06.06.14

Best Practice: Top Tips for Getting the Best out of Loudspeakers

AUTHOR: HiddenWires
Peter-Aylett

By Peter Aylett, Archimedia Middle East. Getting the best out of speakers is a combination of engineering and experience. This list is...

Peter AylettBy Peter Aylett, Archimedia Middle East. Getting the best out of speakers is a combination of engineering and experience. This list is by no means the complete story but it is a great place to start experimenting and learning about how to get the best out of speakers no matter what the cost or type. Use Appropriate Cables and Terminations The choice of speaker cable will affect the sound of any speaker. For installation cables (those buried in walls over long distances), it is important to follow the guidelines set out in the CEA/CEDIA-2030-A Multi-Room audio cabling standard . The standard sets out what thickness of conductor to use for combinations of cable length and speaker impedance. High-quality Hi-Fi and home cinema speakers deserve cables of a higher quality than is generally used for installation. Choose a cable appropriate to the cost of the speaker - it would be misguided to use a £500 pair of cables on a £300 pair of speakers, but those same cables might be totally appropriate for a pair of £4000 speakers. With clients, I equate speaker cables to tyres on a car - why spoil a great car with cheap tyres! Bi-Wire or Bi-Amp Many speakers are bi-wireable, meaning that a separate set of cables is used for each of the speaker drive units. Bi-wiring speakers generally improves their performance by keeping the signal for bass and treble separated during the speaker cable run. [caption id="attachment_5688" align="aligncenter" width="600"]Bi-wiring, that is, having dedicated cables for the bass and treble speaker drive units, generally improves performance. Bi-wiring, that is, having dedicated cables for the bass and treble speaker drive units, generally improves performance.[/caption] Bi-amping is the practice of using an amplifier channel for each speaker drive unit. This is different from an active speaker as the speaker is still using its internal passive crossover. [caption id="attachment_5689" align="aligncenter" width="600"]Biamping, that is, using an amplifier channel for each drive unit, further improves performance. Biamping, that is, using an amplifier channel for each drive unit, further improves performance.[/caption] Bi-amping further improves the sound quality over bi-wiring due to each amplifier channel only having to drive a single speaker driver rather than multiple drives. For both bi-wiring and bi-amping, please ensure that you remove the jumper (or bridge) from the speaker terminals before connecting the speaker cables. [caption id="attachment_5684" align="aligncenter" width="400"]If bi-wiring or bi-amping, remember to remove the jumper or bridge between the speaker terminals (image courtesy of Russ Andrews). If bi-wiring or bi-amping, remember to remove the jumper or bridge between the speaker terminals (image courtesy of Russ Andrews).[/caption] Support Speakers Correctly Speakers should be supported so that they do not wobble or rattle. If you are placing speakers on shelves or in furniture, put the speakers on some shallow cones. Using three cones rather than four will ensure that the speaker does not wobble. [caption id="attachment_5686" align="aligncenter" width="400"]Using three supports ensures that the speaker will not wobble. Using three supports ensures that the speaker will not wobble.[/caption] If speakers are floorstanding or standmounted, use either spikes for carpeted floors or hard rubber feet for wooden or tiled floors, that have been adjusted and tightened so that the speaker is stable and level. Beware of Cavities When you place a speaker inside a cavity such as a piece of furniture or wall cabinet, the cavity will resonate. To hear the effect of this, put your head in the cavity and speak - your voice will sound very different! To reduce this effect, pack the rest of the cavity with foam sheets. [caption id="attachment_5687" align="aligncenter" width="400"]Pack the cavity in which the speaker is placed, with foam sheets. Pack the cavity in which the speaker is placed, with foam sheets.[/caption] If there is lattice or fretwork in front of the speaker, try to position the speaker tweeter (and midrange if it has one) through a gap in the lattice. Box-in Speakers that have no Back-box Most in-ceiling and in-wall speakers have open backs without a back-box. These speakers will sound much better if a box is bought or constructed into which the speaker fits. This can be done before the plasterboard (drywall or gypsum) is fixed, as once the wall or ceiling is built, it will be extremely difficult. Talk to the speaker manufacturer to find out the correct volume for this box and ensure that it is both airtight, and filled with fire-resistant acoustic wadding. Depending on the building regulations in your country, this box could also act as a fire-rated barrier. The box will also help to prevent sound from leaking into adjacent rooms. [caption id="attachment_5690" align="aligncenter" width="600"]Speakers without a backbox will benefit from having one fitted. Speakers without a backbox will benefit from having one fitted.[/caption] Keep Speakers out of Corners Although there are some exceptions, as a general rule, speakers do not sound good when put in the corners of a room. Reflections from the side walls will combine with the sound from the speaker to make it sound louder, but not as clear. Similarly, putting a bookshelf speaker or centre-channel speaker directly on the floor will muffle the sound. Understand the Effect of Back Walls Those same reflections from room corners also happen from walls behind speakers. Because, however sound is more directional as frequency gets higher, the back wall tends to affect mostly low frequencies only. The closer you put a speaker to a back wall, the more bass you will get out of it. Speakers are normally designed to give a balanced sound when placed a certain distance from a wall, so check with the speaker supplier for a particular model to get a starting point. Use music with which you are familiar on a range of different systems to position the speakers so that the bass sounds balanced with the rest of the sound. Small movements can make surprisingly big differences. Some powered and active speakers have controls on them that can be adjusted to compensate for how close to room boundaries they are placed. Experiment with Toe-in Most speakers sound different when listened to off axis, that is, when you are not straight in front of the speaker. Because of this, it is often beneficial to angle the speakers into the listening position. Many in-wall speakers have steerable tweeters to accomplish the same effect. [caption id="attachment_5685" align="aligncenter" width="389"]Angle or toe-in the speakers towards the sweet spot. Angle or toe-in the speakers towards the sweet spot.[/caption] Conclusion Using great equipment is only part of the equation of getting great sound. Trust your ears, experiment and listen to the effects of all the above tips. In isolation, they all make a difference. In combination, they can elevate a system from sounding merely OK, to sounding incredible. Peter Aylett is a world-renowned speaker and lecturer in residential technology, and the Technical Director at Archimedia, a multinational high-end residential integrator in The Middle East. He is also currently Chair of CEDIA’s International Technology Council Applied Content Action Team, and a regular contributor to HiddenWires. www.hometechassoc.com You are welcome to comment on this article. See below.