How to Bi-Wire and Bi-Amp Stereo Speakers

This article explains how to get a little extra performance from your audio hardware by bi-wiring and bi-amplifying stereo speakers. Small increments can surely add up, often transforming a great system into an excellent one.

How to Bi-Wire

1. Check for the correct terminals, because not every speaker can be bi-wired.

   A speaker must have separate terminals (two pairs of binding posts) for the woofer and midrange/tweeter. They're sometimes marked by the designation "high" and "low." Other times, they're not marked at all.

   If you're unsure, it's recommended to reference the owner's manual for further information before attempting to bi-wire any speakers.

2. Remove the shorting bar.

   If you've been using your speakers normally (single wire), you might have noticed the little accessories that connect the positive and negative terminals. Once you take these out, the speakers are ready for bi-wiring.

   Be sure to remove these accessories first before connecting the speaker wires to prevent possible damage to the speakers or amplifiers.

3. Connect the wires by plugging in each pair of cables from the amplifier/receiver to the terminals on the speakers. Since the cables are identical, it doesn't matter which wire pair goes to which crossover side. If you happen to be using banana plugs, make sure that the connectors allow you to attach a wire from the side, else you'll be left with ends going nowhere.

Bi-Wire Details

There are some potential benefits to bi-wiring, although it's not guaranteed due to the subjectivity of sound. However, before you start, you'll have to make sure the option even exists. 

Many newer, often high-end, speakers offer a bi-wiring/-amplifying connection. These models feature two pairs of binding posts on the back of each. So, bi-wiring involves connecting two lengths of speaker wire to each speaker — one going to the woofer section and the other to the midrange/tweeter section.

Bi-wiring a speaker can be a relatively inexpensive way to improve overall sound quality. Ideally, one would run two identical lengths (and type and gauge) of two-conductor wire to each speaker. One wire handles the tweeter and the other the woofer for each speaker. Sets of bi-wire speaker cables can be purchased and used to the same effect.

What bi-wiring can do is reduce the negative effects of the impedance differences between high and low frequencies traveling through a single wire. Bi-wiring speakers with separate wires can also help reduce interaction between the two signals, thereby improving overall sound quality.

How to Bi-Amplify

1. Connect the high frequency first.

   Assuming that you've already bi-wired your speakers, disconnect the ends of cable that are plugged into the source. Connect these to the amplifier designated to handle all of the high frequencies.

2. Connect the low frequency.

   Now repeat the above step, but with the cables and amplifier assigned to handle the low frequencies.

3. Choose passive or active bi-amplifying. If you're going with passive bi-amplifying, connect both amplifiers to the source output. If active bi-amplifying is your goal, the two amplifiers will first connect to an active crossover unit; then, plug the active crossover into the source output.

Bi-Amplify Details

If you really want to go the extra mile, bi-amplifying speakers can offer another level of customization and control over sound quality. However, this can end up being a more expensive option since it often involves having to purchase separate amplifiers.

Some multi-channel receivers feature multiple amplification channels, thereby eliminating the need for buying new equipment. However, the benefit of bi-amplifying speakers is that it allows the system to further isolate the frequency signals with separate amplification channels. This way, specific demands can be met without having to overwork the hardware and possibly lead to increased distortion.

For more appreciable results, some recommended the use of an active crossover setup rather than the passive crossover built into the speakers. The former method splits the signal into high and low frequencies before feeding them into separate amplifiers that lead to the speakers, while the latter sends the full-range signal to the amplifiers first, which then forces the speakers to use internal filters to block the appropriate frequencies.

One drawback to bi-amplifying (other than the added cost of amplifiers, crossover, and cables) is an increase of cable connections and system complexity.