Interconnect Basics Flashcards
What are the four types of audio signals?
Microphone Lvl.; Line lvl.; Instrument lvl.; Speaker lvl.
Mic Level Stand
Describes the voltage generated by a microphone when it picks up sound, typically just a few thousandths of a volt.
Line Lvl. Signal
About one volt, signal traveling from pre-amp to the amplifier.
Instrument lvl. Signal
Any lvl. put out by an instrument, commonly from an electric guitar or bass.
What is required to bring an instrument signal up to a line level?>
Preamplifier
Speaker lvl. Signal
Post amplification signals, much higher in voltage
What do speaker lvl signals require for a safe signal trasner?
Speaker Cables
Which Audio signal is the weakest?
Mic level
Where is a mic-level input typically on?
XLR connector
What are the two types of line levels?
consumer and professional
What is a typical line-level?
RCA jack; 1/4 inch jack;or 3.5mm phone jack
Impedance
The resistance of a circuit to the flow of an electrical current (AC)
Z
the abbrev. and symbol used in place of impedance
Lo Z
Low Impedance
High Z
High Impedance
Hot Lead
The wire carrying the desired signal or sound
Cold Lead
The wire carrying the desire sound/signal flipped out of phase
Braided Shield
Surrounds the hot and cold lead so no electrostatic noise enters the signal
Ohm
A unit of resistance to the flow of alternating electrical current
Output Impedacne
measures the source impedance that drives the next unit
Input Impedance
Measures the load that the unit represents to the driving source
When is a D.I. Box used?
When a nonstandard unbalanced output needs to interfere w/equipment w/the standard balanced input of the mixer
D.I. Box
Helps match impedances between different connections
Microphone Cables
Carry the audio signal to its destination either balanced or unbalanced
Unbalanced Line
Audio cable carrying an unbalanced signal using two wires: signal and ground
How long are Unbalanced Lines typically?
no longer than 20-30ft. because of RF interference
List some examples of unbalanced lines?
Guitar Cables; Keyboard Cables; Pin connectors; “Tip Sleeve Cable”; RCA connectors (DJ’s)
RCA Cable
unbalanced analog audio connection that sends stereo audio over a right channel
TS 1/4”
Most commonly used w/electric guitars, which often output to an amplifier
Balanced Line
Has a ground wire, but also carries two copies of the same incoming audio signal.
What is a balanced line often referred to as?
A “Hot” and “cold” signal
What’s the difference between the hot and cold signal?
The two signals are reversed in polarity/phase, so as they travel down the cable, they cancel each other out
List Examples of Balanced Lines
Microphone Cable; Powered Speaker Cables; Stereo Guitar Cables; “Mixer Out”; “Tip Ring Sleeve”
TRS 1/4”
(Tip Ring Sleeve) Used to send either mono(balanced) or stereo(unbalance) signals.
XLR Connector
Designed to keep you from being electrocuted. Sometimes referred to as “earth”
What’s the difference between a speaker cable and a guitar cable?
1) Speaker cable doesn’t require a braided shield
2) The 2 wires in the speaker cable are usually composed of many thin strands of copper wire and identical
What happens when a speaker cable is used for a guitar cable or vice versa?
1) Instruments are susceptible to RF interference, etc.
2) The 2 wires in the speaker cable are identical, therefore would cause an impedance problem
How to tell the difference between a speaker cable and an instrument cable?
Speaker cable- has equalized sized conductors
Instrument Cable- Has a braided shield together and a larger center conductor
What is a thicker speaker cabling recommended for?
- Long wire runs
- Higher Power Amplification
- Low Impedance Speakers(4-6 ohms)
What is a thinner speaker cabling recommended for?
- Short wire runs
- High-impedance speakers(16-18 ohms)
- cost effective
What are some connector types?
- RCA
- Dual Banana
- 1/4”
- SPEAKON
- XLR
What is a dual banana typically used for?
Connecting the amp to the speaker enclosure
What are 1/4” typically used for?
Instrument or speaker cables
What are XLR typically used for?
Mic cables and DMX lighting cables
