Help with bit perfect and foobar2000

Ok so I'm on the quest to achieve bit perfect sound. My setup is an Asus Xonar Dx card which goes to an Audio gd FUN via an optical cable. I have do the DTS test as many have suggested and at first I was getting like a snow noise, but then I found out I need a DTS decoder, so I went and got the decoder for foobar (in the components page) and now it plays it and I dont here snow. So from what I read, at this point I should have bit perfect sound. Just for fun, I turned on a bunch of DSP in foobar including the equalizer and even moved all the bars in the equalizer and the DTS file STILL PLAYS. From my understanding, as soon as you use a DSP like an equalizer, its not bit perfect. So what am I doing wrong? Shouldnt I be hearing the static again when I play the file with DSPs on? The DTS file is 44.1kHz /16 bit as well as all of my settings.

Quote:

Originally Posted by Mad Max 

It should always play as long as the DTS decoder decodes the file or else the FUN's SPDIF (or USB) receiver will not "understand" the data.

WASAPI output  plus all DSPs tuned off is all you need for bit-perfect output from your PC.  DTS decoder is mandatory for DTS files or they will not play through the FUN or any DAC that does not have a built-in DTS decoder.

Then I don't get why people say to test bit perfect with a DTS file. I read that if you hear static, your not bit perfect, if you can hear the file, you are bit perfect. I purposely left the Equalizer on (which we know isnt bit perfect) and the DTS file plays normal. So how is this a true test of bit perfect?

Quote:

Originally Posted by Mad Max 

Beats me, lol.

You should be able to process the DTS file after it has been decoded with EQ effects and what not and still get a "legible" PCM stream to the receiver in your DAC.

Ok a couple more questions.

1. If I choose a 24 bit output using WASAPI in foobar, is this still bit perfect considering the fact that songs on a CD are only 16 bit or is 24 bit setting only beneficial when playing vinyl?

2. If I play a DTS file in iTunes, I hear static, this is because I need a DTS decoder for my computer because right now I ONLY have one for foobar via the component correct?