One of my recording students who owns a home studio recently asked me if there was any way he could remove some of the “reverb” from recordings he had made of some classroom lectures. In his case, “reverb” meant the ambient reflections from the room in which the recordings were made, but what I’m about to describe here could be applied to recordings to which reverb effects have been added as well.
Fortunately, I had come across this situation a few years ago while I was mixing and mastering the audiobook version of a client’s autobiography.
My client had hired a voiceover artist to do the narration for the audiobook. The voiceover artist did a good job with the narration, but the recording had been made in a small, less-than-ideal space, with the mic a little too far away. So there were a lot of background reflections in the audio, making the narration sound a bit like it had been recorded in a tiled bathroom – not intimate at all. As it turned out, I was able to remove most of the room ambience and save the recording.
While completely inconceivable a few years ago, audio technology has advanced to the point where removing these background reflections after the fact is not only possible, but can also be very effective, depending on the characteristics of the original audio. There are several approaches to doing it, but I’ll cover two of the most straightforward ones here.
The first way to remove reverb or room ambience from a recording is to use a type of audio plug-in that has become quite common in recent years, generally called a transient designer (it goes by other terms, but that’s the most common). The idea behind a transient designer is that it enables you to manipulate the time immediately before and the time immediately after the arrival of a sound. Transient designers have many, many possible uses on audio tracks for producing all kinds of interesting results, but a very common use in modern mixes is with drum tracks, particularly snare drum. The transient designer allows you to finely control the duration of the ring of the snare that occurs after the initial hit of the stick on the drumhead. You can make the ring shorter than it actually was when recorded, to get a very snappy, “tight” snare sound. Conversely, you can make the ring longer than it actually was when recorded, to get a big, hollow, “roomy” snare sound. Transient designers work particularly well on single, mono tracks, where the sound you’re working with is fairly discrete, i.e., there’s not a lot of sound from other instruments “bleeding” into the track.
The same technique can be applied to the reflections coming off a room’s walls and other surfaces in a spoken-word track like a book narration or classroom lecture. Using the transient designer, you can shorten the duration of those reflections at the ends of words or phrases, so the audio sounds closer and less like it’s bouncing off the walls. You can also use this technique on an electric guitar track, where you might have used a little too much reverb on the amp when you recorded it.
Sometimes this transient designer trick is all you need, and can be very effective depending on the source material and the degree of ambient reflections. At other times, it just doesn’t give you enough control, and can even make the audio sound really weird (and unusable). Fortunately, there’s a new class of more sophisticated “reverb removal” (or “de-reverberation”) plug-ins that use a combination of audio techniques like phase cancellation in addition to transient manipulation. I happen to like this class of plug-ins because they get me the results I want much faster and with less trial and error on my part.
There are a number of transient designer plug-ins available, probably the most popular being the SPL Transient Designer (available in several native versions, as well as part of Universal Audio’s UAD series). Another example is the Transient Master from Native Instruments. My DAW of choice, Steinberg’s Cubase, comes with its own, built-in transient designer plug-in called the Envelope Shaper, as do some other DAWs like Apple’s Logic.
As for the more sophisticated “reverb removal” or “de-reverberation” versions, there are several to choose from. SPL’s version is, not surprisingly, called De-Verb. Zynaptiq makes one called Unveil. My favorite (and the one I used on that spoken-word narration project I mentioned above) is DyVision’s Reverb Remover. I like it for several reasons: it’s very effective (at least on the material I’ve used it on – your mileage may vary); it’s dead-simple to use (only 3 knobs – yay!); and it’s really well priced (only $49.37 as a no-hassle, instant download). It also has a demo version that you can try out before you buy.
The next time you need to take a little “wetness” out of a track, consider using a transient designer or reverb removal plug-in. You just might find that you’ve saved a recording that you thought was toast! 🙂
Have you used a transient designer or reverb removal plug-in before? Have another one to recommend? I’d love to hear about your experiences in the comments below.