One mic or two? Mono or stereo? Hear the differences.
This column continues the unlikely premise of last month's installment. We used the digital models from Universal Audio's Ox Amp Top Box to make audio comparisons between electric guitar recording techniques.
Yeah, it's weird using a digital box to illustrate analog techniques. But it's useful here because Ox's models are so realistic. The process also isolates the variable in question. You hear the same guitar, pickup, amp, amp settings, and recording path throughout.
Last time we looked at speaker size, single-speaker versus multi-speaker cabs, and microphone types and placement. Now let's explore options that arise when using multiple mics.
Variable 1: One mic vs. two. In Clip 1 you hear single-mic clips featuring virtual versions of three common electric guitar mics: a Shure SM57 dynamic, a Neumann U 67 condenser, and a Royer R-121 ribbon. (We discussed their characters last month.) Next come three possible pairings: 57 plus 67, 57 plus 121, and 67 plus 121. In the modeling, the virtual mics are positioned near each other and close to the speaker.
TASTING NOTES: A single mic has the pointiest, most direct sound. Adding a second mic introduces phase cancellations as the two mics “listen" from slightly different perspectives. This can add cool complexity and texture, though it often softens the impact.
Variable 2: Panned vs. non-panned mics. With two miked guitar tracks, you can choose how far apart to pan them, if at all. Clip 2 compares mono sounds (both mics at center) and the same mic combinations panned far left and right. You hear the 57 and 67 in mono and then in stereo, the 57 and 121 in mono and then stereo, and finally the 67 and 121 in mono and stereo.
TASTING NOTES: What's best: stereo or mono? Duh—it depends on the context! A mono sound often has the most impact, but a panned sound can add interest and depth. Panning can also maintain a prominent guitar sound while leaving the mix's center clear for vocals, bass, and kick drum—at least in a conventional mix.
Tip: When combining two mics, always try reversing the phase of one of the tracks within your DAW. One setting will probably sound much better than the other. Use that one.
Variable 3: Dry sound vs. room sound. Ambient room miking is one of the defining qualities of rock guitar. Somewhere in the vast catalog of Led Zeppelin outtakes there's a clip in which someone solos the two mics on Pagey's “Heartbreaker" amp. First you hear a dry, close-miked sound, then a boomy room sound, and finally the two mics together. Suddenly it sounds like Led Zeppelin—and countless other rock guitar recordings since that 1969 session.
But with today's tech you can get similar sounds with a single close mic and a good digital room reverb, as heard here. Clip 3 features the 67 plus 121 blend with no ambient room miking. Next is the room sound only, as it might be captured by a condenser mic positioned six feet or more from the amp. Finally, you hear the blend: first with just a bit of room, and then with more ambience.
TASTING NOTES: A close mic is in your face. A distant mic is out in space. At risk of oversimplifying, close miking alone often works for groove parts where the guitar shouldn't hog the limelight, while a roomier sound might be better if the guitar is front in center for big riffs or solos. Also, consider the quality of your tracking room. If you're working in a great studio, it can be a crime not to capture the ambient sound. If you're in a crappy-sounding bedroom, an ambient mic might not be worth your while. (But remember, an unusual ambience is sometimes cooler than a “good" one.)
Tip: When recording a band with the guitar amp isolated in another room, room sound can make the guitar sound more like part of the group. That could mean re-amping the guitar track in the room where you'd previously recorded the drums, or applying the same simulated ambience (in varying amounts) to all the tracks.
Variable 4: Stereo vs. mono room miking. With enough mics, you can choose whether the ambient room sound is captured in mono by a single microphone, or in stereo via two mono mics or a stereo mic. Two close mics and a stereo room sound means four tracks to blend and pan. Clip 4 showcases a few options. First you hear the ambient sound alone in mono, then in stereo. After that you hear mono close miking plus mono room sound, stereo close miking with mono room sound, and finally stereo plus stereo.
