Meyer Sound MM-4CEU LINE LEVEL OUTPUTS, SPEAkERSENSE INPUTS, mm-4CEU/mm-4 CONNECTION DIAGRAm

CHAPTER 2

NOTE: Most source equipment is safe for

driving loads no smaller than 10 times the

source’s output impedance.

For source equipment with driving capability of 600 ohms,

16 MM-4CEUs could be safely driven in parallel (10 kOhms

divided by 16 equals 625).

CAUTION: Shorting any input connector pin

to the chassis can create a ground loop and

cause hum.

TIP: If abnormal noise (hum, hiss, popping) is

produced from the loudspeaker, disconnect

the audio source from the MM-4CEU. If the noise

stops, the problem is not with the MM-4CEU; check

the audio input and AC power.

LINE LEVEL OUTPUTS

The MM-4CEU features push-pull outputs capable of

driving 600 ohms and using three-pin XLR male connectors

wired as follows:

Pin 1 — Earth ground/chassis

Pin 2 — Signal +

Pin 3 — Signal -

NOTE: The MM-4CEU is a balanced pass-

through device (balanced signal in - balanced

signal out) and therefore has no effect on the

polarity of the signal it receives. Ampliﬁer XLR

polarity, along with its output wiring, will determine

the polarity of the entire system.

Use standard audio cables with XLR connectors for

driving balanced signal inputs. Telescopic grounding (pin

1 disconnected on one end) is not recommended. Each

MM-4CEU output can drive multiple power ampliﬁer

signal inputs in parallel, to a minimum load impedance of

600 ohms. Refer to your power ampliﬁer speciﬁcations

to determine input impedance and calculate the net

impedance of multiple paralleled ampliﬁer inputs. For

example, one channel of a MM-4CEU could drive 20

ampliﬁer channels with 12 kOhms input impedance (600

ohms total impedance).

SPEAkERSENSE INPUTS

For each MM-4CEU channel, connect a cable from the

ampliﬁer output to the corresponding SpeakerSense

input. If you are driving multiple ampliﬁer channels from a

single MM-4CEU output and using MultiSense, connect

the two ampliﬁer output channels with the highest gain

(not to exceed 30 dB of ampliﬁcation gain) to a separate,

corresponding SpeakerSense input.

CAUTION: When using MultiSense, make

sure the two ampliﬁer channels with the

highest gains are the ones connected to each of the

MM-4CEU's two SpeakerSense inputs.

CAUTION: When using MultiSense, both

ampliﬁer outputs MUST be connected with

the same polarity. Observe the polarity labels on the

MM-4CEU rear panel.

mm-4CEU/mm-4 CONNECTION DIAGRAm

Figure 2.2 on the following page illustrates a typical

MM-4CEU connection using four 2-channel ampliﬁers and

32 MM-4 loudspeakers.