Basic Sound Training Part I Hoong Ern Ng hoongng@fas.harvard.edu This is NOT a lecture! =D
What we will cover What does doing sound mean? The Input Mixing Output model (Basic signal flow) Inputs (Microphones, Instruments, Computers, Ipods [eww], etc.) Mixers what they do & how you use them Output Amplifiers & Speakers The cables (RCA, TS, TRS, 1/4, 1/8, XLR, etc.)
What we will cover Other bits of equipment (Microphone stands, DI boxes, etc.) Setting up all the equipment Playing with the equipment (sound check & mixing) Breaking down equipment Carrying the equipment! (The best part)
Doing Sound Large venues need amplification Doing sound means not being there! (Making sure people don t notice your job) Being transparent, so that people can listen to the music without noticing anything Making sure the equipment is set up & working Let musicians play music instead of worrying about sound Balancing instruments to achieve a cohesive mix which people can enjoy
Signal Flow The path through which a [sound] signal travels from when it was created to its destination (e.g. Speaker, recording) Can go through many different components to simplify things, we group them into 3 parts: input, mixing/processing, and output stage
Input Stage Any device which outputs a sound signal as an electric signal Examples: Microphones, Guitar pickups, Keyboard/Computer output Dynamic/Condenser microphones (Shure SM57/SM58, AKG C451B, Rode NT2-A) Phantom Power (+48VDC) for condenser microphones/di boxes
Mixing/Processing Stage Multiple inputs are (pre)amplified, EQ ed, panned, processed and are mixed together in various ways before being sent to the output stage. Mixer the mystical device which does it all! Other Processing Dynamic Processing, Outboard EQ, Other Processing Dynamic Processing, Outboard EQ, Effects units, etc.
Mixers, in detail Also known as consoles Analog/Digital Specifications include # of input channels, n-band EQ, no. of aux sends/returns, busses, subgroups Yamaha MG82cx Analog Console Mackie 1604VLZ3 Analog Console Yamaha 01V96 Digital Console
Mixers, in detail Mixers have 2 parts channel strips, and a master section The channel strip (to the left) affects a signal input channel, where you can control functions like Low Cut, Trim/Gain, Aux sends, EQ, Panning, Mute/Solo, and fader levels The signal generally comes from the top and travels down through the channel strip EQ on channel strips is used to enhance input sound, i.e. to make a guitar brighter, to make a vocal less boomy, etc.
Mixers, in detail The master section (left) controls features like main mix levels, monitoring options, and metering Also used to control overall mixer settings like master Aux level sends, Subgroup assignments, etc. Master I/O (below) handles the mixers outputs
Output stage Normally refers to power amplifiers and speakers Built-in amplification (Into mixers or speakers) Can also refer to speaker processing (to split main mix into multiple parts i.e. crossovers / EQ) Yamaha Power Amplifiers Yamaha Powered Mixer JBL Powered Speaker
INPUTS Sample Signal Flow Chart Vocal 1 : SM58 : Ch1 Output EQ STAGE MONITORS Vocal 2 : SM58 : Ch2 Aux1-2 send POWER AMPS Guitar : DI : Ch3 MIXER Main L-R send Keys : DI : Ch4 (MAIN) SPEAKERS Portable Music Player : DI : Ch5-6
