.
adamr316
Well-known member
@truelife:
I guess Sony did it this way to maximize quality and configurability...just like the rest of the EX1. It's better that we have control over the attenuator than just "set and forget". I think the Sony defaults around to -44 and -47...it's what mine are set to now anyhow.
With my Sennheiser G2 wireless setup my receiver AF out is set to -30ish as well so that its signal is lowered (at 0 it's way too distorted). Does Lectrosonics work the same? If so then this is accurate.
Basspig's suggestions were based off a -37dB rated condenser mic. The Wendt and Lectrosonics more than likely have different output levels. If EX1 users keep the audio attenuators set to the defaults then they should be fine (much like a Betacam) but to MAXIMIZE the signal to noise ratio of the camera basspig's suggestion of not going over 5 on the gain pots and instead using the menus to set coarse level is accurate.
It's much like an audio mixer. You set the faders to Unity gain or 0 and then you set the trim knob to whatever your source audio is so that your level meters average/peak at 0dB. The trim knob in the Sony EX1 is the attenuator menu setting. And 5 on the audio knob is equal to unity fader gain. The limiter is engaged BEFORE the signal reaches the audio knob pots, not after. And in order to see the true output of the EX1's preamp you need to set the audio pots to 5. Set your levels so that they average -20 to -10dB (digital 0) and you're gold.
If it's a 1kHz tone you're using, set it so it equals -20 dB, which is broadcast quality "digital zero." -12dB is consumer quality "digital zero" and since the EX1 is the bees knees in terms of S/N ratio -20dB is where it's at...LOL!
This of course will all depend on your audio source...a mixer or a direct microphone or whatever. At least this is how I see things...am I right basspig? I hope this mixer/camera analogy helps everyone.
I guess Sony did it this way to maximize quality and configurability...just like the rest of the EX1. It's better that we have control over the attenuator than just "set and forget". I think the Sony defaults around to -44 and -47...it's what mine are set to now anyhow.
With my Sennheiser G2 wireless setup my receiver AF out is set to -30ish as well so that its signal is lowered (at 0 it's way too distorted). Does Lectrosonics work the same? If so then this is accurate.
Basspig's suggestions were based off a -37dB rated condenser mic. The Wendt and Lectrosonics more than likely have different output levels. If EX1 users keep the audio attenuators set to the defaults then they should be fine (much like a Betacam) but to MAXIMIZE the signal to noise ratio of the camera basspig's suggestion of not going over 5 on the gain pots and instead using the menus to set coarse level is accurate.
It's much like an audio mixer. You set the faders to Unity gain or 0 and then you set the trim knob to whatever your source audio is so that your level meters average/peak at 0dB. The trim knob in the Sony EX1 is the attenuator menu setting. And 5 on the audio knob is equal to unity fader gain. The limiter is engaged BEFORE the signal reaches the audio knob pots, not after. And in order to see the true output of the EX1's preamp you need to set the audio pots to 5. Set your levels so that they average -20 to -10dB (digital 0) and you're gold.
If it's a 1kHz tone you're using, set it so it equals -20 dB, which is broadcast quality "digital zero." -12dB is consumer quality "digital zero" and since the EX1 is the bees knees in terms of S/N ratio -20dB is where it's at...LOL!
This of course will all depend on your audio source...a mixer or a direct microphone or whatever. At least this is how I see things...am I right basspig? I hope this mixer/camera analogy helps everyone.
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