How To Mic A Guitar Amp For Live Sound: A Step-By-Step Guide To Follow

how to mic a guitar amp for live sound

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Will you be performing with a live sound, but for that, you need to know about miking up a guitar amp? If so, then you’re definitely in the right place.

Miking a guitar amp for live sound is a delicate yet necessary process. You need to place your mic in the right position and at the right distance according to the venue. Even slight changes in the angle or positioning could have a significant impact on the tone.

In this article, you’ll get to know all about miking your guitar amp, how to mic a guitar amp for live sound, the significance of having the right mic position, what type of mic to choose, and more. Stick around to find all the answers that you’re looking for.

Why you should mic a guitar amp for live sound?

Miking up a guitar amp is an extremely delicate process. Even slight changes in the angle and positioning of the mic relative to the amp’s speaker cone are significant. It can have a huge impact on the overall tone. Of course, you don’t really need to mic the amp at all. There are potential alternatives to that as well. 

However, miking the amp is still the best way of getting the natural tone for a live stage. It’s important, as it’ll be well worth the extra effort. It isn’t exactly rocket science, especially once you have done it a couple of times.

How to mic a guitar amp for live sound?

Guitar amps have been having constant improvements ever since the first amp was invented. With advancements in technology and new brands coming to the limelight, amps have achieved major improvements in every category. There are a few challenges that accompany the guitar amps. A common issue is putting it through the PA system. There is nothing that can potentially replace the tone of miking up an amp and having its natural tone for live sounds. An alternative would be to plug it directly into a PA system or mixer, as most amps have this option.

Materials you’ll need

The materials that you’ll need to learn how to mic a guitar amp for live sound include –

  • A guitar amp (combo or a head with speaker cabinet)
  • Microphone stands
  • Microphone cables
  • Microphones (dynamic or condenser)

Step 1: Know the venue properly

You will rarely get to perform at a perfect venue that has a perfect stage. After reaching the venue, the first thing that you should do is find where you’ll be positioning the amp. Moreover, find out how it will be oriented.

Working with mics on a loud stage is extremely tricky. They can easily pick up something that you don’t particularly want to have in the mix. Ideally, you’ll need to put it as far away from the drums as you possibly can. At the same time, your drummer has to be able to hear what you are doing. You should feel free that you orient the amp a bit towards them if possible.

You should also leave a bit of room in front of the amp to place the mics and mic stands. Of course, many venues have smaller stages and the situation might not be ideal. You should still try to ensure there is enough space for the microphones that you’ll be using.

Step 2: Know your amplifier and the tone you’re looking to get

Every amplifier model is different. When talking about tube amps, they may not be as consistent as solids-state ones. This happens as their tone quality tends to change over time as the tubes start heating up. You need to know the qualities of the amp and which part of the audible spectrum they’re pronouncing the best.

At the same time, you should also have a specific tone in mind. This won’t just come down to how you’re setting up the equalizer and other parameters on it. The mic placement will play a key role in how the amp sounds when it goes through a PA system. If you’re playing the bass guitar, don’t play the bass through a regular guitar amp. It won’t sound right, as it could cause serious damage to the speakers. You should look for a dedicated bass amp or something that is capable of handling both instruments.

Step 3: Set up your microphones and microphone stands

The next step will involve setting up the mics and mic stands. One of the most important things that you should remember is that they must be close to the amp. However, they shouldn’t bother you or any of your fellow bandmates during the live performance. Ideally, you will need to use specialized microphone stands for guitar amps or smaller stands that fit in more easily in front of your amp’s speaker. There are many options that can attach to the amp.

In certain cases, you should place a regular mic stand behind the amp and make it go above the amp. The mic should be facing directly toward the speakers. The alternative method can work well for some settings. The small “boom” mic stands will work very well, both for condenser and dynamic mics. These are the same type of mic stands that you can use for bass drums.

The biggest advantage here will be that they consume less space than other mic stands. Additionally, you can even use two or more of them. It’ll help achieve the same tone as you’d get with regular microphone stands that take up more space on the stage.

Of course, there are many settings where you cannot use a microphone stand. You might not have one, or you just don’t feel like bringing them along on a gig. The solution will is simple – you can simply duct-tape the microphone to your amp cabinet’s speaker grill. The mic should be positioned at a 90° angle from the speaker cone axis. This tremendously impacts the tone and smoothens it out. 

Step 4: Placing the mics in front of the amp’s speaker

This is the most important part – place the microphone in front of the amp’s speaker. This is an incredibly delicate process. Your sonic output through the PA system relates directly to where and how you’re putting the mic in front of the speaker. This applies to both the distance and the angle at which your mic is facing the speaker. Although it may sound weird, even a difference of a couple of inches can greatly impact the overall tone. The most common way would be to face the microphone directly towards the speaker cone. With this type of setup, you’ll get the most realistic representation of the guitar amp’s natural tone. 

