Reverb is one of the things that can make or break a mix. Too much and it will either sound like it's from the eighties or just plain too cluttered to be able to hear correctly. Too little and you feel like every instrument is attacking you at once.
Every few weeks, we revisit some of our reader's favorite posts from throughout the history of the site. This tutorial was first published in July of 2010.
Reverb is used to create space in a mix, realistic or thematic, and a different use of reverb can give the same song a completely different character. Give two mixers the same mix and only allow them to change all the reverbs. Chances are those mixes are going to come out very different from one another.
In the following Basix tutorial I'll go into the different parameters, reverb modes and use of reverb. With the use of audio examples to demonstrate what I'm getting at, it's my hope that I can clear some doubts that you have surrounding it.
Typical Reverb Parameters
In every reverb engine we have some of the same parameters to fiddle with. The more basic reverb plug-ins only have one or two parameters but some of the more advanced ones have almost unlimited capabilities for customization. Let's look at some of the typical parameters we usually see in a reverb.
Room Size/Type – You can usually choose how big you want your reverb to be. This can be either selected as pre-determined reverb modes(more about reverb modes below) or just the size of the reverb in seconds. A 0.5 second reverb sounds much shorter and smaller than a longer lush 3.3 second one.
Pre-delay – You can use pre-delay to distance the reverb from the source sound. Think of pre-delay like the distance to the walls. By adding more pre-delay you are pushing the walls back allowing more time between the source sound and the reverb. This can be good when you have a big ballad with lots of reverb on the vocal but you don't want to drown out the phrases of the singers with too much reverb.
Early Reflections – Early reflections are all the combined reflections that happen after the original source signal. Theoretically, since these early reflections are the first reflections that bounce back from the nearest walls of our imaginary space our ears can pretty accurately gauge how large a room is supposed to be. If the early reflections are nearly instantaneous we are in a small room, but if the reflections don't bounce back as quickly we can determine that we are in a larger space.
Damping - Most rooms have all sorts of things that absorb higher frequencies. The carpet on the floor, the couch in the middle of the room as well as any blankets and clothes you have lying around. By using the damping factor on a reverb you are essentially determining how much high frequency energy is absorbed. Some reverbs have damping parameters for both high and low frequencies, and it works very similar to EQ.
Density – How dense do you want your reverbs to be? The more dense a reverb is, the more the reflections continue to reflect and pack together, creating a thicker sound. The lower the density, the more space between each reflections, creating something that's more similar to distinct echoes instead of a natural reverb.
Diffusion – Diffusion determines the rate at which the reflections scatter and die down. A diffuse space is usually a controlled live space, with reflections that don't pack together but rather disperse and die down.
Frequency Filters – Most high quality reverbs have dedicated EQ controls on them, but some reverb engines just have frequency filters that allow you to filter out either unwanted high or low frequencies. This can be good if there is too much low bass in your reverb cluttering up the mix, or if there is too much high energy hiss annoying you.
Wet/Dry Mix – Reverb are time based effects and therefore should almost always be used as a send effect rather than an insert. By using them as a send you can treat the reverb separately from the original source, allowing you more control over your source and reverb signals. If send effects confuse you, take a look at Joel Falconer's tutorial on them here.
The Different Reverb Modes
The spaces around you all sound different. The spacious reverb you get by walking into a European Cathedral is not the same as you would get from walking into your living room.
Spaces interact with each other, sounding bigger and bigger as there is more of it. Audio engineers know how the different spaces sound and what we can accomplish musically by choosing the right space to give to our songs. The different spaces we can choose from in our productions are called room modes. Reverb modes are basically categories of different spaces that have a distinct character and sound.
I'm going to be using a drum beat as an example of the various reverb modes, so before we put different reverbs on it, listen to it dry below.
I'm adding the reverb to all of the drum tracks equally for demonstration purposes. Usually, we don't necessarily need to add reverb to everything. Maybe putting a little reverb on the over-head microphone tracks is enough to give a drum-kit its space, but for the sake of listening we'll be putting the whole drum-kit into the reverb.