TASTING NOTES: This parameter can be pretty darn subtle. It might be meaningful on a solo guitar recording, but in a full-band mix you might not hear a difference. Our ears sometimes perceive stereo and panning in strange ways. If, say, the drums are panned dramatically in stereo, there's a good chance you'll think the mono ambience is stereo as well. For more drama, take a mono close-miked track and a mono room track and pan them wide. Yeah, that's “fake" stereo, but it can sound epic.
Get creative with faux-analog delay tones.
Many modern players are smitten with the quirky, warts-and-all character of pre-digital delays. Partly, that’s nostalgia. It’s fun to clone Scotty Moore’s rockabilly slap or David Gilmour’s spatial grandeur.
But there’s more to it than looking backwards, I think. While pre-digital delays were designed to mimic the effect of playing in reverberant spaces, the results rarely sound realistic in the way that, say, digital hall reverb algorithms can sound like actual rooms. Much of their charm lies in their “not found in nature” artificiality. This sonic character can convey many emotions: warmth or iciness, spaciousness or claustrophobia, relaxation or tension, and more.
or tension, and much more.
This column and my next one are about crafting faux-analog delays, especially unconventional ones. I’ve used SoundToys’ EchoBoy plugin throughout. But while EchoBoy is powerful and versatile, you can try these techniques with many delay plug-ins or with relatively sophisticated delay stompboxes that feature tone controls in addition to the usual time, feedback, and mix knobs.
Analog Artifice. Let’s start by faking analog sounds. Old tape, oilcan, and bucket brigade delays aren’t very good at reproducing higher frequencies, and the treble content diminishes with each echo. Check out Ex. 1, with its relatively hi-fi delay tone.
Ex. 2 is the same recording, but with much treble removed. I’ve also added distortion using EchoBoy’s saturation control. (Don’t worry if your delay doesn’t have a distortion setting. Next month we’ll see how to add distortion to delay using separate delay and overdrive plug-ins.) Image 1 shows the settings.
You can hear the same properties in Scotty Moore’s definitive rockabilly slap on Elvis Presley’s classic “Mystery Train.”
Ex. 3 uses a small tweed amp model and a similar delay setting to approximate the dark, somewhat distorted sound of Moore’s Echosonic, an amp with built-in tape echo. For a similar sound, cut lots of delay treble, turn the feedback control to zero (just one echo), and add a touch of distortion if possible. Try delay times between 100 and 150 milliseconds, depending on the song’s tempo.
That rockabilly slap is a great sound, but for better or worse, a familiar one. So let’s explore some cool alternatives.
Echoes of Africa. Tape delay was a popular sound for African guitarists from the late 1960s through the ’70s. It adds a lovely liquid fluidity to the pretty arpeggios and double stops of Central African pop guitar playing. Here's a fine example, “Malala,” by the great Congolese guitarist Nicolas Kasanda (better known as Docteur Nico), one of the creators of the guitar-driven rumba-rock style later known as soukous.
It’s a brighter tape sound, with a longer delay time and two or three echoes rather than single slap. Here it sounds like le Docteur is playing through an amp. But many guitarists from Africa—a continent rich in music, but poor in gear—recorded directly into the mixing board, adding tape delay to their squeaky-clean tones. In Ex. 4 I bypassed the amp model for a similar effect. Image 2 shows my EchoBoy settings, with a delay time of 285 milliseconds, some high and low cut (but not as dark as the rockabilly sound), and lots of simulated tape saturation.
It sounds a little chaotic soloed like this. But somewhat counter-intuitively, the rhythm seems more coherent when you add bass, drums, and dry-toned backing guitars, as in the Dr. Nico example. This musical style often features three or four guitars, and the echo on the lead guitar helps it stand out as the solo instrument.
Image 2
Authoritative Echo. Here’s a slapback variation I call “the Great Dictator,” because it makes me think of some autocrat addressing a stadium full of followers, with a hard, steely echo bouncing off of reflective concrete surfaces. For this sound I keep the treble strong, cut some bass, add modest distortion, set a delay time of about 250 ms, and select a low feedback setting—maybe two or three echoes. [Ex. 5.]
