Understanding relative volume and 0db on my receiver.

[j0nnyfive]

Howdy.

Well, I've read various articles online, but I find the answers to be confusing/vague/incomplete.

I'm trying to understand how my receiver "knows" it won't clip if I turn it up to 0db (assuming no EQ or calibration. I'm just running things straight).

I don't plan on running it this loud, but it would give me more peace of mind to understand this topic me thinks. For instance, some music is very compressed (runs hot). Movies can have large swings in SPL. How does my receiver (Yamaha Aventage) "know" that it won't clip if I set the volume to 0db?

And, if it is set to +1 db, does this mean it will most likely clip while watching a movie?
If set to -1db, is it possible for this volume setting to clip, depending on the source?

I've looked in the manual, but I couldn't find an explanation of this. Could someone help me understand this? (No hurry though.)

Thanks!

[mikesiskav]

Howdy.

Well, I've read various articles online, but I find the answers to be confusing/vague/incomplete.

I'm trying to understand how my receiver "knows" it won't clip if I turn it up to 0db (assuming no EQ or calibration. I'm just running things straight).

I don't plan on running it this loud, but it would give me more peace of mind to understand this topic me thinks. For instance, some music is very compressed (runs hot). Movies can have large swings in SPL. How does my receiver (Yamaha Aventage) "know" that it won't clip if I set the volume to 0db?

And, if it is set to +1 db, does this mean it will most likely clip while watching a movie?
If set to -1db, is it possible for this volume setting to clip, depending on the source?

I've looked in the manual, but I couldn't find an explanation of this. Could someone help me understand this? (No hurry though.)

Thanks!

Are you sure that your Yamaha has that feature? I haven't noticed any clip limiter function on any receiver I've ever used.

Some QSC amps do have a clip limiter function (The DCA-1622 for example). In the manual it says this:

Clip limiter
Description
When the audio signal drives the amp's output circuit beyond its power capability, it clips, flattening the peaks of the waveform. The clip limiter detects this and quickly reduces the gain to minimize the amount of overdrive. To preserve as much of the program dynamics as possible, limiting occurs only during actual clipping. Each channel has its own clip limiter, and you can switch it on or off independently, as shown at left.

When to use it
When driving full-range speakers, clip limiting reduces high frequency distortion caused by bass overloads. It also protects high frequency drivers from excess overdrive and
harsh clipping harmonics. We recommend using the clip limiters in all cinema applications.

[mikesiskav]

BTW, notice that it says it reduces the gain after clipping occurs. It does not eliminate clipping altogether.

[j0nnyfive]

Hello Mikesiskav!

I'm not thinking of a clip limiting feature per se. I just want to understand what is happening, power-wise, when you turn the receiver up to "0db". In other words... What is it, mechanically, that 0db represents? How much power is this?

The receiver gives you something like -80.... -40..... -20....-10...-5.... (0)....+5....+10, etc.

So, I want to know how loud I can turn the receiver up without worrying about any clipping. Is 0db safe? -5db? And, how does one know this? My understanding is that there is some kind of attenuation process happening when the volume is set at, say, -20 or -10. But, at 0db, supposedly, there is no longer any attenuation taking place. But, I wonder what +5 gives you? Or +10?

I'm really just trying to understand what is happening, "mechanistically", inside the AVR when you set the AVR to 0db. Or +1db. Or -5db. etc.

I know this may not be a very clear question, but I'm no audio expert either, please forgive me about that.

Thanks Mikesiskav!! Maybe you can help clear me up here.

[j0nnyfive]

To clarify:

When the volume is set to a negative number, does this mean the input signal is being attenuated digitally?
(I'm curious).

When the volume is set to a positive number, what is happening then?

Is there a "safe" volume level at all? I would assume that at -30, nothing will clip. But what about -5? -10? 0?

My current understanding, from what I've read elsewhere: Below 0d, the receiver performs "cuts" to the signal. Above 0d, the receiver "boosts" the signal. I would assume that at 0db, the system is simply amplifying the given signal by some predetermined amount (whatever this is). I could be wrong about all of what I just said. I'm speculating.

My input: HDMI from a PS3 or blue tooth from my phone. Digital input into the receiver.

My output: 2 speakers (L and R) only. No other speakers.

[curtis]

To clarify:

When the volume is set to a negative number, does this mean the input signal is being attenuated digitally?
(I'm curious).

When the volume is set to a positive number, what is happening then?

Is there a "safe" volume level at all? I would assume that at -30, nothing will clip. But what about -5? -10? 0?

My current understanding, from what I've read elsewhere: Below 0d, the receiver performs "cuts" to the signal. Above 0d, the receiver "boosts" the signal. I would assume that at 0db, the system is simply amplifying the given signal by some predetermined amount (whatever this is). I could be wrong about all of what I just said. I'm speculating.

My input: HDMI from a PS3 or blue tooth from my phone. Digital input into the receiver.

My output: 2 speakers (L and R) only. No other speakers.

Jonny,

You got it all wrong. The volume knob is a signal attenuator from beginning to end. You receiver/amp is always "amplifying" the signal. The volume knob controls how much the signal is amplified.

The scale is arbitrary. To make it useful, you should calibrate your system to where 0db is reference level at the listening position. So, when you are at -5db, you are listening at -5db from your reference, or at +5db you are 5db over your reference.

That said, volume levels also change with sources depending on output signal of that source.

Is there a safe level? Depends on the variables: the speakers, the source, the calibration, the material you a listening to.