[claytontstanley]

I just started resampling my 16/44.1 cd audio to 96kHz using Foobar2000 and the SRC plugin, and I'm definitely a fan.

Question though:

Does the SRC resampler plugin for Foobar2000 up the bit rate from 16-> 24, or does it just up the sample rate?

I looked around the net and couldn't find a straight answer to this question.

My receiver shows the sample rate changes when I use the plugin, but it doesn't display bit rate, and the SRC plugin for Foobar doesn't show the bit rate it's using, so I'm not sure if SRC is upsampling my 16/44.1 to 24/96 or 16/96.

Hopefully it's the former, as it would theoretically make the waveform more natural; not sure if it would make an audible difference though... but it certainly couldn't hurt right?

Thanks for your time,
-Clayton

machine info:
Windows XP
Foobar 0.9.6.7
SRC resampler version 1.03
Tascam US-144

[claytontstanley]

Just a quick note on this topic.

Mathematically, it makes more sense for the waveform's bitrate to be increased from 16->24 first, before increasing the sample rate from 44.1->96, and not vice-versa.

To try and say why, I'll use a painting analogy. Let's say you have only the 3 primary colors on your palette. You want to use mixes of these colors on your canvas, but you don't have the space on your palette for them. So naturally, you go and grab a bigger pallet, and then start mixing your 3 primary colors to make other shades. But you certainly wouldn't do it the other way around, right?
 
Also, Steve recommended to order it this way on a previous post: http://www.audiocircle.com/index.php?topic=69069.0 where he said he could actually hear a difference between the two orderings.

[claytontstanley]

After reading a few posts, it seems that the term SRC is used for all resamplers, so I need to be more specific.

I'm talking about the 'Secret Rabbit Code' SRC plugin for Foobar2000.

Did they really have to use the same 3-letter acronym (SRC) for their particular SRC?

On this note, I've seen some posts that an old SRC for foobar 0.8.3 did 24/96, and sounded good. Anyone have a link to the dll?

-Clayton

[claytontstanley]

I did some systematic testing tonight, and I'm fairly certain that the src resampler does not convert to 24 bit before upsampling.

So, using the src plugin, and setting the sampling rate to 96khz:
16/44.1 -> 16/96
24/44.1 -> 24/96
24/96 -> 24/96
16/96 -> 16/96

I used Wave Editor and imported some 16/44.1 flac files, and then exported them to 24/44.1. I then placed the 16/44.1 & 24/44.1 flac files side-by-side, with the src resampler set to 96khz, and did some a/b testing. The 24/44.1 flac files sounded much better than the 16/44.1 flac files, meaning that the src resampler must not be touching the bit rate before upsampling (for if it was, these files would sound identical).

To save space, I was trying not to have to re-encode all my 16/44.1 flac files to 24/96 if I could help it, and instead upsample on the fly. But since the foobar-plugin resamplers don't touch the bit rate, I'm going to have to convert all my 16/44.1 flac files to 24/44.1 so that I get 24/96 during real-time playback when using the foobar-plugin resamplers.

Note that, without the resampler enabled in Foobar, the 16/44.1 & 24/44.1 files sound identical (and worse than both the resampled versions), as they should. It's only when you upsample that you gain anything from increasing the bit rate. But by increasing the bit rate first before upsampling, you gain more than merely upsampling alone.

-Clayton

[audioengr]

Usually, I select 24-bit Fixed Point in Foobar Preferences before I select the SRC upsampler.

Once reason that 24-bit sounds better, even with 44.1 is the Core Audio I believe.  With Vista, the data is unmodified at 24-bit.  If its 16-bit, it modifies the data.  This was straight from a Microsoft audio section engineer.

Steve N.

[claytontstanley]

Usually, I select 24-bit Fixed Point in Foobar Preferences before I select the SRC upsampler.

Once reason that 24-bit sounds better, even with 44.1 is the Core Audio I believe.  With Vista, the data is unmodified at 24-bit.  If its 16-bit, it modifies the data.  This was straight from a Microsoft audio section engineer.

Steve N.

Steve,

I'm currently using XP, so the fact that both my 16 & 24 44.1 files sound the same could still fit, assuming that XP either modifies/doesn't modify them both. Or I just need to listen a bit harder / my equipment can't produce a difference / etc.

Using ASIO4ALL, my ability to choose the bit rate has always been greyed out, so I've never been able to mess with this. As far as I know, I'm forced to use ASIO4ALL with my Tascam-US144 when using the digital out of the Tascam, because that's the only way that I can pipe the audio from the computer to the stereo digital outs on the Tascam, instead of the stereo analog outs. Am I mis-informed here?

-Clayton

[audioengr]

Usually, I select 24-bit Fixed Point in Foobar Preferences before I select the SRC upsampler.

Once reason that 24-bit sounds better, even with 44.1 is the Core Audio I believe.  With Vista, the data is unmodified at 24-bit.  If its 16-bit, it modifies the data.  This was straight from a Microsoft audio section engineer.

Steve N.

Steve,

I'm currently using XP, so the fact that both my 16 & 24 44.1 files sound the same could still fit, assuming that XP either modifies/doesn't modify them both. Or I just need to listen a bit harder / my equipment can't produce a difference / etc.

Using ASIO4ALL, my ability to choose the bit rate has always been greyed out, so I've never been able to mess with this. As far as I know, I'm forced to use ASIO4ALL with my Tascam-US144 when using the digital out of the Tascam, because that's the only way that I can pipe the audio from the computer to the stereo digital outs on the Tascam, instead of the stereo analog outs. Am I mis-informed here?

-Clayton

Clayton - if you have a stock Tascam, this is probably the case.  Unless you use a DAW software (Digital Audio Workstation), then the digital outputs cannot be controlled properly.

The mods that I make to the Tascam to work with the Pace-Car allow it to be used with other players at all supported sample-rates.  I use it at 44.1, 88.2 and 96 using my Mac Mini.

Steve N.