Again, it can seem rhythmically chaotic. But if you dial back the wet level, you get a spacious sound that stands out against backing instruments, as in Ex. 6.
Now let’s introduce a new idea: subtlety! A not-so-secret trick among pop producers is to add a single short echo to lead vocals, in addition to reverb and other effects. The echo can be nearly subliminal, yet it helps a lead vocal (or a guitar!) stand out in a mix. The lead guitar that enters at 00:07 in Ex. 7 is as present as a poke in the nose, even though the track has generous amounts of spring reverb.
Ex. 8 adds a touch of echo on the lead part, paradoxically helping the sound blend into the mix and command centerstage.
This time I didn’t add the delay effect directly to the guitar’s channel strip, but placed it on an aux bus. Routing the sound this way opens up many more sonic possibilities—ones we’ll explore next month!
This ugly effect can be a thing of beauty.
Imagine an effect that can single-handedly destroy everything guitarists traditionally love about tone. How awesome would that be?
Don't dream it—use it! It's called bitcrushing, and it's been around since the dawn of digital audio. This harsh, clangorous distortion is everything that “classic rock crunch" is not. It produces dissonant, chaotic sounds with sharp, steely edges. Taken to extremes, bitcrushed audio degrades into insect-like clicks and farts, often with bizarre and unpredictable rhythmic side effects.
Yes, it's that cool.
Crush, kill, destroy. Admittedly, large doses of bitcrushing can be hard to swallow. But applied judiciously, the effect can animate an arrangement with unexpected colors and quirky rhythmic glitches. Also, bitcrushed sounds can cut through anything, so they can be especially useful for adding guitars to dense EDM tracks. Bitcrushing is the hydrochloric acid of audio.
Many DAWs include bitcrushing plugins, such as Ableton Live's Redux, Reason's Scream, and Logic Pro's imaginatively named Bitcrusher. There are also some great free bitcrushing plugins. In fact, Tritik's Krush is so cool that you should probably just grab a copy now. It's free, feature-rich, and fully functional, and there are versions for both Mac OS and Windows. I used Krush to record all the audio for this column.
Do the numbers. While you're downloading, let's discuss the effect. Like all things digital, bitcrushing involves numbers—two, specifically. The first is bit depth, which is roughly akin to resolution in a photograph. If you compare, say, a studio recording at its original 32-bit depth and the same recording at a CD's 16-bit rate, you probably won't perceive a loss of highs or lows. But the 16-bit recording probably sounds “shallower." If you listen on studio monitors with your eyes closed, the higher-bit-rate recording can seem to have a deeper “soundstage," with more of a sense of instruments being nearer and farther in relation to the listener. At lower rates, it can sound like the musicians are all lined up next to each other on a narrow stage. Dynamics may feel relatively squashed, and the quietest sections—the final ring of a decaying chord, for example—can feel grainy and relatively low-res.
But we're not talking about the usual “dumbing down" that occurs when transferring 32-bit recordings to CD-quality 16-bit. Heavily bitcrushed sounds display increasing amounts of noise. Pushed to the limit, you get mere pops and clicks. In Clip 1, a guitar phrase gets subjected to decreasing bit rates. Behold the devastation and weep!
The other important number is sampling rate: the higher the number, the higher the fidelity. We listen to CDs and MP3s at 44.1 kHz, though we often record at higher rates such as 96 kHz or 192 kHz. Meanwhile, a talking musical toy from the 1970s might have had a 10 kHz sampling rate.
When you drop the rate below 20 kHz or so, you audibly and increasingly lose high end. Go low enough, and the sound degrades into clangorous noise. This process is called downsampling. In Clip 2, the sample rate descends from full frequency to a coarse grumble. Can you hear how low-rate settings might work as (or at least with) bass sounds?
