Sample Rates: The What, Why & When for Voice Recording
The sample rate refers to the number of samples of audio carried per second, measured in Hertz (Hz). It determines the fidelity of digital audio reproduction, indicating how frequently the analog audio wave is sampled and converted into a digital format. Common sample rates include 44.1 kHz (kilohertz) for CDs and 48 kHz for professional digital audio. A higher sample rate typically results in better audio quality but requires more storage space and processing power. Conversely, lower sample rates may sacrifice some audio fidelity but are more efficient in terms of file size and processing requirements. Audio sample rate plays a critical role in digital audio production, influencing the clarity, accuracy, and overall perception of sound reproduction. But most of us won’t be able to tell the difference between audio recorded at 44.1 kHz or 48 kHz. So why does it matter?
DAWs and Sample Rates
Most DAWs let you choose your sample rate- even basic recorders like Twisted Wave and Audacity (which don't technically count as DAWs). Apple's GarageBand is one that doesn't let you change the rate. It maxes out at 24bit, 44.1 kHz. I have taught classes in GarageBand over the past few years primarily because there were mistakes actors were making while using it that affects their auditions and sessions. I recall someone giving me a hard time about that on social media- but I will tell you that many working voice actors do perfectly fine auditioning and running session backups on GarageBand- which is a path of least resistance, since it's already on their Mac. So what's the issue?
As every voice actor knows at this point, Source Connect from Source Elements is a part of your life now. It is largely accepted as the best sounding and most reliable option for recording talent remotely. A powerful yet admittedly under utilized component of Source Connect is Q Restore and Replace. This option appears on the Pro and Pro X versions, while voice actors are generally on Standard. This feature allows the engineer at the studio to replace their audio recorded live with Source Connect Pro with the backup files from your computer. This means that if there is a dropout, the engineer might opt to use the restore function to fix it in the background. We discuss this in my class Critical Connectivity: Source Connect and Beyond, so keep an eye out for that in the events tab or look for the option to view a replay. This is one of the many features that set Source Connect apart from all other remote recording options. If you're curious about the details of Q Restore and Replace, check out this video of the team at Source Elements doing a live demo. But there's a catch... and it involves sample rate!
"My advice is to stick to the industry standard of 24 bit, 48 kHz for everything you do."
In order for an engineer to make use of Restore and Replace, they need you to be at the same sample rate they're at, which is generally 48kHz. If you're on GarageBand, this won't work. Source Connect will easily convert your 44.1 kHz audio to 48 kHz behind the scenes with no sonic impact over Source Connect, but the files on your computer won't match what the engineer on the far end is going to need- rendering the whole thing useless. This is one of the many reasons we prefer you to be at 48 kHz. If you're simply running a backup, you might be better off using something else for that purpose- even Quicktime will let you do it! Source Elements makes other products that also rely on the users on both ends to have matching sample rates. Installed along with your Source Connect Standard is the Q Manager. You should be familiar with it in case an engineer asks you to use it. It's where your backup files are being stored for them to retrieve if needed, and all you need to do is open it when you launch Source Connect.
But I'm an Audiobook Narrator, and ACX only wants 44.1 kHz!
True! Your deliverable for ACX is 44.1 kHz- but this shouldn't stop you from recording at a higher sample rate and then exporting your chapters as 44.1 kHz MP3. When I handle audiobook mastering, I always urge the narrators to capture the highest quality sound going in, so that any processing and exporting/ converting has less of an impact on the sound quality.
Who in their right mind would ask for 96 kHz??
There was an uproar on social media a little while back when a video game audition was making the rounds. Among the things that outraged voice actors that work from home were the following asks: a Neumann U87 AND a Sennheiser 416 with at least two feet clear in all directions from both mics, and a sample rate of 96 KHz. Non-negotiable. The production company was working out of a space in LA, and this is a fairly commons setup for higher-end video games. If you wanted to work remotely, this is what you needed to have- which rules our almost every home booth I've ever seen. Comments like "They don't know what they're doing!" to "No one can hear the difference between 48 k and 96 k!!" demonstrated to me these social media voice actor "experts" have clearly never worked on projects of that caliber. And that two mic setup is fairly common in animation and gaming- but that's another story. Why would they want 96 kHz as their sample rate?
I often like to use digital photography as an analogy. Photographers tend to shoot in RAW format, which is a much larger file size than the JPG files we're used to seeing from our phones. When you take a JPG file and blow it up, at some point it starts to become grainy or pixelated. A RAW file has much more data, and can blow up quite a bit larger (think billboard advertising) without degrading. RAW files also allow for more processing and manipulation in Photoshop without impacting the quality of the image.
Sometimes videogame audio files go through quite a lot of processing- pitch shifting, effects, time compression, etc, and just like digital photography- starting with the highest quality allows you to maintain the integrity of the file throughout the process.
So when should you change your sample rate?
My advice is to stick to the industry standard of 24 bit, 48 kHz for everything you do. You'll be ready to rock for commercial work, animation, video games and more. You'll be on the same page as the studios in terms of quality and functionality. Export your files to whatever the deliverables are if you're doing the kind of work that also needs you to be the engineer. ACX wants 16 bit 44.1 kHz MP3? Great! Export it that way. A commercial client wants 24 bit 48 kHz WAV files? Great- just send them your takes that way, assuming your working with a DAW that lets you access your files. Pro Tools is pretty great for that, in case you're still using a recorder that makes you have to export each take instead of having it stored in a folder.
As always, if you need help or advice on your current workflow and need some help or eyes and ears on your setup, I'm here for you! If you're signed up as a member of my website, you have access to the Forums to post, comment and dig a little deeper into topics like this. When you take one of my classes, you're now given access to a private group that continues the conversations and lets you share what you're learning and experiencing. I hope to see you there!
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