Topic: Sony D50 48k24bit to 44k Audio CD recorder any advice?

[shadowbill]

I have WAV files recorded at 48k 24bit with the Sony PCM-D50.

I have the Optical Digital cable to use the Output from the D50 to the Input on a Pioneer Home Audio CD recorder.  The CD recorder has a built in sample rate converter to change the 48k to 44k.  But the "users manual" has nothing in it about converting 24 bit signals input digtally and converting them to 16 bit before it burns it to CD-R.

I've made a couple of discs, so far they seem to playback fine and sound like the source WAV file.  My ears cannot tell the difference between the CD-R and the original WAV file.

My questions: 

is the method I'm using now a decent way to make this conversion from 48k 24bit to 44k 16bit?

is it possible that the 24bit isn't being converted to 16bit because the users manual only lists that the built in converter changes 48k to 44k and says nothing about 24bit signals that are input to the deck?

so is this an acceptable way to make CD-Rs or do you tapers recommend another way to create CD-Rs from my WAV files?  I've read that some tapers use the computer and music software to change and make their high quality WAV files into CD compatible WAV files.

Thank you for any advice or thoughts and opinions to help me make better CD-Rs.

[alloyv]

Here a hardware solution : Behringer SRC2496 : http://www.behringer.com/EN/Products/SRC2496.aspx
It can convert any signal.

[udovdh]

Depending on the noise in the signal from the Sony, noise in the CD-recorder etc it will be all good.
You just need a bit of dithering at the 16th bit.

[shadowbill]

What is Dithering at the 16th bit?

Do I do this before send the WAV file to the CD recorder via Optical cable (Output from D50, to Input CD recorder)??

Or do I do this after I make the CD-R?

Thanks.

[stantheman1976]

Dithering means converting the 24 bit to 16 bit.  There's no way to convert the on the D50.  You have to do that on a PC.  If you're going from the D50 to the CD recorder with an optical feed you should be fine.  CD is 16 bit standard.  That never changes.  So if you feed the CD recorder a 24 bit signal it will automatically be changed on the fly to 16 bit when the CD is created. 

[alloyv]

As someone says somewhere else on this forum, sox http://sox.sourceforge.net seems to do it very well.

[Brian Skalinder]

So if you feed the CD recorder a 24 bit signal it will automatically be changed on the fly to 16 bit when the CD is created. 

Though it will probably truncate the least significant 8 bits rather than dithering.  I think it's best to transfer the 24/48 to computer then use software to perform sample rate conversion (resampling) and word length reduction + dithering.  Check the stickied post at the top of the Computer Recording forum for free or pay software to accomplish both.

[prof_peabody]

Here is a graphical representation of why you shouldn't truncate:

Original (18 bit) image:


Tuncrated (8 bit) image:


Dithered (8 bit image):

[dallman]

Very nice visual representation ^^^

Here is a very good program for dithering from 24/48 to 16/44.1, and it is free.

http://www.voxengo.com/product/r8brain/

[prof_peabody]

Izotope also has some nice images and a dithering free guide on their website.  The guide is not specific to their own MBIT+ algorithm.