Tascam owner manual Output Connections, Connection and Installation, TASCAM PA-30

Connection and Installation

Output Connections

Each channel of the PA-30 will drive a minimum load impedance of 8 ohms. Connecting a load of lower impedance will result in current limiting and may trigger the Protection circuits to shut down the amplifier.

Figure 7 shows a normal stereo-mode connection of two individual speakers to the PA-30 outputs. When making loudspeaker connections, always be sure to maintain correct polarity; if you wire the speakers out of phase with one another, you will get acoustical phase cancellations.

There are two basic methods for connecting multiple speakers to a single amplifier output: series connection and parallel connection. Loudspeakers connected in series present a higher net impedance than any single unit alone. Parallel connection, by contrast, lowers the net load impedance. Sometimes, the two methods are

combined to obtain an optimum load impedance. Figure 8 shows what happens to the net load impedance when multiple loudspeakers are connected in various ways. (In all cases, it is assumed that all speakers in a given system have the same impedance.)

Generally, only parallel connection is used in professional audio, for two fundamental reasons. First, if one of the speakers in a parallel system fails, the others will still function. (Remember those old Christmas lights that all went out the minute one bulb failed? They were connected in series.) Second, parallel connection results in a lower net impedance. The closer the load impedance gets to the allowable minimum for the amplifier, the more efficiently is the amplifier's power capability used, since the lower load impedance draws more current from the output stage.

120V

Figure 7. Typical Stereo Output Connection

Each Unit	Two In Series	Three In Series	Four In Series
4 OHMS	8 OHMS	12 OHMS	16 OHMS
8 OHMS	16 OHMS	24 OHMS	32 OHMS
16 OHMS	32 OHMS	48 OHMS	64 OHMS

Each Unit	Two In Parallel		Three In Parallel	Four In Parallel	Four In Series/Parallel
4 OHMS		(2 OHMS)	(1.33 OHMS)	(1 OHM)	(4 OHMS)
8 OHMS		(4 OHMS)	(2.66 OHMS)	(2 OHMS)	8 OHMS
16 OHMS		8 OHMS	(5.33 OHMS)	(4 OHMS)	16 OHMS

Note: Impedances shown in brackets are too low for the amplifier. Do not use three loudspeaker configurations.

Figure 8. Connecting Multiple Loudspeakers

8 TASCAM PA-30