You are here

Recording Resonator Guitars

How To Capture Their Distinctive Sound
By David Greeves

Jimmy Heffernan, with a ‘dobro’, a square-necked guitar designed to sit on your lap and be played with a slide.Jimmy Heffernan, with a ‘dobro’, a square-necked guitar designed to sit on your lap and be played with a slide.

Part six-string, part speaker cabinet, resonator guitars are like no other instruments. Here’s how to capture their distinctive sound.

The phrase may now be more familiar to us in a digital audio context, but back in the 1920s, musicians were engaged in a loudness war of their own, and with electronic amplification still a few years away, it was acoustic volume that counted. Though it would go on to dominate popular music in the second half of the century, the humble guitar lacked the volume to really cut it as a lead instrument, and hard-working strummers were struggling to hold their own alongside horns, pianos and drums. While some manufacturers experimented with larger body sizes, when an enterprising instrument repairer named John Dopyera hit on the ingenious solution of placing a spun aluminium cone inside the guitar to pick up and amplify the vibration of the strings, the resonator guitar was born. Dopyera had not just given the six-string more volume; he’d created a new class of instrument, with a tone and character entirely its own.

Though its fortunes have waxed and waned over the decades, the resonator (or, more properly, the resophonic guitar) has been a continual presence in blues, folk, roots, country and bluegrass music ever since, and the last 10 years have seen a dramatic revival in interest. To help us figure out the best way of capturing the resonator on record, I’ve enlisted the help of two experienced session player-producers, one on either side of the Atlantic. Nashville veteran Jimmy Heffernan is a well-respected country and bluegrass player, producer, and teacher who has toured or recorded with numerous artists including Joe Diffie, Brad Paisley and Charlie Louvin. Meanwhile, Michael Messer is the UK’s foremost authority on all things slide, having spent the last 35 years exploring the limits of the instrument, from blues, folk and Hawaiian styles to fusion and beyond.

Michael Messer playing a round-necked ‘national’, usually played more like a regular acoustic guitar, albeit often with a slide.Michael Messer playing a round-necked ‘national’, usually played more like a regular acoustic guitar, albeit often with a slide.

Shining Examples

The reason I’ve tracked down both exponents is to cover both sides of a clear divide, between square-neck and round-neck instruments. Square-neck resonators (as typified by the output of the Dobro guitar company and hence colloquially referred to as ‘dobros’) are designed to be played with the guitar positioned horizontally like a lap-steel or Hawaiian guitar. Widely used in country and bluegrass, these slide-only instruments are generally played using a metal bar, and their thick square necks and high string action (the strings sit up to an inch off the fretboard) offer superior sustain.

On the other side of the divide, round-neck or ‘Spanish’ resonator guitars feature a conventional neck and string action and can be held and played just like a regular acoustic guitar. However, these instruments (sometimes known as ‘nationals’, after the National guitar company) are closely associated with blues slide guitar, played using a slide or ‘bottleneck’ made of glass, metal or ceramic material. While the dimensions of the guitar’s body, the material it’s made out of and the style of cone it uses all have a distinct effect on the sound produced, much of the difference comes down to these playing techniques — and to the sound the player is aiming for. While modern country and bluegrass dobro players tend to favour a clean, smooth sound, bottleneck blues played on a national is generally a more rough-and-tumble affair.

Before delving deeper into these different approaches, let’s take a closer look at the instrument itself, to understand where this unique sound in coming from.

Recording Resonator Guitars

Not Just A Guitar

Although for all their oddities resonator guitars are reassuringly guitar-like, Michael Messer is quick to dispel any illusions of familiarity we might have: “A resonator guitar, though it is a guitar-shaped object and it’s played like a guitar, in many respects it’s not a guitar as far as sound goes,” Messer says. “It’s more like a speaker cabinet, with the resonator cone acting like a loudspeaker — that’s really what it is. And the way that you would record an amplifier in a room is different from the way you would record an acoustic guitar in a room.”

A conventional acoustic guitar sends out sound waves from a variety of places — principally the top, or soundboard, but also the sound hole, the back and sides, and the strings themselves. The resonator guitar adds a further element, the resonator cone, which picks up string vibrations via the bridge and amplifies them, sending the sound up and out of the instrument but also down inside to then emerge from the soundholes.

“The body has less influence on the overall sound than on, say, an acoustic guitar,” says Jimmy Heffernan. “The main sound is the sound of the resonator cone, coupled with the ported sound of the screen holes — they’re basically bass ports.”

