Recording and Mixing Electric Guitars
The electric guitar is the most successful and widely adopted instrument in modern popular music. In fact, a recent study shows that the electric guitar has now overtaken the violin as the most popular musical instrument for children to learn. Traditionalists might sneer at the changing musical demographic, but the fact remains, electric guitars are extremely versatile and therefore have a broad appeal spanning many musical genres.
When it comes to studio recording, the very things that make the electric guitar so versatile are also some of the aspects that make it a challenging instrument to record. Fortunately, there are some guidelines that can be applied quite broadly, and thus, it needn't be rocket science to get professional results. The following are some of the basics you should know.
Setting Up - Get the Source Right First
We've covered a wide range of instrument recording techniques in the past, and almost all of them start with getting the source right first. Some guitar players are lazy when it comes to recording in the studio and follow the assumption that it can always be "fixed in the mix." This fundamental misunderstanding of how recording works is at the heart of what leads to most demos sounding rough and unpolished. Although modern mixing techniques can work minor miracles, they can only get you so far. The best approach is always to ask yourself a simple question: 'Is this how I want the recording to sound?' If the answer is no, then you need to return to basics before pressing the big red button. Here's what to address:
1) Is Your Guitar Set up Properly?
Since we're talking about getting things right at the source, the most logical place to start is the instrument itself. Old strings not only feel nasty to play, but they're also likely to have poor tone, tuning stability, and intonation. Be sure to change your guitar strings the night before any recording session. Secondly, ensure that you check the instruments setup and intonation. A poorly setup instrument will not only affect your performance, but it could also ruin a perfectly good take if the intonation is out due to poor maintenance. Consult with a guitar setup specialist if you're not comfortable with the basic principles of guitar maintenance. Alternatively, if you suspect the instrument might not be up to the job, it's seriously worth considering hiring a good one for the job. Remember, this is your chance to get those ideas down on tape - figuratively speaking. The last thing you want is a tarnished result before you've even reached the mixing stage!
2) Once Your Instrument Is Ready, Your Attention Will No Doubt Be Turned to the Amplifier.
There are many variations in guitar amps, from valve amp to solid state and from cabinet to stack amp. As the topic of selecting amplifiers can form an entire post in its own right, we will stick to the basics.
One of the most common misconceptions about guitar amps is the notion that bigger is better, louder is better, and even more distortion is better. In actual fact, the complete opposite is almost always true. It is far easier to achieve great results with a small combo amp, at low wattage with only one speaker cone than it is to record a 100-watt stack amp with four speakers per cabinet. This theory is particularly relevant in a small home or project recording studio where a large stack amp is simply too loud for the typical room size.
A small valve amp of say 15 watts — with the master volume pushed high and the input gain set to moderate levels — can actually sound bigger than a very saturated distortion sound driving a large stack amp with the master volume set low. In other words, preamp gain without the guts of master volume can sound rather 'thin' or 'fizzy' and the smaller your amp, the easier it will be to adequately drive those power amp valves at sensible volumes. Try it next time you record; downsize your rig and you might just be surprised by the result.
Choosing the Right Mic
Once you're happy with the source sound from your guitar and amp, you'll need to select the right mic to best represent your lovingly crafted tone. There are no right or wrong options when it comes to selecting a microphone, only options and results. Dynamic, condenser, and ribbon options are all capable of reproducing a great guitar sound, with your selection very much dependent on application and personal taste.
By far the most commonly used type of microphone for guitar cabs is a dynamic instrument mic. Their solid sound and smooth high end — combined with their capacity for high sound pressure levels — makes them very appropriate for a wide variety of genres. Additionally, they are – for the most part – fairly inexpensive, meaning that you don't need a big budget to get professional sounding results.
For a little more low-end oomph, you could also consider a large-diaphragm dynamic mic. They usually have an increased frequency response due to their large housing and diaphragm, while still maintaining the smooth and solid sound characteristics of a typical dynamic mic.
Next up are condenser microphones. Their greater sensitivity and wider frequency response will allow you to capture a brighter, more detailed and open sound. If this is your thing, look for a large-diaphragm model with a -10 or -15dB pad to allow greater capture of low frequencies while also handling high SPL (sound pressure levels).
Last but not least are ribbon microphones, which used to be a staple in the record business before falling out of favour to their more robust condenser counterparts. Modern innovations, however, have lead to the development of more robust ribbon mics, and subsequently, they have made something of a comeback in recent years. Famed for their smooth high-end, ribbon microphones have a fantastic wide frequency response, without having the aggressive bite that can come with condenser microphones. For this reason, many engineers swear by them for guitar cabs.
For more information on the fundamentals of microphones, read our previous post, here.
Microphone selection is but only half the battle. Once you're content with your mic selection, it is imperative to combine your choice with the appropriate placement to ensure great results. Once again, just like in previous posts - investing the time here is critical. The results captured at this stage will greatly determine the final output; lazy mic placement will only lead to a headache during mix down. Invest your time wisely, however, and your mix should be 80% there already!
The most common approach is refreshingly simple. Take a dynamic mic, place it a few inches from the grill pointing at the centre of the speaker cone and make minor adjustments to taste. Moving a mic to the side will result in a warmer tone, while keeping the mic pointed dead centre will deliver the brightest, most aggressive tone.
If your dynamic mic has a cardioid polar pattern, then you will also need to factor in the proximity effect, which dictates that low frequencies increase as the mic is moved closer to the sound source. With this in mind, remember that within the context of your actual mix, too much low-end could conflict with your bass guitar and kick drum. Therefore, in some circumstances, you will benefit from easing the mic away from the speaker grill. Backing the mic away slightly will also result in a more accurate representation of the whole guitar cabs tone. In any case, what works for you will require some experimentation to achieve the best results.
