Does the protools mixer use dBFS, dBu, dBv etc?

[illution1]

Question number 1:

This might be a very dumb question, but as a novice pt user I was always a bit confused between the different metrics of reading dBs. I have heard of dBfs, dBu, dBv etc. I am a little overwhelmed by the differences.

Question number 2:

Why does the pt mixer have two kinds of numbering systems? To the left of the fader the meter reads from 12 to -90. To the right of the meter reads from 0 to -60. What is the difference, reason and application for these two numbering systems?

Thanks in advance!

[illution1]

Question number 3:

I would like to also know scientifically what the meters mean when they are moving fluidly vs when they hold on to a periodic peak for a few seconds.

[albee1952]

Originally Posted by illution1

Question number 3:

I would like to also know scientifically what the meters mean when they are moving fluidly vs when they hold on to a periodic peak for a few seconds.

That could be a graphics issue, or peak-hold, or...?? While I applaud your curiosity, I would not get too hung up on it

[Drew Mazurek]

Originally Posted by illution1

Question number 1:

This might be a very dumb question, but as a novice pt user I was always a bit confused between the different metrics of reading dBs. I have heard of dBfs, dBu, dBv etc. I am a little overwhelmed by the differences.

Question number 2:

Why does the pt mixer have two kinds of numbering systems? To the left of the fader the meter reads from 12 to -90. To the right of the meter reads from 0 to -60. What is the difference, reason and application for these two numbering systems?

Thanks in advance!

#1. The dB is a HUGE topic. It's basically meaningless unless you have a reference point. Each of the various dB "versions" you list have a different reference point. dBu or dBv (they're the same) is .775volts with a 600ohm load. dBV references 1volt with a 75ohm load. blah blah blah... dBFS is dB full scale and is used in digital devices. But these devices need to be "calibrated" to ultimately coincide with the real analog world of voltage. For example, PT defaults to -18dBFS equaling 0dBVU which is +4dBu. but enough of that!!

#2. PT's scales can show you both dBFS and whatever other scale you've chosen it to show you.

[Jay_uk]

Originally Posted by illution1

[B]
Why does the pt mixer have two kinds of numbering systems? To the left of the fader the meter reads from 12 to -90. To the right of the meter reads from 0 to -60. What is the difference, reason and application for these two numbering systems?

Thanks in advance!

The numbers on the left are for the volume fader that you move up and down. The 0 there is unity gain, where the volume corresponds to the original volume of the channel. You can adjust this up or down from -infinity to +12. The actual numbers here have little to do with the LEDs you see to the right. The fader changes the channel volume.

The numbers to the right of the LEDs are for the level meter. This is the important one for clipping info. These LEDs and numbers show the signal level.

[illution1]

I am sorry, but I don't understnad what this means:

For example, PT defaults to -18dBFS equaling 0dBVU which is +4dBu. but enough of that!!

aside from the above, so far this is what I understand about the meters in pt:

So, the numbers to the left of the fader only represent relative fader changes you are making (basically how many dB you are choosing to boost or attenuate) right?

The numbers to the right of the meter represent the actual signal input which is measured in dBFS? Or is it dBv/dBu?

Here is another question also: What the heck is dBVU?

[Shifted Music]

Originally Posted by illution1

Question number 1:

This might be a very dumb question, but as a novice pt user I was always a bit confused between the different metrics of reading dBs. I have heard of dBfs, dBu, dBv etc. I am a little overwhelmed by the differences.

Found this little article on what you are asking.

http://www.soundonsound.com/sos/1994.../decibels.html

Regardless of all the gobbley goop (I mean technical data)

Keep the meter levels in PT hovering around the middle when recording (via-pre fader metering) and the same when Mixing (post fader metering) or lower depending on your source.

This will keep good headroom on your master fader and or Aux tracks.

For basic configurations outboard or in plug in chains I always monitor levels from INPUT To OUTPUT and then again input of the next plug in or device then output all the way down the line.

Many times when using bit of audio from samples or libraries I have to first adjust the level of the audio file by reducing it a few DB or more (using clip gain is awesome for that) SO that my starting gain is again. . more towards the middle - IE around -18 or so on the RIGHT side of the PT metering (in pre fader mode or in post fader mode with the fader at 0 on the right left side of the meter or at unity as in NO Change) ... give or take a few.

That's a good starting point for then adding plug ins and again monitoring the in and out of the plug ins (when possible) making sure I'm heading downstream or to the next plug in in the chain, appropriately.

Disregard the real world metering usage if thats old new and just wish to research the definitions... the article above would help with that.

[illution1]

Shifted Music,

Thanks very much for the info guys, you are great. That article helped me understand the proper definition of dBFS.

I am still stuck on understanding what dBu/dBv is used for? Let's recap my current level of knowledge:


1. dBFS is used for the led meter in the pt mixer.
2. ???? is used for the fader in the pt mixer. (is this simply JUST dB?)
3. dBVU is used for ???????????????????????????.
4. dBv/dBu is used for ????????????????????????.

[Drew Mazurek]

Originally Posted by illution1

I am still stuck on understanding what dBu/dBv is used for?

It's for measuring the dB in its "native land", as voltage. When you turn a knob on a piece of analog gear, and it's labeled in dB, depending on the nominal operating level of the device (+4dBu, -10dBV), you're increasing/decreasing the amplitude by a certain amount of voltage, which is where this comes in.

dBVU stands for Volume Units. These are the units used by mechanical VU meters (thingies with the needles). Since the needles are slow to respond, they can only show the previous 300ms "average" amplitude which makes them good for judging volume but terrible for showing peaks.

PT11 is trying to emulate this behavior with its various meter modes.

[illution1]

Originally Posted by Drew Mazurek

When you turn a knob on a piece of analog gear, and it's labeled in dB, depending on the nominal operating level of the device (+4dBu, -10dBV), you're increasing/decreasing the amplitude by a certain amount of voltage, which is where this comes in.

Ok, so dbVU stand for deciBels Volume Units. So what is 0 dBFS equated to dBVU (orr vice versa)?

Also, what is 0dBVU equated to dBv/dBu?

I am basically looking to find the relationships and comparisons of all forms of dBs in order to understand completely the differences between all of them and the practical uses for all of them.