So, while the cone delivers more of the brash, high-mid content of the instrument’s sound, the ports in the body provide more of the warmth lower down the frequency range. Michael Messer agrees with this diagnosis. “There are various types of soundholes on resonator guitars,” he says. “You’ll see f-holes, grilles, little things that look like tea strainers on dobros. You put the mic up to one of those holes and you’ll get a good bottom-end sound. Depending on where you put mic (over the cone, over the back of the cone, close, far away, over the f-holes and so on) you get a complete range of sounds, something it’s actually harder to get from a regular acoustic guitar.”

Favourite Position

Where you choose to position your mics is likely to depend on what balance of these various elements you require. For modern dobro playing, the aim is usually a balanced sound reflecting the full frequency range of the instrument.

“You can get great results with a single mic but, depending on the situation, you can also get wonderful results stereo miking,” says Jimmy Heffernan. “Of course, it depends on context. A lot of engineers, being new to recording dobros, or even new to hearing them, tend to think, ‘Well, it’s a slide guitar and it needs to sound thin’! It’s quite the opposite, actually — it needs to be rich, full-bodied and not thinned out. Stereo miking does wonders for that. A big feature of country and bluegrass playing is the use of syncopated riffs that alternate between the high and low strings, so you really need to capture the full range.”

When using a single mic, it’s often a good plan to start by pointing it somewhere between the resonator cone and the f-holes — but if close-miking, try not to mic too close.When using a single mic, it’s often a good plan to start by pointing it somewhere between the resonator cone and the f-holes — but if close-miking, try not to mic too close.

If you have the luxury of a decently sized, good-sounding recording space, you’ll be able to capture a more complete picture of the instrument’s disparate sound sources by miking further away. That could mean a single large-diaphragm mic or a stereo pair, but Heffernan also says, “I’ve got good results using a small-diaphragm condenser up close, aiming at a point between the cone and bass port, and a more ambient large condenser two feet away, capturing a more rounded picture of what I’m hearing, together with the more punchy sound from the close mic.”

Michael Messer prefers a single-miked approach. “I’m not a great fan of using more than one microphone,” he says. “Occasionally I do. There are always exceptions to rules because there are no rules in the studio as far as I can see. It’s trial and error. I’ve been making records for 30 years, but every time I start it’s as if I’ve never made one before. But I do prefer one microphone. I prefer it in the mix, with the sound coming from one point rather than more than one point.”

There is, however, one thing about which both players are in harmony. “When recording resonator instruments,” says Messer, “I would say generally don’t mic too close, as you tend to only get the sound of the picks. You’ve either got plastic or metal picks in most cases, and that can be a nightmare.”

The squared-necked resonator is usually played with finger and thumb picks; the type of pick will have a significant bearing on the guitar’s tone.The squared-necked resonator is usually played with finger and thumb picks; the type of pick will have a significant bearing on the guitar’s tone.

“The sound of the picking is kind of built into the sound of the instrument,” says Heffernan, “but you try not to have the mic picking up the picks that much. I would never have a mic anywhere close to the picks. It would be on one side or the other of my right hand. There are very few professional dobro players in the world and, almost to a man, they live over here [in the US]. So if you’re recording a dobro player, probably what you’re going to encounter is somebody that has little recording experience. That includes everything from setting up their instrument, to the strings, to knowing where to play and all that. So your first encounter with a dobro may not be with a professional musician.Recording Resonator Guitars

“On any instrument, it’s a journey to learn how to play on a record. You have to learn how control this instrument which is basically meant not to be controlled. You’ve got metal picks and a metal bar on metal strings, across a metal apparatus that amplifies that metal contact, so the opportunity for noise is unbelievable. The good players have spent their life trying to contain it.”

”I have numerous slides made of different materials,” says Messer, “and there are a few that produce less string noise and which I might use sometimes when recording. Some players on electric guitars like roundwound strings. I don’t. I like to use the same set of strings for the whole album. I clean them every day and look after them, because I don’t want to have to put a new set on and play them in. Some modern dobro players will change strings every time they play — literally once an hour — because the modern sound is that bright, fresh, punchy sound.”

Although it’s largely up to the player to minimise unwanted noise, being aware of its sources — principally the contact between the fingerpicks and strings at one end of the guitar, and between the slide and the strings at the other — is important. Of course, for blues slide playing in particular, some of this noise may in fact be desirable, adding some grit and authenticity to the proceedings. Again, the right approach will very much depend on the desired outcome.