Those are the basics, though some bitcrushing plug-ins add additional tools. Krush is a great example. Check out the interface (Image 1).
Image 1
Two of the big knobs control bit crushing and downsampling (labeled “dwsp"). The leftmost knob sets the drive level feeding the effect. Higher drive settings are wilder and noisier.
To the right of the big knobs are simple low-pass and high-pass tone controls that siphon off highs and/or lows downstream from the digital distortion. The res control adds resonant feedback at the filter cutoff frequencies. At the far right are wet/dry faders. (All examples heard here are 100 percent wet.) The bottom row is the modulation section, with an LFO that can sync to a track's metronome. There are four modulating waveforms to choose from. The remaining knobs specify which parameters are subject to modulation. Impressive for a free plug-in, huh?
You can combine bitcrushing and downsampling, as heard in Clip 3. (The settings are those shown in Image 1.) Obviously, bitcrushed sounds can be so degraded that they have no definite pitch. That's not a bad thing, necessarily—you can say the same about many cymbal and drum sounds. But as you downsample, there's a strong resonance at the filter cutoff point, which you can use to roughly tune the effect.
You might not identify the primary pitch in Ex. 4 as D. But when the Dm bass-synth riff enters after four bars, they kinda/sorta cooperate harmonically.
Image 2
The heavy downsampling in Ex. 4 yields a more bass-like tone. Image 2 shows the settings.
Image 3
Now let's try incorporating Krush's modulation section, as seen in Image 3. With the lowpass filter resonance set high and fast 64th note triple modulation routed to both the filter frequency and the downsampling amount, you get the splish-splash water effect of Clip 5.
Naturally, once you capture such sounds within your DAW, you can stir up additional trouble. In Clip 6, for instance, I doubled the guitar recording, processed each clip with its own Krush setting, and panned the two tracks in stereo. Note how the glitching adds rhythmic tension as it clashes against the quantized electronic beats. It's similar to the way rhythmically imperfect loops can add tension and character to hip-hop tracks.
Bring the noise. Here we've looked at downsampling within your DAW. But you can create similar effects without a computer thanks to recent bitcrushing stompboxes such as Catalinbread's Heliotrope and Malekko Heavy Industries' Scrutator, which convert your analog signal to lo-res digital.
Obviously, these flavors aren't for everybody. But before you shriek “never!" I urge you to explore these sounds in musical contexts. Bitcrushed audio can be brutal on its own, but you may be surprised by how often this abrasive effect can lend texture and interest to a mix, especially alongside less extreme sounds.
T’aint bass, t’aint guitar, ’tis versatile.
This column was inspired by a fine April 2014 Premier Guitar article: “Deep 6: A Brief History of the Tragically Underused Electric Baritone Guitar” by Thomas V. Jones—better known as TV Jones, famed pickup maker and luthier. Tom’s right. Baritone is tragically underused. So let’s ameliorate the tragedy with an overview of ways to arrange and record with bari.
Here’s how Jones defines baritone guitar: “a long-scale guitar tuned below standard E tuning, but not as far down as a full octave. Most baritone scale lengths are between 26" and 30".”
My definition is looser: any fretted instrument that specializes in bridging the bass and guitar registers. That can include purpose-made baris like Jones describes, 6-string basses tuned E to E (the original tuning for Danelectro and Fender 6-string basses), and even standard-scale guitars cranked down to B or A. With the latter option, string gets floppy and intonation suffers. And sometimes that’s awesome.
Here’s an example on YouTube. I recorded all the guitar tracks on Tom Waits’ “Going Out West” with a vintage Telecaster tuned down to B, without even installing heavy strings. The intonation is abysmal! It’s a sour-sounding racket! And Waits wouldn’t have had it any other way. The amp was a blackface Super Reverb. I’d applied reverb and trem, but just before we rolled tape, Tom turned both controls up to 10.
