Useful Stuff to Know » article » Introduction to Recording Metal Rhythm Guitars » Apr 23, 11:49 PM

Introduction to Recording Metal Rhythm Guitars

Looking to record rhythm guitars for metal and make it sound big, heavy, and thick?

You have a couple options:

1) Use a microphone and guitar cabinet – the authentic way, but this only works if you have a good amp, good room, good mics, and none or good neighbors who will put up with your noise.

2) Use a virtual guitar amp simulator – the easiest way to get consistent tone without disturbing neighbors. Only problem is it will never be as authentic or punchy as a real mic and amp. But it will still sound better than a crappy mic and amp recording.

3) Use a real preamp run into a virtual cabinet simulator – here you let real tubes do the most important part, which is distort your guitar while preserving pick dynamics. Then this is run through cab impulse responses to simulate a mic+cab+room combination. Can be more realistic than an amp sim, but still not as punch as the real thing. Good compromise though.

First let’s look at what goes into a recorded guitar sound. For a real mic + amp recording, here are the main factors, in order of importance:

  • amp distortion circuitry and settings – where your main sound comes from. This is the body of the sound signal. Bad signal here equals bad final product. Nothing beats genuine tube distortion. Digital or transistor distortion gets you 90% there at best. To adjust the gain, palm mute the E string and do some eighth notes as you adjust the gain — turn it up until you hear the high end fuzz kick in, then back it off slightly. You can turn up the treble on the amp if you need more sharpness after that. Do not allow the distortion’s high frequency buzz to continue throughout the length of the eighth note; it should decay halfway through at most. This is so that you retain dynamics and attack in your sound, otherwise it will all blur together. Also, if you layer two takes, their distortion will combine and seem more than it is; so if each take is with gain at noon, two layered together in your recording will sound like gain at 2 o’clock, which is fine.
  • amp speaker type – 8” diameter speakers are horrible. 10” is better but not good enough for heavy guitar recording. 12” is ideal. Among the 12 inchers, the type of speaker (brand, model) makes a definite difference in how your amp sounds.
  • position of microphone – aimed straight at the center equals a fizzy weak sound. Aimed at the outer edge equals a boomy muddy sound. Aimed halfway equals a rounded mid sound. Angling the microphone 45 degrees mixes the sound from adjacent regions. Closer to the speaker equals more bass. Farther away equals thinner sound. I prefer 1” away from the speaker grill, 45 degrees aimed toward where the center cap meets the cone. If using just one dynamic, then move it away from the center just to where it starts to lose the fizz. You’ll hear in a lot of metal recordings no fizz at all. You can turn up the treble later in EQ if you need more definition.
  • microphone type – these are like filters and lenses on a camera. They affect the flavor of your sound. Dynamics capture less of the full spectrum of sound from a smaller portion of the speaker. Condensers capture sound from more areas of the speaker and have more room acoustics coming in. The reason people use two different dynamic mics sometimes, is because each mic has frequency deficiencies that the other makes up for; a condenser has a flatter frequency response, but sometimes is too transparent and clear and doesn’t impart enough character and roundedness to the sound like a dynamic does. It’s good to use a dynamic up close as described above but more toward the halfway point between center and edge of the speaker for a more rounded mid sound, and then layer that with a separate take of a condenser 3-4 feet away aimed straight at the center of the speaker. The condenser will capture the crispness and upper mid “whole” sound of the amp, while the dynamic takes care of the lower beef. Recommended dynamic mics: Shure SM57, Sennheiser e906, and Audix i5. Under no circumstances should you ever record with a computer microphone, the kind used for voice chatting. Get a real mic with an XLR pinout, something in the $75 or above range.
  • amp cabinet size and type – for recording, a 1×12 will give you less phase problems than 2×12 or 4×12 cabinets, thus a more direct and articulate sound. Remember that in a mix, guitars tend to be high-passed around 100 Hz anyway, so the deeper resonance of a 4×12 doesn’t always translate into the mix. Closed back cabinets give more thump, open backed … well their sound changes drastically depending on distance from wall, making it all the harder to get the right sound.
  • room acoustics – especially if using a condenser and/or turning the amp up really loud, the sound of you room comes into play. Avoid small spaces like closets unless they are very well sound proofed, because it will indeed sound like a closet otherwise.
  • position of amp/cabinet – if the amp/cabinet is on the floor and near a wall, reflections will interfere with the recorded signal and lead to comb filtering, which is an EQ effect that chops out certain intervals of frequencies in your sound spectrum and sounds horrible. Keep it 1/3 of the room width away from the wall, and raise it up on something like a milk crate.
