Making all audacity output the same volume

Hi. First time posting here so apologies if this question has been asked before. I have tried tp search around the forums but the question I have doesn’t seem to have been answered. There are answers about “normalising” or “compressing” tracks te level the volume across the whole file but that’s not what I need.

I am making some backing track mp3’s for use with my guitar and the whilst I don’t need the volume changed on any specific part of a single file what I do need is that the mp3 files that are output from Audacity are ll the same volume. This is so I don’t have to continually change amp or guitar volumes because each backing track file is a different volume.

It’s like normalising the volume across all the tracks on a music CD so no one track is louder than another.

I hope that makes some sense. Is this possible with Audacity?

Yes … Loudness Normalization - Audacity Manual

alternatively … MP3Gain - Wikipedia

Hi, thanks for the quick response.

I have just tried the Loudness normalisation with a couple of tracks and whilst closer together one still sounds slightly louder than the other?

I’ll mess around with and see what I can do. Maybe one was recorded to quietly in the first instance!

Yeah… MP3Gain can batch-process. Also ReplayGain or Apple Sound Check.
The advantage of these is that by default they check the peaks so they don’t push the peaks into clipping/distortion. (Some quiet sounding-tracks won’t hit the loudness target, but that’s usually better than distortion…)

With Audacity’s Loudness Normalization you have to check that “manually”, and it depends on what you chose for a loudness target.

For future reference -

Normalization is linear. It makes ONE volume adjustment, like adjusting the volume control before playback starts.

Dynamic compression is non-linear. In general, it makes quiet parts louder and/or loud parts quieter. In practice, usually the loud parts are “pushed-down” and then make-up gain is often used to make “everything louder”. Limiting is a kind of fast-compression that pushes-down the peaks, and automatic volume control (or automatic gain control) is a slow-kind of compression.

Regular normalization is peak normalization. It adjusts the volume so the peaks are 0dB (1.0 or 100%). But the peaks don’t correlate well with perceived loudness. Most commercial music is normalized/maximized and that includes lots of quiet-sounding songs. Another application calls it “maximizing” which is a better English word, but “normalize” is the proper audio terminology.

Loudness Normalization is “loudness matching”. It uses an advanced algorithm to determine and target a perceived loudness. In order to do that, many/most songs are reduced in volume because so many quiet-sounding (or average-sounding) songs are already peak normalized and they can’t be boosted without clipping.

All of the popular streaming services use loudness normalization.

Broadcast stations use compression to make everything constantly loud and as a side-effect that makes everything about the same volume.

With only a few tracks, that’s usually done by-ear. The algorithms aren’t perfect. And sometimes there are tracks that are intentionally quieter or louder. Of course, almost all commercial productions have some limiting & compression so that gives them more flexibility.

ReplayGain or MP3Gain is good for your entire music library, and there’s an option of “album gain” which adjusts the album as a whole, retaining the original difference between loud & quiet tracks.