[lazybum]

Hi i'm a bit confused about how clipping is related to gain and playback volume.
 
Ok so i understand that if a signal goes above 0db clipping will occur? So to prevent clipping gain is usually lowered to give more headroom?
Then how does playback volume fit into the equation?
 
When the gain is lowered, volume is lowered. But its possible to pump up the playback volume such that it sounds as loud as the original, but clipping no longer occurs. Why is this so? Whats the difference between gain and playback volume?
 
Will a very low gain but high playback volume sound different from a normal gain and normal playback volume, if the loudness is matched?

 

[Soaa-]

Well that would depend where the clipping occurs. If the clipping is in the headphones, then you're just driving your headphones too loud and you're damaging your ears.
 
If the clipping is already in the recording, there is nothing you can do about it.

 

[brconner]

 
Clipping doesn't necessarily occur at 0dB. Clipping has to do with the amount of "headroom" an amplifier has and the physical capabilities of a speaker. 
 
Let's say I have amplifier A thats powered from a single 9V battery and amplifier B that runs off of an 18V battery. Amplifier B has a much higher headroom because it can output a signal thats bigger than the one out of amplifier A. So lets say that I have an identical signal going into these amplifiers and the size of the signal keeps increasing. Amplifier A will start to distort before Amplifier B. 
 
To answer your last question,  there will not be a loudness difference between the two so long as the amplifier can output that signal. It could sound different though and I'll try to explain why.
 
Lets say we're trying to record someone singing, so we have a microphone plugged into a sound mixer and then the output of the sound mixer is going to some type of recording device. The signals coming from a microphone are very very small, so it needs to be amplified to a workable level. This is accomplished by sending the signal through a "gain stage". The purpose of this stage is to amplify or attenuate the signal so that its as loud as it can be without clipping. You might ask, "Well why not just have a lower gain setting so its definitely not going to clip?"
 
Whenever a signal goes through electronic equipment noise will be added, period. Keeping the signal as loud as it can means that the sound you want is much much louder than the noise so you don't notice the noise. Gain stages are designed to add as little noise as possible. Noise is just compounded into the signal as it goes through  the equipment, so that first stage needs to be really quiet since the noise will also get amplified through the system.
 
After the gain stage the signal may be EQ'ed or have other signal conditioning. Finally we get to the "playback volume", well right now the signal is probably louder than we need it to be, so we use the volume to adjust the sound to however loud we want it to be in the mix.
 
By keeping the signal as loud as possible in the early stages we have reduced the amount of noise that will get into the final mix after it's volume has been adjusted.
 
Hopefully this clears up your questions, I tried to simplify as much as I could so if I didn't explain something clearly let me know and I'll try again haha.

 

[lazybum]

Quote:

Well that would depend where the clipping occurs. If the clipping is in the headphones, then you're just driving your headphones too loud and you're damaging your ears.
 
If the clipping is already in the recording, there is nothing you can do about it.

Ok I was more interested in clipping at the source. Should have clarified it in the op. But if the clipping is already in the recording, its possible to lower the gain of the song?
 
Quote:

 
Clipping doesn't necessarily occur at 0dB. Clipping has to do with the amount of "headroom" an amplifier has and the physical capabilities of a speaker. 
 
Let's say I have amplifier A thats powered from a single 9V battery and amplifier B that runs off of an 18V battery. Amplifier B has a much higher headroom because it can output a signal thats bigger than the one out of amplifier A. So lets say that I have an identical signal going into these amplifiers and the size of the signal keeps increasing. Amplifier A will start to distort before Amplifier B. 
 
To answer your last question,  there will not be a loudness difference between the two so long as the amplifier can output that signal. It could sound different though and I'll try to explain why.
 
Lets say we're trying to record someone singing, so we have a microphone plugged into a sound mixer and then the output of the sound mixer is going to some type of recording device. The signals coming from a microphone are very very small, so it needs to be amplified to a workable level. This is accomplished by sending the signal through a "gain stage". The purpose of this stage is to amplify or attenuate the signal so that its as loud as it can be without clipping. You might ask, "Well why not just have a lower gain setting so its definitely not going to clip?"
 
Whenever a signal goes through electronic equipment noise will be added, period. Keeping the signal as loud as it can means that the sound you want is much much louder than the noise so you don't notice the noise. Gain stages are designed to add as little noise as possible. Noise is just compounded into the signal as it goes through  the equipment, so that first stage needs to be really quiet since the noise will also get amplified through the system.
 
After the gain stage the signal may be EQ'ed or have other signal conditioning. Finally we get to the "playback volume", well right now the signal is probably louder than we need it to be, so we use the volume to adjust the sound to however loud we want it to be in the mix.
 
By keeping the signal as loud as possible in the early stages we have reduced the amount of noise that will get into the final mix after it's volume has been adjusted.
 
Hopefully this clears up your questions, I tried to simplify as much as I could so if I didn't explain something clearly let me know and I'll try again haha.

Thanks that helped a lot. So the reason why we do not set the lowest gain possible and max the volume instead to reduce noise? Because "playback volume" amplifies everything including noise?

 

[Soaa-]

If the clipping is occurring on the recording, then all sonic information that's beyond 0dB is lost forever. You can't recover it. Even if you lower the gain, it'll still be distorted.

 

[brconner]

 
 
Quote:

Ok I was more interested in clipping at the source. Should have clarified it in the op. But if the clipping is already in the recording, its possible to lower the gain of the song?

 
If there's already clipping then there isn't anything you can do to fix it with the gain or playback volume.
 
 
 
Quote:

Thanks that helped a lot. So the reason why we do not set the lowest gain possible and max the volume instead to reduce noise? Because "playback volume" amplifies everything including noise?

 
Yes, that is whats most commonly done. There are some recording situations were a low gain is required because of the dynamic range of the source. Classical music for example can be extremely dynamic. What that means is there are really quiet parts and then there are really really loud parts. So the gain has to be set low so that the loud sections don't clip. Thats why classical music is often times so much quieter than other recordings. Jazz is another genre that can also be extremely dynamic as well.