Axiom Home Page Forums General Discussion Technical Questions Very Simple Question

On a multi channel receiver or pre processor, what are the volume numbers referenced to? Is there a standard?

For example, if my volume display shows -30 dB, what is it telling me for each of my channels?

Oooo, a test; we went through this just the other day!

Generally speaking......

Lets see now; The +10 point is where clipping may begin.

"0" is kinda like where all goodness resides, except on THX where it actually means some kind of reference point.

Ok, ok, I've been outta school for a long, long time! Might want to try a forum search!(or wait for a more in-depth responce)

Some recievers, like my onkyo, give you a choice: 0-100 and the relative +/-db scale. That's kinda cool.

Yeah, it's not standard between manufacturers. Usually, 0 is reference level, but this can vary wildly. For example, on my H/K, it says to calibrate at -15 to reference level. So who knows...

I was reading another board and one fellow was testing two different units. He made the comment that it didn't sound as loud with his new unit set at xx dB as his old unit set at xx dB.

I started wondering if it should sound the same??? My 7 year old Kenwood receiver has the volume scale in dB, but I never gave it much thought. If I wanted it louder, I turned it up. If I wanted it less loud, I turned it down. I didn't care what the dBs were!!

I guess that it is just another case of fancy gear displaying information that really doesn't mean much.

>>I guess that it is just another case of fancy gear displaying information that really doesn't mean much.

Bingo

As far as we can see, 0dB means something different depending on the power output of the receiver, ie 0dB on a big honkin' receiver is louder than 0dB on a little wimpy receiver.

I always assumed 0dB was some kind of reference output level (implying that a more powerful receiver would have more numbers above 0dB) but apparently that is not normally the case.

Yup, another theory of relativity; entirely relative to our own(audio)frame of reference.

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A very simple answer:

Ahh…the mysterious zero db on receivers nowadays. It’s amazing how something so small can affect so many…or something. Many “experts” have many different “explanations” as to how the 0 point is derived by different component manufacturers. They are, of course, all wrong. All their talk of “clipping” and “headroom” is just fancy-lad talk for, “They wave their magic voodoo sticks of voltage over the thing as they cast the remains of long dead woofer spiders of divination and whatever the gods of audio decide – so let it be written, so let it be done.” The truth of the matter is as difficult to explain as it is easy to calculate. I’ll spare you the complexities of the mathematical figures (mostly because every time I look at the equations I flash back to my advanced thermalductionivity class and start flopping around on the ground like a fish – it’s a defensive behavior (much like a possum) that has got me out of more than one final) and I’ll use an analogy.

The 0 point on the receiver is much like a spring flower…a man eating spring flower. Well, technically, a woman eating spring flower. Ok, forget the flower…there are no flowers. Ok, let’s start again. This mollusk walks up to this crab….oh, wait, that’s a different one. Let’s go with the carnivorous gender hating bloom. The 0 point is like that. Understand? No? Hmmm….Ok, everyone knows that 0 is not very loud right? Right. You know that. Your wife knows that. Your mother-in-law knows that. Receiver engineers understand that you want things to be LOUD. For most of us, the louder the better. What better way to justify playing something LOUD than being able to say, “But honey, it’s only at -20!” I mean come on! -20? How loud can that be? And if it sends your mother-in-law running from the room…so much the better. See, just like a woman devouring spring flower. Sheesh.

Thanks for reminding me about Advanced Thermalductionivity class,(we used it big time in small jet engines bypass ducts)and that was back in the day of the Slide Rule.

We use the relative scale on our receiver cause my Mother-in-Law died many years ago. And my wife is much too sharp to be deceived for long!!

(Actually,...watching the numbers go Down while the sound goes Up, confuses..uh...Me!)

In reply to:

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we used it big time in small jet engines bypass ducts

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Really? That was that was about? I thought it was about how to get duct tape off of water heaters. I don't know. There was a cute teacher so I signed up for it but after an unfortunately slide ruling accident (involving rules that were apparently NOT made to be broken...like restraining orders and ...gravity) I ended up having to drop out. Intermediate sarcasm was open so I audited the class. Best move I’ve ever made….unless you ask my wife…or family…or coworkers…or, well, just about anyone.