Crown Audio 133472-1A manual Crown Amplifiers In-Depth, Each speaker has an impedance

14 Chapter 1: Crown Amplifiers In-Depth

Each speaker has an impedance		Parallel Impedances
rating, typically 4 or 8 ohms. Connect-
		4 Ohm Speakers	8 Ohm Speakers
ing one 8-ohm speaker to an amplifi er
channel presents an 8-ohm impedance	1 Speaker	4 Ohm	8 Ohm
to the channel.
	2 Speakers	2 Ohm	4 Ohm
If two or more speakers are wired to
	3 Speakers	1.3 Ohm	2.7 Ohm
the same channel, the net impedance
	4 Speakers	1 Ohm	2 Ohm
presented to the channel will be either

more or less than one of the speakers alone, depending on whether they were wired in series or in paral-

lel (see Figures 1.20 and 1.21).

When speakers are wired in series, the net impedance pre- sented to the amp is the sum of the individual impedances. When wired in parallel, the net impedance becomes less than the impedance of one of the speakers, as calculated with the following formula:

You can use the table in Figure 1.22 to fi nd the net impedance for many common speaker combinations.

Note: for best results, do not wire speakers of differ- ing impedances (one 4 ohm and one 8 ohm for example) together.

If two 8-ohm speakers are wired in series, they form one 16-ohm load for the amplifi er, since impedances add when speak- ers are wired in series. If, on the other hand, the same 8-ohm speakers are wired in paral- lel, they form one 4-ohm load for the amplifi er. The 4-ohm load will cause the amplifi er to produce much more power than the 16-ohm load, and much more waste heat as well.

Figure 1.22

Parallel Impedance Chart

Figure 1.23

Wire Size Nomograph.

Amplifier Application Guide