Audio effects, we all know what they are, sort of. They are used to manipulate audio in ways that are not available with traditional playing and recording techniques. If you’re like me, and enjoy dabbling in audio production, you’re probably familiar with all the basic effects. Reverb is one of them, and probably the most easy to explain; it adds space to your audio. Delay on the other hand, is a little bit more difficult to explain. Again, if you’re like me, you want to fully understand how these effects work, so that when you go to use them you know them inside and out. Today’s article we will be discussing reverb and delay, how they work and why they work the way they do.

  

Reverb

Sound produced in an enclosed space, reflects off of surfaces and blends together, creating reverberation (reverb for short). So, basically, reverb is the reflection of sound waves from a solid surface to our ears. It is most easily identified when the sounds stops, but you continue to hear the reflections as they decrease in amplitude. Large rooms or chambers are some of the best producers of natural reverb. There are a few different types of electronic reverberation mechanisms that produce reverb artificially. There types are:

  

1.        Plate reverberators – This type of reverb uses large metal plates suspended by strings, which are in turn inside of damped cases to manufacture the effect. Transducers are used to apply a signal to the plates, and electronic pickups are then used to convert the plate’s vibrations to an electric signal.

2.        Spring reverberators – These reverberators are similar to plate reverberators, except instead of using plates, springs are used instead. Spring reverberators are often integrated in instrument amplifiers, and are considered to be the most artificial sounding reverb types.

3.        DSP reverberators – DSP reverb units use signal processing algorithms to create the reverb effect, using long delays, envelope shaping, and other processes. This type of reverb is the most widely used and the most flexible form of reverb.

4.        Chamber reverberators – This is the most “natural” form of reverb, but can also be made artificially. Chamber reverb is basically a room with solid walls, a loudspeaker at one end, and microphones at one end. The audio is played through the loudspeaker, bounced off of the walls, and then recorded by the microphones.

  

Delay

The basic delay effect records an input signal, and then plays it back after a set period of time. The first wave of delay used reel-to-reel magnetic recording systems and tape loops to produce the effect.

  

5.        Analog Delay – This was the first type of delay employed in the audio engineering field. One type of analog delay unit used magnetic tape as the recording and playback medium. Motors would guide the tape through the device, with different mechanisms modifying the effect’s parameters. The tape used in this type of delay would break down after a while, so the tape would have to be replaced from time to time to maintain fidelity of the audio. Other types of analog delay used magnetic drums, or spinning magnetic discs instead of tape as a storage medium for the audio information. The main advantage to these types was the increased durability of the storage medium.

  

6.        Digital Delay – This type of delay unit became popular in the late 1970’s. But, at the time, were only available in the form of an expensive rack mounted unit. The BOSS DD-2 changed that in 1984, as it was now available in the form of an affordable foot pedal. Digital delay works by sampling the piece of audio being processed, recording the bit to a storage buffer, and then playing back the bit of audio based on the parameters set by the person using the unit. There are many different types of digital delay units that offer different digital signal processing options, so I can’t really expound on anything in that area. But in my opinion, digital delay effects units seem to be the most powerful and flexible of the two types. Many guitar players use this effect, although some people believe that digital delay sounds a bit artificial compared to its analog counterpart.

  

This is the first part in my continuing series on audio effects. I’ll be covering some of the more standard effects first, like today’s subjects, and then move on to the more advanced effects later on. I hope that this shed some light on the subject, making your next foray into audio recording or editing a little easier and more fun.

  Jason Cole and DiskFaktory Mastering offer great professional mastering services and information regarding audio engineering and CD mastering in California. Get the professional mastering information you are seeking now by visiting http://diskfaktory-mastering.com/evaluation.htm

If you have been following my Microphones 101 series of articles, you would have read about 4 of the most important microphone types. These were: Dynamic Microphones, Condenser Microphones, Ribbon Microphones, and Carbon Microphones. This last update will cover a couple less used mic types. Laser Microphones, lavalier mics, contact microphones, and parabolic microphones. If you jumped in on this article without reading the first two, here a little re-cap of how microphones work. How microphones work – in a nut shell.

A microphone captures sound waves with a thin and flexible piece of metal known as a diaphragm. Sound waves are introduced into the microphone, vibrating the diaphragm. The vibrations are then converted by various methods into an electrical signal that is an analog of the original sound.  There are various types of microphones, today we’ll be discussing laser, lavalier, contact, and parabolic microphones. 

1. Laser Microphones

A laser microphone utilizes, well, laser technology to capture vibration and convert it into sound. The laser will be reflected off of glass or another flat and rigid surface that vibrates with the sound nearby. The laser measures the distance (very accurately) between itself and the surface it is reflecting off of, and measures the fluctuations of that surface when the sound waves from nearby vibrate said surface. This form of mic is portrayed in movies as spy equipment. But contrary to it’s portrayal, the device is very new, expensive, and not very portable. 

2. Lavalier Microphones

This type of microphone is commonly used for hands-free operation, usually clipped to a person’s lapel. They usually have their own power source and can run directly into the mixer, or may be wireless, making it ideal for television. 

3. Contact Microphones

In the world of microphones, contact mics are a little different than the rest. They are designed to pick up sound vibrations from solid objects, instead of vibrations carried through the air. This is mainly used to record low level sounds that you would not be able to pick up with a regular mic. These mics consist of a moving coil transducer, a contact plate and pin. The contact plate is placed on the object which you would like to record, the vibration is passed through the plate to the pin which passes it to the transducer. The experimental electronic music group Matmos used this on their album “A Chance to Cut is a Chance to Cure”, to record the neural activity of a crayfish. 

4. Parabolic Microphones

Parabolic microphones use a parabolic reflector to pick up and focus sound waves for a microphone receiver. It is similar in function to a satellite dish in the way that it pick up radio waves. These mics are commonly used for law enforcement surveillance. But they are not very well suited for regular recording, as their low frequency response is very poor. So this wraps up our Microphones 101 series of articles. I hope you all learned as much from these articles as I have from researching and writing them!  Jason Cole and DiskFaktory Mastering offer great professional mastering services and information regarding audio engineering and CD mastering. Get the professional mastering information you are seeking now by visiting http://diskfaktory-mastering.com/evaluation.htm