Even with the great technological advancements in the world of music, the good old conventional guitar amplifiers are still the most popular choice both for recording and performing musicians. Yes, there are some practical advantages of devices like Kemper or Axe-FX, as well as countless guitar amp emulation programs. But if you have a good amp, it would be a shame not to use its full potential.
However, there’s a catch. To do this, you’re supposed to capture its tone with an actual microphone. Some amps have separate outputs that you can use, but the most realistic tone comes through its speakers. And this often presents a challenge, especially when you use this conventional setup for live shows or if you’re recording more instruments at the same time. The mics should be set up in such a way to represent the amp’s tone in the best possible way, and yet to avoid all the other instruments and noises as much as it’s possible.
And even recording isolated guitar tracks in a studio can be problematic. After all, microphones won’t ever capture it the same way that your ear does. Also, there are a few different ways how you can completely change your tone with your mic setup.
In case you love your amp but don’t know how to make it sound good on a recording, we’re here to help you out. Here is a brief guide on how to mic up your guitar amp.
What microphones should I use?
Before getting into it, you should first choose the most suitable microphone or a set of microphones. There are a few things you should first get familiar with.
As you may already know, we have dynamic and condenser microphones. Dynamic microphones are good at capturing loud and “booming” sounds, as well as powerful vocals. They often focus more on the mid-section of the audible spectrum and are quite often a choice for live performances. They are also more durable, cheaper, and easier to maintain.
Condenser mics are a bit different, as they focus more on the higher end of the spectrum, they have wider polar patterns, and are generally intended for more “delicate” work. Almost exclusively, condenser mics are used in the studio and are not the most suitable solution for live settings. One of the rare exceptions is when you need something to mic up cymbals on live shows. Overall, condenser microphones are more expensive, require an additional power source (like phantom power), and are way more sensitive.
As far as guitar amps go, dynamic microphones are more common, both for studio and live use. However, it’s also not unusual to see condenser mics used for this purpose. You’ll also often see one condenser and one dynamic microphone, with each of them going to an individual channel. These two are then blended in the mix, sometimes even along with the guitar amp’s direct output signal.
How different microphones affect the tone
Dynamic and condenser microphones have a completely different impact on the guitar tone. Both are used to produce different effects, depending on the tone musicians and producers are aiming for. The dynamic mics are the most obvious choice, mostly for two reasons. First, they handle loud noises better, and second, they do a better job of capturing the mids. And the most common model is the legendary Shure SM57 which is, at this point, an industry standard. What’s more, this is an affordable mic and it’s used by both professionals and amateurs.
Overall, such a mic is good for a few reasons. Firstly, the low-end is not pronounced. Everything below 200 Hz is almost unnoticeable, while there’s also a slight roll-off between 300 and 500 Hz, which gets rid of that “muddiness” in tone. Shure’s SM57 also pronounces anything between 2 and 12 kHz and has a sharp drop after that. This kind of tone is more “focused” and cuts through the mix easily. Just like other dynamic mics, this one features a directed cardioid polar pattern, making its performance very focused.
As far as condenser microphones go, you’ll be able to capture the higher end of the spectrum much better, and the tone will feel more “grainy.” This does not make it worse by any means, it just sounds different. Although it doesn’t cut through the mix as well as the tone of dynamic mics, condenser mics still find their use.
They’re also good at capturing the low-end. Their most pronounced part of the spectrum is between 5 and 15 kHz, although they’re often “flatter” in response over the entire spectrum. What’s more, condenser mics can be placed further away from the amp and even capture the room ambiance.
Best microphones for guitar amps
If you’re looking for some good mics for recording guitar amps, we’ve compiled a brief list of some good options. Here are the dynamic mics that you can consider:
And as far as condenser mics go, we’d recommend these:
Now that we’ve covered some of the basics, let’s look more into how you’re supposed to position a microphone in front of the amp or cabinet speaker. It may seem weird, but even the minor difference or 1 or 2 inches can cause a noticeable change in tone. So you must find the position that suits your needs and secure it.
