Converting from 24 bit 48k to 16 bit 44.1k: ProTools vs. Rosetta 200 -?

[mixerguy]

Converting from 24 bit 48k -> 16 bit 44.1k - ProTools vs. Rosetta 200 -?

Hello all

I do a lot of work at 24 bit 48k. (48k is common in the film world) I sometimes mix ITB, using external hardware outboard.

Once I have my mix printed (recorded with busses ITB or bounced ITB) at 24 bit 48k (usually using the L2 plug), I then also bounce to disk internally and at the same time convert to 16 bit 44.1k - using L2 plug to reduce and dither down to 16/44.1 Sometimes I’ll use the ‘export selected file as’ command from the existing 24/48k mix to get to a 16/44.1 file.

I have always been disappointed at how the mix collapses, and becomes flatter doing it either way within PT. (Or in Digital Performer, for that matter)

If I buy a Rosetta 200, I could go digitally out of one rig, into the Apogee, then use it’s SRC UV22HR to sample rate convert + dither down to 16/44.1 and go digitally into a second rig and record it there. (I already have multiple computers and interfaces at the ready)

Has anyone done comparisons betwen Digi’s bit and sample rate conversion ITB and using the Rosetta 200 to do the same? Any opinions / info?

many thanks!

[Dave Peck]

You may also want to consider going out of the box via a 48k D/A converter, then into the analog ins of a 44.1k A/D converter. Basically, it's sample rate conversion in the analog domain. If you have decent A/D and D/A converters it can sound better than some digital domain SRCs. It also allows you to add analog processing between the converters. Mastering studios often use this technique for going from 96k to 44.1 with analog processing in between.

Dave Peck

[mixerguy]

Originally Posted by Dave Peck

You may also want to consider going out of the box via a 48k D/A converter, then into the analog ins of a 44.1k A/D converter. Basically, it's sample rate conversion in the analog domain. If you have decent A/D and D/A converters it can sound better than some digital domain SRCs. It also allows you to add analog processing between the converters. Mastering studios often use this technique for going from 96k to 44.1 with analog processing in between.

Dave Peck

I hear that the Apogee Rosetta 200 does a very good SRC. I also want my 16 bit 44.1 mix to sonically match the 24 bit 48k (so I don't want to add analog processing)

Has anyone done comparisons?

thanks!

[smarsland]

Originally Posted by Dave Peck

You may also want to consider going out of the box via a 48k D/A converter, then into the analog ins of a 44.1k A/D converter. Basically, it's sample rate conversion in the analog domain. If you have decent A/D and D/A converters it can sound better than some digital domain SRCs. It also allows you to add analog processing between the converters. Mastering studios often use this technique for going from 96k to 44.1 with analog processing in between.

Dave Peck

I can do this now! Except I don't have an EQ yet. I'm thinking a QUALITY hardware EQ vs. a plug. Thoughts?

mini-me --> PT (edits) --> mini-DAC --> EQ that I don't have yet --> Hardware L2 --> CDRW2000



s

[mixerguy]

I would prefer it if this thread is was not hijacked.

I restate my original question:

Has anyone done comparisons between Digi’s bit and sample rate conversion ITB and using the Rosetta 200 to do the same? Any opinions / info?

Thanks

[smarsland]

Originally Posted by mixerguy

I would prefer it if this thread is was not hijacked.

I restate my original question:

Has anyone done comparisons between Digi’s bit and sample rate conversion ITB and using the Rosetta 200 to do the same? Any opinions / info?

Thanks

sorry.. will post that question another time.

[mixerguy]

So..... Has anyone done comparisons between Digi’s bit and sample rate conversion ITB and using the Rosetta 200 to do the same? Any opinions / info? Thanks!!!!! thumbsup

[mixerguy]

anyone?

[mixerguy]

OK so I finally did get my Rosetta 200....

I did comparisons using it's SRC and UV22 HR dithering.....

and - the Rosetta 200 does sound better than having either ProTools or DP do the conversion from 48k 24 bit to 44.1 16 bit.

[ghellquist]

Do compare as well using the r8brain software. It is much better than the PT built-in SRC.

Gunnar

[mixerguy]

Originally Posted by ghellquist

Do compare as well using the r8brain software. It is much better than the PT built-in SRC.

Gunnar

Here is a link

******//www.voxengo.com/product/r8brainpro/

I thought the Apogee Rosetta 200 SRC and UV22 HR dither sounded VERY good... so i'm set.

[Roadworthy]

Mixerguy,

Thanks for taking the initiative and posting your results. I started following your thread back in January and have been wondering myself... The 48/24 bit video world requirements and the 44.1/16 bit audio world requirements were concerning me as well. I, too, just recently purchased a Rosetta 200. Not being as well versed as most of you audio gurus, I had my doubts on whether or not this would actually be a good solid solution. Thankfully, after spending that much cash, it appeared to be just what I was looking for--retaining the quality of the original mix AFTER the conversion. Grateful to hear someone else like you found similar results. Thanks again.

[StudioRhythm]

I'm not surprised that you don't like the sound after bouncing a 24/48 file down to 16/44.1 in one step -- when you do it in one step, your dither is not working properly, since you're applying dither before the SRC takes place, which negates the effect of the dither. So, your final mix ends up as a truncated 16 bit file!

What you should do (if you're doing it all in PT) is to take your 24/48 mix, and bounce to disk to a 24/44.1 file. Then, open a 24/44.1 session, import that bounce, and either bounce it again with dither to a 16-bit file, or use the export regions command (which uses built-in dither and is quicker).

That will make a HUGE difference in your sound quality -- truncated vs. properly dithered is a pretty night and day difference. I haven't compared SRCs myself, but I would bet that doing the PT SRC correctly would put it on a much more level playing field with some of the other options out there.