Information and Data

Why Sound Services?

  • Qualified advice from experienced people
  • Solid warranty
  • Advice before you buy
  • Email and telephone support
  • Good stock holding with back-up from our trading partners
  • Sound Services – a specialist family business since 1987

The Difference Between Low Impedance 8Ω and 100v Line PA Sound Systems

Commercial and professional PA sound advice

Essentially low impedance 8Ω sound systems are used at home, in the car, for bands, discos and musicians and places where the loudspeakers are fairly close to the amplifiers or where high sound volumes (SPL) are required. Usually, a low impedance amplifier can have no more than two 8Ω speakers connected to each output channel – this results in a 4Ω loading to each amplifier channel. The power handling of the loudspeakers should be 50% higher that the amplifier output to avoid damage. Cable should be of a high current rating so that maximum power is delivered to the loudspeakers. If you need more loudspeakers then you will need more amplifiers

Conversely 100v line constant voltage sound systems allow the use of much longer cable runs of thinner cable around a venue or site. Many loudspeakers with integral 100v line transformers can be wired in parallel without complication as long as the basic 90% wattage rule is followed. 100v line loudspeakers are rated in wattage rather than impedance – the total wattage of all loudspeakers on an amplifier output should not exceed 90% of the amplifiers rated output. A 120w 100v line amplifier could have a 20w loudspeaker, 4 x 10w loudspeakers and 3 x 6w loudspeakers connected and still have capacity for some future expansion

Regulations, Installation Guides, Technical Data and Sound Advice

Our knowledge pages include technical know-how, PA sound system advice, 100v line advice, guidance on regulations & licenses, product literature & user manuals together with manufacturer’s guides & product information – all of which is free to use and distribute, but please credit the source

Sound Services Terms of Trading
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Useful Links to other websites
Sound Services WEEE takeback scheme

Circuits, wiring, connecting and terminology
Induction loops for the hard of hearing
Wiring and installing 100v line PA sound systems
Licenses, rules, regulations and information
Stage sound and live PA
Wireless microphones frequencies, radiomics and In Ear Monitors in the UK

Wiring and installing low impedance speakers and sound systems

Licences, Rules, Regulations and Information

Wireless microphone licenses
Recorded, broadcast and live music licenses
British Standards – BSI
IP Ratings
PAT (testing)
Noise levels and decibels

Installing 100v Line and Low Impedance PA Sound Systems

Wiring and installing 100v line PA sound systems
Circuits, wiring, connecting and terminology
Wireless mic frequencies

AVSL guide to digital audio
AVSL guide to power ratings

Wiring and installing low impedance speakers and sound systems


Stage Sound and Live PA

Circuits, wiring, connecting and terminology

Wireless Microphones, Radiomics and In-Ear Monitors

Wireless microphones frequencies, radiomics and In Ear Monitors in the UK

AVSL guide to wireless audio

Circuits, wiring, connecting and terminology

Stage Sound, Live PA and DMX Lighting

Stage sound, live PA
Wiring and installing low impedance speakers and sound system

AVSL guide to digital audio
AVSL guide to power ratings

DMX lighting
Download this handy DMX DIP switch app

Circuits, Wiring and Connecting

Circuits, wiring, connecting and terminology

User Manuals, Instruction Sheets, Circuit Diagrams and Data

Sound Services hold a large selection of instruction books, circuit diagrams, data and user manuals for Monacor, IMG Stageline, Adastra, QTX, Chord, Citronic, Eagle, NJS, SoundLab, Clever Acoustics, Toa, Carlsbro and Pulse and other leading PA sound and associated products

We are continually building our library of public address and PA sound system handbooks and manuals for current and discontinued products – please email to enquire about user manuals for discontinued and legacy products or see the website listing which will include the user manual for currently available products

PA Sound Hire

PA sound hire in North Hampshire and Surrey border area
Hire public address sound systems for your small to medium sized event in and around North East Hampshire
Please email with your requirements