An overview of cables used in Music Production. This is Assignment #1 for the course "Introduction to Music Production" @Coursera.

1. Studio Cables
Assignment #1
Music Production @Coursera
July 24, 2014

2. Introduction
• I am Ranjit from California, USA.
• I play synths & program music using ChucK.
• This lesson is my assignment for week 1 of
Introduction To Music Production @Coursera.
• I will provide an overview of the types & use
of cables in a music studio.
• Thanks for your time!

3. LESSON
Studio Cables

4. Guiding principles
• “When it comes to cabling, it pays to have the
right connections”
• Don’t skimp on cables & connectors
• Choose the right cable for the task.
• Know about balanced & unbalanced gear
• “Sound quality of your audio chain is only as
strong as your noisiest cable”

5. Unbalanced cables
• An unbalanced electrical signal runs along two wires
– Ground (aka Earth), a voltage reference
– Positive (aka Hot), which carries the signal
• Signal strength is defined by comparing Hot to Ground
• Susceptible to noise
– Becomes audible on cable runs > 20’
• Unbalanced lines should be kept as short as possible

6. Balanced cables
• A balanced electrical signal runs along three wires
– Ground
– Positive
– Negative (aka Cold)
• Hot & Cold wires carry same signal with opposite polarity
• Noise picked up along the cable run is common to both wires
• Receiving device inverts Cold signal
• The noise common to both wires cancels out!
• This technique is called “Common Mode Rejection”

7. Direct Box
• A Direct Box (aka DI Unit) converts an unbalanced signal to a
balanced signal
• Typically used to connect instruments with unbalanced 1/4" output
(e.g. electric guitar) to gear which requires balanced input (e.g.
mixing board)
• Often have an Unbalanced output which functions as a pass-
through e.g. to connect to a monitor

8. CABLE TYPES

9. ¼” TS
• Characteristics:
– Unbalanced
• T = Tip (Hot)
• S = Shield (Ground)
• Uses:
– Guitar to amp
– Sound card to mixing console
• Cons:
– Susceptible to noise / hum

10. ¼” TRS
• Characteristics:
– Balanced: uses 3 wires to carry signal
• T = Tip
• R = Ring (Cold)
• S = Shield
• Pros:
– Reduced noise especially for long cable runs
• Cons:
– 2x the price of Unbalanced cables

11. ¼” TS & TRS cables
1. Sleeve (Ground)
2. Ring
3. Tip
4. Insulating rings

12. XLR
• Characteristics:
– Balanced
– 3-pin connectors (like TRS) [other pinouts are also available]
• X = original name of product line
• L = Locking mechanism for more stable connections
• R = Rubber insulation
• Uses:
– Transmitting mic or balanced line-level signals
– Connecting mics to mixers
– Connecting outputs to powered speakers
• Pros:
– Reduced noise
– Design reduces signal clicks when inserted or removed
– Supplies Phantom Power e.g. to condenser mics
• Cons:
– More expensive

13. MIDI
• Before we get to the cables, let’s learn about MIDI. Wikipedia says it best:
– MIDI (Musical Instrument Digital Interface) is a technical standard that describes a protocol,
digital interface and connectors and allows a wide variety of electronic musical instruments,
computers and other related devices to connect and communicate.
– MIDI carries event messages that specify notation, pitch and velocity, control signals for
parameters such as volume, vibrato, audio panning, cues, and clock signals that set and
synchronize tempo between multiple devices.
• Characteristics
– MIDI cables are purpose-built to transmit MIDI data between MIDI devices
– 180° five-pin DIN connector
– Three pins commonly used: ground, a balanced pair of conductors that carry a +5 volt signal
– Spare pins sometimes used for Phantom Power
• Pros:
– Compactness (an entire song can be coded in a few 100 lines, i.e. in a few KB)
– Ease of modification and manipulation
– Choice of instruments

14. Other types of cables
• RCA
– Primarily used in consumer devices for audio/video.
– Usually need a gain stage to amplify from -10dB (consumer)
to +4dB (pro)
• Optical
– For transferring digital audio, these cables contain optical
fibers which carry light.
– TOSLINK (Toshiba Link) is a standardized optical fiber
connection system.
• 1/8″ TS or TRS
– Smaller form factor, used primarily for headphones
• Y Cable
– Used to split a signal into two parts or combine two signals
into one
• S/PDIF (Sony/Philips Digital Interface Format)
– Consumer format for interfacing digital audio equipment
– Implemented with both RCA & TOSLINK form factors
• FireWire (IEEE 1394)
– First developed for high-speed data transfer. Now widely
used for audio digital interfaces.
• TDIF (TASCAM Digital InterFace):
– Widely used by pros for digital transfer of more than two
tracks of audio over a single cable

15. Types of problems
• Gain mismatch
– Mixing consumer grade devices (-10dB) with pro
gear (+4dB)
• Impedance mismatch
– Causes signal reflection which can degrade quality
• Cable capacitance
– Caused by poor shielding or long runs
• Poor connections
– Cable breaks or bends => use L connectors

16. Bibliography
• Choosing Studio Cable: Tips & Techniques
• Instrument cables
• Cable Buying Guide (Sweetwater)
• Direct Box
• TOSLINK
• MIDI

17. Reflection
• I approached this assignment with some uncertainty but it
turned out to be really useful for me to reinforce my
knowledge on the specific subject of cables.
• I’m quite familiar with Powerpoint, so decided to stick with
that for now. I plan to learn more about recording/editing
for future assignments.
• I spent 3-4 hours on this, continuously cross-referencing the
lecture and various online sources.
• I wanted to add a few more slides around studio setups,
cable selection, pricing, etc. but concluded that might be
overkill 8-)
• I hope you, the reviewer, found this useful and learnt at
least one new fact about cables. Cheers!