Sample Setup Plan (From Encounter 2008) Mackie 1604 Mixer channels and signal chain: (ch1-16 +48V Phantom) 1: Voc 1 to grp1-2/lr <-- XLR1 snake <-- Shure SM58 <-- Vocal 2: Voc 2 to grp1-2/lr <-- XLR2 snake <-- Shure SM58 <-- Vocal 3: Voc 3 to grp1-2/lr <-- XLR3 snake <-- Shure SM58 <-- Vocal 4: Voc 4 to grp1-2/lr <-- XLR4 snake <-- Shure SM58 <-- Vocal 5: Keys to grp3-4/lr <-- XLR5 snake <-- IMP2 Direct Inject <-- Keyboard 6: A.Guitar to grp3-4/lr <-- XLR6 snake <-- IMP2 Direct Inject <-- Guitar 1 7: A.Guitar to grp3-4/lr <-- XLR7 snake <-- IMP2 Direct Inject <-- Guitar 2 8: Bass.Guitar on aux5-6/lr[panr] <-- XLR8 snake <-- Countryman Type 85 Direct Inject [Parallel to amp] <-- Bass 9: E.Guitar to grp3-4/lr <-- XLR9 snake <-- Shure SM57 <-- G.Amp <-- Pedal <-- Electric Guitar 10: Sax/Vln to grp3-4/lr <-- XLR10 snake <-- SM57/58 <-- Instrument 11: Kick on aux5-6[panl]/lr(?) <-- XLR11 snake <-- SM57/58 <-- Kick Drum 12: -- Unused -- 13: Computer L <-- TRS from E-MU 1616m Out5 14: Computer R <-- TRS from E-MU 1616m Out6 15: -- Unused -- (FX-Ret?) 16: -- Unused -- (FX-Ret?) Note: Subgroups 1-4 are assigned to main mix L/R (stereo) Mackie 1604 Mixer Outputs: MainL: TRS snake TRS-Return1 --> Ch5/6(L) on Yamaha mixer/amp MainR: TRS snake TRS-Return2 --> Ch5/6(R) on Yamaha mixer/amp Aux1: Aux1 snake TRS-Return3 --> Ch1(mono) on small Mackie mixer Aux2: Aux2 snake TRS-Return4 --> Ch2(mono) on small Mackie mixer Aux3-4: Unused Aux5-6: E-MU 0404usb [to 1616m via s/pdif] In1-2 Grp1-2: E-MU 1616m In1-2 Grp3-4: E-MU 1616m In3-4 Direct1-8: -- unused -- (anyone have a ADAT 8ch TRS line level ADC?) Yamaha mixer/amp Inputs: Ch1-4,7-end -- unused -- Ch5/6: from Mackie 1604 Main L/R via snake TRS-Return1&2 Yamaha mixer/amp Outputs: SpkrL --> Left speaker [possibly parallel to 2nd left spkr] SpkrR --> Right speaker [possibly parallel to 2nd right spkr] Small Mackie mixer inputs: Ch1: from Mackie 1604 Aux1 via snake TRS-Return3 - assign to Aux1 Ch2: from Mackie 1604 Aux2 via snake TRS-Return4 - assign to Aux2 Small Mackie mixer outputs: Aux1: TRS--XLR to Event TR8 studio monitor Aux2: TRS--XLR to Event TR8 studio monitor E-MU 1616m I/O: Besides those already mentioned: MicA (Input): 50ft XLR-XLR to drum overhead L (AKG C451B) MicB (Input): 50ft XLR-XLR to drum overhead R (AKG C451B) I think that that should be most of the setup. Cables required: 13x XLR-XLR [I have 6x, AACF has about 4x, so about 4 more cables would be good] 7x 1/4" TS-TS [I have 1x, AACF has about 4x, so about 2 more cables would be good] 10x 1/4" TRS-TRS [I have 10x] 2x Speaker cable (Speakon to 1/4" TS) [AACF has these] 2x 1/4" TRS-XLR [I have these] 1x S/PDIF [I have this]
Cables The magic stuff which connects everything together. No cables = no sound Microphone cables, Instrument cables, Interconnect cables, Optical cables, Snake cables, cables, cables, and cables XLR, TS, TRS, [1/4, 1/8 ], Speakon, RCA, BNC, Toslink, MIDI
Cables XLR Connectors Used for Microphones, and also as professional interconnects Female normally output Male normally input Typically carries 1 channel of balanced audio TS/TRS Connectors TS/TRS Connectors TIP, RING, SLEEVE Comes in 1/8 or 1/4 variety (others exist) 1/4 TS normally for unbalanced signals i.e. electric guitar, bass, etc 1/8 TS not used much 1/4 TRS either single balanced signal (mixer outputs, some keyboard outputs) or dual unbalanced signal (headphones) 1/8 TRS headphones, computer output, ipod output
Cables Speakon Connectors Used for high-powered connections (e.g. speakers, power) Safer and more robust than ¼ (No shortcircuiting & contact) Twist to lock, untwist to unlock RCA/Phono Connectors Used in older devices, as well as standard consumer devices (Hi-fi receivers/amps etc) Used for video as well as audio Transmits one unbalanced signal
Cables BNC Connector rarely used in audio, but seen a lot with video, and antennas and electronics (Oscilloscopes, Signal generators, etc) Toslink Connector Not used much in live audio, but in studios (ADAT lightpipe) and homes (S/PDIF). Transmits digital data via optical wire (light). MIDI/DIN Connector Not used much in live audio (except keyboardists) seen a lot in computer music and keyboards/synthesizers And there are more cables and connector