The dobro, with its raised nut, must be played with a slide, and the more guitar-like national is often played with a slide too (though it doesn’t have to be). As with the picks, the type of slide you use will affect the sound of the instrument, so it can be useful to have a few options.The dobro, with its raised nut, must be played with a slide, and the more guitar-like national is often played with a slide too (though it doesn’t have to be). As with the picks, the type of slide you use will affect the sound of the instrument, so it can be useful to have a few options.

Mic Choice

This is something very evident in Michael Messer’s approach to mic selection. While he favours a single-mic approach, the mic in question could be just about anything. “It depends if I’m looking for a high-fidelity recording or a character recording,” he says. “With a lot of the recording I do, I’m looking for character and that doesn’t necessarily mean a good microphone. If I’m going hi-fi, I might well use an sE Rupert Neve condenser or something like that. But if I’m going for character, there are no rules. I’ve used all kinds of things at all kinds of distance from the guitar.

“For example, on my album Lucky Charms there’s a track called ‘Knife Song’. That was recorded using — and this is an extreme version of what I’m saying — a very cheap, very old AKG microphone that I had in the bottom of a bag. It was so old and on-the-edge that the body was live. The whole thing was microphonic! We put it on a stand about six feet from the guitar and recorded it as an overdub and it sounded amazing. Why? Because it just did.

“I like going for character in that way,” Messer continues. “A lot of the records that I listen to, and a lot of the recordings that I admire, are amazing recordings not necessarily done on amazing equipment. Chess Records, things like that. Go back even further to 78rpm records and the way they would have recorded Robert Johnson. Yes, they used good equipment for the time but with a very narrow frequency range. One of the things we all love about those old recordings is, in fact, that you can’t hear it all properly.

“Let’s put it this way — Robert Johnson would sound equally amazing if you were in the room with him, but if he was close-miked with a hi-fi sound, I’m not sure it would sound as good as it does the way we hear it. Because it creates a warmth. You’re not getting any highs and lows, it all sits in a bandwidth that’s very comfortable. It works. Modern recording is too good, in a way. Sometimes high-fidelity recording, like looking in a perfect mirror, is not necessarily the best way of getting a great sound.

In a good-sounding room, a multi-mic approach can work well, with something like a Neumann KM84 placed fairly close, as in the previous picture, and another mic placed more distantly.In a good-sounding room, a multi-mic approach can work well, with something like a Neumann KM84 placed fairly close, as in the previous picture, and another mic placed more distantly.

“If I was recording a solo national guitar for a high-fidelity recording sitting on its own in the middle of a pair of speakers, then I might use two microphones — perhaps a ribbon at the back of the cone and a condenser towards the bass end. But there are all sorts of problems related to high-fidelity recording and slide guitar — and that problem is the sound of the slide. I’ve often done sessions where the first thing the engineer or producer says, if they’re not used to recording the instrument, is, ‘Oh God, all that string noise!’. You’re actually better off sometimes putting an SM57 on it — something that just naturally cuts some of that stuff out, but still gives you a great sound.”

In Jimmy Heffernan’s world, where high-fidelity is more usually the order of the day, mic selection is generally more orthodox. While some Nashville producers, like Bil VornDick, favour a pair of large-diaphragm condensers such as the AKG C12, Neumann U67 or U47 for dobro, set up in an X-Y configuration above the instrument (which, let’s remember, sits flat on the player’s lap), Heffernan has particular affection for a classic small-diaphragm condenser, and he is not alone.

“My favourite mic is a Neumann KM84 or KM184,” he says. “One of the guys who is lauded as having some of the best tone ever was a friend of mine named Mike Auldridge who recorded everything with a KM84. I’ve done sessions with him and he would just move that thing around in whatever space he was in and find the sweet spot. Because every space is a little different. He would sit down then move the instrument, move the mic. He was very careful about that. I tend to agree with him.

“I get an incredibly warm sound with the KM184. The thing would be to get it pointing in-between the cover plate [which covers the resonator cone] and the port, not at the centre of the coverplate and the hands. It’s a killer mic. That’s my go-to. I’ll also use large-diaphragm mics like the Peluso P12 or Neumann U87. I use a Lawson L47 — that’s a U47 clone — and that gives me great results also. Also to some extent ribbon mics, like the Royer R121 and the Beyer 160. They’re all going to give you good results.”

