Using Effects Effectively Part 1
The Effect That Started It All: ReverbBy: Gary Allen

Most guitarists are familiar with the reverb effect to some extent or another. This is not surprising because it is built into most amplifiers on the market today. Most amplifiers incorporate a type of reverb called spring reverb. It is literally a spring in the amplifier that vibrates from the sound waves of the guitar and creates an echo in the final sound. However there are many types of reverb and many ways to create the effect other than you guitar amplifiers built in spring reverb. In this installment of “Using Effects Effectively” we will look at what reverb is and also discuss the different types of reverb and how they have evolved over the years.

What Is Reverb?
Natural reverb is made from the reflections and absorption of sound waves. Take for example the guy who stands above the Grand Canyon on yells “hello” only to hear the word hello echo back at him over and over getting quieter every time. Essentially what happens here is that the original sound is reflected back at him from surfaces in the natural environment less the sound that is absorbed by these same surfaces. The reflected sound is then again reflected off other surfaces less the absorbed sound. This continues to happen until the absorption rate becomes greater than the sound being reflected and the sound eventually goes below the level that can be heard by the human ear. This makes reverb a time based effect. By understanding this simple concept we can see why the echo gets quieter with every reflection and eventually disappears completely. The number of audible refection depends entirely on the absorption rate of the surrounding natural environment. Now that we have an understanding of what reverb is we can now look at the different types of reverb that are used in musical applications.

The Reverb Chamber
Believe it or not, some of the earliest cathedrals and concert halls incorporated designing to give the best reverberation effect possible. The engineers designed elaborate networks of reflective surfaces in conjunction with absorbing surfaces to maximize the quality of sound. Unfortunately recording studios did not own any cathedrals and concert halls. They had to find new ways to produce reverb effects. One of the earliest ways they found to get over this hurdle was to design reverb chambers.

Reverb chambers were special rooms built specifically to produce reverb effects. These were generally very large rooms. The original sound source would be directed into the room through a speaker and then microphones strategically placed around the room would pick up the reflections of sound from the environment of the room. The reflections would then be blended back into the original sound on the recording media. These expensive rooms however did not have much flexibility. The better reverb chambers would have removable panels that could be replaced with other panels of different material and absorption values. These rooms needed to be designed to strict standards or there would be no way to guarantee that they would sound good.

The Infamous Plate Reverb
Another way the studios found to create reverb was to attach a transducer to a large metal plate. A transducer is a device used to convert one type of energy to another. In musical applications a transducer converts electrical energy into sound waves or visa-versa. By attaching these transducers to a large metal plate they would create a metal plate speaker. They would then place contact pick-ups at various places on the plate that would pick up the reflections and convert them back into an audio signal that could be blended with the original signal. These metal plates could be anywhere from six to eighteen feet in diameter. While the sound of this kind of reverb was very good it did pose a few problems. The plates were susceptible to outside vibrations so they usually had to be put in a dedicated room. The only way to alter the sound of the reverb was to use plates of different sizes or metals and move the contact pick-ups around the surface.

“Reverb Chambers” and “Plate Reverb” are rarely used today. There are a few reasons for this, the least of which is the rising cost of real estate causing studios to use their space in the most efficient manner possible. Another reason is because there are so many smaller, cheaper, and more versatile options on the market today.

Spring Reverb
As you probably already figured out, “Reverb Chambers and “Plate Reverb” were not options that could even be considered for live sound applications because of their lack of portability. However reverb improved the sound of instruments and vocal so much in the studio, musicians wanted to have it as an available option for live show applications. Necessity being the mother of all inventions, the engineers started working on small more portable options for reverb. One of these inventions was “Spring Reverb”.

Spring reverb has been used for years in amplifiers and small mixing consoles. The basics of spring reverb are very similar to plate reverb on a much smaller scale. In spring reverb a transducer is attached to one end of the spring which converts the audio signal into a sound wave and sends it through the spring where another transducer converts the sound wave back into an audio signal. The vibration of the spring as the signal passes through them creates the reverb effect. The original spring reverbs suffered from a lack of quality of sound. Compared to the reverb chamber and plate reverb methods they were thin sounding. Much of the sound quality has been made up by incorporating multiple springs parallel to each other. This broadens the sound and minimizes the thinness of a single spring. The reverb can also be altered by the size, tightness of winding, and the materials the spring is made from.

Digital Reverb
Just 10-20 years ago the average home studio could not have even considered owning the effects that are available today for a very small investment. High quality reverbs were not immune to the digital arena. Now for about $250 USD you can own a unit that will give you more different styles and environments of reverb that you could ever use. A great example of one of these units would be the MidiVerb4® by Alesis. This is the unit I use for acoustic guitars, electric guitars, drums, and bass guitars. I have also used it for vocals and keyboards on occasion. It is an exceptionally versatile unit. Digital sampling gives you the ability to recreate a huge array of environments and reverbs with the push of a button or turn of a jog wheel. All this is in a one space rack mountable unit. You can choose reverbs that range from a cathedral to a closet and anywhere in between. You can also choose from various reverb chambers and different styles of plate reverbs. When it comes to reverb, now you can have it all….. all..... all..... all..... all..... all….. all….. all….. all……….


Tips For Reverb Use
As a general rule less is often more when it comes to reverb. Too much reverb can turn you sound into a muddy sounding mess and end up drowning out other instruments and vocals. Reverb is a very easy effect to learn to use. Be aware of how it is affecting your sound at all times and make small adjustments to find the sweet spot.

When you practice or play your guitar by yourself a lot of reverb may sound really good. However when you add your guitar to a mix of other instruments it will suddenly sound really muddy. Be aware that what sounds good on its own may not sound good in a band situation. Many studios record the guitar dry (without reverb and some other effects) and then add reverb to the guitar track during the mixing phase. The reasoning behind this is that it is impossible to take reverb out of a track once it is recorded. It is much easier to add it to the guitar track at a later time for best results.

Another thing you will need to consider with reverb is that every room or club you play in is going to have a different natural reverb signature. Size, shape and material used to construct the room are all factors that can change this signature. A carpeted room will have more sound absorption than a hardwood floor. A reverb setting that sounds good in one room or club may sound awful in another even though they may look similar. The best advice I can give you is to get to a gig early to set up and do a sound check. Do the sound check with the whole band so you can set the sound and effects to the proper level. Always carry a notebook with you and make notes for the level settings for that establishment. That way if you play there again your set up will be much easier.

The last thing I want to talk about that can alter your sound and affect the way your reverb is working is the crowd. The more people you end up with in a room the more sound absorption you are going to have. Of course the reverb you add to your sound will still be the same the natural reverb of the room can diminish. This will usually not pose a problem. Just remember that when you set your reverb level it is mixed with the natural reverb of the room. If your signal has a dramatic change as a result of the absorption level you may consider adding a little more to the signal. Just remember that if the crowd lessens by the end of the show you will need to dial it back again.

In the next article about “Using Effects Effectively” we will talk about another time based effect called Delay. I hope you found this article useful.

Gary Allen
gary@guitargearheads.com

Copyright © 2004 Allen & Halberg Publishing