Mic’ing your guitar amp helps you increase the volume while keeping a similar tone. It’s ideal for people who don’t want to buy a bigger amp, but it can also help tremendously during live performances.
To mic a guitar amp, choose a dynamic microphone, then place it within four in (10.16 cm) of the amp at a 45-degree angle. Adjust the amplifier to the desired gain and volume. Do the same with the pickup on your guitar. Placing your mic on the floor or elevating it also provides different tones.
Throughout this post, I’ll cover all of the steps you need to know to properly mic your guitar amp. I’ll also provide you with a few things to avoid during the process.
1. Choose the Microphone
There are many types of microphones that you can use to mic a guitar amp. Sweetwater recommends using dynamic microphones because they work best at pulling sounds from in front of them without distortion. However, you can also choose a condenser microphone or a ribbon microphone.
Let’s take a look at each of your options below.
These microphones are some of the best for micing an amp because they can pick up high volume and high frequencies very well. Furthermore, they don’t sound too bassy when playing through speakers. The only downside to using a dynamic mic in front of a guitar amp is that it can sound a bit rugged, which removes some of the treble from your amp.
Condenser mics often cost more than dynamic mics, but they typically pick up a higher range of frequencies. Additionally, the quality carries over from the amp very well. If you choose a condenser mic, you’ll have to keep it a bit further from the amp since these microphones are a bit more fragile than most others.
Ribbon microphones are almost the exact opposite of dynamic mics. They’re extremely sensitive, which means they can break easily. However, they don’t sound rugged. Their crisp, clear audio input and output often make for the ideal guitar amp mic’ing setup. Much like condenser mics, ribbon microphones are a bit pricey.
Regardless of which microphone you choose, proper placement is one of the most overlooked and important aspects. Knowing which kind of mic you have will help you determine where it pulls sound from. For example, a cardioid mic pulls sound from all directions, so you could use it with multiple amps (but it also has the possibility to create white noise).
Tip: Unidirectional mics are much better than bidirectional mics for this purpose.
Check out our guide on the Best Microphones for Guitar Amps
2. Proper Mic Placement
There are several rules when it comes to proper microphone placement. Putting it too close to the amp will muddy the sound, whereas setting it too far away risks creating white noise. The goal is to get all of the amplifier’s unique tones without changing it as much as possible.
Consider these five tips for the perfect mic placement:
- MXL Mics suggests placing your mic about four inches (10.16 cm) away from the amp. Make sure the microphone isn’t closer than an inch (2.5 cm), but you likely won’t need it that close anyways. If it sounds muffled or quiet, turn up the volume on your amp, pickup, mic, or the speakers that are connected to the mic.
- Keep your mic at a 45-degree angle to prevent abrasive audio distortion. Placing your mic perpendicular to the amp (head-on) will make it sound like you just ramped up all of the effects at once. Everything will sound muddy and unprofessional. You can put it up, down, left, or right, but it needs to be pointed at the middle.
- The mic should be as centered as possible in relation to the amp’s built-in speaker. The front of the mic faces the amp, while the mic’s body is off to the side. It can seem a bit confusing, but it allows the mic to pick up the clearest frequencies. You’ll end up with a mic that sounds exactly like it does coming through the amp, just a bit louder.
- Tilting the mic in different directions changes which frequencies it picks up. For example, tilting the mic’s body toward the outer edges of the cone increases the treble, whereas pointing it closer to the middle of the cone enhances the bass. Keep it completely level if you want a rounded tone.
- Consider getting a shock mount to prevent unwanted mic vibrations. Your microphone should be on a mic stand or mounted to another surface. If it moves around, the speakers will sound awful. The same goes for the rest of your gear. Everything needs to be mounted, level, and stable.
3. Adjust Your Amplifier
Once you’ve properly set your mic in front of the amp, it’s time to make a few amplifier adjustments. For example, you’ll have to monitor the volume, treble, and bass. Those with modeling amps should also mess around with the tone, chorus, ambiance, and other built-in audio effect loops.
