If you’ve read through Parts 1 and 2, chances are you now need a way to get all of this analog gear into your PC. In this guide, I hope to outline two avenues for converting that audio chain into a digital signal through either interfaces or mixers. Depending on your streaming setup (one PC or dual PC) you may be looking for different functionality.
With one PC, you may simply be interested in getting your microphone/compressor collective as an audio input without added features. In that case, you’ll want to check out the interface route. If you want to run your mic through gear for added sound effects or because you’re also inputting music, game audio, or other sounds and want to adjust those levels on-the-fly then you’ll want to focus on mixers.
As I mentioned in the first installment of this guide series, my plan is to also include some gear recommendations so that these guides are informational as well as practical. However, if you have questions about specific gear, please PM me rather than comment below. I’d like to keep the comments section devoted to questions about the guide and gear-related inquiries can quickly take over with a plethora of specific questions and nuances.
Interfaces, Bit Depth, and Sample Rate
An audio interface is simply a box which converts your XLR (or ¼ inch) input from analog to digital and feeds it to your computer via USB (although there are FireWire/Thunderbolt/PCI routes as well, we’ll be focusing on consumer-level USB). While your sound card is also technically and audio interfaces, its limited I/O and low-grade line level input do not make it ideal for your spiffy professional equipment. As many will notice, inputting a 1/8 in mic cable via the motherboard jack (like a cheap headset mic) will often result in static and unwanted noise. The reason for this is the electromagnetic and radio interference from the other circuitry in close proximity on the board.
I’m going to assume you already have a preamp and compressor, so my interface recommendations will not be based on the quality of preamps or the presence of phantom power. Since most interfaces in the consumer-level price range operate in much the same way, I’ll be keeping my recommendations to a minimum. Instead of a long list, I will outline the technical specifications to look for and what they mean; that way you can make an informed decision before purchasing a model.
With every interface, bit depth and sample rate will be the most common (and often first) spec you see listed. Let’s talk bit depth. When it comes to audio conversion and processing, bit depth has a huge impact on your sound. If we get technical, 1 bit is equal to 6db which means that 16-bit audio (the standard for CDs – do they still make those?) has a total dynamic range of 96db. However, the problem would be that the digital noise floor is pretty high, but the remaining dynamic range is pretty small. So if one were to work at 16-bit, the softer portions of the audio would tend to be noisy. As such, most professionals opt for 24-bit audio (or 144db of range) in order to process audio smoothly.
On the other hand, sample rate is much more subjective. Think of each sample as a digital snapshot of the captured audio. The CD standard (44.1kHz) takes 44,100 digital pictures of the incoming audio every second. The uppermost range of human hearing is around 20kHz so technically 44.1kHz is more than enough to capture and reproduce every sound we can hear. However, there are additional considerations (all of which are technical) that may or may not suggest higher sample rates capture valuable information. That’s why most audio professionals choose to work at 48kHz, 96kHz, or even 192kHz.
At the end of the day, bit depth and sample rate are nothing in comparison to the quality of the digital converter you use. A low-end converter may “process” 24-bit/96kHz, but it also may not give you the professional fidelity you’re after. Most interfaces nowadays have great insides and the parts are certainly enough for the introductory level. Specifically regarding an interface I’ll suggest that generally more expensive will mean better quality, but that’s certainly not a rule as it can also just mean more inputs/outputs.
Depending on how many inputs you need, you can go with:
- PreSonus AudioBox USB ($99)
With the tech specs outlined above, you should now be equipped to find interfaces that suit your needs and I/O amount!
The mixer you choose will largely depend on how many inputs you need and if you’d like to apply effects to those lines. The more channels a mixer has the more stuff you can hook up to it (and the more expensive it will be). Channels come in different flavors and can be either mono or stereo. They’ll accept line inputs (1/4 in) or XLRs and normally have some kind of preamp to boost the
input to an appropriate level – plus a fader for adjusting the channel’s final output. Some higher end mixers will slap on an equalizer and pan control for each channel, but these are usually rudimentary and don’t offer too much control.
Although there are digital mixers, powered mixers, as well as line mixers, I’ll only be covering analog mixers. In this case, analog means that every channel, preamp, EQ, and other component is comprised of physical circuitry (wires, resistors, potentiometers, switches, etc.). The advantage to this type of outboard control is that once you know your way around an analogue board, you can quickly figure out what needs adjustment.
