One of my most fond memories from opening for blues bands (aside from Buddy Guy’s outstanding guitar tone) is of the sound of the club itself. These venues were often built for hundreds — not thousands, like today’s venues — of people; and the hard walls, minimalist acoustic treatment and sheer number of high-frequency-absorbing humans resulted in a special kind of ambience.
I had never been able to re-create this sound with conventional digital reverbs, but once convolution reverbs became affordable, I had hope: All I needed was an acoustic impulse file to provide that sound. When I couldn’t find any, I decided it was time to go rogue and make my own. I did it, and you can too. It may seem daunting, but it’s easier than it sounds if you know how to use a DAW. What’s more, the settings aren’t all that critical, so take some time to experiment. Want to make your virtual club bigger? Simply increase the impulse’s length.
Here’s my step-by-step guide to creating your own blues club convolution reverb:
1. First, you’ll need a white noise sample that lasts from about one-half to one second. This can be created from a synthesizer bundled with your recording software, or you can download a sample from the internet (check out https://mc2method.org/white-noise).
2. Load the sample into your recording software or digital audio editor, trim it to about 500 milliseconds, and insert an EQ plug-in followed by a chorus plug-in.
3. Next, filter out the sample’s low and high frequencies. Set a low-cut (high-pass) filter with a 24 dB/octave slope to around 700 Hz, and a high-cut (low-pass) filter with a 24 dB/octave (or higher) slope to around 4 to 5 kHz. The slopes and frequencies aren’t too critical, but these settings worked well for me.
4. Now, add chorusing to create the comb-filtering anomalies that resemble room acoustics. The type of chorus doesn’t matter too much, but set the initial delay to around 15 ms and the LFO speed and width to the minimum possible (you don’t want modulation).
5. Finally, set the mix to 50/50 delayed and straight sounds. Depending on your plug-in, that may require setting the mix at 50% or 100%. Check your plug-in’s documentation.
6. Add a concave fade-out to the white noise clip starting at about 300 ms (a linear fade can work too).
7. Bounce or export the clip so that it incorporates the effect from the signal processors and the fade-out, and then save the rendered clip as a WAV or AIFF file.
8. Now, create a new track for your guitar, load your favorite vintage amp sim sound, insert a little spring reverb if that’s your thing, and follow it with your convolution reverb plug-in.
9. Check your convolution reverb’s documentation to find out how to import an impulse, and then load the file you just exported.
10. Now it’s time to play. Tweak the reverb’s mix and other controls to create a vintage sound, then close your eyes. You just might feel like you’ve been transported back in time and are about to hear Muddy Waters sing “No Escape from the Blues.”