Learning About BPM, Microphones, Headphones, Speakers and TermsIn our second Garageband Workshop for Beginners (GWB 02) we’ll be talking about BPM, Microphones, Headphones, Speakers and Recording terms. Microphones, Headphones, Speakers and MIDI Controllers are what we refer to as “peripherals”. Peripherals are simply just hardware devices that can be attached externally to your iPad or computer. Another example of a peripheral would be a printer, keyboard, mouse or external hard drive. We’ll also be discussing some of the basic “terms” associated with music production and recording. Please keep in mind while reading the following outline, that some examples here are not suitable for the younger grade levels. These subjects will be addressed accordingly. Additionally, many of the examples I’ve set forth here are of a dual purpose in that they’re cross related with other academic areas of learning such as the sciences, English and mathematics.
1. BPM – Beats Per MinuteEveryday, there is sound all around us. Rhythm is all around us on a daily basis too and can play a large role in our lives. Sometimes you may not even be aware that they’re (beats or rhythmic sounds) around. They we hear them everyday and can easily take them for granted. Many of these rhythms fluctuate, meaning their beat is not steady whereas others have a very steady rhythm and can be easily measured. How do we measure a rhythm? Easily! With a clock! A clock goes tick, tock, tick, tock endlessly (unless we forget to change the batteries or our power goes out). We use a clock to determine how many beats per minute (BPM) that a rhythm has. Can you think of some of these rhythms? Consistent Rhythms Clock Metronone Heartbeat/Pulse Car Engine Inconsistant Rhythms Footsteps Knocking Applause Genre Related Tempos: A “genre” simply refers to the style of a particular type of music, i.e.: Rock ‘n Roll, RnB, Hip Hop, etc.. Some genres, such as Hip Hop, are very reliant on particular tempos whereas others such as Rock, Classical, and Pop are not reliant on specific tempo ranges.
- Dubstep is around 140 BPM
- House music varies between 118 and 135 BPM
- Hip Hop is around 80-115 BPM
- Trap is around 140 BPM
- Largo is 40-60 BPM
- Larghetto is 60-66 BPM
- Adagio is 66-76 BPM
- Andante is 76-108 BPM
- Moderato is 108-120 BPM
- Allegro is 120-168 BPM
- Presto is 168-200 BPM
- Prestissimo is 200+ BPM
2. HeadphonesBenefits of using headphones when recording sounds that use microphones. Sounds we use in our songs are not always created digitally. That is to say, we need to make some sounds ourselves and not rely solely on sounds that come with the recording software, i.e. Pianos, synths, drum machines etc. Instances that we’ll want to record “live” acoustical sounds would be an acoustic guitar, and electric guitar (through an electric guitar amplifier, a vocal, a real piano or any number of other acoustically originating sounds. We use headphones when we record acoustic instruments in order to isolate the particular sound that we’re trying to capture. If we didn’t use headphones, the microphone would also record the musical instruments that are being played through the speakers. When recording a live piano, or other acoustically originating sound, we must use headphones in order to prevent other unwanted sounds (the sound of music emanating from studio monitors). Headphones also provide us with the ability to hear the instruments we’ve already recorded so that we can play along with the song while recording our new instrument or vocal.
3. MicrophonesIn order to record some of these sounds we use microphones (mics). Mics are a device used for converting sound waves into electrical energy (reference to science – sound waves, what’s electrical energy? What’s this mean in kid talk?
- The definition of a microphone is something you talk into that amplifies your voice or makes it louder. An example of microphone is something a singer sings into so people in the back row can hear him.
- Our ears vibrate in a similar way to the original source of the vibration, allowing us to hear many different sounds.
- Dogs can hear sound at a higher frequency than humans, allowing them to hear noises that we can’t.
- Sound is used by many animals to detect danger, warning them of possible attacks before they happen.
- Sound can’t travel through a vacuum (an area empty of matter).
- The speed of sound is around 767 miles per hour (1,230 kilometres per hour).
- The loud noise you create by cracking a whip occurs because the tip is moving so fast it breaks the speed of sound!
- When traveling through water, sound moves around four times faster than when it travels through air.
- The scientific study of sound waves is known as acoustics.
- Although music can be hard to define, it is often described as a pleasing or meaningful arrangement of sounds.
- The sound of thunder is produced by rapidly heated air surrounding lightning which expands faster than the speed of sound.
