Balance between channels

[philipa53]

Hello everyone. Just started using the newest version of Audacity recently and I'm transferring all of my old vinyl to my PC. One slight issue I'm having is, as is suggested might be the case in the manual;

'basic consumer-level equipment can often record with channels unbalanced. Note that Normalize defaults to retaining the existing balance between stereo channels. To correct unwanted volume differences between left and right, uncheck "Normalize stereo channels independently".

My left channel is slightly stronger than the right. So when normalizing, I've tried with the 'normalize stereo channels independently' unchecked (which was the default setting) but the left channel remains stronger and thus the sound level is always slightly greater in the left. What am I doing wrong?

Cheers

Philipa

[kozikowski]

You do want to Normalize independently. You want the filter to work on the right without affecting the left.

Can you remember where it said that in the manual? Our postings are usually vetted by multiple people to catch errors like this.

Koz

[philipa53]

It's in the manual that saved onto my PC when I downloaded Audacity under; Basic Recording, Editing and Exporting; Step 4: Adjusting amplitude, last two lines. It made sense to me too that this box should actually be checked, so logically I tried it. However, this doesn't correct the imbalance either. Just for clarity, this isn't just a one off, it's the same on every single I put on to the deck. It's only about 3db in difference, and I guess it's that closeness that makes it all the more annoying. When I've headphones on the balance is just on my left eye!

Any further ideas about what I may not be doing right or whether Audacity simply can't correct the imbalance?

[DVDdoug]

There is a potential issue with normalizing independently... Normalizing works on the peaks. Peaks don't correspond that well with perceived loudness, and with vinyl transfers you can have a "click" in one channel that represents the loudest peak. That one "little" click becomes your normalization reference for that channel.

One way to do this (other than by-ear) is to check the RMS (or average) levels for each channel, and adjust-down the louder channel (by the dB difference) to match the RMS level of the quieter channel. The problem is... The Wave Stats plug-in for Audacity can't analyze the whole file.

SOX (FREE!!!) has a Stats "effect" that can read the RMS levels.

It's best if you start by normalize both channels independently before balancing. That gives you a starting-point to make sure the overall file is normalized/maximized after channel-balancing. Alternatively, you can match the RMS levels first and then normalize non-independently to maintain the balance.

It's also a good idea to make one big file for the whole album so that you don't mess-up the original volume relationships between the files (quiet songs remain relatively quiet, and loud songs remain relativley loud).

Or if you want a "one-click" solution, GoldWave ($50 USD) has a MaxMatch effect that maximizes (normalizes) and matches (balances) at the same time.

[philipa53]

Thanks for your replies guys. The issue is a relatively small one and from reading the manual I thought that normalizing would correct this. I'm using the click filter first so this shouldn't affect what I'm trying to achieve (any click in one channel giving a false reading) so I'm a bit at a loss as to why the 'balance' isn't being corrected.

But as a novice I'll put up with the very slight difference - maybe when I have more time, or if it becomes a real issue for me, I'll see what else is out there and take your advice. Otherwise I'm super-happy that the 'warmth' of the vinyl remains totally intact. For example if I play a track I have put onto my laptop from vinyl, and compare it to the same track on a commercial CD, I know which I prefer - no contest.

[waxcylinder]

Your workflow should be:

1) capture/record

2) remove any DC offset (if present) - use Normalize for this withount any amplitude adjustment at this stage

3) remove any clicks (Personally I use Brian Davies' ClickRepair to do this)

3) You can then Normalize processing the channels independently to bring the peak level to say -6dB

4) do all your other editing

5) raise amplitude levels to sayy -3dB with either Normalize or Amplify

6) Export production WAVs, MP3s or whatever.

See this workflow tutorial in the manual: http://manual.audacityteam.org/help/man ... ation.html

WC

[jarome]

My problem is that one channel gets clipped during the recording, so I need to manage the balance on my Mac WHILE is is recorded.
And also, in the Audacity display, which channel is the top one? That is always louder.

[DVDdoug]

on my Mac

This is the Windows sub-forum.

It's the analog-to-digital that gets clipped so you have to reduce the analog level before it's digitized. What's your set-up? Can you do that?

The left channel is on top.

Audacity now has Loudness Normalization effect that allows you to adjust the channels independently to make both channels the same loudness.

The relationship between peak and "loudness" is unknown so after that you should run the Amplify or Normalize effect before exporting to prevent clipping. (Audacity can temporally/internally go over 0dB without clipping.)

[jarome]

I am recording from Qobuz using BlackHole 16ch. They have no balance control.
It would be nice if Audacity labeled the channels
But it was probably just a defective album...

[jademan]

My problem is that one channel gets clipped during the recording...

See also, Clip Fix

I hope this helps.