Fake It till You Make It: No Room Mic, No Cry


Anyone who’s ever miked or mixed a drum set knows that a putting up a room mic—and getting a good room-mic sound—is unbelievably useful for shaping the tonal picture of acoustic drums.

There’s a problem though, one that rears its head in these days of declining budgets, where people often flock to home studios—or their own living rooms—to record drums: it’s not always possible to put up a room mic. Maybe your interface doesn’t have the real estate. Maybe a sloppy engineer patched the wrong input, and you got a duplicate of the tom track instead of the room mic.

That last scenario has happened to me. More than once. In those situations, I felt as though bussed-out ambiance wasn’t cutting it—my drum sound lacked the meaty, punchy, and atmospheric center only a well-positioned room mic can provide. I was disappointed. But did I give up? No, and neither should you, because we are engineers. We never give up. We fix things, often in post.

So for this post in our “Fake It till You Make It” series, I’m going to walk you through techniques for reverse engineering a room-mic sound.

This is a parallel processing technique, one based on grabbing the best drum sounds you have and going from there. Accordingly, your first step is to balance your session’s existing drum sounds. Process as little as possible here—focus on level balancing, fixing phase issues, and minimal corrective EQ. In creating this balanced kit, pan your overheads if you wish, but keep in mind that for these techniques we’re going to be working ultimately with a mono return.

Why? Because an authentic stereo room-mic sound can be a huge asset, to be sure, but the approximation thereof can introduce pesky phasing issues. We want to keep those to a minimum, and above all, we want to be efficient, which means less time fine-tuning millisecond delays by ear, and more time for the mix as a whole.

This brings us to another issue: after balancing your drums, it might seem tempting to add some delay (roughly one millisecond for every perceived foot), but you’ll quickly find that this won’t cut it—that any delay might add more problems than it would solve. This is because a room-mic sound is far more than the distance between that mic and the drums; it’s the character of the mic and the character of the room.

So let’s get to it.

Mic Your Speakers

This is a great solution, provided you have a good mic, good preamps, decent monitors, a well-treated room, a fair amount of time for experimentation, and real-estate for multiple/simultaneous stages of AD/DA conversion. If you don’t have those things, skip to the next section. If you do, the process is fairly simple, if a bit time consuming. You put a mic up in your room, mute its output in your DAW, solo the auxiliary drum-buss you’ve just created, and record.

But here’s where the time-suck comes into play: definitely start with the mic at the sweet spot of your equilateral triangle, about ear level. From there, though, you’re going to want to move the mic, depending on how the resulting track sounds. And if you’ve left your drums in stereo at this point (which is fine for this stage of the game), you’ll want to pay extra attention to mic placement, because the resulting mono sound will vary drastically.

Next come the obvious tweaks in signal: different microphones, different preamps, different preamp settings, and so on. Tie in the fact that you won’t be able to monitor the differences in real time (unless you’re doing this all from a separated control room, with an assistant moving the mic around until you tell that person, over text, to stop), and the time starts to add up. Still, if you practice this technique enough times, you’ll get a feel for what chain/placement works for you, and it can eventually become a “set it and forget it” situation.

Emulate the Experience of Miking your Speakers

If you’ve skipped to this paragraph, welcome. If you’re just interested in cutting out the time outlined above, hello. For this technique, you’re going to want to sum that balanced drum sound to mono at the outset, because we will be putting it through an amplifier emulator.

Before you object, keep in mind, we’ll turn the actual amplifier section off in the plug-in. Software such as AmpliTube 4 and Guitar Rig Pro 5 (found within Native Instruments Komplete) will let you do this. You just want the sound of the aux going through the cabinet. Choose a cabinet you like—always blending the aux in with your actual drum buss (already level-balanced, panned, and checked for polarity issues)—and start tweaking the cabinet/virtual microphone placement until you get something you like.

IK Multimedia AmpliTube 4 - Guitar Amplifier and Cabinet Emulation Software

Keep in mind, this is a very esoteric way of doing things. It might not work for every situation. When it does, the results can astound. When it doesn’t, it’s time to move on to the next technique.

EQ Matching & Reverb

Many digital EQs—Fabfilter’s Pro-Q2 and iZotope’s Ozone 7, for example—sport matching capabilities; so do the EQs of many DAWs, like Logic Pro. A matching EQ essentially analyzes the frequency response of a given sample and matches its quintessential curve to the sound source you’re trying to effect. With such an EQ, you can come close to the sound of a source example. You won’t ever match it perfectly, but perfection is the enemy of good.

FabFilter Pro-Q2 EQ Plug-in Software

In this case, I invite you to grab a room mic sound that you already enjoy. You can pull one from another unrelated session, or take one from a multi-tracked session freely available online (hunt around and you’ll find one). Using a matching EQ, grab the sonic signature of that unrelated room-mic and then apply it to the auxiliary track within your session. Tweak to taste, of course, and you’ll wind up with something approximating the character of room-mic’s sound.

That’s only half the battle. Next is the character of the room, and from here, you have a couple of options. You can add a reverb with suitable early reflections—something with a stage or room setting, preferably. I personally like Lexicon verbs for this. Alternatively, you can slap on a convolution reverb like Altiverb or Waves IR and load up the impulse response of a studio you like (conversely, a DAW like Logic will have its own convolution reverb, and from here you can hunt online for impulse response—they’re plenty of great free ones). Whichever approach you choose, the result will be more convincing than if you just added a reverb to your overall drum buss.

Waves IR1 Convolution Reverb - Reverb Plug-In

What Do You Do Now?

From here, process the sound as you would any other room mic track. Slap a character compressor on it, or mess with its envelope with a plug-in like Transient Designer. EQ it to taste. Whatever you do, be sure you only tweak the track in relation to the rest of your drum sound; remember, it’s all about blending in with the bigger picture.

SPL Transient Designer 4

Those are some of my techniques. Have any of your own? Leave us a comment, below.

1 Comment

I've used Toontrack Drumtracker to convert the individual drum audio tracks to MIDI. Then drop that into EZ Drummer and record the room mic from a kit/room that I like. It can be a little tedious, but it works pretty well. I'm going to try the Amplitube trick first next time. Probably a quicker solution if it works for the song.