The basic position for any setup is a mic directly facing a speaker cone. This way, it can capture the main characteristics of any amp’s tone. However, there’s another important issue – which part of the speaker should you aim at?
Well, it depends on what you’re trying to achieve. The main rule is that high-end, high mids, and mids are more pronounced at the center of the speaker. As you move away from it, you’ll notice a drop in these frequencies and a more pronounced bottom-end. At the very end of a speaker cone, you’ll get that muffled bassy tone.
In case you want to pronounce highs and mids but are still dealing with a lot of “harsh” frequencies, you can try and change the angle at which the mic is directed towards the speaker. The best idea is to start with the mic pointed directly and then slowly shift its position to fine-tune and smoothen out the high-end. These off-axis positions are pretty common for guitar amp recording.
Distance from the speaker
The distance from the speaker also causes significant changes to one’s tone. There are two basic rules here. Firstly, the closer you get to the speaker, the more the high and higher mid-end of the tone will be pronounced. Secondly, as the mic goes away from the speaker, you’ll see a significant increase in the bottom end.
If you’re using dynamic microphones, they are usually pretty close to the speaker, about 1 to 3 inches away from the amp’s grill. You should then fine-tune it so that it would work for your desired tone. You can even move it further away and experiment.
But if you’re using condenser mics, you can go away from the speaker. While some recommend distances of 8 to 12 inches, you can even move it further away and capture more of the room’s ambiance. However, they too can be pointed directly in front of the speaker, depending on what you’re trying to achieve.
How should I set it up?
One of the most common setups is just one dynamic microphone positioned directly towards the speaker. If you’re on a budget, we recommend one SM57 mic. Start by pointing it directly towards the speaker, about mid-way between the center and the edge of the cone. After setting your tone, record a sample in this position and see how it sounds. If you need more mids and higher mids, then move it closer to the center. In case you need more bottom-end, then move it further away.
In case you’re hearing unwanted razor-sharp high-end, then change the mic angle or move it away from the source. When moving the mic away, take care that the mic is still facing the same spot on the speaker cone.
If you don’t have a microphone stand, you can duck-tape the microphone to the amp’s grill, with it facing upwards and 90 degrees off-axis. This is far from a perfect setup, but it gets the job done if you have no other options.
Guitar amps are most commonly recorded with two microphones, usually one dynamic and one condenser. You can also use two dynamic mics at two different positions and then blend them in the mix. However, there’s way more versatility in using one dynamic and one condenser mic. While the setup might be a bit trickier to figure out, just stick to the rules we talked about and fine-tune your tone.
For instance, you can put both mics directly towards the speaker, with each pointing at different parts of the cone. A dynamic mic can be near the center, while the condenser one can be a bit further away and facing the outer parts of the cone.
You can also try and put them roughly at the same spot, at the same distance from the speaker, and with one of the mics facing the speaker off-axis. Although at a similar position, they won’t capture the amp’s tone the same way.
In the end, the exact setup comes down to you and your preferences. You just first need to know what you’re aiming at, and then follow the rules that we discussed above.
One more thing that you should pay attention to – when recording with two microphones, make sure to record it as two separate channels. For this, you’ll need an audio interface with at least two input channels.
Dealing with acoustics
Recording at home is far from a perfect setting. Unless you have a room that’s been completely adapted for this purpose, which is usually not the case. While recording, it’s recommended that you have all the metal and glass surfaces in the room covered. This way, you’ll get rid of any unwanted “ringing” and reverb in your tone.
If you’re recording with the backing track or a full mix, it’s also recommended that you use headphones instead of speaker monitors in order to avoid feedback. Also, be aware of your amp’s position and how it impacts the tone.
While getting a good tone is more than just tricks and tips, you can try a few things and see how it works. For instance, to make the sound tighter, you can even cover the amp and your mics with a blanket. Some are even building their own isolation cabinets filled with blankets or pillows and are putting them in front of their amps. Any of these ideas can help when you’re trying to isolate your tone and get rid of any room ambiance.