Baffle: The cabinet of a speaker onto which the drivers are mounted. "Infinite" baffle speakers have no bass port.

Bass port: Also known as a "reflex port". A specially tuned hole in the speaker’s cabinet which is designed to maximize bass performance.

Bipoles and Dipoles: Used in home cinema as a rear channel, bipole and dipole speakers feature a duplication of drivers on two opposite faces of the speaker. When mounted on a wall behind the listening position, this provides an effective spread and more diffused soundstage compared with conventional "monopole" speakers. Although almost identical in operation, the speakers on one side of a dipole speaker operate out of phase to those on the other side (when the drivers on side push out, the others pull in) - whereas the drivers on both sides of a bipole speaker move in phase (in the same direction) at the same time.

Biwiring: Biwireable speakers have separate connections for bass and treble signals. This enables upgraded biamplified systems to be used to run the speakers, which gives improvements in scale, dynamics and better control over the frequency range.

Biwireable speakers also benefit on normal integrated amplifiers. To biwire speakers with such amplifiers, four core cabling is required (many of the speaker cables on this site can be bought in two or four core patterns).

Biwireable speakers can also be wired in the normal manner using two core cable, however by using the four core cabling and biwireing you will achieve the best results from your speakers. This can be done with any amplifier - special connections are not required (see diagram below).

The gains are a tighter more focused sound with greater clarity.

Crossover: The electronic circuit inside a speaker which filters the signal to the drivers.

dB: Stands for "decibel" - a measure of the speaker's efficiency. The higher the figure, the easier the speaker is to drive and the less power is required from the amplifier to achieve the same output volume. Most hifi speakers are between 86 and 92dB. Figures much lower may require more powerful or tolerant amplifiers.

Magnetic shielding: Useful if you're going to place your speakers close to a television or computer monitor. The magnetic radiation from speaker magnets can cause distortion to the picture if placed too close to your television (usually less than 40 cms). But if the driver's magnets are shielded, this will not occur.

Ohms: A measure of resistance. Speakers have an average resistance which is most commonly about 8 ohms. As a general rule, amplifiers can cope happily with speakers rated at between 4 and 8 ohms. Some less common models have resistances outside of this range. Such speakers may require more tolerant amplifiers.

Satellite speakers: A small speaker, commonly used as a rear channel in home cinema systems, or as a discrete hifi speaker - often accompanied by a subwoofer. By the very nature of their size, satellite speakers do not produce as good a bass extension as conventional designs (hence the common pairing with subwoofers).

Spikes: Floor-standing speakers commonly have spikes to sit on. This has the effect of decoupling the speaker's cabinet from the floor and reducing the bass vibrations which otherwise travel through. They also improve stereo imagery by tightening up the speakers' soundstage and prevent speaker footprints being left on carpets after long periods.

Subwoofer: A type of speaker designed specifically to produce very low frequencies only. These are used in combination with normal speakers to provide more powerful and deep bass and can be used in both hifi and home cinema systems. Dolby Digital and DTS home cinema systems make specific provision for a dedicated subwoofer channel.

Passive (non-amplified) subwoofers are available, but are usually ineffective unless built for and matched with a specific speaker model. Active (built in amplifier) subwoofers are vastly preferable as they offer independent volume and often frequency control to allow the bass to be tuned with the room and any existing speakers. With Dolby Digital and DTS systems, an active subwoofer has to be used. All our subwoofers are active!

Tweeter (HF): The treble driver of a speaker, designed to produce high frequencies.

Watts: The power handling of a speaker. A larger figure denotes a higher power handing, but this figure has no bearing on the power of the amplifier necessary to drive the speaker. For example, a speaker which can handle 100 watts can be driven by a 20 watt amplifier. What has a bigger bearing on a speaker’s ability to be driven by a given amplifier, is its efficiency (measured in dB) and impedance (measured in ohms).

If you intend to play your hifi louder, a more powerful amplifier is usually required. This is because a lower powered amplifier will run out of current and start to distort at a lower volume, compared with a more powerful design. It is this distortion from lower-powered amplifiers that most commonly leads to damaged or "blown" speakers. You can also get more volume from the same amplifier by using more efficient speakers.

Woofer (LF): The bass driver of a speaker, designed to produce low frequencies.