4 ms·

> assume that the volume control on your operating system controls the DAC rather than doing the stupid thing of digital volume reduction Is this a safe assump

by ZoFreX 14y ago

> assume that the volume control on your operating system controls the DAC rather than doing the stupid thing of digital volume reduction Is this a safe assumption though? As much as I consider myself knowledgeable in this area, this is way off my radar. Even if this assumption does hold, the answer does make a good point when it comes to per-application volume controls, which are certainly performed digitally. Your point on SNR is a very good one, particularly on the low-end, but I would question whether any computer at max volume would produce a signal strong enough to cause distortion. I generally run my computer at around 90% volume but that's merely a habit carried over from having an analog hifi stack.

klodolph 14y ago
It would be easy enough to test -- download Right Mark Audio (free, but Windows only), connect your audio input to output with a patch cable, and test at different volume levels.
SeanLuke 14y ago
> Is this a safe assumption though? No it's not -- I was just pointing out that he's going on about various stuff without hitting the critical meat of the issue at all.
hammock 14y ago
Guy with some sound knowledge here. It doesn't matter if the attenutation is done digitally (as described by the top SE comment) or in analog fashion. The answer is always the same. In the music biz the general rule is: you want to put as much gain as early in the chain as possible. In other words, start at the source of the sound, and working your way towards the speakers, turn it up as loud as you can without distorting it. Take the example of a guitarist. He turns his guitar up as high as he can, then the amp gain as high without distorting it. Then at the sound console. etc The reason for this the later in the chain you are, the more electronics and cable is involved which adds noise to your signal. Highest signal-to-noise is achieved by ensuring you have as much signal as you can running thru from the get-go. In the case of a computer, again it doesn't matter how volume changes are done- crank up your software as high as you need (but not beyond the point of distortion), then adjust it further at the speakers.
- anthonyb 14y ago
  > Take the example of a guitarist. He turns his guitar up as high as he can, then the amp gain as high without distorting it. Then at the sound console. etc Without distorting it? Are you sure you have some sound knowledge? That doesn't sound like you know many guitarists... ;) qv. https://www.youtube.com/watch?v=4gDsbOraiqg https://www.youtube.com/watch?v=4gDsbOraiqg
  - iamdave 14y ago
    I've worked in Austin as a live sound mixer (FOH engineer, as we say) for a while now, and it's evenly split-some will say build your gain structure using the exact method; up until you clip, and back off from there.
- macrael 14y ago
  How do you determine the highest possible volume that doesn't introduce distortion? My sense in trying to find the right volume ratio for listening to an iPhone in my car is that it's best to not turn the iPhone volume all the way up, usually I use 75% or so. Is turning it up until you start to hear something funny the only way to do this or is there a more reliable way?
  - nitrogen 14y ago
    In pro audio there's usually a meter you can watch, or at least a clip LED that turns red during clipping. Otherwise you use your ears, or if you're really serious, you can use an oscilloscope with test tones and watch for the shape of the waveform to change, or beyond that, you can use dedicated test gear (or software) that measures THD directly.
- klodolph 14y ago
  It's not that simple. I've found in my rig, minimum noise is achieved with the guitar volume at 7 or so and preamp gain at minimum. If I turn up the volume on the guitar I can switch on the pad on the preamp, but this adds noise. I then add tons of distortion and gain in the software realm, so every dB of noise floor counts. Even clean guitar sounds are usually distorted. The sound console is different. You want everything in the console to be trimmed to around 0 dB on the console's meters, and NOT as loud as possible without distorting. Trimming it to 0 dB gives you consistency between channels making it easier to work with the faders, and gives you however much headroom the console is designed to work with. "Loud as possible" will mean somewhere like +24 dB on some consoles, which is too hot to work with. Yes, they have that much headroom -- nominal line level is +4 dBu, around 1.2 V, and consoles have internal voltages in the 15-24V range. The same goes for recording, you typically want things to peak at something like -18 dBFS. Making things peak "loud as you can without distorting" is the job of the mastering engineer, and it happens right before you stamp out CDs or MP3s or whatever.

by ZoFreX 14y ago

klodolph 14y ago

It would be easy enough to test -- download Right Mark Audio (free, but Windows only), connect your audio input to output with a patch cable, and test at different volume levels.

SeanLuke 14y ago

> Is this a safe assumption though? No it's not -- I was just pointing out that he's going on about various stuff without hitting the critical meat of the issue at all.

hammock 14y ago

Guy with some sound knowledge here. It doesn't matter if the attenutation is done digitally (as described by the top SE comment) or in analog fashion. The answer is always the same. In the music biz the general rule is: you want to put as much gain as early in the chain as possible. In other words, start at the source of the sound, and working your way towards the speakers, turn it up as loud as you can without distorting it. Take the example of a guitarist. He turns his guitar up as high as he can, then the amp gain as high without distorting it. Then at the sound console. etc The reason for this the later in the chain you are, the more electronics and cable is involved which adds noise to your signal. Highest signal-to-noise is achieved by ensuring you have as much signal as you can running thru from the get-go. In the case of a computer, again it doesn't matter how volume changes are done- crank up your software as high as you need (but not beyond the point of distortion), then adjust it further at the speakers.

anthonyb 14y ago
> Take the example of a guitarist. He turns his guitar up as high as he can, then the amp gain as high without distorting it. Then at the sound console. etc Without distorting it? Are you sure you have some sound knowledge? That doesn't sound like you know many guitarists... ;) qv. https://www.youtube.com/watch?v=4gDsbOraiqg https://www.youtube.com/watch?v=4gDsbOraiqg
- iamdave 14y ago
  I've worked in Austin as a live sound mixer (FOH engineer, as we say) for a while now, and it's evenly split-some will say build your gain structure using the exact method; up until you clip, and back off from there.
macrael 14y ago
How do you determine the highest possible volume that doesn't introduce distortion? My sense in trying to find the right volume ratio for listening to an iPhone in my car is that it's best to not turn the iPhone volume all the way up, usually I use 75% or so. Is turning it up until you start to hear something funny the only way to do this or is there a more reliable way?
- nitrogen 14y ago
  In pro audio there's usually a meter you can watch, or at least a clip LED that turns red during clipping. Otherwise you use your ears, or if you're really serious, you can use an oscilloscope with test tones and watch for the shape of the waveform to change, or beyond that, you can use dedicated test gear (or software) that measures THD directly.
klodolph 14y ago
It's not that simple. I've found in my rig, minimum noise is achieved with the guitar volume at 7 or so and preamp gain at minimum. If I turn up the volume on the guitar I can switch on the pad on the preamp, but this adds noise. I then add tons of distortion and gain in the software realm, so every dB of noise floor counts. Even clean guitar sounds are usually distorted. The sound console is different. You want everything in the console to be trimmed to around 0 dB on the console's meters, and NOT as loud as possible without distorting. Trimming it to 0 dB gives you consistency between channels making it easier to work with the faders, and gives you however much headroom the console is designed to work with. "Loud as possible" will mean somewhere like +24 dB on some consoles, which is too hot to work with. Yes, they have that much headroom -- nominal line level is +4 dBu, around 1.2 V, and consoles have internal voltages in the 15-24V range. The same goes for recording, you typically want things to peak at something like -18 dBFS. Making things peak "loud as you can without distorting" is the job of the mastering engineer, and it happens right before you stamp out CDs or MP3s or whatever.