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Which should be the master volume control?

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#1
Here is another noobie question. What should I set as the master volume control? I playback music from my laptop thorough iTunes, feeding my active speakers. Therefore, I have three volume controls, i.e., my laptop, iTunes, and active speakers. Is it better to setup the volume as max for the laptop and iTunes with the speaker's volume control as the master or the other way round?
 

sergeauckland

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#3
Probably best (ie highest signal to noise ratio) to use the volume control on the speakers.
Agreed.

I use a Squeezebox Touch as my main source, and I leave the volume control of that at 100%. The SBT feeds a normal pre-amp with the volume control and the output of that goes to my active 'speakers that don't have their own volume control. It would be preferable to have the 'master' volume control between the 6 outputs of my digital active crossover (2 channel ADC going in, 6 DACs coming out) and the power amps, as that would reduce the noise levels from the crossover and also drive the crossover ADC harder, but as I don't have noise problems, it's just easier to do it the way I have.

In your case, certainly I would keep the PC and iTunes volume controls at 100% and control volume on the 'speakers.

S.
 
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#4
Set the speaker volume to about 30%, iTunes to 100% and vary the master volume to your comfortable listening level.

Since every PC and DAC are built differently, there will be times when 100% master volume will create more noise than the speakers.
 
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#5
Set the speaker volume to about 30%, iTunes to 100% and vary the master volume to your comfortable listening level.

Since every PC and DAC are built differently, there will be times when 100% master volume will create more noise than the speakers.
Thank you for your suggestion. I will try that.
 

pozz

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#6
Set the speaker volume to about 30%, iTunes to 100% and vary the master volume to your comfortable listening level.

Since every PC and DAC are built differently, there will be times when 100% master volume will create more noise than the speakers.
Is this accurate? At what % does Windows or Mac volume control reach unity?
 

RayDunzl

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#7

pozz

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#8
Doesn't "unity gain" stand for an unattenuated/unboosted signal when referring to a source feeding a chain?
 
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RayDunzl

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#9
Doesn't "unity gain" stand for an unattenuated signal when referring to a source feeding a chain?

Unity gain (in my book) means the voltage going into a device (which may be capable of gain or attenuation) is equal to the voltage coming out.

Which two are we comparing?
 

RayDunzl

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#10
You could expand that to digital, where the digits going in (or the source digits) equal the digits coming out, in which case, I would say 100% on the Windows/Whatever digital volume would be "unity".

Checking the properties of the Playback devices on my Win10 machine, the maximum for each is 0dB (unity with source).

On the Recording side, some are limited to 0dB, others provide the capability to amplify the digits received (multiply the sample values by some factor). The UMIK-1 microphone permits a 24dB boost.
 
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pozz

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#11
Unity gain (in my book) means the voltage going into a device (which may be capable of gain or attenuation) is equal to the voltage coming out.

Which two are we comparing?
To be clear, my question is basically the same as the OP's.

The comparison as I see it would be between the initial signal and its processing through the master volume control.
 

pozz

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#12

RayDunzl

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#13
I doubt there is any firm relationship between digital and analog output voltage level on consumer desktop/laptop analog outputs.

My previous motherboard had a much weaker output to the analog speakers I uses than the new motherboard with "improved" sound. I have to turn down the Windows volume for the same audible level than with the old motherboard. The ancient powered speakers in use have no volume control.

Professional devices may be calibrated, but then there's a range of levels you might choose from.

My DAC:

1558496791242.png


0dBfs = full scale digital signal, and converts to
24dBu = 34.72V pk-pk
14dBu = 10.98V pk-pk
4dBu = 3.47V pk-pk
depending on the output pad chosen
 
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Blumlein 88

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#14
To be clear, my question is basically the same as the OP's.

The comparison as I see it would be between the initial signal and its processing through the master volume control.
Too many variable to say.

Gives us details of what gear feeds what until you get to the speaker, and maybe there is an answer.
 

pozz

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#15
Benchmark? Nice DAC.

Gives us details of what gear feeds what until you get to the speaker, and maybe there is an answer.
Not relevant for my main system, which is PC (SPDIF passthrough) into a Benchmark DAC3 DX into two ADAM S2Vs.

But at work I use an HP laptop feeding an JDS Labs Atom Amp and Final Audio Design E3000 iems.
 

Blumlein 88

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#16
Adam S2V max input 24 dbu. Benchmark DAC3 DX has 0 db level of 24 dbu with the analog clipping point at 29 dbu. The Adam can provide some 12 db of gain itself. So I'd set the Adam for 0 db gain, and use the Benchmark straight in. It could drive the Adams to their max sound level and the DAC 3x will do a fine job of handling volume without the noise floor intruding.
 

Blumlein 88

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#17
Final Audio Design doesn't give a max input level. But looking at the sensitivity it takes 100 mw to reach 120 db SPL. The Atom can put out 10 times that amount. So you need to lose 10 db to protect your hearing. I'd set the Atom for low gain 1.0x. Assuming your feeding it from an on board sound card you might need to drop the signal a little. .5 volts would reach 120 db at max output. Without knowing the soundcard in the HP hard to say, but probably puts out about 1 volt at max. The volume control of the Atom might be working at a rather low volume setting. If so I'd reduce the gain in playback software until the Atom volume was sitting between 10 and 12 oclock at normal listening levels. Assuming your playback software isn't mangling the volume control.
 

pozz

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#18
Assuming your playback software isn't mangling the volume control.
That would be Youtube. The work machine is locked down fairly heavily and doesn't allow many applications. I assume the cleanest way out in this case would be to increase the impedance through a device like iFi's iEMatch.

Great audio fidelity through Youtube, I know—I want to hear the cleanest aliasing and compression I can.

It's more a matter of curiosity. I was hoping someone on this forum would chime in with a definitive answer about how the volume control was implemented or would point to some documentation (which I've failed to find on my own).

Thanks for all the advice in any case.
 

RayDunzl

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#19
I was hoping someone on this forum would chime in with a definitive answer about how the volume control was implemented or would point to some documentation (which I've failed to find on my own).
Essentially, digital volume control is math.

Want to take 6dB off the signal? Multiply every sample value by 0.5 or divide by 2.

13.7dB? Multiply each sample by 0.206538 or divide by 4.84172

Or is there some deeper question?

(I'm good at misinterpretation)
 

pozz

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#20
I think you get me. My question wasn't about digital volume controls in general, but about how Windows and Mac have implemented those controls.

My DAW at home for example, Reaper, uses 64bit FP internally for DSP calculations and references the outputs to dBFS meters. Despite looking into it several times and R'ing TFM I've never found an answer when it comes to my OS. Which is frankly irritating.

So it's a question about gain staging through the Windows master bus and... Youtube. Trivial, but there you have it.
 
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