OVERLOADING & UNDER LOADING : If the net resultant impedance of group / groups of loudspeakers, is say 4 ohms, and these are by mistake connected to ‘COM’  & 8 ohms tap ,it will result in overloading (partial short circuiting ) of the amplifier. The result will not only be bad quality of sound but likely damage to the amplifier. This Must Be Avoided.

EQUAL MATCHING: When the group / groups of loudspeakers having resultant impedance of 8 ohms is connected to ‘COM’ and 8 ohms, it will be equal matching. This way amplifier will work at rated efficiency & is best possible transfer of power from the amplifier to the loudspeakers.

UNDER LOADING : When the same 8 ohms Group / Groups of loudspeakers if connected between ‘COM’ & 4 ohms tap, the transfer of power to speakers will be reduced to about 100 watts. This under loading / no loss of quality of sound reproduction occurs & no damage to amplifier. Therefore the under loading Connections can be Useful Where two or Four Units are to be Connected with Powerful Amplifiers,

1 / PHASING LOUDSPEAKERS : Two or more speakers/ units are facing in the same direction and are installed in the same area, it is essential that their cones/ diaphragms act in unison. Otherwise, the sound level of one speaker will be canceling the sound level of the other. To avoid mistake, the terminals of all driver Units are marked L 1 & L 2 (For correct wiring refer to sketch of loudspeaker).

2 / HOW TO CONNECT TWO SPEAKER TO AMPLIFIER : Connecting two loudspeakers to a powerful amplifier is not recommended. However, in extreme necessity, two speakers may be connected only as illustrated and explained. The speakers can be connected in series between ‘COM’ & 4  in PH-300. In this under loading  condition PH-300, will not deliver more than 80 Watts of power output. In this case Amplifier should be operated at low volume.

Resultant Impedance  = 16 ohms x 2 units = 32 ohms

3 / HOW TO CONNECT FOUR SPEAKER TO AMPLIFIER : Four speakers are first wired in two groups of two speakers each and then the two groups are connected in parallel. Impedance of two speakers/ units  of  16  ohm. each connected in series(16x2)=32 ohms. Two such groups are when connected in parallel the resultant impedance will become 32 ohms divided by the number of groups (32 ÷ 2)=16 OHMS.

The power requirement for driving four speakers would be about 120 watts (in any case not more than 160 watts). Therefore four speakers should be connected in series / parallel as shown in the sketch. In this arrangement, the resultant impedance works out to be 16 ohms, but connecting the speakers between ‘C ’and  8 ohms will again create a condition of UNDER-LOADING ensuring that the amplifier PH-300 can only deliver about 160 watts power output.

4 / HOW TO CONNECT SIX SPEAKER TO AMPLIFIER : Impedance of two speakers / units of 16 ohms each connected in series (16 x2)=32 ohms. There such groups are when connected in parallel the resultant impedance will become 32 ohm divided by the number of group (32 ÷ 2)=10.66 ohm. These should be connected between ‘C’ and 8 ohm tap. This is also a case of ‘UNDERLOADING.

5 / HOW TO CONNECT EIGHT SPEAKER TO AMPLIFIER : Pls. see picture no. 5