Compression is one of the most commonly used dynamics processors in music and audio production and the reason for this is simple: it appears to make everything sound better. Compression lowers the loudest parts and increases the quietest parts of an audio recording, essentially “flattening” or equalizing the volume peaks.
It’s not hard to imagine why this is so valuable. For the bass guitar, for example, a compressor will amplify any of the notes that weren’t played quite loud enough. And for the guitar, it will function in the same way (and many others as well). But what if you tried using a compressor marketed for a guitar for a bass guitar instead?
Generally speaking, you can use almost any guitar pedal for a bass guitar, including a compressor pedal. Some compressor pedals might perform better with a bass guitar due to their specific frequency response, but the vast majority of them will function satisfactorily.
Before getting into some of the differences between the compressor for the bass and the 6-string guitar, we’re going to dive into the attributes of the audio processor, including some of its functions.
What Is A Compressor?
If you’re new to compression, there are just a few things to understand right off the bat. Essentially, a compressor lowers the volume of the loudest sounds and increases the volume of the quietest sounds.
In the early 2000s, the compressor first became available as a software plug-in commonly used in digital audio workstations (DAWs), that almost every music producer, musician, and performer is at least somewhat familiar with.
Before then, it typically came in two different formats, the rack format, such as the Universal Audio LA-2A, or the compressor pedal, like the Dyna-Comp from MXR (on Amazon).
However, with the advent of computer technology, they now come in a plug-in format that everyone can gain access to and use (Fab Filter’s Pro-C 2 on Plugin Boutique is probably the best example).
There are a number of terms that describe what the compressor does, including “squash,” or “squeeze,” and in conjunction with the explanation I gave above, it makes a lot of sense if you think about it.
Because the compressor attenuates the loud sounds and increases the quiet sounds, it makes the audio file smaller.
Take a look at the two images below, the compressed and the uncompressed, and you’ll notice the one looks a bit thicker than the other.
What Are The Compressor Parameters?
The compressor commonly comes with 4 different knobs, the gain, the attack, threshold, and ratio, and sometimes the input.
The gain is the total output of the sound, in other words, the volume. Turning the gain up is going to increase the volume of the final compressed sound.
It’s basically how much you’re hearing the final product of the compressor performing its function.
The threshold is the point at which the compressor kicks in. The threshold is determining at what points the compressor is working, in dB, so you can pinpoint what part of the sound is actually receiving the compressor’s treatment.
The difference between the threshold and ratio is that while the threshold is determining at what point the compressor kicks in, the ratio is adjusting how much that signal is actually being compressed.
Explained in another way, the ratio is determining the strength of the compressor.
2:1 is low compression
4:1 is medium compression
8:1 is high compression
10:1 is getting much closer to limiting, and anything past 10:1, say, for example, 20:1, is like a brick-wall limiter.
You might find that the range between 4 and 8:1 compression is the sweet spot, sometimes a little more around 9:1 is going to do the trick, depending on what you’re using it for.
In case you didn’t know, the limiter and the compressor are essentially the same audio processing units, except that the limiter has a fixed ratio and is used for a different purpose.
The attack, on the other hand, is the speed of the compressor, or how long it takes for the compressor to actually grab on to the signal and start performing its function.
A slow attack is more suited to the bass guitar, whereas a slightly faster attack is going to be more suited to the 6-string guitar, but it really depends.
A common use for the compressor on the acoustic guitar is a fast attack, which will actually increase the sound of the plucking, or the pick hitting the strings.
According to Bobby Owinski in his The Engineer’s Handbook (from Amazon), it’s not uncommon at all for engineers and mixers to use a fast attack setting on the acoustic guitar to essentially accentuate the picking sound, to the point where the picking might even be heard more than the actual notes playing.
You can hear this style of compression on the acoustic guitar in a lot of music, but frankly, I’m not a huge fan of it.
It depends on the role of the instrument in the mix. For instance, if the acoustic guitar is the primary instrument in the mix, alongside the vocals, a fast attack will be utilized less so.
The release is different from the attack, although, it’s a little more self-explanatory. The release setting adjusts how quickly the note is let go after the compressor grabs onto it.
In the case of the bass guitar, you would want to have a slow attack and a much faster release, that way there is time for the compressor to drop the previous note and then adjust the next note that the bass guitarist plays.
The input knob is seen on some pedals, like the MXR bass compressor pedals, and it controls how much of the bass’ signal is actually being fed into the unit for compression.
In other words, the input knob determines how much of the signal is actually being compressed, but it’s different from the threshold.
Explained in a different way, the threshold is the point at which the compressor starts working on the signal that’s being fed into the unit, whereas the input is controlling how much of the signal is actually being altered.
In some cases, a bass guitar compressor will come with an input knob rather than a threshold knob, which means that the threshold is actually fixed, so that’s something worth considering.
Why Use A Compressor For Bass?
