TP-Link RX-7-248 instruction manual Function Details, Phantom Power Switch, Phase Switch

Function Details

The RX-7 is a sophisticated mixer with many functions. Details on important functions are shown below in order for you to get the best operation and performance and also to avoid mistakes in operation.

*Phantom Power Switch

The switch on the front panel of both IPM-7 and PHM-7 provides for 48V DC phantom powering for condenser microphones through the input connectors on the modules. Fig. 16 elaborates on the phantom powering circuit, and shows that balanced outputs of associated equipment should be connected to the inputs. Connection with unbalanced outputs does not

damage the RX-7, but may cause troubles like noise, etc. Accordingly, turn the switch "off"

whenever unbalanced inputs are connected.

(Fig. 16)

The Lift position on the ground lift switch cuts the phantom power even if the phantom power switch is "ON". The ground lift switch therefore must be set at "Normal" position whenever phantom power is required.

*Phase Switch

The use of more than one microphone for picking up the same program source may cause an out-of-phase condition resulting in acoustic phasing cancellations. The acoustic phasing

cancellation is particularly noticeable in the low frequencies and the low frequencies may not

be sufficiently reproduced. Accordingly, all inputs on the mixer must be in principle in the same phase. The following method is advisable for checking inputs for correct phase.

1.Place mics 1 and 2 close to the same sound source with appreciable bass, setting the phase switches at Normal positions.

2.Adjust the level of both mics, using the input level switches and trim controls on the mixer.

3.Listen to the blend of the two mics through the cue headphones.

4.Reverse the phase of mic 2 Phase switch.

5.If the bass increases, leave the switch in the Reverse position. If the bass decreases, return the switch to the Normal position.

6.Check all other mics in the same manner, comparing with mic 1.

In some cases it may be desirable to intentionally reverse the phase of certain mics for

improving the sound.

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