Audio basics for streamers part 3: levels, filters, and effects

Last time we wrapped up our look at the hardware components; in this post, we’re going to wrap up by looking at what you can do in OBS (and probably other software) to enhance that signal with some finishing touches. First things first, let’s talk about levels, which means that we actually need to step back into the hardware realm for a bit.

Input levels

Remember when I said that preamps are used to boost a mic level signal to line level? Well, there’s a reason why there’s a knob to control how much you boost it. If you just crank it all the way, you’ll be overloading the preamp and distorting the signal. Similarly, if you don’t boost it enough, then it’s going to be hard to hear and your signal-to-noise ratio (the difference between your input signal and the noise floor of the preamp) will not be very good. What’s the sweet spot? Well, it’s pretty simple to find, really. Turn up the gain on your preamp while speaking the loudest you might possibly speak/yell/whatever. Many interfaces have a clipping indicator on them; typically, red indicates that your signal is too loud. Once you hit the red, turn the gain back down until you stop hitting the red. Easy peasey, right?

The only catch is that you might find that your normal speaking voice is significantly quieter than your loudest possible sound and that, actually, you almost never get that loud in the first place. In that case, it might actually be better to turn the gain up a bit so that your normal speaking is more audible. Yes, if you happen to get super loud you might distort a bit, but in the grand scheme of things, that’s not that big of a deal. It’s better to have a good signal level with some clipping than no clipping and low signal level.

Filters and effects

Here’s where the fun really begins. OBS comes with several useful plugins, but I would also suggest downloading the excellent ReaPlugs from Cockos: https://www.reaper.fm/reaplugs/. These come with their recording software Reaper, but are also available for free for use with other software. You don’t need all of them; when you install them, I recommend ReaComp, ReaXcomp, ReaEQ, ReaFIR, and ReaGate. I’ll talk about what each of these do in a minute, but for now, it’s enough to know that the plugins serve a couple of purposes: reducing dynamic range, expanding dynamic range, noise reduction, and equalization. In OBS, you can find the filters by clicking the gear/cog icon next to the audio source you want to apply filters to in the mixer and choosing “Filters” from the menu. From there, use the + button to add a filter. ReaPlugs are added by choosing the VST option from that menu.

Noise reduction/suppression

Noise reduction should always be the first thing in your signal chain. OBS comes with both an expander and a noise gate, though the gate is technically just an expander with a high ratio. ReaGate does the same thing, but offers a few more options. Essentially, you specify a signal level that you want to be the minimum level and anything below that will be reduced (with an expander) or cut completely (with a gate). This also means that if you don’t talk above that threshold, you won’t be heard, either. For that reason, it’s best to cut noise at the source (turn off your A/C, close the windows, etc), but the noise gate is still a useful tool to get rid of the last bit of noise.

With an expander, you can make the cutoff a little more subtle since the audio is only reduced instead of cut. The ratio determines how much the sound is reduced. With ReaGate, you can also blend in some of the dry sound (that is, unaffected sound) and use the lowpass and highpass filters to control what frequencies actually trigger the gate.

With expanders and gates, I find that the default settings for the gate in OBS work quite well. The only thing you really need to adjust is the threshold as the cutoff point is going to depend on your gear and your voice.

OBS also comes with a noise suppression plugin, but I do not recommend using it. It’s designed to monitor the incoming audio for noise and filter out just that noise. In theory, this sounds much better than a noise gate; in practice, it also has a big impact on the sound of your voice and usually causes a noticeable degradation of quality. This is where ReaFIR comes in. It’s a pretty complex plugin that can do a lot of different things, but for our purposes, it’s an extremely effective and transparent noise suppressor. Change the mode to “Subtract,” then click the “Automatically build noise profile” checkbox. You want to be completely silent at this point so that it is only detecting the noise you want to filter out. You’ll see a red line come appear and, at some point, settle in. Once it stops moving (probably after a few seconds), uncheck the box. That’s it! This isn’t foolproof and is really only effective for things like A/C noise, fan noise, or other rumbles and white noises, but I find that I can use just this without any gating and get very clean audio.

