A Guitarist's Guide to Microphones and EQ

One of my favorite and most useful tools in DAWs is the EQ. I'm guilty of allowing myself to “sort it out with the EQ” on a few occasions. That is not a crime but let's face it: not having to use EQ is the goal if you're recording live material. Let me show you a few tricks I use myself.

Setting up your recording with Multiple Microphones 

Using multiple microphones is by no means a secret, but not often used with guitar recording which is what I'm going to focus on here. Typically, no more then two microphones at one time are found when an electric guitar is recorded; using a multi-microphone setup however, can offer a few benefits if done with care. In a recent article found here on the MPV Hub, I wrote about Logic's “Sample Delay Plug-In” and how to use it as a tool to correct phase issues in Logic. The phase issues I referred to were due to recording with multiple microphones. So, why do it?

Here's an excellent reason why: If you are recording with 4 or even 5 microphones at once, you can extract certain sounds from each mic that, when blended together, form an ideal representation of the sound you're shooting for. This in turn alleviates the need for EQ and/or reduces the amount that is used. Basically, each microphone is a complex equalizer in itself. If the source is captured using an array of microphones, you can select from the total and extract whichever suit your goals. If that selection results in the right sound, you can add compression if needed and skip adjusting the EQ in post. This could result in less artifacts and phase distortion. But this would mean selecting microphones to yield the variety of frequency and color ahead of time. You can adjust your EQ mix so to speak by adjusting the levels of your independent microphones.

Note: Caution, bass build up is possible. Use low cuts on your microphones if you have them, best to start there then to have to take a drastic EQ action in post.

Mic placement as EQ

Get your mic placement set up to offer the variety of sound colors you're looking for. Generally, center cone will provide a stronger bass, Mid and full sound. Edge of cone will be lighter, brighter and less low end etc. You can also use the distance from the source to get you a character and tone otherwise not possible with a close-up mic. It is a good idea to experiment with each mic for this optimized placement. 

So, how do you do this placement and hear your result at the same time? There are a couple of ways: If you have a friend who can play the part over the amp and speaker you're recording, that will do fine. If you're looking to hear a very specific part and it is not possible to have another person around, you can do what is known as “Re-Amping”. Re-Amping is where you use a device like the Radial X-Amp and play your guitar into your amp through the X-Amp box. The guitar signal is sent to your amplifier in real time while also being recorded at the same time as a line level directly into your DAW from your audio interface. This creates a recording of your guitar part which you have played live into your amp. 

Why do it this way? When you're playing your guitar with the amplifier sending sound waves back towards you, there are vibrations which create unique interactions that are imparted to the guitar from the amplifier's output. These nuances will also be captured and recorded in your DAW as a line level signal to be used to playback while you're setting up your microphones. This is also a great way to get a great performance captured and saved in the event you want to play that part a second time using another guitar amplifier or even an amp simulator. This unique action offers some special sound variations not found by simply recording directly into your DAW. 

Time to place the microphones

After you've made your recording, save your work and set your now captured performance in cycle mode. Select the output of your recording channel strip to feed out of your audio interface and through your Re-Amp box. The Re-Amp box such as the Radial X-Amp will allow you to drive your intended guitar amp and speaker. There are typically a few adjustments you may want to make to help get your sound just like your original guitar source with adjustable level and a ground lift, if needed.

So now your amp is blasting away, and it's you—or the “Virtual You”—playing your amp. Put on some good headphones and set your headphone volume loud enough to hear your microphone output over the live amp. Plan to set your amp volume close to your intended volume for recording. You may have to lower the guitar amp's volume a bit so you can hear the resulting output in your headphones. The mic placement procedure begins. Setting up the mic is fun. You will hear a lot of things going on with the microphone while moving it. But remember: it will be a good idea to try and focus on getting the particular mic you're placing to get its optimal sound. If it has a brighter sound, try to find a good balance for it on that basis. 

Repeat this procedure for the remaining microphones you're planning to use. 

Time to set up a phase test

I won't reiterate this process in full but defer to my previous article on Phase Correction Using Logics Sample Delay to proceed into the next needed step. Once this is competed, you can now actually use each recorded track as independent EQ recordings. This is the ultimate goal and can prove to be a very valuable trick.

I've also found a couple of good plugins that might be handy in assisting you in adjusting phase,. Check out a plug-in called VOXPHA2. This is a great phase adjustment plugin for any situation but you might find it especially useful here.

Seems like a lot of work. Is it worth it? This is a lot of work, but try and keep this in mind: If you want to have a different sound, you're not going to get there doing what everyone else does. Getting your own voice is what you should shoot for. Creating a different guitar sound that can stand out in the mix is not always as easy as it looks. With as many options as you can get from the start, this can be a big advantage along the way.

Hopefully you will extract an excellent sound to start with from one, two or more microphones allowing you to mix up the ideal sound. In the event you're not 100% there, you can use EQ to assist and use it without to much phase distortion. I find this method allows for 1 or 2 dB increments of adjustment along the way. I also find that if I am looking for a specific sound, I might compare my individual mic sounds to a reference source and if it works out with only one or two mics and a small bit of EQ along the way then the sound is very pure. Having the option is key to achieving your best result.

Trail blazers like Edward Van Halen and engineer Don Landee did not just do things the same way as everyone else and get radical results. If you want to achieve something spectacular, I'd recommend starting by keeping your sound as organic as possible. A good tone is not always in need of lots of processing. 

Finally, in today's highly processed sound environments, we can forget that good microphones are one of our best friends and can really bring out the best in a live performance. Guitars are electrified and there are many things that can be done to them along the way. Hearing them in the genesis of the creative process is also very inspiring and should be something to strive to retain. Removing the phase distortion in your recording process means a better mix and a better hand-off to the mastering engineer.

conclusion

I would strongly suggest taking the time to find a good set of quality microphones which will serve your needs and if you're able to collect them, do it with the idea that each one will contribute a unique sound of its own and will make for a good contribution to the sum. There are some fantastic Capacitor and ribbon mics now on the market that are not like the traditional versions long thought to be bright or dark. I have also read of some even better gains in condenser mics and large diaphragm microphones that offer terrific sound quality without lots of money. You will be surprised how many are now on the market at low cost!