There’s absolutely no doubt that it’s the best time to be a home-bound guitarist and music producer. Sure, you won’t get as popular as the legends from the good old times. But you have so many options at your disposal. Amp modeling, great audio interfaces, even software that’s free of charge – it’s all at your disposal. However, capturing the sound of an actual amplifier using a microphone seems to be the best way to go. But an important question is posed here: How loud should my amp be when I record?
There are a lot of guitar questions that I can answer in a simple manner. But it’s not the case with this particular issue. The simplest answer would be that you need to think of what your microphones can handle first. Every microphone has what’s called “maximum SPL” or “maximum sound pressure level,” but we’ll touch upon that below.
Another issue is about the kind of tone that you’re aiming for. This is especially the case with tube-driven amps as they can change their tone completely when you push the volume knob up high. But even solid-state amps can impact the tone quality when you’re playing at high volume. However, this is mostly about the relation between your amp and mic, as well as with room acoustics.
Most musicians record at 90 to 110 dB. A volume that is lower or higher than this will sound noticeably different.
Although the topic is a bit broad, I’ll try to sum it up within this brief guide. With some patience (and luck), you’ll have a better grasp of the issue. Just bear in mind that the guide is oriented towards home-recording enthusiasts and amateur-tier studios.
Table of Contents
Find the Right Microphone
So, as mentioned, the first thing to think about in this equation is the microphone. Every mic has its threshold when it comes to the pressure that it can withstand. This is defined through the parameter referred to as the “maximum SPL.” It’s something that you should check out before buying a mic for guitar amplifiers.
Maximum SPL? What’s That?
In case you haven’t done much research about mics in general, you’re probably wondering what’s this “maximum SPL.” The “SPL” part is actually “sound pressure level” and the maximum of this parameter is basically how much noise the mic can handle before the captured sound begins to distort. And no, it’s not the kind of distortion that you’d like. Think of it as that annoying clipping sound, like that “tearing” that you hear on badly done mixes.
If you want to get more technical about it, maximum SPL is the highest sound pressure that a microphone and its components can handle before the distortion occurs, and it’s measured at the frequency of 1 kHz. If we’re talking about measuring distortion, we should also mention total harmonic distortion, which is aimed to be at only 0.5%. Some manufacturers let it go up to 1%.
But not to get too geeky about this, what you need to know is that the mic’s sound should be as clean as possible. All the other “dirt” in there should come from your pedals or amps (unless we’re talking about experimental settings).
These days, standard microphones are made for different purposes. Be it condenser or dynamic mics, they’re often intended for both vocals and instruments. In terms of maximum SPL, they’re usually designed to withstand pretty loud settings, even going over 140 dB SPL at 1 kHz.
In most cases, you won’t have to worry about hitting the maximum. Some exceptions to this rule include those modern USB mics with integrated audio interfaces. For instance, Blue Yeti handles up to 120 dB. But in a practical sense, it would probably not be the best choice for very loud guitar amps, even at 100 dB.
Know Your Amplifier(s)
However, things go beyond microphones. I’d say that a more important issue here is the kind of amp you’re using. After all, mics can usually withstand a lot of noise without distorting the sound. Any standard amp for home use won’t surpass it.
But what you should think about is how your tone changes when you apply different volume levels to it. This is mostly the case with tube amps, especially vintage ones, or those that are modeled after them. For instance, reissue of old Fender amps come with lower wattage and have just one channel. The only way to achieve distortion is to push the volume high and let it “break” there.
What this means in a practical sense is that when your amp is quiet, it will sound completely different compared to when it’s loud. Additionally, every tube amp model will respond differently to your playing dynamics at higher volume settings. Using power attenuation (or “power soak”) settings on your tube amp can help you achieve the same tone at lower volumes.
On the other hand, solid-state amps are different in this sense. Having more headroom, they won’t add more distortion at higher volume levels. It may happen with some solid-state amps, but only if you push the volume near maximum.
If you’re using vintage-oriented tube amps, you’ll also notice that they have two inputs. This can also impact the output volume and sound quality. I’ve talked about this issue and you can check it out here.
What Can Your Amp’s Speakers Handle?
Before you actually go and push the volume into those dangerously high levels, be aware of what your amp can handle. In most cases, speakers are designed to withstand the full power of the amp. But be aware that some long-term damage can happen if you use it on higher volume settings too often.
Additionally, you should test your amp and see how the speakers behave when you push the volume up high. This is especially the case with solid-state amps. While their circuitry can handle high volume without distorting, maybe their speakers won’t. In the end, you might even ruin your speakers in the longer run, making them sound “dull.”
How Loud Should My Amp Be When I Record? Just Don’t Go Too Loud
So how loud should you go? From practical experiences, recording at 90 to 110 dB would be a “standard.” If the volume is lower, at around 50 to 70 dB, it will sound noticeably different. Of course, if you have a smaller amp, record at that volume, just know that your mic will respond differently to it. In this sense, there are no “right” or “wrong” ways. Just find the tone that works the best for what you’re aiming for.
The problems can occur if you go too loud. If you pass the 110 dB mark, or even 120 dB, you’ll get a lot of compression both from your amp and microphone. It may work for some settings, but there are two issues you should think about here:
You may damage your amp: It’s not advisable to play at higher volumes for longer periods.
You’ll lose a lot of the desired tone qualities: At over 110 or 120 dB SPL, you can lose a lot of dynamic qualities, making your guitar sound too “compressed.” Both the amp and the microphone will react differently to it. Additionally, there’s a chance that the amp won’t reproduce the mids that well, making your tone a bit “scooped.” Unless you’re aiming for a compressed tone that sounds overly distorted and slightly scooped, we’d recommend that you keep it under lower volume levels.
You Can Use an SPL Meter
If you really want to get precise with your recordings, or just keep track of the SPL, you can always get an SPL meter. They’re usually not that expensive and you can get one through regular retailers, like Amazon. Radio Shack has quality SPL meters. There are SPL meter apps for smartphones, but they’re not that reliable as actual physical ones.
Dynamic or Condenser Microphones + Microphone Placement
The simplest way to go is to mic up your amp with a dynamic mic. Shure SM57 is an industry standard and it’s even not that expensive considering its qualities. Dynamic mics are usually placed near the amp, about 1 to 3 inches from the speaker cabinet grill. The closer you are to the center of the speaker cone, the more high-ends you’ll get in the captured tone. And the more you go towards the edge, you’ll get a “softer” and darker tone.
Condenser mics can also be used for recording guitar amps. However, they’re usually used as secondary mics in addition to dynamic ones. They can add more high-ends and higher mids to your tone, giving it more presence. They can also be a great solution for capturing room ambiance. You can also use them as the only mic to record a guitar amp, although it’s a less common method.
Condenser microphones can also be a good choice for clean tones. You’ll just need to play around with the placement to see what works the best for your desired tones.
To Sum It Up
So to sum it all up, here’s a list of the things that you should think about when it comes to recording guitar amps and their volume level:
- Type of microphone: What’s the max SPL, condenser, or dynamic mic
- What your amp and speakers can handle
- How your amp reacts to high-volume settings
- The tone you’re aiming for: It will get compressed, overly distorted, and somewhat “scooped” at really high volume levels