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Gear / Technical Help => Microphones & Setup => Topic started by: obsidian on January 11, 2018, 09:36:52 PM

Title: Self-noise Performance
Post by: obsidian on January 11, 2018, 09:36:52 PM
I am looking at a mic that has the SPL that I like but at a higher self-noise performance (27dBA). Is this "too noisy" for a mic used for recording concerts or does the surrounding crowd kind of negate this? I would love to have some advice in this.
 :shrug:
Title: Re: Self-noise Performance
Post by: EmRR on January 11, 2018, 10:03:29 PM
For noisy shows, you'll probably never notice that.  For classical or sparse attentive jazz gigs, you will. 
Title: Re: Self-noise Performance
Post by: obsidian on January 11, 2018, 10:57:33 PM
For noisy shows, you'll probably never notice that.  For classical or sparse attentive jazz gigs, you will.

That's what I was thinking. I usually tape bands like Deep Purple and what not ... Thanks for your opinion.
 :guitarist:
Title: Re: Self-noise Performance
Post by: goodcooker on January 12, 2018, 10:34:28 AM

For an audience recording - especially a rock and roll recording -  the noise floor of the environment - crowd moving, chatter, HVAC etc - will far surpass that self noise number.

The only way it may backfire on you is if you record at crazy low levels and have to amplify considerably after the fact - example - low volume quiet song in the middle of a loud show - you were running levels conservatively to keep from peaking on the loud pats and now have to amplify (add gain) to the quiet tune - if you add 40 dB you amplify that self noise by the same amount which could become noticeable if the program material is quiet.
Title: Re: Self-noise Performance
Post by: obsidian on January 12, 2018, 11:42:11 AM

For an audience recording - especially a rock and roll recording -  the noise floor of the environment - crowd moving, chatter, HVAC etc - will far surpass that self noise number.

The only way it may backfire on you is if you record at crazy low levels and have to amplify considerably after the fact - example - low volume quiet song in the middle of a loud show - you were running levels conservatively to keep from peaking on the loud pats and now have to amplify (add gain) to the quiet tune - if you add 40 dB you amplify that self noise by the same amount which could become noticeable if the program material is quiet.

THANK YOU!  I did not think about that. I am a "paranoid" taper who does tend to record on the low side. Thanks for the input. That really helps.
Title: Re: Self-noise Performance
Post by: Gutbucket on January 12, 2018, 01:24:52 PM
^
Some low level hiss during quiet moments is far better than clipping distortion during the loudest parts.  Just right is Goldilocks, but too low is safer than too hot.

For an audience recording - especially a rock and roll recording -  the noise floor of the environment - crowd moving, chatter, HVAC etc - will far surpass that self noise number.

^this.

Quote
The only way it may backfire on you is if you record at crazy low levels and have to amplify considerably after the fact - example - low volume quiet song in the middle of a loud show - you were running levels conservatively to keep from peaking on the loud pats and now have to amplify (add gain) to the quiet tune - if you add 40 dB you amplify that self noise by the same amount which could become noticeable if the program material is quiet.

No.  Amplification afterwards does not change the relationship between the self-noise of the mics, the noise of the rest of your signal chain (preamp, recorder, ect), and the noise-floor of the environment in which the recording was made.  You are simply amplifying everything together as you mention - raising the noise floor of the recording by the same amount as the music.  The noise-floor of the recording is still going to be dominated by the noise-floor of the environment in which you are recording in almost all cases, even during quiet songs.   Yes you may suddenly notice noise during those quieter parts after amplification, but it's just that during those quiet songs you can much more easily hear the noise of the room, which will still be louder than the self-noise of the microphones in almost all live music environments. 
Title: Re: Self-noise Performance
Post by: obsidian on January 12, 2018, 01:40:05 PM
^
Some low level hiss during quiet moments is far better than clipping distortion during the loudest parts.  Just right is Goldilocks, but too low is safer than too hot.

For an audience recording - especially a rock and roll recording -  the noise floor of the environment - crowd moving, chatter, HVAC etc - will far surpass that self noise number.

^this.

Quote
The only way it may backfire on you is if you record at crazy low levels and have to amplify considerably after the fact - example - low volume quiet song in the middle of a loud show - you were running levels conservatively to keep from peaking on the loud pats and now have to amplify (add gain) to the quiet tune - if you add 40 dB you amplify that self noise by the same amount which could become noticeable if the program material is quiet.

No.  Amplification afterwards does not change the relationship between the self-noise of the mics, the noise of the rest of your signal chain (preamp, recorder, ect), and the noise-floor of the environment in which the recording was made.  You are simply amplifying everything together as you mention - raising the noise floor of the recording by the same amount as the music.  The noise-floor of the recording is still going to be dominated by the noise-floor of the environment in which you are recording in almost all cases, even during quiet songs.   Yes you may suddenly notice noise during those quieter parts after amplification, but it's just that during those quiet songs you can much more easily hear the noise of the room, which will still be louder than the self-noise of the microphones in almost all live music environments.

I was hoping you would come on and reply to this thread. I've learned so much from your posts. Thanks my friend.
Title: Re: Self-noise Performance
Post by: Gutbucket on January 12, 2018, 02:02:13 PM
Noise is a tricky thing.

To clarify-

It really makes no difference if you increase level while recording or afterwards when you get home, unless the noise dominating the noise-floor of the recording is that of the gain-stage you are adjusting while recording (which is the preamp or input-stage of the recorder).  You are amplifying the self-noise of the mics and noise-floor of the venue by the same amount either way, and the relationship between the two does not change.