I just bought my first reciever that displays volume in negative and positive decibels, every other one I've owned just had a volume number. What are the negative numbers in relation to?

Only the manufacturer knows for sure unless it's stated in the manual/specifications.

In the overall picture, negative dBs indicate a lesser volume with respect to the 0dB point.

Generally, from what I read, the most common assumption seems to be that 0dB indicates the point of rated power output.

However, if one goes by that premise, it's true only when a user is using a load impedance/resistance and input signal level and frequency the same as was used for establishing the 0dB point when the receiver was being developed.

If one assumes 0dB is rated output power, then your negative reference dBs are with respect to that output power. So, if 0dB was equal to 100 watts of output power, -3dB would be equal to 50 watts output, -10dB would be equal to 10 watts of output power, and so on.

Again though, this is all an assumption. The only way to know for sure is to get the 0dB reference info from the mfg.


EDIT: I should add that the dB reference on the volume control can also be indicative of the approximate volume level when the 0dB reference point is calibrated to some known sound pressure level. For a typical HT calibration, playback at 0dB is often calibrated to the 105dB peak volume level of Dolby "reference level".

So, if your system was calibrated like that, putting the volume control at -15dB would mean that peak levels during playback are about 90dB.

Generally, from what I read, the most common assumption seems to be that 0dB indicates the point of rated power output.

However, if one goes by that premise, it's true only when a user is using a load impedance/resistance and input signal level and frequency the same as was used for establishing the 0dB point when the receiver was being developed.

That's how it usually works.

And it does depend on the input signal from the source. With my system you get a normal volume level for TV viewing at around -30db. But when I switch to the DVD player it has to go up to -20db to get the same volume. And the reason my volume setting is so low is because my pre/pro outputs a much stronger signal than my amps need. For DVD's -20db is pretty darn close to reference level volume.

It's all relative. And it's really better if you get good volume from a low setting on your receiver. That generally means that everything is operating well within the system's capacity and you're in no danger of blowing something up. If you have to push the volume way up to get good volume, I'd be worried that something is about to break. Namely the speakers, either from clipping the amp or exceeding the drivers mechanical limits.

BTW, Ikari Warrior? I played the **** out of that game when I was a kid. :D

I just bought my first reciever that displays volume in negative and positive decibels, every other one I've owned just had a volume number. What are the negative numbers in relation to?
This is taken from the standard recording measurement scale where 0db is used for calibration as it is considered maximum recording level before distortion begins (although various amounts of headroom are built into the recordings depending on which medium is being used). I think db is actually the British scale because typically American equipment reads on the VU scale. Lower levels are measured on the negative side of 0, hotter is on the plus side.

Someone asked a similar question a few months ago about reference volume and I wrote this (http://www.avsforum.com/avs-vb/showthread.php?p=9735317#post9735317) post that might answer your question as well. It explains why the numbers on your receiver are basically meaningless without some research and understanding on your part.