The slippery slope. Baritone guitar’s musical uses are equally varied. On one end of the spectrum are low single-note parts that might double a standard bass, or simple single-note melodies near or below the bottom of the guitar register, like, say the iconic Bass VI melodies Glen Campbell played on his ’60s hits “Wichita Lineman” and “Galveston.” The Bass VI in Clip 1 is tuned from E to E as Leo intended. (As on nearly all baritone guitar recordings from the 1950s and ’60, the strings are flatwound.)
Thanks to the Bass VI’s extended 30"-scale, low notes are authoritative and higher notes are reasonably well-intonated. It’s a far cry from the loose, sloppy sound of the Waits track. But low-tuned standard-scale guitars don’t always sound so anarchic. I’ve had great luck recording with a Baldwin Virginian, a standard 25.5"-scale semi-acoustic that I snagged back in the ’90s for a mere $90 (Clip 2).
If the Bass VI resonates like steel bridge cables and the low-tuned Tele is like a clothesline flapping in the breeze, this is like … a tightrope, maybe? It’s reasonably in tune, and the shorter scale facilitates chordal/fingerstyle playing. I tune it A–E–A–D–F#–B—like dropped-D, but down a fourth.
Clip 1 and Clip 2 were both recorded guitar-style, with amp, reverb, and tremolo sounds. But there are other possibilities. Check out Clip 3, a quickie demo track featuring drums, bass, acoustic guitar, and electric guitar. There’s no bari—yet.
Let’s consider some ways you might incorporate bari here. In Clip 4, I double the original bass line in unison using the Bass VI—the same technique employed on many vintage Nashville recordings. The Fender certainly brings out the bass line, especially against the deep, dark-sounding Guild Starfire bass on the primary bass track. This time I recorded direct, straight into a preamp with no amp or effect simulation.
I don’t miss an amp sound here, though it would probably sound just as good with one. Still, I manipulated the track in the mix, filtering out a lot of low end on the bari so it wouldn’t muddy the sub-200 Hz frequencies. I also added plate reverb and panned the parts slightly in stereo. Conventional wisdom says bass tracks should be dry—a great principle to violate! Here, though, blending dry bass and wet bari creates a cool ambience while maintaining melodic clarity.
Clip 5 flips the equation. Here I double the electric guitar part an octave below using a 29.4"-scale Gretsch Spectra Sonic baritone, an instrument created by TV Jones himself. (Gretsch no longer produces these, though Jones sells them directly.) This creates a mutant 12-string effect.
The Spectra Sonic is a great “compromise” guitar. It has sufficient tension and scale length for classic baritone sounds, yet it’s relatively comfy for chordal and fingerstyle playing. I tune it A–E–A–D–F#–B, same as the Baldwin.
Did you know that Robert Smith used Bass VI on many, many Cure tracks? But he rarely doubles guitar or bass parts. Instead, he plays simple, stepwise countermelodies that weave around the vocals and other guitars. Sadly, Clip 6 sounds nothing like my beloved Cure, though the musical concept is similar. It’s the Baldwin again.This is far from a complete list of baritone guitar techniques. We didn’t even get into reinforcing distorted guitar riffs with extra low notes, a long-running metal/rock technique. But the real adventure happens when you discover your own techniques. You don’t even need a dedicated baritone guitar to experiment. Just install a set of heavy-gauge flatwounds on a standard-scale guitar and tune B to B. Or for a less traditional bari sound, just use your current strings. Intonation may become an unobtainable fantasy, but you’ll have good anarchic fun.
What’s the best way to record acoustic guitar in stereo? X-Y? M-S? A-B? Or just plain old mono?
Not that I deserved it, but Santa was very kind this year. And by “Santa,” I mean my father-in-law, Allan Malmberg. He’s an ace recording engineer whose business, Opus One, specialized in classical recording. Allan was winnowing down his gear collection and he gifted us several superb mics. A merry Christmas indeed!
The bequest includes an AKG C 426 B, a great-sounding and ultra-versatile stereo mic. Among other things, it’s perfect for comparing and contrasting various stereo-miking techniques for acoustic guitar.