Location of Microphone DiaphragmWhen the diaphragm vibrates, it causes other components in the microphone to vibrate. These vibrations are converted into an electrical current which becomes the audio signal. Note: At the other end of the audio chain, the loudspeaker is also a transducer – it converts the electrical energy back into acoustical energy. Types of Microphone There are a number of different types of microphone in common use. The differences can be divided into two areas: 1. The type of conversion technology they use This refers to the technical method the mic uses to convert sound into electricity. The most common technologies are dynamic, condenser, ribbon and crystal. Each has advantages and disadvantages, and each is generally more suited to certain types of application. The following pages will provide details. 2. The type of application they are designed for Some mics are designed for general use and can be used effectively in many different situations. Others are very specialized and are only really useful for their intended purpose. Characteristics to look for include directional properties, frequency response and impedance (more on these later). Science Stuff: Mic Level & Line Level The electrical current generated by a microphone is very small. Referred to as mic level, this signal is typically measured in millivolts. Before it can be used for anything serious the signal needs to be amplified, usually to line level (typically 0.5 -2V). Being a stronger and more robust signal, line level is the standard signal strength used by audio processing equipment and common domestic equipment such as CD players, tape machines, VCRs, etc. This amplification is achieved in one or more of the following ways:
- Some microphones have tiny built-in amplifiers which boost the signal to a high mic level or line level.
- The mic can be fed through a small boosting amplifier, often called a line amp.
- Sound mixers have small amplifiers in each channel. Attenuators can accommodate mics of varying levels and adjust them all to an even line level.
- The audio signal is fed to a power amplifier – a specialized amp which boosts the signal enough to be fed to loudspeakers.
5. TermsUnderstanding Some Terms Used in These Workshops There are specific terms we use associated with recording music. Understanding these terms makes it easier to communicate your ideas. During the workshops, terms will be discussed and explained thoroughly. Here are some simple examples we use: Vocals Monitors/Speakers Track Microphone Acoustics Sound Rhyming – Quantize, Synthesize, Vocalize, Harmonize Sound Wave/Waveform: MIDI: Musical Instrument Digital Interface. The MIDI standard is supported by most synthesizers, so sounds created on one synthesizer can be played and manipulated on another synthesizer. Computers that have a MIDI interface can record sounds created by a synthesizer and then manipulate the data to produce new sounds. For example, you can change the key of a composition with a single key stroke. MIDI Controller Keyboard DAW: Digital Audio Workstation. Digital Audio Workstations are software programs designed specifically for making digital recordings, i.e.: GarageBand, Logic Pro, Pro Tools, Cubase, etc.. Digital: Computers are digital machines because at their most basic level they can distinguish between just two values, 0 and 1, or off and on. There is no simple way to represent all the values in between, such as 0.25. All data that a computer processes must be encoded digitally, as a series of zeroes and ones. Analog: In general, humans experience the world analogically. Vision, for example, is an analog experience because we perceive infinitely smooth gradations of shapes and colors. The opposite of digital is analog. A typical analog device is a clock in which the hands move continuously around the face. Such a clock is capable of indicating every possible time of day. In contrast, a digital clock is capable of representing only a finite number of times (every tenth of a second, for example). Synthesizer: A sound synthesizer (often abbreviated as “synthesizer” or “synth”) is an electronic musical instrument capable of producing a wide range of sounds. Synthesizers may either imitate other instruments (“imitative synthesis”) or generate new timbres. They can be played (controlled) via a variety of different input devices (including keyboards, music sequencers and instrument controllers). Synthesizers generate electric signals (waveforms), and can finally be converted to sound through loudspeakers or headphones.
Plug-ins: Once DAW’s became the new recording standard, companies such as Waves Audio began making “Plug-ins”. Plug-ins are software based components that your DAW uses in order to achieve different results. Typical software plugins are Delays, Reverbs, Compressors, Equalizers, and even Instruments such as a piano, a synthesizer and even drums. There are four basic types of plugins: VST, AU, RTAS and MAS. The reason there are four types is because different DAW’s use different technologies when it comes to processing audio signals. Prior to using DAW’s, recording studios use “outboard gear” or hardware based processing units. These units were often very expensive, took up a considerable amount of physical space and required qualified recording engineers in order to properly insert them into the signal path via a patchbay. (More on this process later)
Finally, after discussing the articles mentioned above, we’ll move on to practical applications.See GWB 03 – Songwriting: Basic Theory, Arrangements, Lyrics GWB 04, Setting a Goal – Creating a Project