Speaker wiring

When wiring up your speakers it is important to "balance the impedance". This is effectively the resistance presented to your amplifier. Too much resistance and the amp will have to work harder for the same sound level (or you need a bigger amp); too little and the amp can overheat.

Speaker cable also has an inherent impedance. In order to avoid it becoming significant in the system a rule of thumb is that it should not exceed 10% of the speaker impedance. This is the basis of the run of cable figures shown for each type cable. For more information click here cable impedance

To achieve the speaker balance you need to combine the speakers in the most effective way. The chart shown above is a good guideline for speakers of 8 Ohms being driven by an amplifier rated at 8 Ohms with a minimum of 2 Ohms. This may apply for many systems but some amplifiers are rated at a higher minimum, and some speakers are rated at 4 Ohms, so care is needed.

In these layouts (which show just one channel ie left or right)

• Figure 1 shows a single speaker wired with correct polarity
  (wiring + to + and - to -)
• Figures 2 shows two speakers in parallel
  (the wiring is + to + to + and - to - to -)
  This is often done by wiring each speaker back to the amp itself rather than the "daisy chain" shown here.
• Figure 3 shows three speakers in parallel
  (wiring + to + to + to +, and - to - to - to -)
• Figure 4 shows two groups of two speakers.
  The two groups are in series; (wiring - to + in between the speakers)
  the two speakers in each group are wired in series as in (2)

In order to help work out the impedance resulting from alternatives, we offer an Excel speadsheet (19Kb) to assist in the calculation: click here (4KB ZIP file)
Please make sure that you understand when you design the wiring. We accept no responsibility for blown amplifiers. If in doubt, please ask!