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[pcstockton]

Curious....

Does anyone know if MC's internal volume is "safe" to use with regards to bit perfection?

Thanks,
Patrick

[Vincent Kars]

Bit perfect is sending the unaltered bits to a DAC
Volume control by design alters the bits e.g. value * .5 to half the volume.
Another and better question is if using digital volume control has a negative impact on sound quality.
MC uses 64 bits for all DSP so a simple operation like volume control won’t result in an audible loss.
The final result depends on your DAC.
If it is 16 bits you can try the 16 bits out format with/without dithering (DSP studio)
In case of a 24 bit DAC the quantization error is -144 dBFS down so way below the noise floor of your gear.

If you like a little experimenting
-   Set digital volume to full and use the analog volume control.
-   Set analog to full and use the digital volume to obtain the same loudness.
-   Compare them

[pcstockton]

Well I Have a very fine DAC (Naim) so I expect all is well on that end.

I just thought I read that Foobar's internal volume was bit perfect, as compared to iTunes and WMP.

I cant say that I have heard serious differences when I do use MC's volume.  But I typically keep it at 100% just in case.

With Foobar I used it without thinking about it.

Thanks,
Patrick

[Matt]

Media Center has the highest quality volume possible.

You can read more about Media Center's volume here:
http://yabb.jriver.com/interact/index.php?topic=60113.0

[pcstockton]

Thanks Matt.  Very interesting read.

Would you mind clarifying something?

I use an ESI Juli@ card.  I dont set it to output anything.  I set it to "Auto", and it then matches whatever the source signal is.  Is this a theoretical problem when I use MC's volume with 16 bit audio?  Although my card is 24/192 capable, I dont think I am sending it anything but what the source file is.

Thanks,
Patrick

[Matt]

I use an ESI Juli@ card.  I dont set it to output anything.  I set it to "Auto", and it then matches whatever the source signal is.  Is this a theoretical problem when I use MC's volume with 16 bit audio?  Although my card is 24/192 capable, I dont think I am sending it anything but what the source file is.

It is best to always send the card the highest bit depth it supports.

If you use ASIO, this happens automatically.  If you use WASAPI, you should pick "24-bit" in DSP Studio.

[pcstockton]

Perfect.  Yes I am using XP and ASIO..... and it sounds fabulous.
-p

[Alex B]

...and it sounds fabulous.

That's the only thing that matters.

Preserving "bit perfectness" until the audio stream hits the DAC is irrelevant. All bits will be lost anyway when the stream is converted to the analog format. It will not be described as zeros and ones after that.

In general, there is no "bit perfect" source signal. The recorded audio signal has been through numerous DSP operations before the final product was finished. A simple volume adjustment with high quality DSP does not ruin it any more than the previous adjustments -- especially if the output mode is 24-bit, but also the 16-bit mode has enough headroom for any practical purposes. Some of the bit resolution will be lost when the signal is attenuated, but also the outputted signal will be the quieter by the same amount, so you will never hear any quality problems.

Absolute "bit perfectness" is a necessity only if you want to transfer encoded audio signal directly to an external decoder through the audio pipeline (e.g. Dolby Digital or DTS soundtrack through S/PDIF).