Amplify settings (2) are always locked together

[rorser]

When I change one of the two Amplify settings the other changes as well, and they are always equal. Is this normal? And, the OK button grays out if I choose a positive dB amount of amplification. What is this all about please?

If I want Amplify to amplify as much as possible without clipping, why do I have to set anything? Especially, why do I tell it how much to amplify?
Confused,
Richard

[Gale Andrews]

Please read the Manual.

The two boxes are interlinked because the Amplification amount you choose determines the New Peak Amplitude (and vice-versa). Choose which box is easiest according to what you want to do. If you know you want to amplify to -1 dB you thus use the New Peak Amplitude box without having to work out the amount of change needed.

If you just want the maximum amplification without clipping, click Effect > Amplify and hit ENTER without changing any values.



Gale

[ignatz]

When I change one of the two Amplify settings the other changes as well, and they are always equal. Is this normal? And, the OK button grays out if I choose a positive dB amount of amplification. What is this all about please?

If I want Amplify to amplify as much as possible without clipping, why do I have to set anything? Especially, why do I tell it how much to amplify?
Confused,
Richard

They shouldn't typically show equal values on a random sound file. Mine don't. But if you change one by 4, the other will change by 4 in the same direction, so they are linked.

If you control one, you control the other. Operate on the one that is easiest for you to understand.

The OK button is grayed out IF choosing a certain amplification level would cause clipping.

If you want the button to appear regardless, you would have to check "allow clipping".

I think the filter analyzes the file when you first choose the filter when a file is open.

I just opened a random file in Audacity and chose the amplify effect. The readings in the boxes were 7.3 db in the top box and 0 in the bottom box. I didn't enter those settings.

My understanding is that that means that the filter is telling me that it is ready to apply 7.3 db boost and if I accept by poking OK, the new peak amplitude will be at 0 DB--the maximum without clipping.

If i try to move the slider to the right to boost to say 9 rather than 7.3, the OK is grayed out because 9 would be a clipping level (1.7 DB above 0 DB)

Suppose I wanted to leave 2 DB headroom below the O DB level. I could do any one of these three things, which all do the same thing:

1: Enter 5.3 in the top box (rather than the 7.3 suggested by the filter)

2: Enter -2.0 in the bottom box (rather than the 0 shown when I opened the filter)

3: Move the slider left until 5.3 is shown in the top box--which will of course also put -2.0 in the bottom box.

The slider is touchy and hard to adjust to .1 increments, so the best thing to do is just deal with 1 of the boxes--either choice 1 or 2 above.

There is no particular point to amplifying to the absolute max non-clipping level (O DB). I always leave 2 DB headroom. I know others use other settings.

[rorser]

Thank you Gale and Ignatz,
The reason my top and bottom numbers were identical is that I had loaded an already Amplified track!
Am I correctly assuming that if I set the Amplify setting to the same value in the max. peak (lower box) for each of my recordings, e.g., -1dB, they well all have pretty much the same volume when I play them on the same equipment?

What is the Preview button for?

And, when might one want to actually de-amplify a recording that is already at, say, -.5dB max amplitude?

Thank you so very much for your patience and support,
RIchard

[Gale Andrews]

Am I correctly assuming that if I set the Amplify setting to the same value in the max. peak (lower box) for each of my recordings, e.g., -1dB, they well all have pretty much the same volume when I play them on the same equipment?

No. The only assumption you can make is that the maximum volume will be -1 dB. Consider a classical piece that may be mostly at -10 dB or so until a cymbal clash to -1 dB at the end, and a rock track that also has a peak of -1 dB but never goes lower than -3 dB.

What is the Preview button for?

Try it to find out! It won't explode. It plays the effect with the settings you have, before you hit OK to apply the effect. By default it will only play the first three seconds of the selection, but if you click Edit > Preferences: Playback, you can make the preview length longer or shorter.

when might one want to actually de-amplify a recording that is already at, say, -.5dB max amplitude?

This is your decision, but you might want to do it in an attempt to make all files sound at similar volume (for example, you might want to de-amplify that rock track in the example above, but not the classical one).

