How do i control volume with BIT perfect and my headphones?

I think you're a bit confused on what bit perfect and asio means.

Bitperfect is a term used for digital output such as coaxial or optical lineout.

It means that the digital data from the digital lineout matches what is decoded by your PC it you are outputting from a cd it'll match the bits from the cd.

since you are not using the digital lineout to feed to an external dac we won't worry about his

asio is a protocal that allows foobar 2000 a mre direct access to the sound card for lower latency.

Basically asio with foobar will bypass windows volume control and stop other programs from using the sound card.

Adjust volume to appropriate levels and just listen normally with foobar.2000

But what about if your headphones are so easily driven that a setting at -25 - -30dB which is far to the left of the volume slider gives normal listening volume and if you even make somewhat slight move to the right you'll blast your ears with music? That's my experience with WASAPI for foobar2000, the foobar2000's volume just won't be enough, need to limit it somehow so I suppose it's really impossible to use without any kind of external volume knob. I suppose there doesn't exist some kind of volume limiter plugin for this purpose that would bring minimal loss of quality and still provide a better result than using the windows mixer.

Bit perfect means that the decoded 1s and 0s of the audio file you are sent unchanged to the DAC chip in your sound card. Volume control while maintaining bit perfection is possible only with analog methods after the DAC chip has done the digital conversion. The most common case is a volume pot with a knob. There are also analog volume pots that are digitally controlled. The FiiO E5 volume control is one such example. I do not know whether any sound cards use this method.

The main reason why we fuss over bit perfect is that media players and device drivers sometimes do unwanted processing to the audio that degrades the sound. This necessarily changes the 1s and 0s. So to be sure that no unwanted digital junk is being added to our audio signal, we check for bit perfect.

However, there are also many times when we do want to change the audio signal. Virtual surround sound for gaming. EQ. Crossfeed. And of course digital volume control. These all change the 1s and 0s, but they are intended changes. Not being bit perfect is fine when it's done for changes that you actually do want.

Bit perfect aside, there are still pros and cons to using digital versus analog volume control. With analog you may get tiny amounts of noise from the volume pot, and possibly channel imbalance. With digital you may lose out on dynamic range because it is "throwing the bits away" to lower the volume. The cons to either method are minimal, and maybe inaudible, when implemented correctly.

Quote:

Originally Posted by Yoga Flame 

 

The main reason why we fuss over bit perfect is that media players and device drivers sometimes do unwanted processing to the audio that degrades the sound. This necessarily changes the 1s and 0s. So to be sure that no unwanted digital junk is being added to our audio signal, we check for bit perfect.

 

However, there are also many times when we do want to change the audio signal. Virtual surround sound for gaming. EQ. Crossfeed. And of course digital volume control. These all change the 1s and 0s, but they are intended changes. Not being bit perfect is fine when it's done for changes that you actually do want.

 

Bit perfect aside, there are still pros and cons to using digital versus analog volume control. With analog you may get tiny amounts of noise from the volume pot, and possibly channel imbalance. With digital you may lose out on dynamic range because it is "throwing the bits away" to lower the volume. The cons to either method are minimal, and maybe inaudible, when implemented correctly.

 

Thank you for such a clear and straight forward explanation.

To the posters in this thread who are having problems with their output direct from their soundcard being much too loud at 100% with wasapi/asio; you guys are probably best off just using the windows volume mixer. It's not perfect, but it is still a very good digital volume control implementation.

I think the reason people here so often say everyone should put all software levels at 100% is because they have invested in a very expensive analog volume control (headphone amp usually) and would rather do the volume adjustments with it.