Algorithmic vs Convolution Reverb

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Hello once again! I am Benson Lim from Melbourne and for the fifth week of “Introduction To Music Production”, I’ll compare and contrast an algorithmic and convolution reverb. I will also demonstrate the difference and the important features in both types of reverb.

What is a reverb? Reverb is when a signal or sound is reflected causing a large number of reflections to build up. For example, when you play an instrument in a cathedral and you’ll get the reflection of the sound. On the DAW, there are two kinds of reverb that you can choose. They are:

  • Algorithmic
  • Convolution

Algorithmic

Most DAW comes with algorithmic reverb plugin. For example, on Logic, AUMatrixReverb is an algorithmic reverb. On Reaper, it’ll be ReaVerbate. Algorithmic reverbs generates the sound by simulating the impulse responses based on the input that you enter into your DAW. Since the algorithmic reverbs are generated based on parameters, it can sound quite fake especially when isolated in a solo instrument case. Though it sounds fake, it gets the job done. This is because algorithmic reverb is really easy to create but hard to master.

sample algorithmic A sample algorithmic reverb plugin in Reaper.

Click here to listen to a sample using algorithmic reverb.

Pros:

  • easy to use
  • do not need a sample

Cons:

  • can sound fake
  • hard to master
  • not suitable for solo intruments (sounds fake when isolated in a solo instrument)

Convolution

Convolution reverbs use real sound samples. For example, we can record the sound sample from an auditorium or a chapel. On Reaper, you can enable convolution reverb by using the Reaverb plugin. In order to get a sample to use with the convolution reverb, you’ll need to use multiple microphones to capture the acoustics of the room. Then, you’ll upload the file to your DAW and your convolution reverb will then filters your sound through this impulse response to generate a “believable organic tail” based on the characteristics of a real room.

Since the effect process for these types of reverbs involves running filters over your signal and mixing that with another signal, they often consumes more resources from the CPU.

sample convolution A sample convolution reverb plugin in Reaper.

Click here to listen to a sample using convolution reverb. And here is the sample sound that I’ve used to create the reverb.

Pros:

  • will produce a much better reverb than algorithmic

Cons:

  • consumes more CPU resources
  • needs to record or have actual sample sounds to produce the reverb

Conclusion

If you’re recording professionally, I would recommend the convolution reverb as it’ll sound more organic and real. But again, depending on the type of genre you’re mixing for. For a typical metal or grunge music, you can get away with algorithmic reverb.

Thanks again for spending time to read this simple demonstration and I hope that you enjoy reading it as much as I enjoy writing it.