Reducing dynamic range (compression)

Compression is usually the next plugin I will add (though you could put EQ first, the difference is subjective). In OBS, there are two plugins that accomplish this: “Compressor” and “Limiter.” ReaPlugs provides several types with the ReaComp, ReaXcomp, and ReaFIR plugins, though we will not be using ReaFIR for that. Compressors serve the opposite purpose of an expander: they reduce the volume of anything over a certain threshold you set. The amount that the signal is reduced is controlled by the ratio, just like with the expander. Typically, a 3:1 ratio is pretty good for speaking. The general idea here is to figure out the volume of your quietest speaking voice and set the threshold just above that. This way, your louder speaking will be reduced in volume to better match your quieter speaking volume. As you might imagine, this reduces the overall volume of the signal, so you can raise it back up using the output gain slider.

Unfortunately, there are no meters within the plugin, so you have to look at the meters on the mixer to determine your approximate levels. This is where ReaComp and ReaXcomp come in. You can easily see your volume levels and set the threshold right on the meter. You may want to experiment to find the exact settings that work for you, but I find a relative quick attack (2-4 ms) and release (10-20 ms) work pretty well. You may also want a bit softer knee for a more subtle effect. I’ve found that a 3 dB knee is pretty good. Tweak the threshold until your levels are pretty consistent, then adjust your output levels to compensate for the decrease in volume. You can try checking the “Auto make-up” box, but, if that doesn’t work, simply increase the “Wet” slider until you get a good output level without clipping. This article provides some good additional reading if you want a little more detail on the settings, but keep in mind that all of these recommendations are just starting points.

If ReaXcomp confuses you, don’t worry about it too much. It is a multiband compressor, meaning that it can compress different ranges of frequencies differently. It’s a more advanced version of compression that I don’t recommend messing with for now, but you might want to play around with it later and might even end up liking it.

Limiters, much like gates, are just extreme compressors. Any compressor with a ratio of 10:1 or more is considered to be a limiter. They are useful for setting an absolute maximum signal level to prevent clipping. You might, for example, put a limiter as the last thing in your signal chain with a threshold of -1 dB just to make sure you can’t clip the output.

Equalization

This is probably the filter most familiar to you, at least in theory. It allows you to raise or lower the bass, mids, and treble of your signal. It’s extremely useful, but, unfortunately, not included with OBS. Instead, you will need to use ReaEQ. This is going to look a little bit more complicated than what’s on your radio, but here’s the gist of it. Each of the tabs is a point that you can adjust. You can have as many or as few as you want. By default, the first one is a low shelf and the last one is a high shelf. The other bands in between will be set to band. A shelf filter basically takes everything below or above a frequency point and increases or lowers it, hence the shelf moniker. A band filter, meanwhile, adjusts a range of frequencies up or down. The range is determined by the bandwidth or Q. You can make it control a very wide range of frequencies or a very small range. In general, wider ranges will sound more natural and narrow ranges will sound more artificial. However, narrow ranges can be useful for filtering out very specific problem frequencies.

In general, you don’t want to make huge changes here. You can boost a bit around the 100 Hz range to increase the low end of your voice or boost with a high shelf around 4.5 kHz and up add more presence/crispness. You might also reduce frequencies around the 200 Hz range or a little above to reduce muddiness. The exact settings are going to depend on your voice, your mic, and your recording environment. For me, a little cut around 3 kHz (to make me sound less nasal) and a high shelf boost around 4.5 kHz works quite well, but you’ll need to find the settings that work for your mic and voice.

Output levels

Now that your voice is sounding good, it’s time to look at the meters and make sure you aren’t blowing out your viewer’s eardrums. If you look at the mixer, you’ll see that 0 dB is at the right (or top in vertical layout). From there, there’s a red zone, a yellow zone, and a green zone. The colors are a little misleading, honestly, but the general idea is to stay out of the red zone so that your overall level doesn’t distort. Maybe one day they will add an overall output meter to give us a better idea what the output really looks like. Until then, here’s how I set it up.

Leave the fader for your voice track at the maximum position. I also recommend going to the advanced audio properties and clicking the “Downmix to mono” for that track, especially if you are using an audio interface, just to make sure your voice is coming out of both speakers. That’s not strictly necessary, but if you see two meters for the track and only one is moving, you’ll definitely want to downmix. While you are adjusting your filters, you want the final signal level to live in the middle to upper range of the yellow portion of the meter. It’s okay if it hits the red on occasion, but you never want it to hit the 0 dB line. You’ll now have a good maximum volume for your voice track. Since that should be the loudest thing in your stream anyway, you can just leave that slider alone.

From there, adjust your other volumes down until you find a sweet spot where they are still audible but not so loud that they drown out your voice. The OBS wiki mentions that you’ll want these non-voice tracks to be somewhere in the green range of the meter, but you’ll probably need to do a few test recordings to find the sweet spot.

