What is 0db level on Yamaha 2500?

[xradman]

I recently found this forum and had a question that has been bugging me ever since I got the Yamaha 2500. With all my prior receivers and amps (Kenwoods and Pioneers), 0db level on the volume knob corresponded to the maximum volume. On Yamaha 2500, I can go higher than 0db (how much higher, I don't know). So what is 0db mean on Yamaha? Does it correspond to some output wattage?

 

[nibhaz]

The search function is great!

I believe the answer you are looking for can be found here. Read the entire thread, if you still have questions, please feel free to ask.

Welcome to the forum!

 

[xradman]

I couldn't search 0db level and Yamaha rx-v2500 returned too many hits to be useful. Thank you for the link. But that still does not seem to answer if 0db on Yamaha mean anything. Does it correspond to Dolby Reference level (I don't think so, since I can't ever recall any theater being as loud as when I turned the system up to -10db or so), maximum power level (again, I don't think so as system is noticibly quieter at -30db setting compared to my previous lower power receivers), or what???

 

[tbewick]

I think the choice of where 0 dB is on your amplifier is entirely up to the manufacturer.

 

[BMXTRIX]

0db should be the level at which the pre-processor is sending audio information to the amplfiers from the source without raising, or lowering the gain on the source at all. It has nothing to do with output volume as that deals with amplification and and your speakers. Strictly, it is a measurement of how much gain, or loss is added (taken) from the input signal.

So, when you have your receiver at 0db, you are at the reference recording level and passing through the cleanest signal possible.

As soon as you go beyond 0db you are adding signal to the original source. As soon as you go below 0db you are taking away signal from the original source.

The output from your DVD player, CD player, FM tuner, reel to reel, or pretty much any audio source, typically is at a 0db level so that you have the cleanest transfer of audio information that is possible.

NOTE: I am not 100% sure this is an accurate description, so any comments that suggest otherwise would help me have a better understanding of this. THX!

 

[malvado78]

0db should be the level at which the pre-processor is sending audio information to the amplfiers from the source without raising, or lowering the gain on the source at all. It has nothing to do with output volume as that deals with amplification and and your speakers. Strictly, it is a measurement of how much gain, or loss is added (taken) from the input signal.

So, when you have your receiver at 0db, you are at the reference recording level and passing through the cleanest signal possible.

As soon as you go beyond 0db you are adding signal to the original source. As soon as you go below 0db you are taking away signal from the original source.

The output from your DVD player, CD player, FM tuner, reel to reel, or pretty much any audio source, typically is at a 0db level so that you have the cleanest transfer of audio information that is possible.

NOTE: I am not 100% sure this is an accurate description, so any comments that suggest otherwise would help me have a better understanding of this. THX!

The above cannot be tru because the 0dB level on a receiver is dependant on how you calibrate the reciever. Almost all HT recievers have the ability to adjust the level of a single speaker. This is to balance the outputs of the speakers. If this balance ranges from -12dB to +12 dB that you can adjust the individual speaker output your 0dB volume level on the reciever could swing 24 dB depending on how you have calibtraed your speakers. THis calibration should be done to all HT systems in order to optimize performance. This is done using a $40 radio shack spl (Sound Pressure Level) meter and either the built in test ones form the receiver or better yet a copy of Avia of Digital Video Essentials. 0 dB is normally called "reference level" (I will use RL from here on out). For Dolby Digital recordings I believe RL is 85 dB and it is slightly different for DTS (95dB???). But when you calibrate your HT you may decide to set 0dB to be 75dB (Because 85 dB is pretty loud and the peaks of a DD recording may go +20dB above 85dB (105dB)). This means your reciever's RL is 75dB and when the receiver shows -3dB, -10dB, +5dB, etc.. You are actually at about -3dB below 75dB (72dB), -10dB below 75dB (65dB), and +5dB above 75dB (80dB). So you can get an SPL meter and measure the level of a test tone from the receiver to know what the level is of 0dB on your Yamaha but the true answer is... It is a relative Reference Level therefore it varies.