As briefly touched upon above, condenser microphones are much more sensitive and have a wider frequency response than dynamic microphones. Using them on your guitar cab can deliver a more detailed, organic sound if that's your thing.
Concerning placement, you could experiment with close micing in a similar fashion to the dynamic example above. In most cases, however, a condenser will benefit from additional breathing room. Anything up to 20 inches away can work - just bare in mind that the further away you get from the amp, the more room reflections can come into play; this is particularly important when using an omni-directional polar pattern.
With distance and mic position, it really comes down to experimentation, personal taste, and musical genre. The best approach is to get yourself a good set of monitor headphones and experiment with small changes in position, distance, and microphone type until you hear the result that works in context with your music or production.
Finally, remember to experiment with the mics dB pad and low-frequency roll-off. These settings are important when using a condenser to record guitar cabs because excessive low frequencies and high SPL levels can really play havoc with your recording headroom. A combination of low-frequency roll off, and around 10 - 15 dB of attenuation on the mic will usually be enough to tame the result.
The approach for placing a ribbon microphone is similar to a condenser mic, but it's important to remember that traditional ribbon microphones are extremely delicate, and subsequently might not take well to loud sound sources when using close mic techniques. Modern ribbon microphones — such as those featuring Shure's unique Roswellite ribbon technology — solve this problem and allow you to take advantage of smooth, warm ribbon tone, without the worry.
Using Two Mics Together
For greater flexibility and breadth of tone, many engineers will use a combination of mics to arrive at the tone they desire. Two approaches apply here:
1) Place two different microphones as close as possible to each other to minimise phase cancellation, and then use a blend of the two to arrive at the desired tone.
2) Place one mic close and the other at distance while paying close attention to the phase relationship between each mic.
Whichever dual-mic technique you choose to experiment with, the commonality between them is the importance of phase coherence. Failure to listen carefully for phase cancellation will result in a weaker sound if cancellation occurs. The phase invert switch is your friend here. Listen carefully while inverting the phase on one channel and then choose the setting that sounds 'bigger' to you.
By this point, you should have a general tone that you're pleased with. If not, it is strongly recommended you go back to the drawing board and get it right. The aim of your mix should not be to change the recorded sound, but instead, tweak and adjust the recording to complement your mix. The following are some examples of typical processing techniques for electric guitar:
Guitar players are heavy users of effects pedals. On the one hand, they can form a vital part of the performance, and therefore, the guitarist needs to hear them while recording. On the other hand, including the effects during tracking can make mixing rather difficult if you decide the effect doesn't work within the context of your track. For this scenario, there are two solutions:
1) Emulate the effects through their monitor mix for the benefit of their performance
2) Do your best to capture the most appropriate sound possible – effects and all – but record a DI backup, which can be re-amped after the performance as a backup. This approach works particularly well because it allows the guitarist to maintain the effect elements that are fundamental to their performance, while giving you peace of mind as an engineer.
Compression added to guitars will help you maintain a more precise level and space within your mix. How much is required to deliver a satisfactory result will depend on the guitar players natural dynamic control, and the microphone you used during tracking.
For example, dynamic microphones tend to exert a small amount of natural compression on guitars. Therefore, the chances are you'll want to use more compression when using a condenser mic. If the guitar player has good dynamic control, you might still only need a small amount. Generally speaking, add as much compression as required to keep levels relatively consistent and help sit the track within your mix. The less you can get away with the better, as too much compression can squash the life out of your performance or even significantly alter the tone.
Typical EQ applications for electric guitar include removing unwanted low-end, reducing mid-range boxiness, and boosting bite to cut through a mix. Here are some examples of how to achieve results:
A large amount of low-end on your guitar might sound good in isolation, but when placed in the context of your overall mix, it could well be too much when combined with the bass guitar and kick drum. Experiment with a high-pass filter to roll of low-frequencies while listening in context with the drums and bass; stop at the point where your mix sounds clear, without losing too much weight.
Boxiness can occur in guitars around the 100 - 250Hz area. To locate the problem, experiment with the Q setting and boost to help locate the offending frequency and then cut at this point.
To add more aggression or bite to your guitar, try boosting at around 2 - 6MHz, which should also help cut through a busy mix.
It is common practice to record guitars with the amplifiers reverb applied during tracking - particularly if the amp in question has a rather nice spring reverb built in. Just like in our effects example, though, flexibility and control is the price paid for tracking with effects. Once again, you'll need to make a judgment about whether you want to trade character for control. Either way, the name of the game with reverb is to create the impression that everything was recorded in the same space. With guitars, a little effect reverb (such as our spring example) combined with a touch of overall room reverb from a plugin will often be enough to give the guitars character and the impression of space.
Most modern digital recording software will come with a good reverb plugin that includes an impressive range of presets covering a wide variety of spaces right out the box. Try using these as a base and then tweak from here. By making minor adjustments to settings like pre-delay and reverb EQ in a similar fashion to our post on vocal recording, you should be able to arrive at some very professional results, fast.
Getting a textbook electric guitar sound is impossible, as the instrument has no true natural sound. Add into the mix the extremely diverse range of musical genres and tonal variety that make up a typical guitar track, and we can only conclude that the correct sounding guitar is the one that works for you. As with all our recording examples, we strongly encourage paying attention to the small stuff - particularly while tracking. Time spent at this stage is worth its weight in gold; if you can get things right at the start, the rest is actually pretty simple. Happy recording, folks.