Unit 26: Live Sound System Specification Learning hours: 60 NQF level 4: BTEC Higher National H1 Description of unit This unit deals with the design and specification of sound systems for a range of performance applications. It provides the learner with a thorough grounding in the theory and practice of producing sound system designs to suit various client needs. Summary of outcomes To achieve this unit a learner must: 1 Assess sound reinforcement requirements for a range of performance circumstances 2 Interpret equipment specifications for the purposes of sound system design 3 Develop an understanding of sound system design theory 4 Produce appropriate sound system designs to a brief. 181
Content 1 Sound reinforcement requirements Indoor: eg venue size, acoustic properties, loudness requirements, feedback and potential system gain, sound field calculations, frequency response, time delay, speech legibility, critical distance, health and safety Outdoor: eg system gain requirements, inverse square law, wind, temperature, humidity, time delay, weather protection, cable runs, health and safety Acoustic measurement: eg sound pressure level, absorption, standing waves, reverberation, room response, test equipment, software analysis, room response plots Performance types: eg rock and pop music, classical music and opera, drama, dance, musical theatre, spoken word, music playback 2 Equipment specifications Amplifiers: eg frequency response, dynamic range, output power, slew rate, harmonic distortion, bridged operation, clipping effects, electrical power and amplifier gain, impedance, load, relationship between power and SPL Loudspeakers: eg power handling, frequency response, sensitivity, impedance, directional characteristics, common acoustic transducers, electromagnetic types, piezoelectric types, low frequency drivers, low frequency enclosures, high frequency drivers, high frequency horns, active and passive crossovers Microphones: eg types, frequency response, sensitivity, pick up patterns, phantom power, impedance, transient response, proximity effect, pop filters and shock mounts, lavaliere, bugs and pick-ups, shotgun, radio microphones Mixing and sound processing equipment: eg types of mixing console, inputs and outputs, microphone and line amplifiers, signal-to-noise ratio, dynamic range, distortion, nominal operating levels, impedance, monitor mixers, microphone splitters, compressors, equalisers, reverberation and delay units, feedback eliminators, control equipment 3 Design theory Acoustic theory: eg the decibel, sound level, wave propagation, diffraction of sound, loudness, effects of temperature, wind and humidity, inverse square law, loudness contours, room acoustics, standing waves, phase summation and cancellation, absorption, reverberation, critical distance Electrical theory: eg Ohm s Law, resistance, capacitance, the decibel and signal levels, units, voltage and current, signal levels and impedance, balanced and unbalanced connections, grounding, transformers, mains voltage, AC safety, power requirements, distribution System architecture: eg signal flow, system logic, bandwidth, groupings, interfacing, ground loops, types of cable, balanced versus unbalanced cabling, loudspeaker cables, multicore cables, cable losses, digital interfacing, amplifier control systems, system equalisation, loudspeaker placement, clusters, distributed systems, fills, suspension systems, trussing, zoning considerations 182
4 Sound system designs Client briefs: eg determining the needs of the client, performers needs, non-technical language, communication, main system specification, monitor systems, loudness requirements, bandwidth, system visibility, practical considerations, touring systems, site visits, health and safety, zoning considerations Budget considerations: eg budget limitations, pricing, tendering, system costing, VAT, costing time, quality, spreadsheets, consultancy fees, expenses, tax considerations Delivering the product: eg logistics, risk assessment, drawings and schedules, installation, sub-contractors, quality control, testing and commissioning 183
Outcomes and assessment criteria Outcomes 1 Assess sound reinforcement requirements for a range of performance circumstances 2 Interpret equipment specifications for the purposes of sound system design 3 Develop an understanding of sound system design theory 4 Produce appropriate sound system designs to a brief Assessment criteria for pass To achieve each outcome a learner must demonstrate the ability to: assess the sound reinforcement requirements of indoor venues assess the sound reinforcement requirements of outdoor venues understand approaches to the acoustic measurement of spaces understand the sound reinforcement requirements of a range of performance types evaluate the specifications of different amplifiers assess the capabilities of a range of loudspeaker types compare different microphone systems for live sound applications determine the suitability of various mixing and sound processing equipment develop an understanding of acoustic theory relating to live sound design develop an understanding of electrical theory relating to live sound design assess approaches to the design of appropriate sound system architecture design sound systems to a range of client briefs produce a budget for a specified sound system design assess the processes involved in delivering the product 184
Guidance Delivery Theoretical delivery for this unit can be classroom based. However, practical skills and techniques must be developed with hands-on experience and appropriate equipment. Learners should be given the opportunity to compare and evaluate sound equipment and should develop understanding through practical application. Where possible, visiting professionals or exploratory visits should provide links with the live sound industry. Learners should be encouraged to experiment and apply creativity in their work and whenever possible, appropriate documentary evidence of any extra-curricular activity should be included in their portfolio. Assessment The main evidence for this unit will be a portfolio of sound system designs for a range of appropriate performance venues and types. Projects should be planned to allow learners to develop a thorough theoretical grounding through smaller briefs, leading to more complex work as they gain knowledge and confidence. All design work should be supported by appropriate documentary evidence, which may include research notes, experiment logs or comparative evaluations of component performance. Links This unit builds upon Unit 4: Music, Health and the Law, Unit 9: Acoustics, Unit 12: Audio Electronics and Unit 25: Live Sound System Operations. It links with Unit 29: Music Electronics, Unit 43: Sound Creation and Manipulation and Unit 45: Studio and Facilities Management. Resources This unit requires that learners be exposed to a range of live performance environments and sound reinforcement equipment. It is important that learners are given the opportunity to practice and experiment with a range of sound reinforcement system components of appropriate quality. Although much of this unit is theoretical, learners must be given the opportunity to apply theoretical knowledge in a design context. Research materials available should include a range of examples of sound system design and learners should be given the opportunity to visit venues for the purposes of research and evaluation. Books and journals relating to sound system design and background theory should be available. A range of electronic test equipment and acoustical measurement hardware and software would be of benefit. 185
Support materials Textbooks Ahnert, W and Steffen, F Sound Reinforcement Engineering (Routledge, 2000) Alton Everest, F Master Handbook of Acoustics (McGraw Hill Education, 2000) Davis, G and Jones, R Sound Reinforcement Handbook (Hal Leonard Corporation, 1989) Eargle, J and Foreman, C JBL Audio Engineering for Sound Reinforcement (JBL, 2002) Hunter Stark, S Live Sound Reinforcement: A comprehensive guide to music reinforcement systems and technology (Mix Bookshelf/Mix Books, 1996) Rapaport, D (editor) Acoustic Musician s Guide to Sound Reinforcement and Live Recording (Prentice Hall, 1997) Talbot-Smith, M Audio Engineer s Reference Book (Focal Press, 2001) Talbot-Smith, M Sound Engineering Explained (Focal Press, 2001) Templeton, D (editor) Acoustics in the Built Environment (Architectural Press, 1997) Yakabusi, J Professional Sound Reinforcement Techniques: tips and tricks of a concert sound engineer (Hal Leonard, 2001) Further reading Live Sound International Magazine (www.livesoundint.com) Pro Sound News Magazine (www.prosoundeurope.com) Audiomedia Magazine (www.audiomedia.com) CD-Roms Moulton, David Golden Ears (KIQ Productions. www.kiqproductions.com) CD based ear training course. Moulton, David Total Recording (KIQ Productions. www.kiqproductions.com) 186