  • degree of tracking – Whether you do just a single guitar track vs two tracks left/right vs four takes layered. Single takes are only advised for clean and solos, never for rhythms unless it’s for effect during a breakdown or intro. Do not do just one rhythm guitar track and attempt to make it stereo through delays, reverb, and other tricks, reason being it will sound bad and on certain pitches the stereo effect drops out. At minimum do two takes, one panned mostly left, other mostly right. If your guitar sound and EQ in each take is good, then that’s all you need. If they are deficient, then doubling each side with another pair of takes using alternate guitar/amp/mic settings can fill in the frequency gaps in the other takes. Best sound is achieved by doing two takes left, two takes right, each with a good guitar sound that could stand on its own. For instance, one take is more sharp but thin and sounds okay, another more beefy but not sharp yet sounds okay too, and the two together cover the sonic spectrum and sound excellent. However, if the song is fast and technical and you’re sloppy, it’s better to stay tight by only doing one take each side with a good mic position and post-EQing, than to attempt to beef it up with doubling and have it be a fuzzy inarticulate mess. Some DAWs (digital audio workstations, aka multi-track audio editors) like Logic 9 for Mac let you drag points in a waveform to stretch and align them perfectly with the beat, so there you can cheat and indeed make fast doubled tracks sound tight as well.
  • post-recording EQ processing – This is very important and a science unto itself. Use a graphic EQ, a couple in succession on your chain if more bands are needed, to try and even out your sound spectrum. It should start rolling off beneath 200 Hz and above 6 Khz. The frequency spectrum should be somewhat of a straight line sloping down maybe 10-30 degrees from the bass to the treble region; a little bulging in the bass area doesn’t hurt. You’ll need to read up on guitar EQing and play around with this to get it right. The most massive guitar tones done with multiple amps and mics will have a smoother EQ spectrum; thus a very jagged and craggy EQ response can mean less full of a sound.
  • guitar amp’s Bass/Mid/Treble settings – turn down the bass so that it’s there but not boomy or prominent, maybe 9 o’clock to 11 o’clock. Do not scoop your EQ here. Keep your mids at noon or above. Treble between noon and 3 o’clock. The rest you can handle in post-recording EQ. You need mids to make your guitar stand out and sound heavy in the mix. Scooping mids leads to a weak body-less sound.
  • amp volume level – the louder the volume, the more the room sound enters the recording, and the more certain nonlinear distortion effects enter the equation. I’m talking about the speaker reaching breakup, which introduces a new kind of distortion. Speaker breakup distortion is kind of throaty, more rounded, more lower-mid oriented than your amp’s own distortion. It adds an extra bit of heaviness to your overall sound. But getting it is sometimes not worth the trouble if you have neighbors, since it does require that the amp volume be turned up quite high. Especially for non-tube amps, having it turned up to medium volume is good enough for recording; only tube-amps really benefit from volume being turned up high. Some amps, especially digital combo amps, don’t sound that good when their speakers break up, so leave them at medium volume when recording. If volume is too low, then you’ll get too direct and fizzy a sound; you need just enough of the nonlinear factors coming in from the speaker and cabinet with a medium volume to help offset the pure electronic sound of the amp’s inner circuitry.
  • quality of microphone preamp / audio interface – Anything under $75 dollars is junk, trust me on that. And that includes the SoundBlaster Live card on a desktop. You’ll need to get a USB or Firewire audio interface that has enough gain for what your microphone needs, generally 45 dB gain or more, with 48V phantom power if you’re using a condenser microphone. Once you get into the 100-300 dollar range for interfaces, you’ll get a clean enough signal that you can make good sounding recordings provided the other factors mentioned here are taken care of. I strongly recommend something in the 200-300 range minimum. Anything above the $300 level is more icing on the cake and not absolutely necessary for home recording. Mainly you just need to avoid the sound card microphone preamplifiers that come with computers (that’s the pink mic-in jack on some of them), and those cheap $30 USB mic interfaces too.
  • position of pickup (neck vs. bridge) – use the bridge for rhythm sounds, as it’s sharp and has good attack. The neck is fine for clean and solos, more of a rounded bassy sound. Using the bridge for clean gives too much of a tinny mandolin sound, whereas the neck on clean gives a nice bluesy jazz or even acoustic guitar type sound.