So, how should you adjust your amp?
Volume and Gain
The gain controls sound waves coming into the amp, whereas volume controls sound waves going out of the amp. If your audio sounds cloudy and it’s too loud, consider decreasing the gain and volume. These small adjustments can help out quite a bit, even if the rest of the effects are exactly how you want them to sound.
Tone and Effects
You’ll rarely have to change your amplifier’s effects loops and pedals if you’re mic’ing it up. Volume and gain are the biggest factors that change when you use a microphone or external speakers. However, you might need to make minor changes if your mic placement, amp alignment, and volume are perfect and they still sound bad.
Bass and Treble
Keep in mind that different mics receive bass and treble in various ways. For example, a unidirectional mic will only pull sounds from in front of it. This means that your amp’s bass and treble won’t be highlighted if the mic is facing another direction. The same goes for bi-directional mics that receive audio waves from the front and back.
Remember, you can mic any amp (even a portable battery-powered amp). However, you’ll have to make several adjustments to make it sound nearly the same as it did before you added the mic. The sound should be the same as it was before you added the mic, just with a higher volume.
Read Also: How to Use a Guitar Amp: The Complete Guide
4. Place Your Amp on the Right Surface
Putting your amp directly on the floor versus on a table will change the way it sounds. Additionally, the surface material alters the bass, treble, and other natural audio effects. Make sure you know which tones and frequencies you want to highlight before deciding what you should put your amp on.
Here’s a quick breakdown of how different surfaces affect your mic’d guitar amp:
- Hardwood, linoleum, tile, and other hard surfaces will echo the amp. This placement can be beneficial if you’re looking for more ambiance or reverb. However, it ruins your guitar’s resonance if you’re playing soft melodies or hard rock. You’ll end up blending everything together without much clarity.
- Putting your amp on a rug or carpet will hush the treble and increase the bass. Many people prefer this layout because it allows them to add bass to their solo performances. You can increase your amp’s onboard treble to counterbalance the issue (feel free to do the same to the guitar pickup, too).
- Elevating your amp on a table or desk slightly reduces the bass, but it’s much clearer than the floor. Increase the bass on the amp and the pickup if you’re worried about losing some of the background audio waves. In my opinion, it’s always better to elevate small amps and keep big amps on the ground.
- You can put a table mat under the elevated amp to prevent bass loss. You won’t have to deal with sharp, tinny treble sounds. Additionally, you don’t have to deal with as many vibrations if the table is made of hard material. Consider using folded towels for extra bass reduction if that’s what you’re looking for.
- Anything on the same surface as your amp can rattle and vibrate through the microphone. This includes headphones, earbuds, and other audio equipment. As a general rule, if your amp is on a small table, nothing else should be on it. I’ve had my amp rattle through a microphone simply because there was a pen next to it.
5. Experiment With Multi-mic’ing
Multi-mic’ing is when you use two or more microphones in front of a guitar amp. This setup allows your microphones to pick up numerous frequencies, providing a much more natural, rounded sound. Additionally, you can use it to increase the bass or treble, both of which shape the performance.
Keep these conditions in mind if you want to multi-mic your guitar amp:
- Premier Guitar recommends keeping the microphones between 6 to 10 inches (15-25 cm) apart. This allows the microphones to pick up all angles coming from the amp without bouncing sound waves between each other. It also helps them sound a lot clearer since they won’t be clipped or distorted.
- Back up the microphones from the amp more than you usually would with one mic. You can follow the same rule of keeping them between 6 to 10 inches (15-25 cm) apart to make it easier. Your dual-mic setup doesn’t need to be super closer because they’ll reduce the treble and other effects.
- Point one mic toward the center of the amp and another toward the outer edges for the best results. You should never point the mics at the same part of the amp. You won’t alter the sound at all from having only one mic. Instead, swap their directions until you find the audio that you’re looking for.