One last note on the mixer. In part 2, I said we’d talk about why you need to think of your inputs as working in pairs and only put mics into every other input. The reason is that OBS does not support ASIO, instead relying on standard Windows audio for inputs and outputs. ASIO allows every input to be a unique input, but Windows, for whatever reason, reads them in stereo pairs. This means that, for a 4-input interface, OBS will see it as two stereo inputs where input 1 is left, input 2 right, input 3 left, and input 4 right. If you want to put different effects on the inputs, this effectively halves the number of inputs you can use. I haven’t tried it, but there is a plugin that adds ASIO support: https://github.com/pkviet/obs-asio. From what I can tell, it looks like this will allow each input to be used separately, so if that’s something you need, give that a try.

Final final thoughts

And that’s really all there is too it! I know this was a lot of information and I probably still missed some things, but I hope this clears up most of the mystery. I didn’t go super in-depth with compressors and gates, but honestly, the default OBS settings (aside from the threshold) are pretty good, so you don’t really need to mess with them too much. If you want to understand them better, there are a lot of good explanations on the web that should help with that. But if you have any questions, let me know!

Audio basics for streamers part 2: preamps, mixers, and interfaces

Last time, we took a look at the different types of microphones and some specific models you might use. We’re going to gloss over cables (because you should always get a quality one) and skip to the next part of the signal chain: preamps, mixers, and interfaces. I’m grouping these all together because a lot of people get them confused and because they are actually somewhat related. Let’s dive in.

Preamps

There are three basic signal levels in the audio world: mic, instrument, and line. Line level is the standard, so the goal of a preamplifier is to increase a mic or instrument level signal to line level. It’s a pretty simple objective, but the quality can vary wildly from one to the next. For example, your computer’s sound card, as long as it has a mic input, has a preamp, but it may be noisy or generally not sound very good. Most audio interfaces these days have decent preamps in them, so that can be a nice upgrade if your computer’s sound card isn’t very good. And you can also buy standalone preamps like the UA Solo 610 I have if you really want an improvement (though that would be extreme overkill for streaming).

Long story short, preamps are necessary, but you don’t really need to think about them as separate from other pieces of gear you need to use with your mic. It’s just helpful to know what they do so you can troubleshoot your signal quality later.

Mixers

One of the biggest misconceptions people have when they are just starting out is that they need a mixer. They saw a picture of a studio somewhere with a big mixer and though, “Wow, I need that!” The thing is, you don’t. Before computer recording was a thing, albums were mixed on enormous analog studio consoles, but these days, most of those are just control surfaces that move digital faders in a computer. They don’t actually process any sound. Similarly, the only real reason to use a mixer these days is for mixing a live show – a concert, for example. With streaming, mixing is done in the computer. If you mix everything with an external mixer before it gets to your computer, you actually end up losing functionality because everything is on a single audio track. You can no longer apply filters to individual elements or split them to multiple tracks in your video file.

The one potential use of a mixer is to take several external analog sources, like retro game consoles, and condense them down to a single output. A lot of old consoles output at different volumes, so this would allow you to balance them to get consistent levels from one console to the next. Of course, if you’re converting their signals to digital anyway, then there’s not much reason to do this, especially since you could just set up different scenes in OBS for the different volume levels. Basically what I am saying is don’t buy a mixer. You don’t need it.

Audio interfaces

Think of an audio interface as a fancy sound card because, well, it is. We just like to use fancy words to distinguish professional audio gear from regular PC components. The core function of an audio interface is to take your analog audio signal and convert it to a digital one (and vice versa). This is where the term AD/DA converter comes from: analog to digital/digital to analog. Most will also have a preamp built in so that you can record your mic or instrument. These days, there aren’t many “bad” choices for audio interfaces, but you may find that some fit your needs better than others. You’ll generally want to find one with low noise and low latency. If you might also use it for recording music, then sure, invest in a better quality one. But for streaming, where you are just talking, the quality differences are going to be negligible.

The one thing to keep in mind with interfaces is that generally the inputs come in pairs. In recording software, you can record each input to its own track, but in OBS, these are typically seen as stereo pairs. So, for example, if I have an interface with two inputs, OBS will see these as a single input with input 1 being the left channel and input 2 being the right channel. So if you need to capture multiple mics, you may want an interface that has two inputs per microphone (with the mics plugged into every other input) so that you can apply different filters and effects to each mic. We’ll talk more about why that happens when we get to the software side of things.