In order to figure out what mixer is right for you, make a list of the parameters you require. Start with channels and inputs. How many do you need? Are you only connecting the mic or do you also want to run a music input or game input through the mixer? Next, move on to EQ. You really won’t be needing this unless your house has some kind of terrible wiring and there’s an audible hiss or hum in the line that you cannot get rid of without, say, a ground loop isolator. Some mixers offer basic low and high frequency adjustments whereas others provide multi-band parametric EQ on each channel. Lastly, do you want onboard processors and effects? One appeal of onboard processing is that you won’t need to run any software on your computer to add effects to the mic line (like reverb or distortion).
I’ve received lots of questions about EQ and so I’ll address some of the most common points here briefly. However, you really shouldn’t need any EQing on your voice. The compressor does most of the work making the volume sound even and, unless you speak with a whistle or have static/hiss that you cannot remove otherwise, EQ is not necessary.
As a general philosophy, I’m a fan of subtractive EQ (cutting away the offensive frequencies to sculpt room for the good sounds to come through) as opposed to boosting the frequencies we like. The most basic tenet is: garbage in, garbage out. If you’re not miked well or your setup has inherent flaws, then you should start by addressing those first. A little EQ is useful for helping making a great signal sound better, but no amount will save a bad signal.
As with everything else, your ears are the bottom line when it comes to applying EQ. I’ll talk about some guidelines, but every voice has its own unique characteristics and timbre and, as such, will respond differently to cutting or boosting specific frequencies. EQ generally offers three parameters to control: frequency selection, gain/cut, and bandwidth/Q. Besides allowing the pleasant frequencies to shine through, another reason I prefer cutting offensive sounds is that adding gain (by boosting frequencies) makes your EQ function as a preamp within the signal flow. Adding any preamp means adding noise and distortion to the sound – not to mention that the preamps in most EQ circuitry are less than optimal…
Most basic mixers will call 10-12kHz the high frequencies, 2.5-3kHz the mid frequencies, and 100Hz and below the low frequencies. If your mic doesn’t have a low-cut switch, then you really should be dialing down the low frequencies to off. Anything below 100Hz, for your voice at least, will just be room noise and meaningless rumble. Not cutting out that sound, means that precious head room in your volume is being eaten up by useless sonic information.
The 2.5-3kHz range is where the high-end of your voice sits, the part that really cuts through a mix and stands out with clarity. In music recordings, this is also known as the “pain” frequency as many engineers have a tendency to boost it, thus causing painful listener’s fatigue.
Finally, the 10-12kHz range is where the high harmonics of your sound sit, but this can also be the location of hiss and static. If you have a particularly problematic setup, this is the only knob I’d recommend touching to remove some hiss. And even then, only a few db of removal, otherwise you’ll darken your voice too much and it will get lost in the mix.
If you notice an irritating frequency that you’d like to remove, make a narrow bandwidth (also called a high-Q setting) and slowly increase the gain in order to boost the frequencies and find the correct one. If you’ve got a basic mixer, you won’t be able to choose the frequencies, but will instead have to try one of three preset choices. However, if you have the luxury of choosing the frequencies, sweep the spectrum with the knob until the offensive frequency stands out. Then slowly cut it out to your taste.
Like I mentioned regarding interfaces, I’m also going to keep the gear recommendations here to a minimum. I’ve selected three quality mixers in the low-end price range, but you can always select a model with more channels as you need them. In price order:
- Yamaha MG10 ($149)
- Mackie ProFX8v2 ($229) [8-channel but other options]
- Soundcraft Signature 10 ($299)
That’s it! You’ve got a microphone, compressor, and now a way to get it all into your PC. We’ve covered choosing the right microphone and some miking techniques for various setups. We’ve also discussed compressors and covered in-depth how they function and what their knobs are for. Lastly, we talked about how to get all of that into your computer – so you’ll sound good, but the content of what you say is up to you.
While the next guide may be a little out of order, I’ve actually written a prequel to this series called Preamps & Channel Strips which will be posted at a later time. Due to the amount of questions I received regarding how to power the microphone and the myriad options available, I realized that my answers to those individuals may be useful to all you streamers. Thanks for reading through this series and I hope it was helpful to you all. My goal was to write informative, in-depth, and advanced guides for those looking to step up their game and really bring professional audio quality to their streams. Happy streaming!