@PENG - I tried this. I can hear the stereo is on all the way down to 1 on the Denon 4700 volume control. It's not very clear and just a small sound. If 80 = 0, would this be considered --79?
My sound meter shows 36db at this level.
How far do you sit? If you can hear what's actually playing in Stereo at volume 1, you likely have the following conditions:
- Your room is near dead silent, what kind of sound meter you have that can measure down to 36 dB? The RS cannot do that, for me I would use my Umik-1 mic with REW.
- You may be listening to a source recorded at high level.
I highly doubt your room is so quiet, please try again but to keep things simple, try using the AVR's test tone, and you will be testing one speaker at a time.
How is this data used to determine the importance of the SINAD measurements?
My rationale is, if you cannot hear what is playing when you reduce volume by X dB, then in theory you cannot tell there is distortions.
Example:
You can hear a 1 kHz test tone clearly at volume -10, say that is your normal volume when listening to music. Assume you are getting 80 dB at you mmp when playing this test tone. Now if you listen to the same signal but it has 0.1% distortion that is made up of a single 3 rd harmonic.
Now consider the following facts:
- 0.1% distortion in log scale is -60 dB, that is 60 dB SINAD.
So if the 3rd harmonic is at a level of -60 dB, that means it is -60 dB below the fundamental that is 1 kHz in this example. So you should be able to hear the 3rd harmonics clearly if your room's noise floor is quieter than 20 dB, because 80-60 = 20 dB.
If you noise floor is -30 dB, then the 3rd harmonic signal would be 10 dB below your noise floor. Turning the volume down to -70 from -10 has the same effect of trying to hear that 3rd harmonic using this example. So if you cannot hear the same 1 kHz signal by reducing it by -60 dB, you can assume you cannot hear the 3rd harmonic when you have the volume at -10. Makes sense? If you, I can try something else.
*There's one person on the ASR forum who is not convince by this at all because he is firmly planted in the misconception, thinking that distortions is build in the ugly waveform so no matter how many dB the harmonic it is below the fundamental you will still hear the effect.
@3db , another EE, joined with me along with at least another member, and we could not change his mind. Now let's see if this could make sense to you..