Negative dbs

[Colleen]

Is it normal for an A/V receiver to show volume in negative dbs instead of positive?

Thanks.

 

[Mort Corey]

In short.....yes I think mine registers from -80 to +20 IIRC, though -30 to -9 (depending on the source) seems to be the widest range I've used. It's all relative.

Mort

 

[Colleen]

Okay. Thanks. It's going to drive me crazy, though, seeing negative numbers up on the display.

 

[Mort Corey]

Just the price ya pay for being an analog person in a digital world I guess

 

[Rob Babcock]

What I'd really like would be for manufacturers of receivers to use 0.5 dB steps and make 0 dB be the loudest. You could have maybe -90 to 0 be the range, with 0 dB being full scale. Ultimately it's just a number, but I'd prefer the 0 setting to represent max output.

Maybe the current range is set the way it is to indicate that at the relative setting, 0 dB is the practical limit of how loudly the average person would play music.

 

[Audioholics]

Mine goes to 11.

 

[keenan]

What I'd really like would be for manufacturers of receivers to use 0.5 dB steps and make 0 dB be the loudest.

The recent Denons use 0.5db steps, but they also top out at +20dbs. I guess it boils down to user preference, but I cannot hear a 0.5db change in volume, in fact I either have hold the volume button down for a brief period or tap it 3 or 4 times before I here any change in volume.

Jim

 

[Rob Babcock]

I occasionally find 1dB a bit too coarse for me, but generally it's fine. My model is just old enough to only allow 1 dB steps (a 3802).

 

[av_phile]

My understanding is that the 0db setting in preamps (that's where your display logic gets the volume setting) is a reference indication that corresponds to the RMS voltage being sent by the preamp to the amplifier so that the amp can deliver its rated power level. Typically, that would correspond to 1V RMS that is meant to drive the amp to its full rated power of, say, 100watts continuous into the required speaker load. Different amplifers have differing input voltage requirements for full power, ranging from 0.8V to 1.5V, more or less.

For some preamps, a 0db setting corresponds to a unity-gain output where the input signal to the preamp circuit equals its output signal. Any db marking above that would indicate some gain in the preamp circuitry.

Hence, the negative db settings correspond to volume levels BELOW the 0db reference. And if the preamp section does have same gain that can overdrive the amplifer near clipping points, it can indicate this by going overboard with positive db levels above the 0db reference. That accounts for some gears having a +6db or +12 db above the 0db, indicating a preamp gain of such an amount above the reference value. Some amplifers that are conservatively rated can tolerate a few more input volts above the value that will drive them to rated power. Other's sound terrible even near the 0db mark.

It's also possible that the 0db mark corresponds to 80% or so of the rated power. So that the positive values up to the max will drive the amp to its rated power instead of going above it. That's entirely within the design prerogatives of the manufacturer.

 

[annunaki]

The recent Denons use 0.5db steps, but they also top out at +20dbs. I guess it boils down to user preference, but I cannot hear a 0.5db change in volume, in fact I either have hold the volume button down for a brief period or tap it 3 or 4 times before I here any change in volume.

Jim

Most people, with music, will not hear a difference in volume until around +-3db. With test tones, depending upon frequency, the threshold is in the +-1db range. Your experience is normal.

It would be great if all manufacturers could design their products as though 0db was maximum volume and would not induce clipping at all. Say that when 0db was reached one would only experience .9% thd. It would also be nice if one could electronically enter the nominal impedance and have a processor allow the volume go to 0db at .9%thd reguardless of impedance used. Another cool thing would be a linear volume attenuator. Meaning that as the volume dropped by 3db on the display it would equate to a true halving of output power or a true -3db.

What am I talking about? That would never happen!! It would make things too easy and things cost more than some of the cheesy stuff being used today.

 

[nick_danger]

Mine goes to 11.

LMAO! Is that movie available in anamorphic?

 

[Votrax]

The volume level is really for reference more than anything. They don't normally correlate between different manufacturers of receivers or even different inputs on the same receiver. On my receiver when using an analog input -45db is equivalent to -30db with a digital input on sound output. So technically it's useless as you typically turn the volume up to your liking anyway.

 

[Rob Babcock]

The # setting on a receiver may not correspond to any reference level, and the settings that are ostensibly 1 dB apart may not really be 1 dB at all. That is to say, the -20 setting may be more than 1 dB louder than the -21 setting.

As far as the threshold of audibility, it varies by frequency. However, when performing DBTs on amps, CD players, etc most good reveiwers will try to level match to withing a few tenths of a dB. If a two components of relatively similar qualities are being compared, a level diff of less than .05 dB will generally lead to the louder one being preferred. This would seem to indicate that half of dB is audible.

 

[annunaki]

Rob as I stated, the +-1db was dependent upon frequency. There is no doubt the ear is very sensitive at certain frequencies. What I stated was an aggregate of normal listeners. Obviously not in a dbt.

 

[Rob Babcock]

Ooops, I meant to say "0.5", not ".05"! Half a dB would skew a DBT, but I'd be surprised if one-twentieth of a dB would. Level matching to within a few tenths is generally preferred, but I can't say where the JND threshold would be.

 

[av_phile]

The volume level is really for reference more than anything. They don't normally correlate between different manufacturers of receivers or even different inputs on the same receiver. On my receiver when using an analog input -45db is equivalent to -30db with a digital input on sound output. So technically it's useless as you typically turn the volume up to your liking anyway.

True, there's hardly an correlation among receivers of different makes. Their volume knob or controls are also a design function that behaves differently from one model to another. One can be an analog or digital volume control. If digital, I am not even certain how linear their behavior is.

Between digital and analog, there's also some disparities as seen by any reciever. There may be some voltage gain after the DAC or that the player's analog out has a lower RMS voltage value. Could be the other way too. Even the output between DVD players and CD players can have disparities. I think most DVD players tend to have lower analog output signals compared with CD players. That's to accommodate the wild dynamic swings that most DVD sound tracks have. So those volume level indicators really have little or no meaning at all. For analog volume, most audiophiles just refer to a 9 O'clock or 11 O'clock volume postion to approximate their preferred volume settings. For digital, anything goes. One's -30db readout might be equivalent to another's -10db readout. Depending on the power amplifier used, speaker sensitivity, among others.

 

[Unregistered]

With a 'conservatively' rated receiver, surely you could reach your desired volume level at 7 o'clock rather than 9 or 11.

"DVD players have lower analog output levels compared to cd players in order to accomodate the wide dynamic range of movie soundtracks". Total nonsense as we've come to expect from someone who claims to be an 'audiophile'.

Read more, learn more, pontificate less.

 

[annunaki]

"Guest",

Please do not bother posting if all your post is meant to do is cause mischief.

Thanks.

 

[Votrax]

"DVD players have lower analog output levels compared to cd players in order to accomodate the wide dynamic range of movie soundtracks".

Dynamic range has nothing to do with the lower pre-amp signal of DVD players. That's just the way they are designed. If your rail voltage is +/- 60V then any signal you send in will clip after it reaches 60V. If the output level is 1.4V p-p on a DVD player it just takes more volume level to clip it than if it was a 2V p-p signal. So the level displayed on the receiver correlates with the input signal strength and doesn't have anything to do with the inadequacies of the receiver.

 

[mtrycrafts]

Level matching to within a few tenths is generally preferred, but I can't say where the JND threshold would be.

It could be at .5dB for some people:

http://www.pcavtech.com/abx/abx_crit.htm

Volume difference affects the whole spectrum, hence more sensitive and detectable at lower level differences. That is one reason .1dB is used in a DBT comparison so level differences is not an issue.