 

[BMXTRIX]

You are confusing two forms of dB I believe. One is sound pressure level, the other is voltage level. (not sure of the correct terms here)

But, most speaker calibration does not include the L&R mains. The center and surrounds are balanced to the L&R and calibrated for distance. But, the voltage passed through to the amplifiers is only reference at ONE specific level. 0dB.

Setting the amplifiers at a specific volume should occur with trimming the amplifier power, not with tweaking the input levels. Though, this is not the common way of tweaking the SPL, I believe that it is the correct way. The cleanest level that introduces zero distortion and takes away no signal is 0dB.

Adjusting your speakers most definitely is adding or subtracting from that, but is not ideal.

Actually, now that I think about it, an optimal configuration is using identical speakers placed in a 100% circle around the listeners so no gain adjustments are necessary for the speakers. So, I am pretty sure about speaker setup for different levels definitely being a manipulation of ideal signal.

SPL dB though should not be confused with pre-amplified dB as they are not the same and not computed the same way.

At least - I'm pretty sure on that.

Where's the audio scientists?

 

[MDS]

Without calibrating the receiver, the 0 dB position on the volume dial has as much significance as any other - none. [That is the point mentioned by malvado78]

This can be confusing because '0 dB' means different things when you are talking about digital audio levels vs volume settings.

Digital Audio
As most are aware, digital audio is just a sequence of numbers (samples) that represent the amplitude of the signal at points in time. The range of the values depends on the bit depth. As an example, CD audio is 44.1 kHz / 16 bit, which basically means for every second of audio there are 44,100 16 bit samples. The samples are signed (the waveform has both a positive and negative component) so there are really only 15 bits (the high order bit is the sign).

0 dB is maximum amplitude and is known as 'full scale digital'. With CD audio that means a sample of value of -32768 or +32767. When people speak of clipping (NOT amplifier clipping, which is different), it means that there are N maximum sample values in a row. It is indicative of the fact that the input signal was probably too high and could not be fully represented with the available bits. There is no headroom in digital audio - if the signal would be greater than the max, it gets set to the max.


Volume Levels
First, the volume control is actually an attenuator. When the volume is at max, there is no attenuation - the full rail voltage is being supplied. When you turn it below max, the signal is attenuated. If the receiver says that it has db accurate volume control, then turning it down by 1 dB will do just that - reduce the voltage by 1 dB. What that means in terms of output SPL can't be known unless you have calibrated to a known level.

Using 0 dB on the volume scale as 'reference level' is purely a convention. You can use whatever you want. We need to distinguish between 'reference level' which commonly refers to the output SPL and 'reference volume' (my term) which is the number on the dial. Dolby Reference Level is well-defined and it is 105 dB peaks at the listening position (+10 more for LFE).

So here is how that is tied to the above explanation of digital audio levels:
The test tones in the receiver output pink noise that is 30 dB below 'full scale digital'. If you want Dolby Reference Level, you need to pick a setting on the volume dial and adjust the channel trims so that the SPL meter reads 75 dB. Doing so gives you 75 dB with a -30 dB input signal. In the moments that the input signal is full scale (0 dB) you would have the 105 dB peak - 75+30=105.

If the test tone you are using (AVIA) is -20 dB then you would calibrate to 85 dB because again 85+20=105.

You can of course choose to calibrate lower because true reference level is quite loud. Alternatively, if you do want to calibrate to true reference level but the loud test tones is really bothersome, then you can just pick a point lower on the volume dial and pick a lower SPL reading; for example you want reference level at 0 dB on the volume scale, but you set the volume to -10 and then calibrate to 65 dB on the meter (if test tone is -30). You now have 95 dB at -10 on the volume dial and 105 dB at 0 on the volume dial.

[Note that none of this has anything to do with passing the cleanest signal possible, full dynamic range, etc - all of that is solely determined by the recording itself].

 

[vlkcheng]

this is very confusing. What i want to know is if I play movies at -8dB, am I putting my speakers and receiver at risk?

