Home Theatre 101: Speakers

Correct speaker choice and placement can mean the difference between bass-laced home theatre glory and total disappointment. Photo / Supplied

They're one of the most important parts of a home theatre system and transform a budget system's audio output from ho-hum to astounding. Conversely Brand X dicey budget speakers can often make audio sound flat no matter what you've got them plugged into. There's also a mind-boggling choice of speaker brands and types available.

At the very minimum a home theatre setup should consist of two front speakers (which will deliver much of a movie's incidental effects), a centre speaker for actor dialog, two rear speakers for surround effects and a sub-woofer which delivers bass for realistic floor thumping explosions.

How to Choose?

Knowing what speakers do what is however only half the battle. There's a near endless array of different speaker styles, types and sizes. This said, there's also no right or wrong choices when it comes to buying speakers as long as you adhere to some basic guidelines:

# Don't mix and match: Making sure all the speakers are from one brand and offer similar audio characteristics is a no-brainer. Mismatched speakers from different manufacturers can add different colour to audio and detract or dominate, leading to a less-than-seamless surround sound home theatre experience.

# Build quality. While price can be a factor figuring quality, so can the materials used and the speaker's cabinet design. Both of these factors can make a massive difference to the amount of distortion produced by a speaker, as does the quality of the actual speaker drivers used. A well-designed speaker cabinet should feel heavy, solid and produce an inert, dull thud when tapped rather than a hollow booming sound.

# Size doesn't matter: Its the stuff of divorce lore. One spouse wants big powerful floor standing for their deep bass response whilst the other sees them as being far too big, dominating the room. Conversely more compact book shelf speakers are usually seen by one spouse as an acceptable alternative for spatially challenged lodgings whilst the other may complain they lack the solid bass output of their floor standing siblings. This conundrum is however easily remedied as most home theatre systems incorporate a dedicated bass speaker (a sub-woofer) giving acres of oonst without the need for big speakers.

# Try before you buy: Everyone has different tastes and needs. If you're a party animal, chances are you're looking for volume. If you're more of a dedicated sit-and-listen type, higher-end audiophile speakers are probably the answer. Regardless of how you intend to use your speakers, take some favourite CD's with you when speaker shopping and try them out. Some audio stores will also let you try speakers out at home on "appro" so you can get a feel for how they'll sound in your own listening environment.


Speaker specs

Deciphering brochures' specifications and making sense out of sales speak can be a real headache for speaker buyers. Here's a quick guide to the specs that matter most:

# Sensitivity is perhaps the most important, yet most overlooked, speaker spec. Speakers with a high sensitivity rating tend to provide more dynamic audio volume per watt of amplifier power put into them.

# Frequency Range refers to the audio output capability which ranges from low frequencies for bass through to higher treble frequencies. A wider frequency range will generally equate to more realistic audio. While most speakers can generate audio up to the range of human hearing (about 18kHz), sound frequencies above and below the range of human hearing can also influence audio perception, dramatically improving sound quality.

# The amount of audio power a speaker can handle is listed as Watts. Most speaker makers provide a maximum peak power wattage figure and a continuous wattage figure. Using the continuous wattage figure, go for speakers whose power handling capability is higher than the your amplifer's power output, so you'll lessen the odds of blowing speakers should you decide to give your home theatre system a real thrashing.

# Measured in Ohms, speaker impedance measures should ideally be matched to your amplifier.

How do I position my speakers?

Assuming you've bought the right speakers, making sure they're correctly positioned will make sure you get the most out of your home theatre investment.

# Big floor standers should be positioned at least 200mm from the walls and at least 700mm from side walls, depending on the type of speakers (check with the retailer when purchasing) you've bought. Smaller speakers should ideally be mounted off the floor on a stand, a wall or placed on a shelf.

# The closer speakers are to walls, the more 'boomy' they can become. This said, if speakers are too far from a wall, they can also quickly loose depth.

# A good rule of thumb is that you should be as far away from the speakers as they are apart from each other. Toeing the speakers on an inward angle so their focus converges on your listening position will help deliver an accurate and convincing soundstage.

# Height-wise, speakers should ideally be placed so their tweeters (the smaller speaker driver that produces most of the treble) is roughly at ear level when seated.

# Centre speakers tend to do the most work with movies, delivering actor dialog, and should be positioned halfway between front speakers, above or below the TV. If the centre speaker sits on top of your TV, move it forward slightly so that its front is level with or slightly in front of your TV's screen. Doing this will reduce audio being reflected off the top of your TVs cabinet..

# Rear speakers can be positioned either on a rear wall, or a side wall and should be slightly behind your listening position. Rear speakers should also be slightly above your head height.

# Make sure you use good quality speaker cable – cheap thin speaker leads can result in a lot of audio information not making it to the speakers. Good speaker wire such as monster speaker cable needn't cost the earth but will make a big difference.

Remember that these are only guidelines and that everyone's taste is different so experiment with different speakers, positions and music before deciding on how to set up your speakers.