Q about recording levels. "Volume addtion", etc.. -ACID Product Family

Subject:Q about recording levels. "Volume addtion", etc.. Posted by: ttuskey Date:7/13/2008 3:43:55 PM I have some questions about recording levels, track and overall (master) in Acid Studio 7.0. I assume it works the same way in all or most software of this type. I've been trying to get some tracks to not "pop red" on the overall volume meter, with little success when having the tracks play concurrently. Let me give you a simple example, something I did for the express purpose of trying to figure this out. (these are all guitar tracks, btw, hence Audio tracks). Track one, hovers mostly at -3, with one spike to 1.5, when played solo. Track two is pretty much the same, averages around -3 with one spike to 1.1 when solo. When I have both playing at the same time, it averages right around 0, with many spikes up as high as 3.6 in the red. The manual mentions that you're "adding volume together". I'm sorry but I just don't get that. I'd think if you have two sounds at x sound level, the combined result would still be x. Can someone point me to a good explanation, rule of thumb, etc? Also here's a shameless plug for me at acid planet: http://www.acidplanet.com/artist.asp?songs=667048&T=3555 Thanks!
Subject:RE: Q about recording levels. "Volume addtio Reply by: Chienworks Date:7/13/2008 3:52:38 PM x + x does not equal x x + x does equal 2x The manual and your own experience both show this to be true.
Subject:RE: Q about recording levels. "Volume addtio Reply by: JohnnyRoy Date:7/14/2008 9:47:54 AM > Chienworks said: x + x does equal 2x That depends on how you measure 'x'. In this case, 'x' is audio which is measured in decibels (dB) where: x + x = x + 6dB ;-) This is an important point. You are correct that x + x = double the volume. Doubling the volume, however, only raises the meter reading 6dB. Likewise halving the volume only lowers the meter reading -6dB. This may be where the confusion lies but more on that later... > ttuskey said: The manual mentions that you're "adding volume together". I'm sorry but I just don't get that. I'd think if you have two sounds at x sound level, the combined result would still be x. What Kelly was trying to say is that if you shout "Go Team" at a baseball game it isn't nearly as loud as when everyone shouts "Go team" together. So clearly multiple people shouting at the same level when added together equals more than one person shouting. This is the same reason that one person talking in a room is a lot lower than everyone talking. Like wise multiple tracks at the same volume when added together equals more volume than one track alone. > ttuskey said: Can someone point me to a good explanation, rule of thumb, etc? Get yourself a 440 Hz sync tone at -12dB (you can make one with Sound Forge or find on on the net). Place this on a track and play it. The meters will read -12dB. Duplicate the track (i.e., place that same 440 Hz sync tone on a second track). Now when you play back both tracks what do the meters read? They should now read -6dB! Why? Two reasons... 1) Volume is additive. More tracks equals more volume. 2) Double the volume is an increase of 6dB. If you added two more tracks (doubling the current two) you would get 0dB. So you see it's not just adding another track, it's about "doubling" the volume. To get from 0dB to +6dB would now require 4 more tracks (8 total). This is why adding your tracks produces high sound levels and more red clipping. The problem in seeing it is that your tracks are not at a constant volume. As one goes up the other may go down so you don't perceive the increase. But when you use test tones at a constant volume it is easier to see (and explain) The rule of thumb is to keep your tracks at a reasonable level so that together they don't exceed 0dB FS on the meters. Start with all of your track volumes at zero. This is what an engineer would do at a "real" mixing desk. All the faders start off. Then you mix your drums, add your bass guitar, add the rhythm guitar, etc. Each time going back to lower the other tracks if the meters bang in the red. It's ain't called mixing for nothing. You need to find the right balance. ~jr Message last edited on7/14/2008 10:14:40 AM byJohnnyRoy.
Subject:RE: Q about recording levels. "Volume addtio Reply by: ttuskey Date:7/14/2008 10:23:57 AM Thanks both of you. I kinda started that approach last night, getting the drums down to stay out of the red, added some guitar, toned that down a bit, etc.. Sounds like the whole ordeal can be a little arduous, especially the more tracks you have (obviously) but the results well worth it. Thanks!
Subject:RE: Q about recording levels. "Volume addtio Reply by: JohnnyRoy Date:7/14/2008 11:26:44 AM > Sounds like the whole ordeal can be a little arduous, especially the more tracks you have (obviously) but the results well worth it. Well... that's why the people who do this for a living are called "engineers". ;-) You've got the concept though. Now just work on it. ~jr Message last edited on7/14/2008 11:27:12 AM byJohnnyRoy.

