How to Use Compression on Acoustic Guitar – The Perfect Settings

The acoustic guitar is another one of those deceptively dynamic instruments. The percussive nature of strumming combined with the fact that it’s difficult to get a consistent performance means you’ll need to reach for the compressor. Compression on acoustic guitar gives you a more consistent presence and energy from a performance, and more sustain on the back end.

Still, using the wrong settings on your acoustic guitar’s compressor can make it sound squashed or unnatural. That’s why I’ve put together this guide for compression on acoustic guitar, so open up your DAW and let’s get into it!

Compression on Acoustic Guitar – Settings

Before we get into compression, make sure that you know how to record acoustic guitar to get the best sound before you even begin mixing. Also make sure you know how to EQ acoustic guitar so that we’re just compressing the good stuff.

Now let’s talk settings for compressing your acoustic guitar.

I’ve put together this cheat sheet which I use every time I drop a compressor on my acoustic. This is to give an overview on the best settings for compression on acoustic guitar, but I’ll go in depth in each one below:

Note in this example I’m using the Pro-C2 from FabFilter. It offers a number of different types of audio compressors in one making it versatile, and incidentally it sounds great for compression on acoustic guitar.

Acoustic Guitar Compressor Threshold

The compressor threshold dictates at which volume the input signal, in this case the volume from our acoustic guitar, must hit before our compressor begins to work. In other words, the peaks on our acoustic guitar signal won’t get pulled down until we tell the compressor where to start listening.

I like to compress practically my entire signal, meaning I set my threshold just above the quietest part of the performance. Note that I don’t mean silence on the track, but the quietest moment of the performance itself.

Also note that, as I specify in the graphic, you may need to automate this threshold or break your performance into two tracks if you alternate between say quieter strumming or picking for a verse before bringing more energy (and volume) during a chorus. Leaving this unchecked for an especially dynamic performance like that will absolutely squash the chorus section.

Having that threshold set at the lowest point of the track, however, gives you a thick, consistent, and professional sounding acoustic guitar.

Acoustic Guitar Compressor Ratio

The ratio dictates to what degree any signal which exceeds the threshold gets pulled down. I give specific examples of how this works in my post on compression ratio explained to better convey how that works.

I typically set my ratio when compressing acoustic guitar to somewhere between 4 and 5 to 1. Here specifically it’s set to 4.28:1. This combined with the threshold, for a performance of guitar strumming with average intensity, I aim for about 8dB in gain reduction at max. This is bringing down those peaks and giving me a smoother sounding performance which fits perfectly in the mix.

Acoustic Guitar Compression Knee

The compressor knee allows you to begin compressing the signal at a lighter scale as it approaches the threshold. In sort of relaxes the threshold and can be used to give you a more gradual and sometimes more natural compression.

As you could see from the initial graphic above, I prefer to use a mixed knee, typically around 12dB or so. This means the compressor largely adhere to the threshold, but it will begin compressing at a lighter ratio as the signal approaches the threshold. This makes for a more transparent blended compression.

The loudest peaks will still be reduced the most, and I like the energy and consistent sound I get from setting that mixed knee.

Acoustic Guitar Compressor Attack

The attack of the compressor dictates how long after the signal exceeds the threshold before the compression on acoustic guitar begins engaging.

The slower you set this, the more transients, or more of that initial uncompressed sound gets heard.

Setting this to the minimum means less punch of those transients is heard. This is why I recommend a setting it to 10-15ms. This allows the front “bite” of those early transients to be heard before we get the effect of the compression.

Acoustic Guitar Compressor Release

The release time on the acoustic guitar compressor determines how long AFTER the signal drops below the threshold that the compressor stops working.

Relatively faster release times sound more natural because they maintain more of the dynamics in the audio. Ideally you want to set this to be roughly the length between the peaks in the song so it can release and be ready to turn back on rather than outlasting more than one peak.

As an effective starting point, I like to set the release on acoustic guitar compression at roughly 50ms on average.

This keeps the compressor from over-compressing parts of the track it shouldn’t and basically squashing the sound. This tighter release time also adds a bit of energy to the performance as it turns on and off.

Note that setting the release time TOO fast, meaning it releases instantly as the signal drops below the threshold, creates a gritty, unnatural sound.

Acoustic Guitar Compression Output Gain

This is a good lesson whenever you’re compressing or adding ANY kind of processing to a track. Make sure that the volume level with the plugin turned on, in this case our compressor, is the same as the volume with it turned off.

Our ears will always favor what’s louder because we inherently perceive that as being more exciting. Therefore, the only way to determine if the compression is helping your track is to first make sure that the input and output level are the same.

Compression by its very nature COMPRESSES a signal, meaning it turns it down. Without makeup gain for the output, this is going to sound quieter, ie worse than it does without the compression.

This applies to the track on its own as well as when played in the context of the mix. For instance, you might play the mix back after adding compression and notice that all of a sudden that acoustic guitar track feels buried or hidden in the mix. Instinctively you might assume that the compression is making that track sound weaker and remove it. Therefore, be aware of the output gain being equal.

You won’t have to make any adjustments to the track level in the context of the mix after the fact if you make sure the in and out are equal, as well.

Most compressors have an option to automatically compensate the “makeup” gain. If you use the automatic option, make sure it’s truly the same as the track without the compression for a fair test.

Compression on Acoustic Guitar Tips

• Compression will bring more presence, energy, and cohesion to your acoustic guitar.
• Set your threshold to trigger at the quietest part of the performance for a fuller, smoother performance.
• Automate the threshold accordingly if single track is especially dynamic (finger picked verses into a strummed chorus).
• Set a hard knee to respect that threshold.
• Set a ratio of 4:1 for a natural and well rounded level of compression.
• Set an attack time of 25ms to get that cohesion while allowing string transients to pass for a punchy yet controlled sound.
• Set a relatively fast release time of 50ms to get an energetic effect while achieving more sustain.
• Make sure your output level sounds equivalent with or without the compressor.

BTW, yesterday I talked about how to EQ acoustic guitar, so check that out for the other big piece of the pie in getting the perfect tone from your acoustic!