Can anyone recommend some software (Mac) that can easily batch convert 24bit .WAV’s to 16bit (sample rate conversion would be great). Something easy to use and ‘no frills’ is what I’m after.
I’ve got a sampler I want to load up, but it only accepts 16bit .WAV files (and the majority of my library is now 24bit 
).
Cheers!
and one for windows 
edit: including a short description so this is forum searchable
If you would like to convert your audio from one format to another, Max can read and write audio files in over 20 compressed and uncompressed formats at almost all sample rates and and in most sample sizes. For many popular formats the artist and album metadata is transferred seamlessly between the old and new files. Max can even split a single audio file into multiple tracks using a cue sheet.
Max leverages open source components and the resources of Mac OS X to provide extremely high-quality output. For example, MP3 encoding is accomplished with LAME, Ogg Vorbis encoding with aoTuV, FLAC encoding with libFLAC, and AAC and Apple Lossless encoding with Core Audio. Many PCM conversions are also possible using Core Audio and libsndfile.
If you are familiar with terminal usage then ffmpeg should do the job. This should do the trick:
find . -name "*.wav" -exec ffmpeg -i {} -acodec pcm_s16le {}_16.wav \;
If you would like to do sample rate conversion (for example to 44,1kHz):
find . -name "*.wav" -exec ffmpeg -i {} -acodec pcm_s16le -ar 44100 {}_16.wav \;
It will do a search in current directory for all files which have extension ending with .wav and then convert them to signed 16bit pcm with sample rate of 44,1kHz and save them with the same file name as original files only with _16 appended at the end of the name.
That is great thank you I’ll give that a shot.
I’ve already arranged my samples into banks/folders, so this could be the way to go 
Also check out http://sox.sourceforge.net/
Though I usually use either Adapter (mac and windows) https://macroplant.com/adapter
or LameXP (windows) http://lamexp.sourceforge.net/
normally you would apply dither when going from 24 down to 16 bits,
I don’t know if a batch converter does also that.
Command line software like SoX does this, Ableton Live actually uses SoX internally for sample rate conversion at export.
another rec for this (inconveniently named) but super useful app
mac only (and not free) but ages ago i sprung for this audio recorder/editor/toolkit app and def use it for batch processes
If one has access to the Adobe Creative Suite, Audition is a very good batch file editor / converter.
Audition is pretty great overall, I use it for many, many projects.
I use this for Mac.
Thank you for all the recommendations 
I didn’t consider dithering, but as the application is far from hifi (the samples will be loaded into a drum machine) I think I should be ok?
I’m going to have a try at a few of the applications and see what fits with me.
Is there a source for this? I would love to share this factoid. SoX is such a great tool.
I’ve been using a an app called Switch Sound File Convertor by NCH software.
It’s described here, under section “32.3.2 Sample rate conversion/transposition”:
Rendering audio from Live with a sampling rate other than the one that was used while working on the project is also a non-neutral operation. As of Live 9.1, however, sample rate conversion during export uses the extremely high-quality SoX Resampler libraryThis product incorporates the SoX Resampler library (http://soxr.sourceforge.net), as licensed under the GNU LGPL v2.1 (http://gnu.org/licenses), which results in downsampled files with extremely low distortion.
Perfect. Thanks!
Audacity is free and it’s an amazing tool for many many things. Here’s an example of batch conversion.
afconvert in /usr/bin
Audio File Convert
Version: 2.0
Copyright 2003-2013, Apple Inc. All Rights Reserved.
Specify -h (-help) for command options