Subject:Q about recording levels. "Volume addtion", etc..

Posted by: ttuskey

Date:7/13/2008 3:43:55 PM

I have some questions about recording levels, track and overall (master) in Acid Studio 7.0. I assume it works the same way in all or most software of this type.
I've been trying to get some tracks to not "pop red" on the overall volume meter, with little success when having the tracks play concurrently. Let me give you a simple example, something I did for the express purpose of trying to figure this out.
(these are all guitar tracks, btw, hence Audio tracks).

Track one, hovers mostly at -3, with one spike to 1.5, when played solo.
Track two is pretty much the same, averages around -3 with one spike to 1.1 when solo.

When I have both playing at the same time, it averages right around 0, with many spikes up as high as 3.6 in the red.

The manual mentions that you're "adding volume together". I'm sorry but I just don't get that. I'd think if you have two sounds at x sound level, the combined result would still be x.
Can someone point me to a good explanation, rule of thumb, etc?

Also here's a shameless plug for me at acid planet: http://www.acidplanet.com/artist.asp?songs=667048&T=3555

Thanks!

Subject:RE: Q about recording levels. "Volume addtio

Reply by: Chienworks

Date:7/13/2008 3:52:38 PM

x + x does not equal x
x + x does equal 2x

The manual and your own experience both show this to be true.

Subject:RE: Q about recording levels. "Volume addtio

Reply by: JohnnyRoy

Date:7/14/2008 9:47:54 AM

> Chienworks said: x + x does equal 2x

That depends on how you measure 'x'. In this case, 'x' is audio which is measured in decibels (dB) where:

x + x = x + 6dB ;-)

This is an important point. You are correct that x + x = double the volume. Doubling the volume, however, only raises the meter reading 6dB. Likewise halving the volume only lowers the meter reading -6dB. This may be where the confusion lies but more on that later...

> ttuskey said: The manual mentions that you're "adding volume together". I'm sorry but I just don't get that. I'd think if you have two sounds at x sound level, the combined result would still be x.

What Kelly was trying to say is that if you shout "Go Team" at a baseball game it isn't nearly as loud as when everyone shouts "Go team" together. So clearly multiple people shouting at the same level when added together equals more than one person shouting. This is the same reason that one person talking in a room is a lot lower than everyone talking. Like wise multiple tracks at the same volume when added together equals more volume than one track alone.

> ttuskey said: Can someone point me to a good explanation, rule of thumb, etc?

Get yourself a 440 Hz sync tone at -12dB (you can make one with Sound Forge or find on on the net). Place this on a track and play it. The meters will read -12dB. Duplicate the track (i.e., place that same 440 Hz sync tone on a second track). Now when you play back both tracks what do the meters read? They should now read -6dB!

Why?

Two reasons...

1) Volume is additive. More tracks equals more volume.

2) Double the volume is an increase of 6dB. If you added two more tracks (doubling the current two) you would get 0dB.

So you see it's not just adding another track, it's about "doubling" the volume. To get from 0dB to +6dB would now require 4 more tracks (8 total). This is why adding your tracks produces high sound levels and more red clipping. The problem in seeing it is that your tracks are not at a constant volume. As one goes up the other may go down so you don't perceive the increase. But when you use test tones at a constant volume it is easier to see (and explain)

The rule of thumb is to keep your tracks at a reasonable level so that together they don't exceed 0dB FS on the meters. Start with all of your track volumes at zero. This is what an engineer would do at a "real" mixing desk. All the faders start off. Then you mix your drums, add your bass guitar, add the rhythm guitar, etc. Each time going back to lower the other tracks if the meters bang in the red. It's ain't called mixing for nothing. You need to find the right balance.

~jr

Message last edited on7/14/2008 10:14:40 AM byJohnnyRoy.

Subject:RE: Q about recording levels. "Volume addtio

Reply by: ttuskey

Date:7/14/2008 10:23:57 AM

Thanks both of you.

I kinda started that approach last night, getting the drums down to stay out of the red, added some guitar, toned that down a bit, etc..

Sounds like the whole ordeal can be a little arduous, especially the more tracks you have (obviously) but the results well worth it.

Thanks!

Subject:RE: Q about recording levels. "Volume addtio

Reply by: JohnnyRoy

Date:7/14/2008 11:26:44 AM

> Sounds like the whole ordeal can be a little arduous, especially the more tracks you have (obviously) but the results well worth it.

Well... that's why the people who do this for a living are called "engineers". ;-)

You've got the concept though. Now just work on it.

~jr

Message last edited on7/14/2008 11:27:12 AM byJohnnyRoy.