Using Digital Reverb Plugins to Spice Up Dry Audio

Reverb is the spice of your audio. Without some sense of reverberation, whether natural or digital, your mixes will inevitably seem lifeless and boring. Too much reverb or the wrong type can unnaturally spoil your audio endeavors, like adding the wrong flavor to an otherwise good recipe. The key is using the right ingredients, knowing how much too add, and knowing when to stop when the mix is just right.

Here's a short clip from the Neo-Nostalgics upcoming album, a tune called John Barber. As with most guerrilla recording environments, the space in which we were recording didn't afford the best acoustics (no high ceilings, no wood floors, etc.-- a basement, basically), so we close-mic'ed every instrument to reduce the amount of room ambiance, since setting up a room mic to collect some natural reverb wasn't an option. As we expected, our final tracks were pretty clean and didn't have much of the unwanted room sound in the mix, but the tracks sound bare-bones dry and don't have that "sparkle" a nice room would provide:



In close quarter recording spaces, the trick is to fake ambiance with digital reverb while not letting on that it's an artificial addition. I start by searching for a nice effect that emulates the sense of real space, but I pay close attention to how the reverb colors my audio, especially if it adds unwanted mud that detracts from the fidelity of the dry source audio. On the other hand, some reverb parameters might react a little too brightly and actively on some transient peaks (like snare cracks or sibilant vocals) which will unnaturally emerge from the mix in ways that real acoustic reflections would never behave. This is a dead giveaway that you're using canned ambiance. To avoid this, I look for a reverb that provides "cutoff" parameters which allows control over what frequencies are included in the effect. For reverbs that don't include this option, you can always bounce a 100% wet signal to its own track and manually apply equalization to get the response you're seeking.

To fake the natural ambiance we're missing from the mix, I add the same base reverb effect to most of the instruments in small amounts. For starters, I'll often choose a small room or hall setting without a lot of bright coloration and a shorter decay time; we're shooting to make the audio sound like it's sitting in a unified space, but again, we don't want the reverb to sound distracting or unnatural. I'll add it to the drums first-- if the reverb blends well and sounds natural with the drums, it will probably sound alright with the rest of the instruments in the mix. I generally don't add any (or much) reverb to the kick or the overheads because reverb on these tracks often ruins the clarity of what we've recorded. For the snare and the toms, I'll add just enough reverb until I notice the effect, and then I'll back it off until I can't notice it anymore. I find the ideal amount of reverb occurs in the area between noticing it and not noticing it, but ultimately it's a matter left up to taste and the style of music you're working with.

After the drums are sounding good, I'll add a small amount to the rest of the instruments to bring them into the same "space," trying to find the right amount that sounds natural for each instrument and always auditioning the wet/dry ratio with the rest of the mix. Keep in mind that the more reverb you add, the more "removed" the original audio will sound from the mix, and the more predominant and possibly distracting the fake ambiance becomes. As a general rule of thumb, you don't want the effect to overtake the natural balance of your mix, so in most cases, a little bit of reverb goes a long way. For my tastes, I find that the snare and the toms will receive the most amount of reverb (e.g. 5% to 15% wet), and every other instrument gets the same effect in less amounts (anywhere from 1% to 12% wet). If I choose to apply different reverb effect to other instruments, I have to be careful that the different settings don't create a conflicting sense of space (unless of course that's the effect I'm going for) and aren't adding subtle tonal and EQ imbalances. Simply put, you don't want different reverb settings to conflict with one another. If I do use different reverb settings for different instruments, a tiny amount of small room reverb added to all tracks will hep smooth over the overall finish and bring all the tracks into a sense of unified space.

After auditioning several reverb settings for the Neo-Nostalgics track, I decided on a lively, bright, medium sized room, to give the overall mix a live jazz club feeling. The reverb turned out brighter and more active than I usually choose for a mix, but in this case, such a decision seemed appropriate for the feel and style of the music. The vocals have a different reverb plugin with a slight stereo delay effect, but I added a tiny amount of the original room reverb to to the vocal to soften the edges and place the vox in the same "room" as everything else. Overall, the room reverb is most apparent on the snare and the guitar, and the vocals now have a shimmer they didn't before, but the cumulative effect is still subtle:



Check back soon for a compilation of links to the most useful free VST reverb plugins available on the web. While you'll get better, more natural sounding results from the higher-end and more pricey plugins, there's still a lot of quality reverb plugins for free that will still do your recordings justice.