Sample Rate and Bit Depth Explained

Hello again! Before we get in today’s video quick tip, I just wanted to share little of feedback I got recently from a viewer name Jordan. Jordan writes in and he says,

“This is completely not a joke and in no way trying to be rude but why does it seem every video here is just your face on the screen. I mean don’t get me wrong. You’re a handsome dude but we wouldn’t maybe having a DAW session or something at least a mixer or some plugins make a lot more sense than just your face talking into the camera. It’s honestly a little weird for a music production blog and has turned me off from your tutorials as I have no desire to stare at your face while you explain mixing tips. Again, this can be taken in a rude way but isn’t intended to be so. I’m just honestly not sure why you need to have your face filmed for music production tips makes any sense in the universe. Like one to two videos is alright but all of them. Come on man!”

So, today’s video quick tip I’m going to be expermenting with a new format based on Jordan’s feedback and I hope you like it. Here we go!

Dezz Asante here from the TechMuzeAcademy with another MixLessons.com video quick tip. This one comes again from the Gear Slutz forums, member asked “I’ve never used 96 kilohertz, should I? I typically use 44.1.”

Well, it’s a good question and I think it’s one that deserves a little explanation. So, I guess today what we’ll do is we’ll talk a little bit about what sample rate is which is what he’s refering to here and what bit depth is and how you should consider them both when you are setting up your project.

So,first of all lets start with an explanation. What does sample rate actually is, is a…its the amount of snapshots of audio when you’re recording that are being captured per second. So, 44.1 is 44,100 samples or snapshots of audio per second. So, it would stand to reason then that 96,000 snapshots per second would probably be a higher quality, higher resolution audio and you wouldn’t be wrong in that assumption.

The other thing to consider is your bit depth. Your bit depth is in each one of those samples, how many numbers are representing the wave form at that point in time? So, for example a 16 bit audio file, 16 bit 44.1 kilohertz means you’re getting 16 digits of information captured per sample and you’re getting 44,100 of them captured per second. So, I hope that’s clear. So…conversely, if we were to record 24 bit 96k we’re getting a lot more information. In other words, the file sizes are going to be much larger, bulkier and a little more cumbersome for the computer to deal with.  At 24 bit, you’re getting 24 ones and zeros that represent every single sample and you’re getting 96,000 of those samples per second. So, obviously a much higher audio resolution.

Now, in my experience the bit depth is a much more obvious and perceivable adjustment. So, if you were to record at 16 bit, what would happen is…by the way 16 bit 44.1 is the CD standard for audio. So, some people will say well if that’s what the CD is anyway then why work at anything higher? And there’s a couple of reasons for it which I’ll get into in a moment. So, if you’re recording at 16 bit, one of the things that happens is with only 16 bits representing every sample, you’ll loose …in comparison to a higher bit depth, you’ll loose dynamic range. So, from the loudest signal possible to the softest signal possible. And this will represent itself in things like…for example, if you were to put on a good set of headphones, listen at a nice volume, and listen to like a hand clap, with some reverb on it. You’ll be able to hear that at a certain point in time that reverb as it’s getting softer and softer and fading out at the tail of the reverb, at a certain point in time it will just truncate and there won’t be any bits left to represent the audio getting softer than that. And this is something you can actually hear. You can experment with this in your own digital work stations at home. Just record something with just a simple short transient like a hand clap or something, a snare shot or what have you and …and then apply some reverb working at 16 bit and have a listen very, very carefully and see if you can hear that reverb fade all the way to silence. Now, when you go to 24 bit there’s more numbers, there’s more data tor represent, more of that signal. So, you’ll be able to hear that reverb tail fade right to silence. At least perceivably so I’m sure in the world of mathematics there’s still some truncation going on I imagine. But you won’t be able to hear it. So, I always recommend working at the highest bit depth possible and…and when you’re considering sample rate…and by the way, higher bit depth is not that much more taxing on your computer. But when you’re working at a high sample rate like 96K or 192 as some systems are capable of. Then thats something that definitely adds a load to  your computer’s processing power. So, my normal recommendation is is to work at the highest bit depth you’re able to work at and I normally work at 44.1 or 48 if my audio is going to the DVD because the DVD standard is 48 kilohertz or 48,000 samples per second. Okay! Now, the sample rate increase is not as  noticeable. Now, I’m probably going get a little flack when I say this because I think that some people are really into getting the most quality in resolution out of their systems as is…you know technologically possible. And certainly nothing wrong with that approach but in my experience I found that the high sample rates tend to be very hard on the computer, tend to have limitations to my system resources. I’m not able to work as freely as I would otherwise. And it’s also not as noticeable an improvement in the sound quality of the file. It’s an improvement that’s for sure and the Mac will tell you that but it’s not as noticeable.

So, my recommendation work at the highest bit depth possible and then work at the sample rate that your end product is going to be destined for. So, if it’s for CD…you know 44.1, 16 excuse me, not 16 bit but work at your high bit depth but 44.1 for your sample rate. When you do get to the end of your mix and you’re about to bounce down an export – the full mix, the final mix and it’s going to be destined for CD, make sure you use a dither plugin at the end of your signal chain on your two mix to…to add some low level noise to the signal to avoid…to avoid the issues that come with sample rate conversion or bit depth conversion as well. Okay! So, hopefully that makes sense. Hopefully, it’s not too confusing. It is  a bit of science. And if you have questions by all means leave comments below the video and  we’ll see you on the next quick tip.

Okay, so I was being a little bit of silly there and Jordan listen, I apprecaite your feedback and I appreciate you being a good sport. To give you a proper response to your feedback. I treat these videos as sort of a converstion with folks that are interested. And so, I chose to do this format because it is just that. It’s me having a conversation with you about the topics that we love to talk about. If indeed I have something to show on the screen, if I’m going to give a demonstration of a technique or something of that nature then ofcourse, that’s exactly what I’ll do – I’ll show the screen. But, I’d like to keep these conversations as that, an informal conversation about audio. So, once again I appreciate the feedback. Anyone has anything that they’d like to share with me by all means let me know. TechMuze Podcast at Gmail.com is a simple way and easy way to get me. Or just leave me a comment anywhere I’m found on the internet and I’ll be sure to …to respond to you. And once again like I said earlier, we will see you on the next quick tip.