A compressor for the bass, like the 6-string guitar, is very useful for the studio and performing musician, because it accentuates the intricacies and details of the bass and evens out the lower frequencies (more on the importance of bass in my other article).
A bass guitar dominates the lower frequencies on the frequency spectrum, which can get quite messy and muddy if not reigned in properly. This is where the compressor comes in.
A compressed bass sound can make it sound much tighter and punchier.
What Does A Compressor Do For A Bass Guitar?
It can be used to get a handle on some of the dynamic range of the instrument, evening out the audio, and all in all, making a very tight, articulate, and punchy bass guitar sound, which is great for rock music among other genres.
As I mentioned above, the compressor can be used for many different types of instruments, but in the case of a guitar or a bass guitar, it basically takes the notes that you barely played and increases the sound of them, and then the notes that are too loud are brought down in volume.
It’s easy to understand why this is such a great thing and why it’s so useful.
When playing the instrument, you might find you used too much attack on a particular note, or perhaps too little on another, so the compressor, essentially, is evening out the dynamics of these notes.
In the modern era, especially in the case of progressive rock and progressive metal, the compressor has become a mainstay among guitarists, for instance, Plini, Intervals, and so on and so forth.
An example of a compressor in action is hammer-ons and pull-offs. Typically, a compressor will increase the volume and velocity of these notes to a point where they actually sound almost equal in volume to the notes that are actually picked individually.
Depending on the techniques you use while playing the bass guitar (some of which are easier than on the guitar as I’ve argued before), the compressor can be useful in a number of ways. For instance, it’s a great audio processor to use if you do a lot of tapping and, as I mentioned above, slurs, or more commonly referred to as hammer-ons and pull-offs.
An additional reason why a compressor is so useful for the bass guitar is that bass guitars typically don’t use distortion, with a few exceptions, so there isn’t an increase in gain that guitar players benefit a lot from in their technique and playing style.
If you own a guitar and a bass guitar, go ahead and try the tapping technique on both of them, with the guitar using a distorted signal and the bass guitar using a clean sound.
It’s a lot easier to hear the intricacies of the distorted guitar because distortion is already compressing the signal. The bass guitar isn’t benefiting from that dynamic because it doesn’t use distortion often.
Like I said at the beginning of the article, a compressor used for the bass is going to accentuate the desired frequencies and add more definition to the sound, ultimately filling it out and making it sound a lot better.
Tricks and Tips For The Bass Guitarist Using Compression
This tip applies to not only bass, but also the guitar, and it is the following: you always want the compressed sound to be equal in output/volume as the uncompressed sound.
In other words, you want the volume to be the exact same when the compressor is turned on and when the compressor is turned off. It’s not desirable to turn on the compressor unit and then suddenly get a massive jump in total output unless that’s the goal.
The purpose of using the compressor pedal is not to increase the total volume of the sound, it’s to adjust the dynamics of that sound, rather than the volume. That is the proper use of the pedal unless you’re trying to do something else.
I mentioned this already at another point in the article, but it’s also a good move to have a slow attack when using a tapping technique because you want those spikes in volume whenever a note is struck.
When the attack of the plucked notes is permitted to shine through the mix, it’s going to sound a bit better and more pronounced.
What Are The Differences Between a Bass Guitar and 6-String Guitar Compressor?
While the compressor performs a similar function for both instruments, the truth is there can be at least some differences. For instance, a bass guitar typically benefits from a much slower attack, the reason being to allow for the initial punch or attack of the plucked note to shine through before the total volume of the audio signal is attenuated.
A guitar compressor, on the other hand, often has a much faster attack, to drop the volume of the note or increase the volume right away.
Bass compressors and other rack units typically come with an attack knob to adjust how much you want, in addition to a light-emitting-diode or a light-dependent-resister rather than the transistor.
In other words, a bass guitar compressor uses the LED/LDR which, from what I understand, is a bit slower and a bit more smooth, allowing for a more bass-friendly compression sound.
It’s not uncommon for a guitar compressor to omit the attack function on the pedal, whereas on the bass guitar compressor, it will almost always come with an attack knob. Although, you can certainly find guitar compressors that utilize the attack knob.
Many people would argue that it’s a good move to get a bass-specific compressor or a rack-unit one, although, a compressor meant specifically for a guitar will work for it as well.
Should I Buy A Bass Instead Of A Guitar Compressor?
Despite the similarities between the types of compressors out there, it wouldn’t be a bad idea to grab a compressor pedal meant specifically for bass, due to the differences that I mentioned above.
However, if you’re not rolling in cash, it might just be best to stick to the guitar pedal compressor you already own for the time being.
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When it comes to gear and audio-processing units, a lot can be done, as evidenced by the huge spike in stomp-boxes and pedals produced and manufactured in the last few years.
However, in the case of the compressor, while there are some differences between the units meant for bass guitar and guitar, one can be used for the other. Even though it’s certainly not optimal to use one for the other, it should work just fine.
Like I said before – if you have the cash, it’s definitely worth getting a pedal specifically for the bass guitar.