Mixing & Processing

Heffernan also has some specific advice to offer when it comes to mixing the sound of the dobro, though he explains that the unusual sound profile of the instrument tends to do some of the work for you. “The frequencies and just the general character of the sound is so different to other instruments that it immediately separates itself from somebody, say, strumming an acoustic,” he says. “Even though this is basically a set of acoustic guitar strings — tuned to different intervals but in the same basic range — you can still sit above an acoustic. Even though you’re not louder per se, you’re cutting through the mix.

“I don’t know about everybody, but I tend to thin out acoustics a bit, and that also creates a space that dobros can fill up with the mid range and low end of the instrument’s sound. In fact I will tend to notch that area out on the acoustic guitar precisely so I can create the space for the dobro to live. But it depends. In other scenarios, where I’m up on the higher strings of the dobro, I won’t need to do that at all.”Recording Resonator Guitars

With its singing sustain and wide dynamic range, the dobro certainly boasts some vocal-like qualities, and Heffernan believes the comparison is an apt one when it comes to dynamic processing. “The one rule of thumb is to treat the dobro like a vocal, especially in a solo context like an intro,” he explains. “You wouldn’t want the sound of an over-compressed vocal. You can get away with that on an electric guitar, obviously on a bass, and on certain percussion instruments. But the worst thing you can do is to take the dynamics away from a vocal — or a dobro, which is very vocal-like. That’s the way I always think about it. It’s like somebody singing. So when I’m dealing with it in a mix or tracking, that’s definitely on my mind.

“The thing I hate the most, and I think most players would agree, is too much compression. There’s a lot of dynamic range in the instrument, and often the first thing an engineer wants to do is compress that or limit it. But the true sound of the instrument is supposed to rise and fall so, when you’re mixing, you have to ride it. It’s part of the modern style to be very dynamic. Individual notes in a single phrase can be wildly different in volume. A lot of notes I play are going to scare an engineer half to death! Dobro players are called in a lot of the time to overdub, so when you’re tracking, rather than compress or limit, what I would suggest is that you take down the level of all the tracks and try to give the dobro player as much headroom as you can. You’ll sense where he’s going to top out at.”

While Messer leans towards emphasising the instrument’s gutsy mid range when recording resonator guitar, especially on characterful blues sessions, Heffernan is more likely to reduce the mid range in preference for the bass and treble in dobro recording.

“Sometimes I’ll EQ out around 300 or 250 Hz, just to get a bit of that low-mid mud out,” says Heffernan. I don’t tend to really do any boosting. I might possibly boost 8-12 kHz by 1dB depending on the track and the way I was playing on it. If I’m playing very hard, there’s going to be more sizzle in there and I wouldn’t have to do that, but if I’m playing quietly and softly, I will boost up there very subtly. One thing I do like to do is take out 800Hz to some extent. There’s a lot of 800 in here; I kind of look at it like there’s more than enough in there. Subtly slicing out a little of it just helps the instrument open up and blossom. But I’d be very subtle. It’s not heavy-handed at all, and it depends on the sound of the particular instrument, obviously.”

Shine Of The Times

Both players are adamant that their instruments have plenty to contribute outside of what might be considered standard resophonic territory. “I think there’s a myth around resonator guitars, and the myth is that they’re just slide guitars,” says Michael Messer. “Yes, a guitar with a square-neck and raised action is only ever going to be used for slide, but anything that’s made with a Spanish-style, regular guitar neck is a guitar. Just a guitar. And anything can be played on it.Recording Resonator Guitars

“New guitars tend to be set up by the manufacturers for slide players because that’s the majority of the market. Old ones tend to have a high action because older guitars tend to. So lots of players just don’t bother to pick them up because of the way they’re set up. But a single-cone national-style guitar is a very powerful acoustic instrument, great for lead playing but also a great rhythm guitar. Used as a rhythm instrument, like electric rhythm guitar, it produces a great sound. It’s powerful — these instruments were made for volume. I’ve used them in that context before, and you wouldn’t really be aware it’s a resonator guitar.”

