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- reality prompts me to scale down my reading, sorry to say
to PLers: do correct my pronunciation please
Is there a limit to how much you can use the Amplify function to raise the volume of a recording? 5-10-20-30 decibels? If there is a limit, what the options to make a recording louder past that point -- is there something else to try or would you have to re-record?
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Yes, there's a limit. The limit is "clipping" - when the wave forms reach maximum.ColleenMc wrote: ↑August 5th, 2019, 5:49 pmIs there a limit to how much you can use the Amplify function to raise the volume of a recording? 5-10-20-30 decibels? If there is a limit, what the options to make a recording louder past that point -- is there something else to try or would you have to re-record?
Audacity will show the maximum amount you can amplify when you highlight and go to Effect/Amplify. The number in the box is the max amount for that selection, where the highest peak will hit maximum. If you go past this (which there's a tick box in Audacity to allow clipping), it loses data (the stuff that went over maximum) and can cause unpleasant distortion. So don't check that box.
What I do to amplify without clipping is use Compressor. It squishes down the spikes so that you can amplify more.
One of Phil's videos on compression: http://www.youtube.com/watch?v=wJ3lOTDsN6c
My default settings are as follows:
Threshold: -13 dB (This is the volume level of the wave form where it'll start to compress. -13 is a very light compression. On other recordings, I've done as much as -23 dB).
Noise Floor: -40 dB (this is the volume of your background noise. Leave it at default.)
Ratio: 2.5:1 - 3:1 (this is how much it'll squish the spikes)
Attack: 0.2 (leave at default)
Decay: 1.0 (leave at default)
NO checks in the check boxes
After compression you can amplify more.
It is best to record at a reasonable level (it's called gain staging) so you do not have to increase or decrease the levels in post production. If you get close to LV's required levels then there is no need to increase (or decrease) levels more than 1, 2 or 3dB. Audacity is good at adjusting these amounts as previously mentioned, and you will end up with a better quality reading. If you record very low, for example, when you increase the gain by 20-30dB in Audacity the noise floor will increase as well and result in a noisier recording, and then you have to employ noise reduction which further degrades the quality.