Imagine you’ve just recorded a perfect acoustic guitar performance, spent countless hours choosing the right mics placements, nearly made an artist hate you because of your meticulous persistence with the performance. But you still think it doesn’t sound like something made by a pro. It sounds good, but not like something you would hear on the record. Well, most likely, you didn’t compress the signal or didn’t choose the right compressor settings for acoustic guitar.
What is compression?
Also see: Best Acoustic Guitar Compressors
Dynamic Range Compressor or simply compressor is a device or software that makes louder parts of the signal quieter and the quiet parts louder, thus reducing the signal’s dynamic range. Regardless of what type of compressor you would get your hands on, they all have very similar if not identical adjustable controls. Ones to consider would be attack and release, threshold, and ratio.
Using the attack settings, we can adjust when the gain is decreasing. Setting the release will increase gain according to the determined ratio. In general, slow attack and release will give you flatter sound; faster settings will provide you with more snappy sound.
Ratio sets the amount of gain reduction and is shown by the proportion. For example, a ratio of 3:1 means that if a signal is 3 dB louder than a set threshold, the output signal will be reduced by 1 dB. This setting shows how obvious or subtle the compression would be. Threshold determines at which level the compressor will start to work.
Compressor settings for acoustic guitar
One thing to remember is that, unfortunately, there is no such thing as a magic button that makes everything sound great. In terms of settings for acoustic guitar specifically, it would very much depend on the objective you are trying to achieve. Compressing solo acoustic guitar is one thing; strumming in the band is entirely another thing. Whether it is a gritty or raw indie-folk track or a glossy and polished pop song, it drastically changes your approach to compression.
Solo acoustic guitar compression
If you are capturing fingerstyle or intimate singer-songwriters’ acoustic performance, you’d probably want to maintain or even define the intimacy. Using a slower attack and release with a moderate ratio will bring up the nuances of the performance. Be careful, though; too much detail isn’t always a good thing. So, you might need to trim some bits and pieces with an EQ. In case you are happy with the amount of details, you might want to add some polish by using very low ratios and the threshold. Something that you would typically use on the master bus.
Mixing acoustic guitars live also could provide some challenges. Generally, your goal is to clean otherwise muddy and imperfect recording. Since frequencies tend to build up in the lower mid-range, you might consider using something called a multiband compressor. The multiband compressor is the same as a regular one, apart from the ability to apply compression to a selected band of frequencies. Or using different compressor settings on different frequencies.
Acoustic guitar in the mix
With acoustic guitar, things might get messy if other instruments are involved. Because an acoustic guitar sounds rich and has a broad frequency range, you might want to slim it down with EQs before applying compression. After doing this, it’s generally a good idea to ask yourself what you are trying to achieve. If you want your guitar to pop out in the mix, use more aggressive settings. Faster attack and release times will make it sound snappier. If you desire to make your acoustic guitar to be something of background support, use a slower attack with lower threshold settings.
All about style
What affects how to use and apply the compression very much depends on what style of music you are working on. Although the modern world, especially in the realm of music, is very eclectic, certain things are almost obligatory to use in specific styles to be convincing. Even if the performance is impeccable, the homage to, for example, 50s rock-n-roll wouldn’t be possible without that era’s gear. Luckily, if you can’t get your hands on vintage gear, there are a variety of software plugins on the market that successfully emulate the sound of said equipment.
When working with styles that require some vintage vibes, such as indie-rock, lo-fi, it makes perfect sense to use some opto-compressor emulation or the tubes one. Basically, those compressors behave the same as the digital ones and give you the opportunity to use the same settings. But with added flavor – like some non-linear imperfections and noise usually generated by analog circuits.
But no one forbids you from using analog emulations in projects that don’t necessarily need some vintage feel. For example, if a modern and synthy pop song features an acoustic guitar track, it might actually benefit from using vintage compressors. It might add some flavor and quirkiness into an otherwise squeaky clean guitar track. Bear in mind not to overdo it by stacking up those plugins; it might make a perfectly recorded song into a noisy and distorted mess. In other words, moderation is always a good idea.
Actual analog gear
Consider yourself one of the lucky ones in a very much unlikely case of you being in possession of an actual hardwire compressor units. Without getting into an ancient argument of what is better analog or digital, you definitely can get quite a few benefits of using hardwire.
Firstly, you can send your acoustic guitar signal through the hardware compressor before it goes to your DAW. It will most likely save some precious time during the mixing stages. The downside of that is if you make a mistake setting up your compressor, you cannot change that while mixing. The acoustic guitar part will have to be rerecorded anew. So, acing this technique might take a lot of time and experimentation.
Secondly, you can use your analog gear as a separate insert in your DAW. It will give you the opportunity to send already recorded tracks into your hardwire and print them on separate tracks. The good thing is that if you’ve made a mistake, you could always take a step back and fix it. The drawback would be that the time of mixing will increase because all your tracks would need to be put through an analog compressor in real-time.
But let’s face it – if you own a vintage 1176, you don’t need our advice anyway.
Tricks Pros use
Apart from common ways of using compression on acoustic guitars, experts commonly use a few advanced techniques. You can route your acoustic guitar track through the separate track and apply compression to that track. Then the original track can be mixed with the processed one by staging its gain. Using quite aggressive compression settings with higher ratios and lower thresholds and mixing those tracks together will make your guitar sound more present, maintaining its natural sound. This trick is called parallel compression.
If you have a very dense mix with lots of similar acoustic guitar parts, you may consider combining them and sending those signals into a separate bus. It will allow you to apply the same compressor settings to all of those tracks without creating too many instances of the compressor, thus lowering your CPU power consumption. Beware though of compressing dynamically different guitar parts the same way. As we know, something that will work on a strumming guitar part will not necessarily work on the arpeggios.
At some point, you may consider stacking up different compressors with different settings on the same track.
It’s very much possible due to modern computers having a staggering amount of processing power. But if your computer is in the lower range, you can always bounce your track onto a stem. You might use, for example, two compressors: first, a completely digital one can trim some peaks in the cleanest way possible, allowing you to use some analog emulation compressor as the second one and to push it quite hard, giving your signal lots of coloration without making it sound overcompressed.
One thing to remember is that there are no universal compressor settings for acoustic guitar that could be applied to any track and sound good. It is impossible to record acoustic guitars with the same dynamic and levels twice, let alone always. Every time you record a guitar, you will get a unique result since it is a highly dynamic, responsive instrument. We can aid you by giving you some general ideas for applying compressor settings for acoustic guitars and inspiring you for further exploration. A deeper understanding of how compression works in general, of all things, will benefit you the most in terms of improving your production.