recording mixes from my DAW -- audio oddities

Happy New Year to all!

I’m running Reaper 4.53 (32-bit) and Audacity 2.0.5 (from the .exe) on a Win 7 Home Premium 64-bit desktop.
The computer has the Realtek High Definition audio card, which came stock with the unit.

I’ve tried to use Audacity for recording my Reaper mixes, and I’m experiencing the following:

  1. a low-level hiss, audible at low program levels and quiet passages, even with dithering turned off.
  2. a sort of compression ‘pumping’ effect, when transients spike. This happens well below the Audacity zero level.

When I record mixes, I have both programs set for the Direct Sound driver. I do my best to manage volume levels and transients in the individual Reaper tracks with my various plugins, but I’ve tested my Audacity-recorded wav files with the ones rendered from software in Reaper, and there’s a definite difference in quality; Audacity’s at a disadvantage here.

Is there a way to improve the performance, or am I doing something wrong? I have experience with analog mixing, so I’m not certain where the trouble is.

Why do you want to do that? Is it just a test, or is there a practical purpose?

That’s because when recording with Audacity, the digital data from Reaper is rendered to analogue by the sound card and then back to digital when recorded in Audacity. The final quality will depend on your sound card.

The obvious solution is to render the audio file directly from Reaper rather than recording it, which leads back to my first question, why do you want to record it rather than render it directly from Reaper?

It’s mostly because I’ve been working with Audacity for the past 7 years. I’m used to the work flow, and it’s a kick-*** editor.

Rendering in Reaper doesn’t allow for real-time fader moves. When I record mixes in Audacity, it closely resembles the analog mixdown process that I’m more accustomed to (old dog, old tricks – studied recording techniques in the late 70’s).

If it can’t be done, que sera sera, but I was hoping for a workaround in the digital domain.

Have you tried the Wasapi input source?
It gives the most accurate rendering I’ve experienced so far.
I wonder a little bit about the issues you have, especially the pumping/compression like corruption.
Have you already compared the two audio files 1:1?
I’m referring to the frequency content (spectrogram), DC offset, synchronicity and so on.

Re. the “pumping compression”, one possibility is that it could be some sort of automatic gain effect. Check that all of the Windows Sound “Enhancements” are turned off. Audacity Manual

Have a look at track automation in Reaper.

Ah, Windows Sound Destruct – I mean, “enhancements”. I should have known. Bleepin’ Microsoft! There it was, right under my mouse’s nose – Loudness Equalization… 2-band spectral compression for tiny USB-powered desktop speakers (never mind that I’ve had a Klipsch ProMedia 2.1 powered system since '07). All options unchecked now.

Well, I was going to have to learn it sooner or later. No more procrastination… :blush:

The one time I tried WASAPI in Reaper, the render crashed. I’ll have another go to check it out. I didn’t do any spectrographic or other detailed analysis in Audacity, but I knew that if I could hear it, it would be quite awful. Thanks for reminding me of due diligence.

I’m working on a home project, but it needs to be commercial-grade. I’ve been around a while, and I know Audacity has the goods. I just need to tune up my work flow and integrate it with Reaper more efficiently.