Cables Most common cables you will see: XLR-XLR (a.k.a. Mic cable), sometimes you ll see XLRF-XLRM (the most common), XLRF-XLRF, XLRM-XLRM ¼ T(R)S-T(R)S (a.k.a. ¼ jack, guitar cable, speaker cable) RCA-RCA 1/8 TRS-2RCA (connects ipod to mixer) Speakon-¼ TS (a.k.a. speaker cable) Other cables: 1/8 TRS-2XLRM, ¼ TRS-XLRM, ¼ TRS-2TS (Insert cables)
Cables 24x4 Snake Cable The proper way to coil cables How to put/pull connectors in/out Snake cables used when mixer is far away from stage. Has sends & returns Sends: Stage inputs go into the sends on the box, and on the loose ends are plugged into the mixer Returns: Loose ends are plugged into mixer sends, and from the box go to amplifiers/monitors
Adaptors Come in a HUGE variety, used to convert one connector to another ¼ TS RCA(F) 1/4 TRS 1/8 TRS 1/4 TRS XLR(F) XLR(M) XLR(M) RCA(F) RCA(F) 1/8 TRS 2RCA(F)
Setting Up! Things to consider before even setting up: Visit the location and figure out what equipment you will need Location! Input location (stage), mixing location (typically where you can hear the mix), output location (where do the speakers go? Consider feedback, where the audience is, room size, etc.) Power outlets and extensions! No power, no sound, full stop.
Setting Up! A sample setup (This is not the hard fast rule!) Set up power Set up mixer Set up output Connect mixer to output Set up stage (Mic stands, keyboard stands, etc) Set up input cabling to mixer Connect inputs (Microphones, DI boxes) Connect power
Setting Up! Connect instruments Ensure all fader levels are set to - db (or muted/off) on all stages (in particular mixer outputs & amp volume levels) Ensure all gain/trim pots are at minimum EQs and Aux sends should be reset Power up! (In order of inputs mixer outputs) If possible, test the mixing output stage with test signals (main mix, aux sends)
Sound check! Each input needs to be checked, ONE at a time (if necessary, kick out those musicians)! How NOT to use those mics! (tap tap, blow blow) Level setting (use PFL, or input level metering to get a reading on the LEDs) slowly bring up gain until you get 0dB on the meters Assuming output stage is already turned on, unmute channel and slowly increase to desired volume. Do the same for monitor sends Repeat for all input channels
Mixing! A good mix should have balance in: Volumes (balance between instruments, vocals, bringing out as necessary) Panning (mono vs. stereo, each instrument having its own location) EQ (Each instrument having its own frequency range) Mixing is a CONTINUOUS process!! Things can change, or you may want to emphasize a particular instrument/section.
Mixing! Stage mix first, FOH (Front-of-house) mix later Stage mix limitations esp with feedback Can t achieve a good mix? Maybe everything is too loud try lowering volumes instead.
Mixing! What to do when FEeeeeDDDbacckk!!!! Identify the problem channel (usually a mic) Lower volume level (for one-time feedback maybe the musician turned the mic towards the speaker!) Can mic/speaker positions be changed to improve the situation? Are you having too many microphones for the room? Lastly, EQ (graphic) can solve the problem
Mixing! A channel disappears or doesn t work Work backwards. Outputs working? Fader turned up? Is there a signal? (Check gain pot) Check the input stage Swap the cable, channel, or input Many times, it can be caused by the guitarist forgetting to turn up his volume, or his battery running out, or a cable plugged into the wrong place, or the power not turned on, etc.
Breaking down! Power off! (In order of outputs mixer inputs) Take away those expensive instruments & microphones! Remember, many microphones can roll around! Pack up. In general, cables first (coiling practice!)