- Room – Rooms evoke feelings of smallish spaces with low ceilings. It can sound like a bathroom (everybody sounds great singing in the shower right?) or a small studio room. The sound a room makes is not as lush or big as a hall, but it does have its character and uses when you need to give an instrument a little space and depth.
In the audio sample below I've added a realistic 0.7 second room sound to our drum track. Listen to how we've put the drums into its own space now.
- Hall – Hall reverbs are big and plentiful. You can add small halls to things, but it's not unusual to use hall reverbs to add lush big reverbs to vocals, big drum-kits and other things you want to make sound like it's being played in a big hall. Small halls still sound bigger than small rooms, and they have a more reflective quality than a room.
Here is the same drum-beat played with a 2.4 second Hall reverb. The space sounds much bigger, and also more reflective than the room sound.
- Chamber – Chambers were the first kind of real reverb that was created in the studios back in the old days. By playing the music through speakers down in reflective chambers that had a microphone that picked up the music with the reflections of these echo chambers the first natural reverb devices were born. Chambers can sound big but usually do not have many early reflections, giving the sound more space without audible reflections.
Here is a chamber sound. If you go back to the room sound you can hear the similarities and differences in the sound. You can hear a similar space surrounding the drum kit, but the chamber doesn't have the immediate slap reflection that the room sound has.
- Plate – Plates are mechanical reverbs and aren't really an emulation of any specific space. Plate reverbs are big electro-mechanical plates that vibrate with the music, with pickups picking up the reverb vibrations that the plate is giving off. Typically, since a metal plate reverb vibrates pretty fast, the sound is full of early reflections and high density.
Plates are popular for drums, especially snares. This audio sample below has a drum plate of 0.7 seconds and it thickens up the sound of the drum-kit and gives it considerable space without adding a long reverb trail.
- Spring – Spring reverbs are the mainstay of the 60's Surf music. I wrote a little bit about the surf guitar sound of the 60s in my last Premium tutorial, but spring reverb is typical reverb every guitar amplifier has. Sound is sent through springs which reverberate and create that boingy, springy sound. Spring reverb is mostly used on guitars but don't be afraid to experiment and see if you can pair your spring reverb with something else entirely.
- Impulse Responses – Impulse Responses (IRs) are like sound pictures of a room. You can take audio snap-shots of famous studio rooms, your own basement or your dining hall and use it in your productions. There are some reverb engines that only work with pre-loaded IRs (Logic's Space Designer, Altiverb) and they come fully stocked with great sounding rooms, halls, plates and every other room mode you would ever want. Also, just by doing a quick Google search you can find people that have taken IRs of everything they can think of. From the pipes in their sink to the space inside their mouth, you can accomplish some pretty weird reverb sounds using warped and alternative impulse responses.
Using the Right Reverb
Now that we've gone over the parameters and reverb modes, you have to know which reverb will work for any given situation. A grand hall reverb might work great on slow piano pieces, or soulful guitar solos, but it might not work that great with heavily distorted rhythm guitars. It doesn't take a lot of experience to instinctively know which reverb mode or reverb time to use, but once you get the hang of how each reverb usually sounds and what works for each instrument you can work faster and more efficiently on your projects.
Let's see how a medium hall setting sounds like on two different guitar parts. The first one is a clean chordal part, that's slow enough to make the reverb shine, but the second one is a rock riff that becomes undefined and muddy once we put the same reverb on it.
Clean chordal part:
Sweet and soulful.
Placing Instruments Into a Room
Say we have a song that we want to sound like it was recorded live, with all the instrument together in the room. All the instrument were tracked (recorded) separately in different studios, but they were all fairly dry sounding, meaning we can add any reverb we want to them. By choosing one nice sounding room or hall we can place the instruments together in that room and make them sound like they are all jamming inside a sweet sounding studio room.
