Something like ReplayGain would help.
http://replaygain.org/
Only works with mp3 and only with certain audio players, such as foobar2000. No idea what else though, but I know it's far from universal.

Does exactly that though.

For what OS?

Thanks for the replies.

mp3gain is fantastic, except some of my tracks get really badly distorted when I turn them up. For example I have a track which is about 84db and want to turn it up to about 96db, but making that big a change distorts it really badly. Is there any way to avoid this?

And dvdhawk, is "OS" an abbreviation for operating system? I'd ashamedly have to admit I don't even know what an operating system is. I have Windows XP if that's relevant?

"I have a track which is about 84db and want to turn it up to about 96db, but making that big a change distorts it really badly. Is there any way to avoid this? "

Leave it at 84db and turn your amp up?

It's meant to introduce a soft limiter into the chain when adding too much volume.
ReplayGain however is designed to level tracks to it's own standards which have plenty of headroom - setting your own values will lead to distortion.

The way that mp3s are normally made louder is through use of compressors and limiting.

Digi_Snax

Yes, OS means Operating System, which in your case Windows XP is your Operating System.

I just wanted to know so I knew where to start looking. I'll get back to you ASAP if you can answer a couple questions for me.

Are these homegrown tracks or someone else's professionally recorded tracks ?

When you get the distortion you're talking about, is it present the whole way through the track or just the loud parts of the song?

Codemonkey, I am illiterate when it comes to technical talk about computers, or sound related things. I know your post wasn't very technical, but it was to me, ha.

I'm just a guy who likes to record some music as a hobby, and unfortunately has to deal with computers to do this properly.

dvdhawk, these are homegrown tracks that I recorded in Audacity and exported as mp3's. Unfortunately the components of my tracks (beat, vocals, overdubs) vary in volume from track to track, which is where I run into problems with arranging them as an album. Also, some of them are as low as 82db, which is far too quiet.

I've found that if I now adjust the sound levels in Audacity, and export the track again, it has the same effect as adjusting the volume of the original mp3's. That is to say that they too distort at the same volume.

The distortion happens mostly at the loud parts of tracks (overdubs for example), but with a couple of tracks it happens more or less throughout, even when the original beat is the only sound present.

Right now I've got all my tracks at roughly 90db after deleting some overdubs, but I'd really like to get them up to about 95-96db.

Well, I'll break it down a little.

You've seen Audacitys blue lines? That is the signal. The grey area it fills is the area it *can* fill. When the blue tries to go past the top, it causes the distortion. What a limiter does it blocks the signal from going over a set level.
Hard limiters basically turn what would be a peak into a flat line, soft limiters are a little more curved around the edges.
Compression is another form of this but which doesn't flatline the signal as much as simply squash it down a little.

Anyway...
ReplayGain will add the trackgain/albumgain values to the track's play level - whatever you're trying to play is amplified - and the aforementioned grey area (better known as headroom) stays the same height - while the blue area (the signal) is boosted - meaning that the previously just-under-distorting levels are now clipping.
[Note: What Replaygain is designed for is to turn down loud commercial songs to add headroom - not the other way around. Which is why you get the distortion.]

To fix the clipping problem, compression is usually employed. It starts with "Squash the errant peaks to allow mild boost" and gradually gets to "Smash anything resembling dynamics out in order to get close to commercial songs". To add 16dB to a track, I think you're looking at "let the speakers catch their breath".

Ah, I see. Thanks for the break down.

I noticed that when I apply the gain to my tracks in MP3Gain, it notes whether or not the tracks have been clipped. I now know what that means thanks to your breakdown.

But I now must ask, what is the effect clipping? Does it effect the sound quality or remove certain sounds from the track? I didn't notice any difference in the tracks of mine that were clipped (at least half of them), but I most definitely do not have an expert ear, or even good headphones for that matter.

So if I understand correctly, MP3Gain applies compression to a point, but is eventually unable to when the increase in gain gets to a certain level, and this results in the distortion?

Unfortunately, digital audio doesn't overdrive nicely like analog tape would. If you clip the inputs of a digital recorder it makes ugly sounding waveforms with squared off tops and bottoms - which sound terrible. (can you zoom in real close on the waveforms with your software?) Digital audio establishes a numerical level it doesn't want to go above - which a standalone recorder would refer to as Zero.

To use your numbers as an example lets call that 'zero' level 100dB. A lot of software will take a quick scan of the song to find the one loudest waveform. So, if you have an 18dB spike somewhere in the song (which is REALLY easy to do if you're not careful) it will make the rest of the song at 82dB - so it can allow for that one single 18dB spike that will hit that max level at 100dB. That spike needs compressed and/or limited to settle it back into a volume more compatible with the rest of the music. Sometimes that takes away from the musicality of it, but you have to decide how much you're willing to trade off to get the volume.

I hope that makes sense.