Sound cards

I’m mentioning these separately because I talked in part 1 about using your computer’s 3.5 mm input for headset and shotgun mics. Despite the fact that I have significantly nicer options for getting audio into my computer, that’s what I’m doing now. Shotgun mic with a 3.5 mm cable into my computer. Nothing fancy about it. Your mileage may vary here, but in my case, my motherboard came with a pretty nice sound card that isn’t very noisy and sounds halfway decent. If you are also going with a headset or shotgun mic, that may be all you need. There are also aftermarket sound cards you can buy (including USB ones) that may offer improvements over your built-in card.

However, if you’re using a mic with an XLR jack (which is most other non-USB mics), you’ll want to get an audio interface instead.

Final thoughts

Ultimately, you will need to consider your entire signal chain (not just your mic) when getting set up for streaming. For example, if you buy a USB mic (like the Yeti), you’ve already got a preamp and an audio interface built into the mic. If you buy a headset mic or a camera-mount shotgun mic, you might be fine with just using your computer’s sound card. If you get an SM7B even though I said not to (it’s okay, I understand), you’ll want to make sure to get an audio interface with lots of gain available. And if you get an XLR condenser mic (you really don’t listen, huh?), your interface will need phantom power, too.

Now that you’ve got signal going into your computer, what do you do with it? Next time, we’ll look at filters and effects to really maximize your sound quality. And I guess we’ll also touch on figuring out the proper levels so you can be heard without distorting.

Part 3: levels, filters, and effects

Audio basics for streamers part 1: microphones

It seems like every day there is a Reddit post asking for advice on fixing an audio problem. What mic should I use? What mixer? How do I get rid of background noise? But most of the advice I see offered is… well, let’s just say it means well. Usually, someone suggests spending a lot of money on something the person doesn’t actually need and probably won’t actually help them. I thought I’d spend some time putting together a guide on every part of signal chain from mics to interfaces and mixers to post processing.

First, a little detour for some background info on me that will, hopefully, explain why I am qualified to provide advice. My degree is in film and TV with a minor in audio recording. I spent some time working in TV after college, joined a few bands, recorded two albums (and mixed one of them), and am currently recording and mixing a third. I also worked at a shop selling pro audio gear for 5 years. This is not to say that I am an expert; I’m not. It’s just to say that I have a fair amount of experience, certainly more than the average streamer, and that I was an audio guy long before I was a streamer. I’ve used some really nice equipment and some really not-so-nice equipment. I own a bit of both and a lot of the stuff in between. I will make some recommendations based on my experience and opinions, but ultimately this guide is about finding the right gear for you.

On to business. The first and arguably most important part of your signal chain (well, other than your voice) is your microphone. Every microphone has a different sound and set of features that might make it more or less suitable for a given voice and a given application. There is no one perfect choice for every person. But if we take a look at the differences between them, we can find one that is a likely candidate for your needs. First, some info on the differences between the two basic types of mics you’ll be looking at, then I’ll dive into some specific mics and why you may or may not want to use them.

Dynamic vs condenser mics

The two main categories of microphone are dynamic and condenser mics (there are others, but you aren’t likely to be using those). Dynamic mics are the simplest types of microphone in terms of their construction. They function more or less like a speaker in reverse. The diaphragm has a magnet attached to it that moves through a coil of wire to turn the physical air movement into an equivalent electrical current. Condenser mics, meanwhile, are typically use thinner diaphragms, require external power, and come in a wide variety of polar patterns (the directionality of the mic) and sizes to fit just about any application.

When it comes to choosing one for your stream, there are a couple general characteristics to keep in mind. The benefits of a dynamic mic are that they do not require external power, can usually handle very high volume levels (maybe not so critical for streaming), tend to be very durable, and don’t pick up background sound very well since they are not very sensitive. That makes them generally better suited for streaming than condensers. On the downside, because they are not very sensitive, you will usually need to be very close to the mic to be heard. This also means that if you move your head, the volume can drop dramatically.

Condenser mics, on the other hand, are very sensitive. This allows them to pick up more details and high frequency information, so they typically sound “better” than dynamics (better is subjective, of course), but they will also pick up more background noise. Cheaper ones may also have issues (ie distort) with louder sounds. They also require power to function. On the plus side, there are a lot of different types of condenser mic that may suit your needs better than a dynamic.

