Understanding culmative audio levels

JHendrix wrote on 7/12/2005, 1:34 PM
If i add an insert FX to a track that is set at -2 dB and want to send the tracks audio to the insert effect. What level would I set the insert send to maintain same output volume of tracks audio


Im trying to understand the formula for how these add together instead of guessing

Comments

bgc wrote on 7/12/2005, 3:18 PM
I'm a little confused in that track FX don't really have sends, but given that:

Do you want to preserve the level or the perceived loudness?

If it's digital dBfs level then one simple "check" is to solo the track and see what level in dBfs of the track is reaching the master buss (assuming that you've also bypassed any fx on the master buss). Then add your track effect and adjust the send to the same level. There's no real "fixed" amount because in general the track effect is going to modify the signal and change the digital levels.

If you want to preserve the loudness this is even harder because EQ or compression or other effects will change the signal in ways that affect the loudness (which isn't necessarily related to digital level, though often times more level is louder).

I know that is kind of confusing, but the issue is complicated and I generally add the track effect and then modify the track effect parameters until "it sounds right". If it's too loud I just generally adjust the track volume.

B.
JHendrix wrote on 7/12/2005, 4:33 PM
I get what your saying but INSERT FX do have sends from the track, thus the confusion over levels when using 1 2 3 or more insert FX
bgc wrote on 7/13/2005, 7:01 AM
Sorry, I was thinking Track FX and not the global FX which have a separate send from each track (I call them Buss FX, even though that's a totally incorrect name).

If that's the case, then the same Master Buss solo check trick will work. It's also the same in that different FX will have different impacts on loudness.

What I do is adjust the send until I get the desired amount of effect and then readjust the volume on the track to make it fit back in the mix. It's really a listening thing unique for each situation and not so much a "if I send -15 dB to the effect I need to lower the volume by 2 dB".

It's like some of the old compressors with just two knobs. The way you use them is to turn the two knobs until it sounds right.
B.
JHendrix wrote on 7/13/2005, 8:03 AM
I agree my friend and thats how I usually do it. This is more of a technical question

Like: Track Volume 0 = 0
ADD Insert FX and set send to 0 as well = ? for both

Would it be 2x0?
bgc wrote on 7/13/2005, 9:00 AM
For a mono track set to 0dB and then sending 0dB to an assignable effect (if it's gain is 0dB) will give you +6dB (or twice the level).
You probably know this but converting 2 times or double the level to dB is:
20*log10(2) = 6.02 dB.

You can test this by putting a full scale tone on a track with volume set to 0dB.
Create an assignable effect that is the Sony Volume plugin set to 0dB of gain and then send the track to the volume effect at 0dB.
The resulting output at the Master Buss will be 6dB or twice the level.

So if you want the level of that original track to be the same as before you did the effect send, you need to lower the track volume by -6dB.

JHendrix wrote on 7/13/2005, 12:45 PM
Thanks!