A speaker with four binding posts is not twice as complicated, it just separates the high and low frequency sections so they can be driven independently. For normal use you leave the metal bridge in place; for bi-wiring or bi-amping you remove it. Here is what each option means.
How to Wire Speakers with 4 Terminals: Single, Bi-Wire and Bi-Amp
Quick Answer / Summary: Speakers with 4 terminals have separate pairs for the tweeter and woofer, joined by removable metal bridges. Leave the bridges in for normal single wiring, or remove them to bi-wire or bi-amp with separate cable runs.
Why 4 Terminals Exist
A speaker with four binding posts has two pairs, usually labeled high frequency and low frequency, or just two sets of red and black. The pairs separate the tweeter crossover from the woofer crossover.
Separate high and low sections
A removable metal bridge, sometimes called a jumper, connects the two positive terminals and the two negative terminals. With the bridge in place, the speaker behaves like a normal single-input speaker.
The four terminals exist so you can remove the bridge and drive the high and low sections with separate cables, which is the basis of bi-wiring and bi-amping.
Single Wiring with the Bridge In
For a normal setup, leave the metal bridges in place and connect one pair of speaker cables to either the top or bottom pair of terminals. The bridge carries the signal to the other pair.
The normal setup
Connect the positive wire to a red terminal and the negative to the matching black terminal, exactly as you would on a two-terminal speaker.
The bridge must be tight and clean, because a loose jumper causes one driver section to drop out or sound dull. Most speakers ship with the bridges already installed.
Bi-Wiring: Two Cables, One Amp
Bi-wiring removes the bridges and runs two separate cables from the same amplifier channel, one to the high-frequency terminals and one to the low-frequency terminals.
Both cables connect to the same amplifier terminals at the source end, but they separate at the speaker, so the woofer and tweeter get dedicated wire runs.
Bi-wiring is a subtle upgrade at best and does not change the load the amplifier sees. It is most useful with long runs or when you want to use different cable types for bass and treble.
Bi-Amping: Two Amplifier Channels
Bi-amping removes the bridges and drives the high and low sections from separate amplifier channels, either two channels of the same amp or two separate amplifiers.
This genuinely increases available power and control, since each driver section gets its own amplifier. It is the real upgrade, unlike the subtler bi-wiring.
For either bi-wiring or bi-amping, remove the bridges, label the cable runs, and keep polarity consistent on all four connections, or the drivers will be out of phase.
Wiring Options for 4-Terminal Speakers
| Setup | Bridges | Cable Runs | Amplifier |
|---|---|---|---|
| Single wire | In place | One pair | One channel |
| Bi-wire | Removed | Two pairs | One channel |
| Bi-amp (two channels) | Removed | Two pairs | Two channels |
| Bi-amp (two amps) | Removed | Two pairs | Two amps |
Real-World Application Scenarios
A user leaves the metal bridges in and wires a 4-terminal floorstanding speaker with a single cable per channel; an enthusiast removes the bridges and bi-wires with dedicated bass and treble cables from the same amp; a serious listener bi-amps the speakers from two amplifier channels.
Recommended Internal Resources
- binding posts and spring clips on the gear
- series, parallel and daisy chaining
- the step-by-step hookup with polarity
See speaker wire terminals for the binding-post basics and speaker to speaker connection for wiring multiple drivers.
Frequently Asked Questions
Why does my speaker have 4 terminals?
The two pairs separate the tweeter and woofer sections, joined by removable metal bridges. It allows bi-wiring or bi-amping when you remove the bridges.
Do I need to remove the bridges to wire my speakers?
No. For normal single wiring, leave the bridges in place and connect one cable pair to either set of terminals.
What is bi-wiring a speaker?
Bi-wiring removes the bridges and runs two cables from the same amplifier channel to the high and low frequency terminals separately.
Is bi-amping better than bi-wiring?
Yes, bi-amping drives the high and low sections from separate amplifier channels, genuinely increasing power and control, while bi-wiring is a subtler change.