Now that we have a grasp on the basics, let’s examine some of the popular mic choices as well as some you may not have considered.

Blue Yeti

This mic became the defacto standard for streamers because it’s affordable, sounds good, and is easy to setup and use. There are now three main variations of it: Yeti, Yeti Pro, and Yeti Nano. The two bigger Yetis have several selectable polar patters, though you’d generally only want to use the cardioid pattern for streaming. The thing is, despite their popularity, they really aren’t a very good choice for streaming. They’re not very directional and, being condensers, they are very sensitive, so you are going to pick up lots of room noise, including your air conditioner, keyboard, dog barking, etc. You’ll also need to get a pop filter so you don’t blow people’s ears out every time you make a “p” sound. For the same price or less, there are several other options that will do a better job. Having said that, if you have a quiet space, quiet keyboard/controller, shockmount, stand or boom arm, and pop filter, you can absolutely get great results with these.

Headset mics

These are typically condenser mics (though dynamic options exist) and may be included with a gaming headset or purchased separately. While the mics on gaming headsets are generally not a good option, add-ons like the Antlion ModMic series can be a really great choice. Since they are worn on your head, the mic is always positioned in the same spot relative to your mouth, so volume levels will be very consistent. They are also just generally very convenient since you don’t need a stand and they plug into the 3.5 mm input on your computer (or USB in some cases). Your results may vary depending on the quality of your computer’s sound card, but generally a quality headset mic is a great option. Just make sure to find a directional (cardioid) one to cut down on background noise.

Shure SM7B and EV RE20/RE320

It’s not hard to see the appeal of these mics. They are broadcast dynamic microphones found in radio studios everywhere, so they seem like a natural fit for streaming. However, they have a number of downsides that might make them a bad choice for you. First, they are extremely low output microphones, so you will need a good quality preamp to amplify them. Most $100 audio interfaces will be good enough, but you may need to purchase an additional add-on like the Cloudlifter to boost the signal depending on your setup. Second, you will need to put your mouth practically on the microphone to be heard. On the plus side, that means that they pick up almost no background noise; on the downside, moving your head even a little can cause a dramatic volume drop. They are also huge, so if you’re hoping to hide your mic, look elsewhere. I’ve seen these mics used to great effect on stream, but I’ve also noticed that the streamers using them are right on top of the mic and move very, very little. If that doesn’t sound like a problem to you and you are okay with making a few tweaks with filters to get a better sound, these can be great options, especially if you really need to minimize background sound. Just keep in mind you are looking at $400+ to get everything you need to make this work.

Other dynamic mics

If the broadcast mics are a little rich for your blood, you can get similar results for a lot less with something like a Shure SM58. Handheld vocal mics are designed for stage use, so they are generally more directional and, naturally, tuned for human voice. Different mics will have different qualities, though. The SM58 is another mic that requires you to be right up on it for good sound, but Sennheiser’s e835, for example, works fine with a little more breathing room. Aside from typically louder output than the broadcast mics, though, most of the same pros and cons apply.

Shotgun/boom mics

Now here’s a category I don’t think I’ve seen any streamer talk about even though shotgun mics are purpose built for recording on-screen talent. That makes them a perfect fit for streaming. They are very directional, so they pick up very little background sound, and can be hidden off camera without reducing quality. In fact, I use one in my living room setup. Even with the surround sound going and no noise gate in use, all that comes through is my voice. If you look for mics designed to be mounted to a camera, you’ll also be able to connect directly to your computer’s 3.5 mm input so you don’t need to buy a separate interface. My personal choice is the Deity D3 or D3 Pro. These cost about the same or less than other mics on this list. The only downside is that it’s possible you might pick up your keyboard if your face tends to hover over it (as the mic should be pointed at your mouth from above), but as long as you lean back, you should get great results. Just make sure you put the mic about 6-8″ from your mouth, more or less above and in front of you, to get the best results.

Hopefully this gives you some ideas about what to look for in a mic. Any of these options can work, but it really comes down to what works for your voice, your setup, and your budget. Next time, we’ll look at the next part of your signal chain: preamps, mixers, and audio interfaces. Then we can dive into the software side of things!

Part 2: preamps, mixers, and interfaces

Starting soon!

That’s what they always say, right? Sadly, almost immediately after I decided I was going to start streaming on Twitch more regularly, I caught bronchitis and am really not fit for appearing on camera. But soon!