  • type of pickups – first of all, use humbuckers and not single coil. The humbucker brand/model affects the clarity or muddiness, the default EQ (level of bass, mids, treble), and general character of the sound that goes to the amp’s distortion circuitry.This is more important when playing clean, since the distortion disguises some of that character. Nonetheless, main thing to avoid are ice-pick thin sounding pickups, and bassy and muddy sounding pickups. The active EMG 81 is a bit thin and digital/compressed sounding when running at 9Vs but sounds more organic with the 18V mod. Its lack of bass can be fixed with amp and post-recording EQ settings. Passive pickups have better dynamics and a more organic sound, but are not as surgically precise and articulate as the active pickups. For passive pickups, I recommend the Duncan Custom and 59 set, Dimarzio Crunch Lab and Liquifier set, or Dimarzio Evo 2 and PAF Pro set. If you only want articulate cleans in the neck, nothing beats the Dimarzio EJ Custom.
  • type of strings – if you want heavy, then use heavier gauge strings, especially if you are down-tuning. The Ernie Ball Skinny Top Heavy Bottom are good for E standard down to C# standard, and any lower I’d recommend Ernie Ball Beefy Slinkies with the G string replaced by a 22 gauge wound. The G string is a real pain in the ass. If you’re doing mostly rhythm stuff, better to use a wound string for it. You can get wounds down to 17 gauge, and it’ll give you a more precise, thick, and harmonically rich power chord versus that howling plain. I use 19 gauge with my Skinny Top Heavy Bottoms for Eb standard, and same setup sounds okay down to C# standard. As for new versus old strings, that addage about old strings making ‘dead’ recordings is only true for clean and slightly overdriven guitars. There you need that metallic sparkle. But I found that this same sparkle adds undesirable harmonics into a fully distorted sound, as in a bit of warble that isn’t there once the strings are a couple weeks old. Thus I prefer ‘dead’ strings with good distortion, but that’s just me. If your E string is too thick, however, attack will suffer because the string is wider and thus more rounded and the pick has to drag across it longer, reducing the sharpness of the attack. Thus a 52 gauge string at C# will sound clearer than a 56 gauge at the same pitch, though at the expense of being looser and more prone to fret buzz.
  • height of strings above pickups – this is similar to turning up the gain on your amp. When strings are close, they lose dynamic, sustain, and sound more fizzy in the distortion. When they are farther, they start losing attack. You can get much more punch and dynamics with the pickup a little too far versus too close. Good place to start is, stack a nickel and penny atop the bridge pickup beneath the fatter E string and raise the height until the coin touches the string, repeat on the high E string using just the nickel. For the neck, use a nickel and two pennies on the fat E, nickel and one penny for the thin E.
  • the pick you use – this impacts the sharpness of the attack by creating the scratchy sound at the beginning of a pluck, some of which is needed during palm muting to make the strums stand out. The harder, more rounded, and thinner the pick, the greater this scratchiness. I like a stiff pick with sharp point and medium thickness, like the Jazz III picks. The thinner and more rounded ones like Fender Medium tortoise shell picks are good for cleans, as they provide a more sudden and sharper attack approximating that of an acoustic.
  • the magic in your fingers – some say it doesn’t matter what amp or guitar you use, it’s all about how you play. Well, for classic rock solos that may be true because they rely a lot on expression and embellishments, but a power chord strummed by a newbie versus a pro will both sound exactly the same on the same equipment, which is crappy if the setup is crappy. For metal, the rhythm guitar needs to be full sounding; you start by getting the long power chord sounding full. Then you can work on getting the attack and dynamics sounding right.
  • amplifier power section distortion – this and other technical terms like “sag” have a slight effect on your sound, but not as much as the preamplifier where the main distortion comes from. This is another “icing on the cake” kind of factor. It’s something missing when you use a tube preamp and impulse responses; you can make up for it by using a virtual guitar amp simulator with just the power amplifier loaded up.
  • guitar body wood – mostly affects the default EQ and level of resonance and sustain of your guitar. With the guitar unplugged, strum the guitar and listen to how loud and resonant it sounds. Mahogany is richer and darker and more resonant. Maple is very bright. Basswood is in the middle but not that rich or resonant. How much of that survives the distortion? Mostly it affects the EQ and the “bite” of the distortion. Generally a pickup needs to be matched to the body; a bright pickup with a dark body wood is fine; bassy pickup with twangy body wood is fine, and so on.
  • guitar neck construction (bolt-on, set neck) – mainly affects resonance and sustain and guitar EQ. In a neck-through, the neck wood will replace the body wood type when it comes to tone. So a maple neck through a mahogany body will have a mostly maple tone and thus be pretty bright despite the body being a dark wood.