The next thing that you should think about is which part of the speaker cone your mic should be facing. The standard rule here is simple. The closer you happen to be to the center of the speaker cone, the higher mids and higher ends you’ll be getting in the tone. As you move away from the center, you’ll start noticing that your mic picks up lower mids and bottom-ends.

microphone placed in the front of guitar amp speaker

If you’re placing it at the edge of the speaker cone, you’ll get a bassy and muffled tone. If you’re working with multiple mics, you should place them in two different positions. This will give you a fuller tone, which is very useful if you’re the only guitarist in the band. 

If you’re working with a dynamic mic like a Sennheiser e945, place it a few inches (1-3 inches) away from the speaker cabinet. Moving it away will cause the tone to sound too spacious and distant. Moreover, your mic could pick up noises that you don’t actually need in your mix. 

Condenser mics are slightly controversial for live stages, as they usually pick up sounds further away from the source. However, if you’ve got a condenser mic with a cardioid polar pattern, and you put it close to the amp, you can get a great tone with some accent at the higher ends. A great condenser mic option would be the Shure SM7B. It wouldn’t be a bad idea to have a combination of a dynamic and condenser mic to get a fuller sound. Of course, it means that you will require more room on the mixing board.

The angle at which the mic faces the cone will also impact the tone. If you notice that the tone is “harsh” so that there are too many higher mids and high-ends, placing the mic at an angle from the main axis of the speaker cone will certainly help. Start by putting it directly towards the speaker and slowly begin changing the angle until you’ve found the sweet spot. You should be able to hear the high-ends in the high-ends, but they are slightly smoothened out.

As you’re going off the regular 90° angle positioning, you will notice a significant drop in high-ends. However, you shouldn’t boost the bottom end by gradually changing the angle. You will have to go away from the center of the cone if you want muddiness in there. Many heavy metal guitarists do that, especially the ones who use electric baritone guitars.

Step 5: Work with a sound engineer and set up the tone

Although it might sound weird, but working with a sound engineer might be the most challenging part of the process. There are many jokes about guitarists who don’t obey what front-of-house personnel recommends, but it isn’t far from the truth. Once you set up the tone and the sound engineer gives their advice for the output levels, you shouldn’t touch anything on the guitar amp. Try out a clean tone and a distorted tone. You should also look to add a clean boost if you’re using it, and let the sound engineer decide upon the output level.

If you feel like you aren’t loud enough, ask them to increase the volume in the stage monitoring system. Otherwise, you can also stand closer to the amp. It’s important to remember that what you’re hearing on the stage isn’t the same as what the audience is hearing.

What are the alternatives?

If you aren’t sure about working with microphones, then you can get an amp with a direct emulated speaker output. While it won’t utilize your amp’s full potential, it’ll still sound pretty good, and it’ll be easy to set up.

Moreover, you can also use an amp modeling unit or a preamp and go directly into the mixing board. In fact, this method is becoming more and more popular. The high-end modelers are capable of emulating different types of microphones and cabinets. You can even play without an amp entirely. If you aren’t playing live, but in the studio, you can always record the guitar directly to your PC.

Important factors to consider when miking an amp for live sound

If you’re having a gig on a big stage, arena, outdoor festival, or large venue, you’ll probably be running your amp into the PA system. The purpose of that is so that your guitar can be heard in situations where the amp alone isn’t enough. There are times, even in smaller venues, when running the amp through the PA is a great idea. This way, you can add a bit of presence and fill out the overall mix of the band. When miking a guitar amp for live sound, there are a few things that you should consider.

Line out

Many amps will have an output jack at the back labeled “line out” or something similar. The jack will output a line-level, non-powered signal that gets fed to a PA system or recording device. This signal is post-amplifier but pre-speaker. As a result, that’ll be fed to the PA or recording device, which represents the sound produced by the amp. In other words, any reverb, distortion, or effects processed by the amp and/or pedals will be the sound output at the line-level. However, it isn’t the actual sound that’ll come out of the speakers.

Of course, the sound that’ll ultimately come out of the speaker will be the true sound that gets heard by the audience. That’s why using the line out jack for feeding a signal to the PA will be the least desirable option.

Mic placement

When placing the microphone on a guitar amp, use a boom or a straight mic sound. Shine a flashlight at the front of the amp and locate the speaker’s face. Place the microphone against the grille cloth in the “offset” position towards the speaker edge instead of directly in the middle of the speaker. This offers the “truest” sound of the amp through the microphone. When performing a sound check, turn up the amp to the normal playing volume. This way, the sound engineer can tweak the guitar level and then blend it with the other bandmates.