 

[mfabien]

this is very confusing. What i want to know is if I play movies at -8dB, am I putting my speakers and receiver at risk?

More importantly, are you putting your ear drums at risk?

Read the following: http://www.lhh.org/noise/decibel.htm

 

[Snap]

this is very confusing. What i want to know is if I play movies at -8dB, am I putting my speakers and receiver at risk?

No Yammy goes all the way to +15 on the master volume. Like you had mentioned in the first post most other receivers only go to 0db and that is the max volume. If I were to watch a movie on my Denon at -8DB the people accross the street would be pissed. But I have my RX-V657 at -10, around there all the time to watch movies and it is fine.

It is simply how Yamaha desided to run the controls on the recievers. Same thing happens in pro use. Some mixers have 0db as the highest the master fader can go, and most can go +15-20 DB. Just depends on the manufacture.

 

[MDS]

this is very confusing. What i want to know is if I play movies at -8dB, am I putting my speakers and receiver at risk?

Maybe, maybe not. If you didn't follow the explanation of what it all means then nobody can give you an answer. Just don't worry about it.

 

[cleblanc]

I am fascinated by this thread because I just got a Denon 3806 receiver and was totally confused by the volume control. I have always had a Sony receiver in the past and the volume would start at zero (no sound) and go up. When I hooked up my 3806 last night I thought I had a problem with the audio because I wasn't getting any sound. After reading the manual, I realized the sound level goes from -80db to +18db. I could not hear any sound until it hit about -35db. I find it comfortable at -25db. This is the first time I've seen volume levels measured like this.
I'm curious as to what is the normal listening volume on these receivers. It seems like the -80db to at least -50db you can't hear at all, so I'm wondering why they start that low. I really thought there was something wrong with my receiver until I turned the volume way up from how it was shipped (at -80db). I found that at 0db it was quite loud and I set that to be the max volume even though it is capable of going to +18db.

 

[MDS]

I'm curious as to what is the normal listening volume on these receivers. It seems like the -80db to at least -50db you can't hear at all, so I'm wondering why they start that low.

There really isn't any normal listening volume. It is whatever you prefer and it will vary with the level of the source and the channel trims. It is odd that the scale would be calibrated so low because you really won't get much sound, if any, when the volume dial is near the bottom of the range unless the level of the input source is extremely high.

Warning...more technobabble

The 'relative' scale is used because it closely matches digital audio, as I described before. Once you've calibrated to a known level, the scale then has meaning. Think about a range of -80 to +18 in a linear fashion - there are 98 steps, so it would be equivalent to using the 'absolute' scale from 0 to 98. The catch is that the channel trims affect the scale. If you bump all the channel levels to +12, the max number will no longer be +18 - it should be +6.

You have to remember that a decibel is a ratio of two quantities. Once you calibrate, you know the ratio. If a volume setting of 0 gives you 85 dB, then setting it to -20 gives you 65 dB.

BUT...it's not that simple (is it ever?). If you did the calibration with the Dolby recommended test tone level of -20 dB then you only get 85 dB SPL when the input signal is -20 dB. Play a modern hyper-compressed CD where the average level is -10 dB and you will get 95 dB SPL. The peaks will still be the same (85+20=105 and 95+10=105) for the occasions when the level on the CD hits 0 dB.

I know this stuff can be confusing until you get your head around it. Just don't confuse 0 dB as a digital level with 0 dB on the volume dial. A 0 dB digital level means 'maximum level' whereas 0 dB on the volume scale means nothing unless you calibrate.

 

[Tomorrow]

I know this stuff can be confusing until you get your head around it. Just don't confuse 0 dB as a digital level with 0 dB on the volume dial. A 0 dB digital level means 'maximum level' whereas 0 dB on the volume scale means nothing unless you calibrate.

MDS....MANY thanks for turning the technical stuff into really clear English for us non-tech, non-EE types. You did an outstanding job. Scary even, as I think I understand. LOL.