Audacity doesn't have an explicit way of amplifying to a value that makes tracks sound "equally loud", but a rough guide is to amplify so that the light blue part of the waveform as at the same height. The light blue is the average or RMS level. This level is an approximation of how loud the audio will be perceived.

If you really want to make tracks sound equally loud, you want to try Replay Gain. In many formats like MP3, this works by giving instructions to an audio player that understands replay gain that tell it how loud to play the file (so the volume of the file itself isn't changed). This information is stored inside the file, just like artist and track details can be stored there. But for WAV, you usually have to modify the volume of the file itself.



Gale

[rorser]

>>The only assumption you can make is that the maximum volume will be -1 dB. Consider a classical piece that may be mostly at -10 dB or so until a cymbal clash to -1 dB at the end, and a rock track that also has a peak of -1 dB but never goes lower than -3 dB. <<

Great answers Gale; you obviously know your audio and Audacity.
What I was hoping to achieve is similar sound levels for background music. So, that I don't have to go running to the vol. control when something starts blaring much louder than the track that preceded it.
I think watching my RMS as you told me is the ticket for this.

Preview button

>>Try it to find out! It won't explode. It plays the effect with the settings you have, before you hit OK to apply the effect. By default it will only play the first three seconds of the selection, but if you click Edit > Preferences: Playback, you can make the preview length longer or shorter. <<

I'm not that timid Gale. I did click it but heard nothing. I think I had >3 sec. silence at the beginning so the second part of your answer was key. Thanks.

when might one want to actually de-amplify a recording that is already at, say, -.5dB max amplitude?

>>This is your decision, but you might want to do it in an attempt to make all files sound at similar volume (for example, you might want to de-amplify that rock track in the example above, but not the classical one). <<

Yeh, that is my goal. I will do just that. Is -1 dB a good max for what I am doing? I am digitizing my reel-to-reel tapes into FLAC files to play on a home Sonos unit for background/work music.

Thank you again,
Richard

[kozikowski]

Nobody in all that mentioned "Normalize" which is Amplify that sets Left and Right individually.

If you're after "flat" background volume, you can't do better than Chris's Compressor.

http://pdf23ds.net/software/dynamic-compressor/

Chris works like an FM radio station loudness processor. Ever wonder why you don't have to constantly change the volume in your car?

Both of those tools are one-click.

Koz

[rorser]

Thanks Koz,
I am not sure that "flat" is what I want. Sounds insipid. I do like to crank up my outdoor sound system and rock out while I work outdoors. I am isolated in my own little valley here in Santa Cruz, so can really go for it. It is background music in that I am not sitting between two stereo speakers in the sweet spot and actively listening. But, I do want dynamic sound.
Also, I do not care about the balance between L & R because I am always moving around in the sound field.
Might this additional info. alter your suggestions for me?
Gratefully,
Richard
Santa Cruz, CA

[kozikowski]

Then Normalize isn't going to do you any good at all, but Chris is still in there punching.

<<<If I want Amplify to amplify as much as possible without clipping>>>

Chris will produce a very significantly louder show without any apparent damage, and certainly without clipping. And to the bargain, it erases overall loudness differences between songs.

It sounds a lot like the overall theme drifting through that thread. You can go through that RMS calculation business, or you can just let Chris do it for you. His design center was to be able to listen to presentable opera in the car.

You can't listen to an operatic performance with Giuseppe sobbing over his recently deceased lover way stage up-left followed by full orchestra entrance of the Duke of Rancor and his evil guards. Can't be done in my car and I suspect I'm not alone. Either you're going to stop traffic with the Duke, or you won't hear Giuseppe whimpering into his paramour's bosoms. Chris uses look-ahead processing to even out the scenes without obviously affecting the actual performance.

Give it a shot. It's free, inexpensive, and doesn't cost anything. Apply it to a show with three or four songs in it and listen to the whole result without trying to analyze what it's doing.

Koz
Los Angeles, CA

[rorser]

What have I got to lose?
Thanks,