I am a big fan of convolution reverbs. I love exploring different free impulse responses. Doing that often sends me off to completely unexpected creative paths. You can even create a trademark sound of your own based on impulse responses alone.

It can be sometimes hard to find good free impulse responses. Here’s a little resource with some great free reverb impulses to explore. First, I’ll give you a quick introduction to convolution reverbs. If you’re already familiar with the topic, feel free to skip the intro.

What is a convolution reverb?

Convolution technology can be used to capture ambiances and then reproduce them on the computer. An impulse file is a short burst of audio recorded in a real space or through a hardware reverb unit. A convolution reverb plugin uses this impulse file to determine the properties of the reverb. It applies those properties onto any sound you are feeding into the plugin. Convolution technique can be applied to just about to anything from reverbs to EQ’s, compressors and preamps. But we’ll stick with reverbs here.

With convolution, you can get the sound of some super expensive hardware units inside your computer for free. What’s the catch? Flexibility.

Convolution technique is somewhat rigid as it is based on recorded samples of the original source. A convolution reverb doesn’t allow the extent of programming you get with normal algorithmic reverbs.

Most convolution reverb plugins have some editing capabilities. But it’s usually a good idea to keep the edits small. Editing tends to destroy the integrity of these fragile impulses. Of course, you are free to experiment. But in my experience, with convolution reverbs it’s best to look for an impulse that works as it is, with minimal to no editing. This preserves the integrity of the source.

It’s good to understand that convolution is still only a reproduction of the real thing. The quality of the outcome very much depends on the execution. However, convolution can sound pretty damn good when done right.

Many DAWs these days come with some kind of convolution reverb plugin. If you need one though, check out the free Convology XT plugin. It works on PC as well as Mac.

Bricasti M7 impulses by Samplicity

The Bricasti M7 is a revered modern unit that offers fine classic reverb sounds. It has been called “the future of reverberation”. The price of the basic unit is around 4000 EUR (4500 USD). And that’s without the remote which costs another couple of grands. Now there’s something to think about.

This collection of free impulse responses by Samplicity includes 136 presets from the M7. These are traditional reverb sounds that sound very smooth and realistic to me. These sounds work well on many kinds of material.

You know sometimes you like a particular reverb sound but it doesn’t seem to sit well in the mix? With the M7 that doesn’t happen as often. Of course, you still have to find the right presets. But my experience with these impulses is that they are very usable and just seem to blend effortlessly in the mix while providing heaps of depth and dimension. Try them out.

Link: Bricasti M7 free impulse response pack by Samplicity.

EchoThief Impulse Response Library

The EchoThief impulse response reverb library consists of more than a hundred real-world spaces sampled from around North America. A great collection of detailed and rich impulses. The sampled spaces are quite interesting – here are a few examples:

The last covered bridge in Wisconsin.

An abandoned coastal artillery battery.

The Batcave from the original 1960s TV series.

A Yup’ik subterranean communal qasgiq.

The Béton Coignet of Cleft Ridge Arch.

The stream bed beneath Byron Glacier.

The Cathedral Room of Shasta Lake Caverns.

An indoor racquetball court.

The Naumburg Bandshell in Central Park.

Link: EchoThief free impulse response reverb library

Lexicon 480L free impulse responses by Housecall

The Lexicon 480L came out in 1986 and at the time they cost more than some cars. Come to think of it, they probably still do.

For a long time the 480L was the standard by which all other processors were measured. These sounds are the classics of the classics, used on countless of popular (and not so popular) records. They are brighter and a bit more aggressive than the Bricasti for example. Draw for the 480L reverbs when you need something that strikes out.

A couple of my favorites:

“Wild spaces/Inside Out” – great pumping when the tempo is right.

“Random hall/Random Well” – another very nice pumping reverb.

Link: Housecall Lexicon 480L free impulse response reverb pack

Lexicon PCM 90 impulse responses by Zidee

The Lexicon PCM 90 is an another classic reverb unit. It’s newer than the beforementioned 480L. The pack contains lots of great sounding reverbs.

There are many gems inside this pack. For one, you have to try the “Inverse Drums” preset found in the Room pack!

Link: Zidee’s Lexicon PCM 90 free impulse response reverb library

Tips for working with impulses

Make custom presets of your favorite impulses. This way you won’t have to look for the impulse files on your hard drive every single time. I kick myself for not realizing I could do that for a long time.

Don’t worry if the sample rate of the impulses is different than the sample rate of the project you’re working on. Your plugin takes care of the conversion.

Try using small ambiences and room sounds for creating a trademark sound for your music. I find convolution reverbs often excel with this.