Downsampling (Specifically Logic Pro)

[AlecBeretz]

Sort of a newbie mastering question. What sample rate do you guys record at, and how do you convert it to 44.1khz?

I feel like 88.2khz would be far easier than 96khz because of the 2:1 sample ratio but I know a lot of people record at 96.

Thanks HR

[jonny deep]

Sort of a newbie mastering question. What sample rate do you guys record at, and how do you convert it to 44.1khz?

I feel like 88.2khz would be far easier than 96khz because of the 2:1 sample ratio but I know a lot of people record at 96.

Thanks HR

You'll find most people record at 44.1KHz, I think. There's no real need to record at higher rates - if your recordings don't sound good, sample rate is the least of your worries. 24 bit recording is generally given the thumbs up, though.

Massive Master wrote a good, lengthy post on this subject recently, but I forget where - I think it essentially boils down to the Nyquist-Whatshisface sampling theorem, which states that to successfully convert sound of frequency up to x Hz you need double the sampling rate. As we can hear up to ~20KHz, therefore around 40KHz sampling rate is sufficient.

[jonny deep]

You'll find most people record at 44.1KHz, I think. There's no real need to record at higher rates - if your recordings don't sound good, sample rate is the least of your worries. 24 bit recording is generally given the thumbs up, though.

Massive Master wrote a good, lengthy post on this subject recently, but I forget where - I think it essentially boils down to the Nyquist-Whatshisface sampling theorem, which states that to successfully convert sound of frequency up to x Hz you need double the sampling rate. As we can hear up to ~20KHz, therefore around 40KHz sampling rate is sufficient.

That said, if you do want to record at a higher sampling rate, then 88.2 is a good idea as moving back to 44.1 for CD is trivial.

Also, determining the best sample rate to use depends on what you're doing - if you're creating sound for DVD, for example, I think you want to use 48KHz, that being the DVD audio standard (IIRC).

[AlecBeretz]

Ok, thats kind what I thought. So, on a DAW, if i recorded at 88.2, do i just bounce it as a 44.1? theres no "conversion software" or specific process?

[jonny deep]

Ok, thats kind what I thought. So, on a DAW, if i recorded at 88.2, do i just bounce it as a 44.1? theres no "conversion software" or specific process?

Depends on the DAW, I guess, but that's the kind of thing I'd expect to be able to do in Reaper's Render function.

[Dags]

Hi Alec

Logic's bounce to disk will do the sample rate conversion for you if you set the output at 44.1. You can also dither to 16bit at the same time (which it does as the last step after SR conversion)

I know that there's all kinds of arguments for and against using various sample rates for recording, but I find 48kHz a useful compromise between the "close to the upper frequency cap before aliasing can potentially occur if a bat starts screeching nearby" 44.1kHz and the "you beaut easy to strip back to CD-compatible format using a simple division factor but enormously processor-hungry and not compatible with lower-end MBox audio devices" 88.1kHz.

Dags

[gecko zzed]

When you do a bounce down, Logic (as someone has pointed out) will bounce down to whatever rate you want. The conversion happens behind the scenes.

What you record at is up to you. Some of suggested 48. Others go 96 or more.

I have not felt any need to use anything other than 44.1, but I do record at 24 bit.

[ashcat_lt]

Most sample rate conversion involves first upsampling and the downsampling. Whatever they do, it's really not a whole lot different going from 88.2 or 96 or whatever. There will still be artifacts either way.

To me, 44.1K is more than necessary (I often low pass my mixes at 18K or so to sort of "help" the anti-alias and "warm" it up a little). It is compatible with CD, with every soundcard, with every mp3 conversion utility...and takes up proportionately less space both on disk and in RAM/CPU. Any process which needs the extra sample rate (mostly distortion-type things which add harmonics) will usually do its own "oversampling" process, but otherwise I prefer to just avoid the possible damage that sample rate reduction can cause.