Consider the mic selection for live sounds

As the sound coming out of the speakers is the most desirable sound, in most cases, placing a mic on the amp is the best way to go. When miking an amp, the first thing that you should decide upon is the type of microphone you are using. With proper knowledge of different guitars and amp sonic capabilities, coupled with decent microphone techniques, you can get the ultimate guitar sound. This sound will perfectly fit the guitar part, live gigs, and production.

guitar amp and microphone

Having a decent guitar sound will start with a talented guitarist, the right guitar, and the amp all working together. It’ll be unrealistic to rely on the sound engineer to turn average gear into amazing-sounding gear in the control room. Mic choices and miking techniques will be great starting points to capture and record electric guitar amp sounds.

The microphone choice will play a key role in the guitar amp’s recorded sound. It’s just as important as the guitar and map used, or the volume at which the music is played. The type of microphone and placement will influence the tone and performance greatly.

Condenser microphones

Condenser microphones work great as well. However, you should take proper care that you don’t get an overly bright sound. Your guitarist might complain that their amp sounds brighter than normal and feel they should readjust the recording knob settings. As a result, you should place them further away from the speakers.

The condenser mics pick up more low frequencies from the amplifier. This might or might not be such a bad thing. Pushing a lot of air could work for heavy metal songs, but it wouldn’t be right for lighter pop songs. There are certain condenser mics that add distortion when close-miking very loud amps. Occasionally, the metal windscreen could get loose and vibrate. Make sure you’re using an attenuator pad and a low-frequency roll-off. The Neumann U87, Shure KSM44, Audio-Technica AT4041, and Neumann U-47FET are great choices too.

Condenser mics will also provide the necessary opportunity to experiment with different polar patterns, like figure-of-eight and omnidirectional. Omnidirectional microphones don’t exhibit the proximity effect and pick up more of the total sound of the amplifier and room tone instead of one particular speaker. Omnidirectional microphones offer more of an ambient guitar sound. Meanwhile, figure-of-eight microphones pick up more of the room, but only from behind the mic’s body opposite the front side.

Speaking of Figure-of-Eight, having a pair of Royer R-121 Figure-of-Eight mics that offer an entirely new range of warm electric guitar sounds will be helpful. Big, old, and cumbersome ribbon microphones have been around for years. However, using them on loud instruments will carry the fear of knocking the extremely fragile elements off the suspension mounts. The smaller, lighter Royer mics will be able to handle huge volumes without much trouble.

A Royer microphone will be able to pick up sound from two opposing sides in what is known as a bi-directional pattern. You can take full advantage of it to get more of recording space in the sound. The sound entering the rear of the microphone will be 180° out-of-phase with it coming into the front.

Dynamic microphones

Shure SM57 cardioid dynamic is easily the most commonly used mic for recording electric guitar. It started back when the more expensive mics had already been used for big tracking sessions. Engineers were only left with the lowly SM57 to handle loud, cranky, noisy guitar amps.

But as it turns out, the Shure SM57 will be perfect for the task. Its frequency response, tailored for speaking, will match the mid-range voice qualities of the guitar. It even has a compression effect on loud sounds, as it’ll squash nicely and facilitate the engineer’s job of maintaining a consistent recording level. You would have seen engineers push a Shure SM57 into the grill cloth of the amp cabinet. You can take advantage of the proximity effect, which will boost low frequencies when the microphone is placed close to the sound source. The SM57 will lock in a certain size for the electric guitars, maintaining an appropriate place in the mix without any additional EQ or compression.

The Sennheiser MD 421U cardioid dynamic is popular as well, as it offers a wider frequency response than the SM57. A five-position rotary switch will adjust the frequency response from a flat position known as M (for music) to the contoured S (for speech). Generally, the 421U is brighter with less of a compression effect than the Shure SM57. These microphones are more directional. It’ll be important for isolating the sound that is coming from one of the speakers in a multi-speaker cabinet.

How To Use Your Amp for Performing Live

Conclusion

Thank you for reading. Hopefully, now you know a lot more about miking your guitar amp, how to mic a guitar amp for live sound, the significance of having the right mic position, what type of mic to choose, and more. Miking a guitar amp for a live sound is a delicate but necessary process if you’re going to perform live. There are certain things that you need to take care of such as the type of microphone you’re using, the amp, and the talent of the vocalist. Moreover, the mic needs to be at the right position and angle. Even slight changes in the angle or position of the mic can have a significant impact on the tone.

Rick Pena

Rick Pena

Rick is the founder of All Stringed. He started playing with a classical guitar when he was 10, but changed soon to electric guitar and later also to an acoustic. You can find more about him here.