So, as you can see, some factors are more important than others. A low quality guitar through a great amp will sound better than a high quality guitar through a poor amp. After that, mic type and positioning come into play.

Methods of Recording

You generally have four avenues.

Use a Line 6 Pod to combine amp, cab, mic, room, effects, and audio interface (in some models) into a single unit. Then all you need is guitar and computer.

Use a software plugin like Amplitube or Guitar Rig to combine amp, cab, mic, room, and effects. All you need there is an audio interface, computer, and guitar.

Use a convolution plugin to combine amp, cab, mic, and room. Then all you need is the guitar, distortion pedal or distortion preamp, audio interface, and computer.

Go real with everything. Real amp, real room, real mic.

Each has its advantages and disadvantages.

The Line 6 Pod is convenient and good enough for making rough draft recordings. If you need to record quietly and want the least amount of hassle, then make it a Pod. Its downside is sound quality, as in already sounding too processed so that in a mix that is further processed the guitars will lack realness and sound too digital. However, you can indeed get good sounds with a Pod, much better than trying to keep it real and not having top quality amp and microphone gear. I’d recommend the Pod if you are on a budget, have neighbors, and are not a perfectionist.

Virtual amp plugins like Amplitube, Revalver, and Guitar Rig have the advantage of huge variety of sounds possible. Downside is that your audio interface quality and volume levels makes a big difference in how the dynamics and attack of your playing come through the virtual distortion. Most of the time you might get a nice distortion sound, but the dynamics suffer. This setup also suffers more from noise. Additionally, this setup is processor intensive, so you’ll need a fast computer to make best use of these plugins. Slower computers will cause chokes and increased latency (delay between what you play and what you hear back processed) which screws up your timing. A Pod does all the processing in hardware, so latency there isn’t as much an issue, while a virtual amp plugin does need a powerful computer and great audio interface to work optimally.

Using a distortion pedal and convolution plugin works too. The HT Dual tube distortion pedal by Blackstar can be run through some Diezel and Engl impulse responses, but an actual tube preamp will have more bite and articulation. Other good preamps include the Peavey Rockmaster, Mesa Triaxis, and Engl 530. Many tube amps, including those of high wattage, have a line out jack, which passes a signal from the preamp distortion stages. This can likewise be sent through a convolver plugin in your DAW loaded with suitable impulse responses.

The impulse responses are files that capture the way sound is process through a real amp, mic, and room. A convolver plugin is what processes the input sound signal through this impulse response. Impulse responses are created using a real setup, the essence of which is distilled into that file. The advantage here is that the most important part of the sound, the distortion, is handled by real equipment (a real vacuum tube running at 300 volts), so it starts off on the right foot.

There are hundreds if not thousands of impulse responses available on the web, just look up “cab impulses” or “cabinet impulse responses” and you’ll find them made from different amps, mics, positions, and rooms. You can aggressively EQ them afterwards to make them sound just right. I select ones that offer the maximum fullness and clarity. So far Engl, Catharsis, Guitar Hacks, and Diezl impulses are among the top. The greatest advantage of all, is repeatability. When you mic a real amp, it will sound different on a different day due to changes in temperature, humidity, and air pressure. That perfect sound you get with one setup, may not be achievable again a month from now. But with an impulse response (IR), that setup is frozen in time so to speak.

What you want to look for in an IR is maximum body and clarity; some responses just sound muddy, tinny, or too boomy. If you’re used to doubling two frequency-deficient takes to make a blended track that sounds right, know that by picking the right IR and applying EQ, you can indeed get away with only one take on each side (Left and Right) that has no deficiency in its frequency spectrum and sounds perfect. Then the only advantage doubling offers is smoothing out the distortion a bit if it sounds too dry.

Lastly, going completely real is the only way to get 100% the sound you hear on albums. The other methods can only get you there 50-90%, with 90% being good enough that only audiophiles and pros can tell the difference.

But to get that 100% with a real setup requires a lot of time and money. You need a good room with no neighbors, a good 1×12 cabinet (or 2×12 / 4×12 if you mic carefully and watch for phase issues), 50-100 watt tube amp (Mesa, Engl, Diezel, etc…), good guitar with good pickups, perfect tuning and intonation on your guitar, volume turned up right near threshold of speaker breakup, and an SM57 / e906 / RE120 or better placed just right, possibly in conjunction with a condenser couple feet away on a separate take, and then proper EQing.

Conclusion

A good metal rhythm has a frequency spectrum without any huge peaks or valleys. It has reduced bass (shelved but not cut below 100 Hz) since that frequency space is reserved for the bass guitar, tight but audible lower mids to give beef and body, clear but not annoying or honky mids and upper mids to represent the pitch, and clarity and attack in the treble range without making it sounding fizzy and harsh. There’s no need for frequencies above 12k when it comes to rhythm metal guitars, and it should already be sloping off after 6k. The spectrum should also show no signs of comb filtering; you cannot fix that through EQ, and must instead have the mic/amp/room positioning changed. Beyond that, bass/mids/treble can be shaped depending on the song mix requirements.

The most convenient way to record is through a Line 6 Pod. The most versatile through a virtual guitar amp program. The most realistic through a real setup (obviously). And the best compromise through a tube preamp signal passed through a convolver plugin loaded with a good sounding impulse response.

Secret tip: if you’re using Logic, pass your signal through the tape delay, set delay to zero, and in the drop down hidden options increase the tape gain. It will get rid of the fizz.