Jimmy Heffernan also likes to use the dobro as more than just a lead instrument. “Away from setting the whole tone of the song around the sound of the dobro,” he says, “it’s incredibly useful in creating parts and lines — ‘sections’ or ‘gang licks’ as we call them in Nashville — where multiple players are playing the same line. If it’s tucked in there it has such a unique quality that it sits in with the guitar or violin or whatever else is playing the line and just gives it so much depth. There are a lot of country records that use that technique. When I produce records I’ll use it quite a bit where I don’t play dobro anywhere else in the song. I’ll just play it on the section. You’d have to really know that it’s there to be aware of it.”

“Style-wise,” adds Michael Messer, “I would say that where resonator guitars are pitched in peoples’ minds — blues, country, folk, roots — that’s not necessarily their only place at all. A good example is Mark Knopfler. He uses resonator guitars in ways you wouldn’t necessarily expect. On ‘Romeo and Juliet’, with that melody and that approach to playing the guitar, you wouldn’t expect to find a resonator there. Dave Stewart in the Eurythmics is another example. Further back, on ‘Lola’ by the Kinks, that’s a national guitar starting it off and used as the rhythm guitar throughout. Around the same period, and probably influenced by each other, was Manfred Mann’s ‘Pretty Flamingo’ — that’s a national guitar all the way through it.

“The thing is, it can also be played gently and melodically and sound very sweet,” Messer continues. “Go on YouTube and you’ll find people crashing around playing blues, playing percussively, using resonators for their power and volume. But the sweetness you can get out of a good one is stunning. The sustain, the overtones — no other instrument produces overtones and harmonics like a resonator guitar.”

Thanks To Jimmy Heffernan and Michael Messer. You find out more about them at and Call Of The Blues by Michael Messer’s Mitra is out now on Knife Edge Records.

Speaking Out

When playing his national live, Michael Messer prefers to use a Shure SM57 dynamic mic, rather than a pickup, as most don’t perform as well as those used on acoustic guitar.When playing his national live, Michael Messer prefers to use a Shure SM57 dynamic mic, rather than a pickup, as most don’t perform as well as those used on acoustic guitar.

If resonators introduce some interesting challenges in the studio, this is doubly true when it comes to live-sound reinforcement; a highly resonant instrument that sounds markedly different depending on where you place the mic is not the average FOH engineer’s idea of fun.

With pickup systems getting better all the time, acoustic guitarists are usually happy to simply plug in. But when it comes to resonator guitars, Michael Messer eschews pickups in favour of his own tried-and-tested mic technique. “If you sit six feet away from someone playing a National guitar, it’s very different to putting your ear up against it,” he explains. “That’s why I don’t like pickups in them. The best pickup for a National guitar is the Highlander, which sits in the biscuit under the bridge. It does an amazing job, the best job of everything that’s out there, but it can’t possibly hear the whole picture. You’ve got your ear glued to the bridge, so you can’t hear the whole thing.

“Unless I’m forced to plug in for reasons beyond my control, I just use a standard SM57,” he says. “I set the EQ flat, or maybe roll off a little top and bottom so it looks like a frown and not a smile, which is the opposite of what most people would set for an acoustic guitar. And that’s it. I would keep the foldback low, at a similar volume level to my guitar so I’m getting a spread of it rather than being hit in the face with a sound that’s going to cause feedback. I then move the guitar around on the microphone — in, out, left and right — to give me different tones and volumes, much like adjusting the controls on an electric guitar.”

For dobro players, the picture is slightly different. In the all-acoustic world of traditional bluegrass, where on-stage volume is inherently low, it’s possible to use condenser mics on stage, with small-diaphragm models often favoured. Where the dobro is being used alongside electric bass and drums, or when the player simply wants the freedom to roam around the stage, a clip-on mic or built-in pickup is required. The highly rated combination of Fishman’s Nashville Series undersaddle pickup and Jerry Douglas Signature Series Aura processing pedal get Jimmy Heffernan’s nod of approval.

“The undersaddle pickup on its own totally misses the sound of the resonator cone,” he says. “It’s just picking up the strings like a piezo pickup on an acoustic guitar. And that’s what it sounds like — an acoustic guitar, and not a very good-sounding one. But in combination with the modelling in the Aura pedal, it’s out of the park, it’s unbelievable.

“So it’s really the only game in town in terms of dobro pickups, but you’re still going to get feedback issues,” Heffernan continues. “This is a resonant box, you know. It’s built to pick up and amplify resonance and it’s going to take whatever is coming back through the monitors and do that. One option is to cover or block up the ports on the dobro, but really the trick is to have a monitor guy that knows how to EQ the monitor feed to avoid feedback.”

Published July 2016