Another Audiofile Question - Why does volume count down Db's
 

This is for my own curiosity.

My new Yamaha receiver, when I turn the volume up the display is counting db's down. Anyone know why that is?

It should be counting up. for example when you turn it on and it is at -40db and you turn the volume up it will go to -35db and so on.

In layman terms, a volume control reduces the voltage going to the transistors in the amplifier stage, therefore reducing the output down from maximum rated power. In theory, the 0dB setting is the maximum 'clean' power you can attain. Of course, music is not a test tone so the dynamic range of it, the efficiency of your speaker, the air volume you are trying to fill etc etc will all impact this.

Ian

As above, it's a scale of attenuation. At full volume there is no attenuation so it reads zero. At low volume there is a higher amount of attenuation, so a higher value.

db is also logarithmic.


if you want twice the volume, you need 10x the power.


Double amplifier power does not double the volume - Geoff the Grey Geek

All true above. Still, call me crazy, but I think the volume control display thing is backwards.

Not all AV receivers show it that way. I owned a Yamaha a few yrs back and it was the same. Have had 2 Sony's since...both show 0 for the lowest volume.

I'll only buy it if it goes to "11"

Are the numbers negative? If the numbers have a - sign, then they aren't counting down, they're counting up. -40 is "smaller" than -35.

Thanks for the explanations. I guess the numbers are actually counting up but starting with a negative number. After reading this thread and some info on the net I have a better understanding of why.

With the new receiver and subs, I can't imagine ever getting to zero db.

Totally!

There actually are "standards" (for movies, anyway) that state certain levels of audio to be on the digital recording, and the system can be calibrated to produce a certain SPL of audio through the speakers with a test noise. Assuming your speakers have a certain capability and your room is perfect and your Johnson rod and muffler bearings are in a certain state of tune, etc. etc.

Music recordings aren't bound by these guidelines and as such they cram their level on the recording all the way to the top. You might find that the loudest you can stand is somewhere between -30 and -18 on your readout there, depending on the kind of music. (very very simplified explanation, though.)

But yeah, for the real world, the plus sign on the remote means louder and the minus sign means quieter.

It's a marketing thing mostly I suspect. I also have a Yamaha receiver that has this and it works fine but seems dumb. For math geeks, if you have a 100w receiver and you are at minus 20db you are at approximately 1w of output power.