Effects Guide: What is Reverb?
How guitarists have embraced the reverberations of the sound world around us.
By Ken Pearsall
Reverberation as an effect is a reflection of the world around us. We hear reverb all day every day, to the point that we don’t really notice it. In fact, hearing completely dry sound with no reverb at all can be strange and uncomfortable. Though we hear reverb all the time, we don’t think of it as such unless we are in a large hall or stadium, and it’s so obvious and rich it almost sounds like an effect.
As guitarists, we take advantage of all means mechanical, analog or digital to replicate and control this acoustic wonder. Players such as Jeff Buckley and David Gilmour are known for their use of reverb to create a sense of time, space and mood to their playing.
What Is Reverb?
Reverb is created when soundwaves from any sound source reflect off surfaces in a room causing a large number of reflections to reach your ear so closely together that you can’t interpret them as individual delays. The result is magnified in larger rooms where it appears that the sound continues after the source has stopped. The larger the room, the larger the potential reverb. Why would we want to replicate this effect? To alter or exaggerate the natural reverb of whatever room we are in.
Our brains are quite good at automatically “tuning out” a good amount of this reverb, which is interpreted as background noise. This is called the “Cocktail Party Effect,” which gets its name from our ability to focus on a single conversation in a sea of chattering people.
However, we need both ears to do this. If you want to get a better sense of natural reverb in a space, you can clap your hands and listen for the decay. Then try it with one ear plugged. In the right room, there will be a noticeable increase in reverb.
These days, you can purchase any number of digital reverbs in stompboxes, rackmount units or multi-effect boards. Of course, it wasn’t always so simple. In the early days of reverb as an effect, you simply couldn’t take your favorite room with you to a gig, and some of the other ways of creating the effect just weren’t portable enough.
In the early days, the only way to use reverb was in recording. Placing microphones to capture the natural sound of the room you were in such as a large studio recording room, echo-ridden basement, or even a bathroom for a more pronounced effect.
Playing live, you were stuck adapting to where you were, and hoping for the best. David Gilmour’s guitar sound on Pink Floyd’s “Shine On You Crazy Diamond” from the live album Pulse (1995) sounds drenched in reverb, but he wasn’t using an effect. This is due to microphones placed out in the arena to capture the sound of the room. In fact, good room reverb is still the basis for most digital reverbs found in most rigs today.
One of the very first artificial means of replicating reverb was the plate reverb. This was actually a roughly 4x8-foot steel plate suspended in a frame and stretched extremely tight. A speaker driver attached to one end of the plate would make it vibrate. These vibrations would travel through the plate similarly to soundwaves through a room, and be picked up at the other end of the plate by a microphone that worked by capturing vibration instead of soundwaves in the air. This poses a problem too, because the microphone would pick up any sound around the unit. This necessitated the need to keep them in isolated rooms away from external noise. The reverb decay in this case was limited by the size and tightness of the plate. The tighter the plate, the longer the decay. Large dampers that would press against the plate to absorb the vibrations could shorten the decay.
There are a few models out there that tried to solve a few problems with the design. This usually entailed using a smaller plate size made from thinner metal, and isolating it inside a sealed dampened box. This allowed use in somewhat noisy environments and made it more portable, but the sound was different. Plate reverb is still very popular today, and the digital reverbs that model this effect are quite convincing.
It would be well-nigh impossible to transport a large plate reverb unit from gig to gig though. Thankfully, along came the spring reverb.
This type of reverb is created in a very similar way to plate reverb, but the signal is sent electrically through springs instead, and does not need speakers or microphones. It has a distinct, splashy sound all it’s own and has become synonymous with surf music due to the heavy amount used. But since spring reverb was being built into most amps of the day, almost all guitarists used it in one way or another, just at a much lower level. One of the best ways to hear this effect if your amp doesn’t already have it built in is on the song “Miserlou” by Dick Dale. You’ll immediately notice the unique character of this reverb.
Fender amps have long been heralded for their unique spring reverb sound. They have a very dense and wet character that blends beautifully with the dry signal when mixed low, and sounds absolutely cavernous when turned up. This reverb is the epitome of the guitar reverb sound we’ve heard on classic albums and modern albums alike.
Good sound never goes out of style.
Digital reverb was a huge benefit to guitar players. These are available in rack mount units, stomp boxes, and multi-effect pedals. These usually are used to emulate the classic room, hall, spring, and plate reverbs. These sound great on guitar and can be very realistic sounding, especially newer versions that use impulse response models of actual rooms (called convolution reverb).
Jeff Buckley used digital reverb to create a sense of isolation and intimacy on his classic cover of Leonard Cohen’s “Hallelujah.”
Adding Reverb to Your Rig
Reverb can be a great tool in your arsenal to help make your playing more expressive. There aren’t too many strict rules with about using effects, but there are some guidelines worth considering.
First off, reverb effects should be as close to the end of your pedal chain as possible, and in your amp’s effects loop if you have one. The reason for this is if you are using other effects, you usually would not want the reverb to be effected by them, as this will destroy the illusion of space. If you run a reverb pedal (like Fender's Marine Layer Reverb pedal) before a distortion for example, the reverb will be distorted as well, which usually sounds very harsh and ugly, with little to no note definition.
Now, take that same reverb and move it after the distortion, and you can have the sound of a huge stack in a giant room. Using a reverb in the effects loop is the best way to do it if you want to use your amp’s distortion. The effects loop is after the preamp in the signal chain, so your reverb will stay completely clean and not be effected by distortion or EQ.
Lastly, these reverbs will have a mix knob. Mix knobs allow you to blend your input signal (dry) with the reverb (wet) to control it’s volume in relation to your guitar tone. Too high, and you’ll lose clarity and definition and can sound like you’re playing in a cave. Blend just enough in to get the effect you desire without losing your playing in it. With reverb, less can often be more.
Reverb can be a guitarist’s best friend. In can fill in space between notes to thicken playing or just make you feel more comfortable in a dry room. It can also be used to simulate a large space and make your guitar huge sounding for ambient effects. But remember to experiment. Try running the effect completely wet with a long reverb time to simulate a distant string section. Doing this after a thick distortion can be used to create extremely textured and interesting beds of sound. Just be aware that however you use reverb, it should compliment the song and your playing. Don’t get lost in the wash.