How to Bi-Wire Speakers

The following text provides a brief explanation as to how to bi-wire your speakers and suggests the likely benefits. High-end systems are invariably bi-wired, and many of the Hi-Fi press reviews of speaker cables use bi-wired or even bi-amped set-ups. For the “Excellent” review in Hi-Fi World’s July 2005 edition (click here for the full review), Brilliance provided 3m bi-wired Prodigy speaker cables for their consideration, (non cryogenically treated).

Bi-wiring speakers is all the rage in the hi-fi and av world at the moment. Traditionally speakers had only one pair of terminals and only needed one two-core cable per speaker. Most modern speakers are equipped with two pairs of binding posts, permitting bi-wiring if the supplied copper links are removed. If you possess the latter, you should consider installing the extra speaker cables to make the most of your system's audio performance.

The following paragraphs contain general information about how to bi-wire speakers. If you are in any doubt about how to bi-wire your speakers or about the suitability of your system for bi-wiring you should consult an audio specialist prior to changing your configuration.

The 'standard' method of wiring speakers to an amplifier is to use a single length of 2-core speaker cable, with red and black used to identify signal polarity of positive and negative respectively. Some speakers possess only one pair of binding posts whereas most modern units possess two sets of binding posts, usually linked-out using the supplied copper bars. The speaker cable is connected between the amp and the loudspeaker respecting the positive and negative terminations provided. Within each loudspeaker is a crossover - an array of simple electrical components that filter the signal directing high frequencies to the tweeter and low frequencies to the woofer(s).

To bi-wire suitably terminated speakers, the copper links are removed and an additional length of speaker cable is connected to the second pair of speaker terminals. At the amplifier, both red and both black conductors are terminated into the same binding post, (or separate binding posts if provided). Within a bi-wirable speaker, the crossover consists of two separate filter circuits, therefore in bi-wire configuration, each filter receives its own full-frequency signal from the amplifier. Each crossover filter blocks all frequencies other than those needed by the drive unit to which it is attached. As a result, each speaker cable only conducts high or low frequencies.

In a single wired system unwanted mechanical and electrical resonances appear as distortion at both sets of speaker terminals. Due to the impedance of the speaker cables these distortions will not be entirely cancelled by the amplifier. Instead, they modulate between the two crossovers, degrading sound quality. With bi-wiring this interaction is minimised as signal distortion is 'seen' at the amplifier's output where it can be more effectively cancelled. Bi-wiring therefore presents a 'cleaner' signal at both the bass and treble speaker terminals, and because the high and low frequencies have already been separated, each has a minimal effect on the other - the bass does not overpower the delicate treble.

In terms of the audible benefits of bi-wired speakers, Soundstage in 1998 said: "There should be more clarity and detail to the midrange and high frequencies. Often the bass becomes less fat in nature, becoming both a bit faster and tighter. Focus and staging should improve nicely as well. You may notice less congestion in dynamic or complex passages. In all, this is a very effective and desirable improvement and only requires the investment in a second set of speaker cables". For details of the full article see http://www.soundstage.com/synergize/synergize031998.htm

Information on our Prodigy range of single and bi-wire speaker cables can be found on our Speaker Cable page.

For more information on bi-wiring and/or bi-amping, we suggest you consider the following links (Note that Brilliance Hi-Fi is not responsible for the content of these sites):

Bowers and Wilkins Frequently Asked Questions

Naim Audio Frequently Asked Questions

The FAQ and glossary sections of the Mission web site also has information on the bi-amping and bi-wiring of loudspeakers.