A good way to do this is to actually solo the reverb by itself and place each element into the room with sends. By sending each instrument separately you can place them closer or farther away in the room you have created. There is less of the drums sent into the room since I want them to be in the background. The bass is a little louder than the drums but the guitars are more dominant than the bass. Finally, the lead instrument, the accordion has the most amount sent to the reverb.
Essentially, what we are creating here is the illusion of all these instruments playing together in the room. So by placing them with sends as you would preferably hear them together in the room makes them glue together better in the final mix. You can change sounds of the original instruments all you want, but now you've established a setting in which these instruments are playing.
Listen to the soloed reverb here. This is only the instrument in the room without the original sounds. It sounds like something you would be hearing coming from a room far away.
Taking Out Unwanted Reverb
EQing reverbs is an age old trick. Since you send your source sound to a specific reverb track you can modify and change your reverb sound as much as you want. The most common use is to put EQ in front of the reverb device and EQ out everything you don't want, or accent a specific frequency that you want to jump out. The most common use is to filter out either highs, lows or both frequency ranges so that a reverb sits better with an instrument.
Here is a drum track that has an overall reverb sound. The low end is a bit much so I've decided to filter out all the low end frequencies to about 500 Hz. That way the kick drum and low end of the drum kit doesn't sound as cluttered but we still end up with a spacious drum sound.
Too much low end reverb:
Low end filtered away:
You can do this to any instrument obviously, and one trick I learned from one of Bobby Owsinski's blog posts about reverb is to high- and low-pass filter instruments to achieve that Abbey Road sound. In this next piano part I've rolled off everything below 500 Hz as well as everything above 10 Khz. It give the piano part a much punchier sound. It has reverb but it doesn't have any muddiness or ringing high frequencies to clutter it up.
Piano without EQ:
A tighter piano sound with EQ:
Just a Little Bit of 'Verb
If you want a punchy rock mix and don't want to touch into glam rock dimension you should be sparse on the reverb. Making things sound dry doesn't necessarily mean you can't use reverb. You just have to use it sparingly with short reverb times, and have them low in the mix. A really dry sound is unnatural to listen to, so when you are mixing your next track that just needs a little reverb to push the elements into place consider these techniques.
Short reverb times – To just add some ambience to an instrument you should use short reverb times, small rooms, plates and small halls to accomplish a liveness without the bigness.
Low in the mix – Keep your reverb tracks low in the mix. Gradually add reverb until you can audibly hear it, then back off the volume a little bit. If you don't notice the reverb but notice something missing when it's muted you're on the right track.
Filter – Filter out the high frequencies if you want the reverb to blend in better. It will add ambience without high frequency reverb trails.
Here is a short vocal passage that has no reverb on the first phrase and then a small hall to add some extra ambience to it. Notice how dry the voice sounds first and then when the reverb kicks there is more life and excitement in the voice.
Mix and Match Reverbs
You can also have different reverbs on different elements of a mix. Take backing vocals for example. There is usually more reverb on backing vocals than the lead vocal, in order to push the backing vocals away from being the leading element. By using different reverbs on backing vocals you can create different contrasts that can sound pretty or in this case, kind of creepy.
Here is an example of a backing vocal mix I did recently. There are two separate reverbs being used, one 2.2 second hall and one 3.3 second hall. We have dry copies of the main vocals panned across the spectrum as well as an ethereal reverbed backing vocal chanting in the background.
Sounds kinda creepy, but that was the goal. First sample is the complete track with all the instruments and the second are the vocals only.
Reverb is a necessary ingredient in any mix, regardless if you want it to be heard or not. You can use it to add ambience, create spaces around instruments, construct specific moods or just make things sound punchier. However you use reverb, it is definitely one of the elements that you need to spend the most time with, experimenting with the different parameters, reverb modes and settings in order to familiarize yourself with how everything works and interconnects.
I hope I have shed some light of how you can use the different reverb modes and given you some inspiring examples that you can use in your mixes. Since this is a Basix tutorial I want everyone to comment with any question they have regarding the doubts they have on reverb. No question is too stupid and everybody has scratched their head at some point over the workings of this ever elusive mixing ingredient.