Nashville Know-How
This isn’t the first time Premier Guitar has covered this topic. One of my fave PG items ever is this Andy Ellis video in which Nashville studio pros Bryan Clark and Adam Fluhrer demonstrate several stereo miking techniques. Check it out! I’ll wait.
I cover similar turf, but with one difference: Thanks to the stereo mic, I can compare the techniques without changing the instrument, the mic, or their relative positions. This provides a reasonably objective basis of comparison.
Note that you don’t need a stereo mic for these techniques. You can use any good-sounding pair, subject to a few limitations we’ll discuss.
SeX/Y stereo
In x/y stereo recording, two mics are positioned as close as possible to each other, with one angled left and one angled right at something like a 90-degree angle. That way the sound reaches the two mikes at nearly the same instant, minimizing phase problems. You set the mics to directional patterns (assuming your mic patterns are switchable). They can be cardioid, hypercardioid, or figure eight, all of which favor sound from straight ahead over sound coming from the sides.
Check out the two examples in Clip 1. (Headphones recommended.) First you hear both mics set to figure-eight patterns, and then both mics set to cardioid. The instrument is an old rosewood classical guitar strung with Thomastik-Infeld rope-core strings and tuned low.
The figure-eight mics produce a nice, fat stereo image, with some room color via the rear sides of the mics. The cardioid version has less stereo drama, but the guitar commands center stage with more impact and presence. Your choice might be a matter of how hard-hitting you want to sound, or whether the ambience in your recording room is worth capturing.
Mid vs. Side
Mid-side technique (m-s for short) can be bewildering at first, though Clark explains it well in the video. To further complicate matters, you usually don’t hear the effect till after you’ve recorded it. But m-s recordings have two advantages: They always sound good when heard in mono. (Phase problems can arise with other techniques when summing to mono.) Also, you can change the stereo width after you’ve recorded.
The side-facing mic must be set to figure eight, so it hears equally from left and right. The front-facing mic can be cardioid, figure eight, or omni (you’ll hear all three). After recording you must duplicate the side-mic track in your DAW, and then flip the duplicate out of phase with the original. (Some DAWs have a phase-reverse switch on the channel strip. Others—like my DAW of choice, Logic Pro—require a plugin.) Pan the side-mic tracks far left and right. If you solo these two tracks, you hear only silence. It’s 100 percent phase cancellation. But if you start with the front-facing recording in the center and gradually raise the two side-facing tracks, a stereo image appears. (The louder the side signal, the more dramatic the stereo.) It’s like magic—at least if you’re not an acoustician.
Clip 2 starts with the forward-facing mic also set to figure eight for a nice, naturalistic stereo spread with a touch of room color. Then I switch the mic to cardioid for a more center-forward sound. Finally, you hear the front mic set to omni for a more diffuse and roomy effect. Again, your choice might depend on how much center impact you desire and whether the room sound is worth capturing.
To A/B or Not to A/B
What about just setting up two mics some distance apart and angled inward, as if they were stereo speakers? This A/B technique provides a realistic stereo effect, though the two sides can often be out of balance, like the left-heavy sound of Clip 3.
Conventional studio wisdom dictates at least three times the distance between the two mics as between the mics and the sound source, and that’s what you hear first. After that I “break the law,” arranging the guitar and mics so that all three objects are about 18 inches apart. This produces a warmer sound thanks to the proximity of the mics, though there’s a slight loss of sparkle due to phase conflicts. Still, it’s still an attractive and usable sound.
Mono Me
There are many appealing options here. For a solo guitar recording featuring this particular instrument, I’d probably go with the m-s arrangements with the front-facing mic set to cardioid (strictly a personal call). Or I might choose something a lot simpler: plain old mono, as heard in Clip 4.
I hope I’ve provided a clear overview of the options so you can zero in on the best technique for your needs the next time you take a walk on the stereo side.