What To Know Before You Mic a Guitar Amp
Before micing a guitar amp, it’s important to know that your guitar’s pickup makes a huge difference. It’s easy to assume that all of the tones come from the amp, but the pickup can change the treble, bass, gain, and volume on many pickups. Making minor adjustments goes a long way.
You should also remember the following details:
Many microphones have onboard settings that let you change the volume and other options. Don’t forget to check the speaker settings, too. You might have your amp and pickups at the right tone, gain, etc. But the mic can stop everything from sounding as it should. For the best results, set everything around ⅓ of the volume that you’re aiming for, then make gradual adjustments.
Your microphone is likely hooked up to speakers to amplify the sound (unless you’re using a computer or a mic with a built-in speaker). Make sure the speakers are pointed toward the center of the room, not toward a wall or a door. Speaker location makes all of the difference in the world when you’re mic’ing your guitar amp.
Many people mic their guitar amps to record them. If you’re not doing it to amplify the sound, you could use computers, smartphones, or tablets with a microphone. Make sure you keep the sound at a lower volume and don’t forget to reduce the gain on the DAW (digital audio interface) to prevent audio wave clipping.
If you have all of the aforementioned settings and positions correctly and the mic’d amp still sounds bad, there could be an electrical problem. Check all of the cables (and make sure they’re high-end cables since they can make or break the experience), then test the outlets with a multimeter. If you’re not getting enough power (between 120V to 220V) your setup will sound bad.
Using a high-quality mic won’t make a low-end amp sound much better. In fact, it’ll highlight the amp’s sound issues. If you’re thinking about micing a bad amp to make it sound like a high-grade one, forget about it. You’re best off improving the amp before worrying about getting a brand-new, high-quality microphone.
Following these tips and tricks will ensure that your amp is always mic’d up perfectly. That being said, there are plenty of beginner mistakes that you might run into. I’ll break down all of them in the section below.
What To Avoid When Mic’ing an Amp
You should avoid touching your microphone to your guitar amp, turning the amp to its highest volume, and mounting the mic or amp on unstable surfaces. Additionally, you shouldn’t tilt the amp forward, though some people prefer tilting it back to increase the volume output in small rooms.
Here’s an in-depth look at each of these issues:
- Don’t touch your microphone to the amp. This setup mistake causes subtle vibrations that make it sound like you turned up the distortion. It can also rattle the mic’s internal parts, causing long-term damage. Your microphone should never be closer than one inch (2.5 cm) away from the amplifier.
- Never start with the amp or mic at their highest volume levels. You’ll blow the speaker so fast that it’ll make your head spin. Starting at a lower level on every part of the equation (pickup, amp, mic, speaker) will keep all of your gear in good condition. Try keeping them at the same level on each part so you can identify the outlier.
- Make sure the mic and amp are on stable, level surfaces. If either piece of equipment moves around when you play your guitar, it’ll vibrate. These shifts can make your smooth guitar amp sound rocky and painful to listen to. Use a leveler tool (I use a smartphone leveler app) to check if everything’s balanced.
- Avoid tilting your guitar amp forward because it’ll distort the sound. You can tilt it back a bit, but tilting it forward won’t do any good. You’ll end up bouncing the sound waves off of the floor, muddying the sound in the process (not to mention the vibrations going through the walls that lose a lot of the bass).
- Make sure your amp and speakers aren’t touching a wall or a door. Much like pointing your amplifier toward the ground, touching them against the wall will alter the desired sound output. Your amp shouldn’t be touching anything aside from the surface that it’s sitting on. You could also use acoustic foam to prevent unwanted vibrations.
These simple suggestions go a long way in improving your guitar amp micing situation. The last thing you want is to have all of the right gear with a horrible set of options or placements. The most important thing is to make minor adjustments to fine-tune the microphone that’s improving your amp.
Anyone can mic a guitar amp if they have a microphone and an amp, but proper placement is key. You can also use any microphone, though dynamic mics tend to be the best choice. Remember to start at a lower volume, then adjust the tone, gain, and volume until you’re satisfied with the results.