Good luck!

I doubt mp3gain actually applies any compression.

I know that in foobar2000 you can add a compressor to the output effects (along with crossfaders, etc) but as far as I'm aware Replaygain/mp3gain only instruct the player to multiply the height of the mp3 signal by some value and it lets the player handle any additional steps.

Clipping: Imagine the curve of a hill. It goes up, levels off, goes down. When that hill is clipped, it goes up to a point, goes flat, takes a sharp turn and goes down again.
The result? Distortion.

I daresay there are numerous lengthy pages about distortion, compression, limiting, and loudness wars. Should you care to get into it then you should be able to find plenty of material.

I advise you just accept that just adding volume to (amplifying) the signal can distort it, compression can be used to minimise peaks of audio (though this is a very quick summary), and limiting can also be used - but usually lightly because it sounds terrible when used in large amounts.

Ok, cheers for the info, guys. I think I understood all or most of that.

dvdhawk, yes you can zoom in on the waveforms in the software I use. And just having a look at a track now I noticed that the waveforms in my instrumental tracks are filling the tracks from top to bottom, whereas the vocal tracks only fill half at most.

I also noticed that the program I'm using has a compressor effect.

Now I have one more question (at least I hope it's the last)...If I apply the compressor to my instrumental tracks, and then export my tracks as mp3's again, should I then expect to be able to increase the gain of the mp3's further, without distortion?

Ok ok, I just tried applying this new theory and it wasn't the miracle solution I'd hoped for. I finally accept the fate of my tracks to be stuck on 90db. At least I'll know for next time to make sure my vocals are recorded at a higher volume. I also learned a thing or 2 in this thread (I hope), so thanks again guys.

Have you tried importing one of your undistorted finished 2-track mixes back into Audacity in a new session and looking at the waveforms after they're all combined? It might shed some light on where the highest volume spikes are in your completed song. You might be surprised. Sometimes it's the sounds you least expected that spike it. If possible zoom waaaaaay in to look at individual waveforms at the spike so you can see the shape. If you overshot the maximum level somewhere along the way the highest peaks and valleys will be flattened like this ___/ rather than the normal curvy or jaggy waveforms.

I'm not familiar with your Audacity software, but I assume it has some audio compression plug-ins available in it somewhere.

Then try using a little bit of audio compression and/or audio limiting to beef up your stereo mix.

Audio compression and limiting are the way to that thickness associated with commercial albums. But as you limit the dynamics you might not like how it affects the purity of some tracks. Or you may love it. You'll have to experiment, it's the only way you'll get the hang of it. If you can't make any sense of it let me know - I'll try to walk you through it.

If Audacity has a "Normalize" function use it last. It guarantees that your loudest waveform in your track is at the maximum volume digital will allow and brings the rest of the song up proportionally - Again, not without it's audio artifacts.

Like Codemonkey I am not a big fan of over-compressing the audio. It becomes very un-musical when it's overdone.

Since you're new to this, another thing you need to be aware of is this - during this whole process - you may see the word "Compression" used in two entirely differents ways. It's important that you don't confuse audio compression with the type of compression mp3s (and other computer files) use to squash file sizes down.

And after you're done tracking & mixing and you're making your mp3s you might see the word compression in the settings where you make adjustments to things like bit/rate and amount of file compression for streaming. This is a very different type of compression that can also make or break your finished product.

I know this thread has taken a tangent from your original post, but I think you need to fundamentally change the way you mix the tracks and change the way you look at output level to get the results you're looking for. You could buy expensive professional CD authoring software to tweak track volumes so the playlist doesn't have radical differences in volume from song to song. But even with the pro software I use, I can't push the levels beyond a certain point without distortion. This software will help you find that maximum point, but the songs have to be well produced to get the best consistency. Again, I think it's the uncontrolled peaks within the song that are holding you back.

Keep with it and your technique keep improving. Hopefully you'll learn something everytime you do it and get better with each song you do.

Also, Audacity does have an amplify funciton. I believe it uses that instead of normalise and defaults to the value that would normalise the track. You could knock a little (2dB say) off the default and amplify your vocal track, or just add to the gain of the track in the mixer.

I'm just gonna let this album go at 90db.

But again, these last posts are helpful and I will certainly keep all this in mind in future. I will also look for you guys on here if I need advice with these things in future. Maybe I'll just bring this thread up again.

The thing is that I wrote this whole album (16 tracks) over a long period, then recorded them all over another shorter period, and have now been editing them all over the last week or 2. It's exhausting and frustrating, and I am well and truly over it.

However, since I have no written material ready to record at the moment, and now have more opportunity to record, I will get in the habit of doing 1 track at a time, from start to finish. This way I can put more focus into polishing off my tracks.

But again, thanks for all the information and advice. I've certainly learned a thing or 2 along the way, and will put all that I've learned into practice in the future.