If you are into electric guitar recording, you already know that the Shure SM57 is considered by many to be the golden standard for that application since the beginning of recorded history. For that reason alone, the SM57 was my first microphone, and the only one for quite some time, when I started recording. However, as I gained more recording experience over the years, our relationship became much more complicated and I learned to be very careful with it. Don't get me wrong, I still use my SM57 a lot and it is still responsible for most of my electric guitar recordings. But just "throwing an SM57 in front of an amp" like I hear many times, is not going to be enough.
Typical SM57 Characteristics & Their Effect
An almost linear high pass filter around 200Hz
This natural high-pass is generally a great thing on guitars for many reasons. It reduces boomy frequencies that are normally unwanted in mixed guitar tracks and leaves that area for bass instruments. It tightens up overdriven and distorted guitars. It reduces the hum you get from amp transformers a lot of times, especially combos, where the transformer is relatively close to the speaker and hence the mic.
Generally speaking, when done carefully, filtering out unwanted frequencies at the recording stage prevents unnecessary hassle and problems later on in the mixing stage.
A ~2db deep around 400Hz
The area that's around 400Hz is where what many people refer to as "muddy frequencies" live. Having that deep there generally brings clarity to your tracks.
A wide boost that starts around 2k, peaks between 5 and 6k and meets unity gain at around 16k
At its peak, we are talking about +6db at around 5-6k, then it goes down and rises again around 8-8.5k. That is exactly what makes the SM57 cut through a mix well and brings a lot of presence and definition to your guitar tracks.
But, that area of the spectrum can very easily become a problem
But, that area of the spectrum can very easily become a problem, especially if your amp is already bright, or your pickups already boost frequencies in that range.
The range that's between ~2k and ~3.5k is where many whistling frequencies live. When these become too dominant, your guitar mix becomes very noisy. If you are not trained to listen for that, you might not be able to identify it immediately, but you will be able to tell that something is wrong. When that happens, the most effective way to fix that kind of issue is simply to record your guitar again and pay more attention to your mic placement, mic choice and possibly EQ on the way in.
The following video demonstrates some of the "bad frequencies" in that range in one of my projects. And, yes. I ended up re-recording those rhythm guitars.
Around 5k, I find that a 6db bump is way too much in most cases. The amp that I normally record is bright enough to begin with, so I don't need more of what I already have.
Working Consciously
Up until now I was focusing on the SM57, but all the stuff I'm going to cover from now on is relevant to pretty much any microphone. So an obvious first advice would always be to experiment as much as possible. No matter what kind of microphone we're talking about or what is the sound source you're trying to capture, experimentation is the most efficient way for you to learn and improve your results. With that said, there are a few common miking techniques that will help you get started. I'm going to list the techniques I have some experience with, what I find them good for and what to be careful from when applying them.
Close On-Axis Miking
This is the so-called "default" position you would normally start with. You simply put the mic in a straight angle with the cabinet grill surface pointing straight to the center of the speaker cone.
Consider this position if you are after bright, in-your-face guitar sound. That position also produces a lot of bass frequencies due to the proximity effect (generally the case with any cardioid mic).
Another reason to consider this technique is a noisy environment. More about it later.
Caveats:
Over accentuated top end
Whistling frequencies
Boomy bottom end
Close Off-Axis Miking
Close off-axis positions are useful if you are still looking for well defined, in-your-face guitar sound, but the on-axis position is too bright. Close off-axis positions still take advantage of the proximity effect and the clarity and definition that come with close miking.
Consider this position if the on-axis position is too bright or harsh. Another reason to consider this technique is a noisy environment. More about it later.
Notes:
Try different distances from the center
Try different angles
Handling Noisy Environments
Another less fun reason to chose a miking technique is a noisy environment. In that case you have to isolate your source and increase the signal-to-noise ratio, so that your source is much louder compared to the noise in the recorded track. In that case your best option is to use a dynamic mic with a cardioid polar pattern (like the SM57) and position your amp in a way that it faces the direction of the main noise source. This way, since cardioid type of microphones reject sound coming from the back, the noise rejection will be maxed and the sound source will be much louder.
Distant Miking
Distant miking would simply be moving the mic away from the speaker. There is no magic formula - just use your ears.
Consider this position if you aim for a more natural sound with more space. The further you move the mic from the amp the more room sound you blend in. I would normally prefer a condenser in that position, but it is really a matter of taste and dynamic mics work here as well.
Bonus: getting the mic away from the amp also reduces unwanted amp noise, like typical high-gain hiss and transformer hum.
Caveat: Room sound can become an issue depending on your room and what you aim for. A room with poor acoustics can sound very bad.
Dual Miking Techniques
Dual miking gets things more complicated and I would generally recommend to try it only after you gain some experience with single mic techniques and with mixing in particular. That experience should help you identify and fix phase issues earlier, which will save you time and yield better results at the end. Anyways, dual miking is a good way to try and capture a more precise, or perhaps just better representation of your tone. The idea is to place two microphones in positions that complement each other and blend them to taste.
I would normally blend an SM57 applied as a close mic with a condenser (or a ribbon mic if I had one). The SM57 will be positioned to capture the mid and high-mid range, which is what that mic excels in. The condenser will be responsible for the bottom end and low-mids and positioned at the same distance from the amp as the SM57, or if I'm going for a roomy sound, I will move it away from the amp.
The sometimes over accentuate mids and top end of the SM57 should not be a problem with this technique, because the sound of the SM57 is only a part of the picture and you can use your mixer to bring it down and get more from the other mic, assuming they indeed complement each other and properly positioned to capture what you want.
Caveats:
Multiple microphones necessarily means potential phase issues. This is why you need to make sure the microphones are either positioned at the same distance from the speaker, or carefully look for phase cancelation issues.
If you're using a condenser, especially away from the amp, be aware that a poorly sounding room cannot be fixed later.
Mic choice and positioning makes things a lot more complicated.
When using a condenser as a distant mic in a small home-studio, make sure it doesn't capture unwanted sound sources such as computer fan, acoustic sound of your electric guitar, foot switch clicks etc.
So, these are some of the miking techniques I applied successfully in my home-studio environment. As you just saw, they are not very strict and leave a lot of room for personal taste and experimentation. These miking techniques are very relevant to any type of microphone, not only SM57s and not only dynamic microphones of course. However, different microphones have different characteristics and a technique that works for one mic, is not necessarily going to work for another on a given source. In addition, after you gain significant experience, you might find that some mics simply don't work for you in specific applications. It can be because of the environment they are used in, it can be because of the nature of the sound source, like a specific guitar or amp you have, or simply because of the way you like your music. In any case, it's fine, no matter what other people say about that mic, or who uses it successfully on which album. It's cool to try different things and it's cool to be different and even better doing so for a reason.
Happy recording!
Miking Experimentation Workflow Tip
If you have a guitar looper, try the following approach.
Record a loop that represents the sound you want to capture.
Set ups your recording interface and microphone and get ready to record.
Place the mic in front of the center of your speaker and right at the cab grill.
Put your headphones on, start the looper and press record.
Record a loop in the starting position and take a note or a picture that describes the mic position.
Move the mic around and try to find a better sound. Once found, allow a full loop to record, take a note and continue.
When done, stop recording, and cut your waveform, so that every recorded position has its own clip.
Normalize all the clips to the same volume
Listen back to all clips and see which sound works best
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