Blaupunkt EMA 255 manual Application options and loudspeaker connection

EMA 255

Application options and loudspeaker connection

Stereo mode
Max power	2 x 110 W / 4 Ω	Fig. 4, 5
Mono mode
Max power	1 x 330 W / 4 Ω	Fig. 6
Stereo mode
Max power	2 x 160 W / 2 Ω	Fig. 4, 5
Stereo mode
RMS power	2 x 55 W / 4 Ω	Fig. 4, 5
Mono mode
RMS power	1 x 165 W / 4 Ω	Fig. 6
Stereo mode
RMS power	2 x 80 W / 2 Ω	Fig. 4, 5
Frequency response	10 Hz - 30,000 Hz
Signal-to-noise ratio	> 85 dB @ RMS power
Signal-to-noise ratio	> 75 dB @ 1 W / 1 kHz
Distortion factor (RMS)	< 0.08 %
Stability	2 Ω (4 Ω in bridge mode)
Input sensitivity	0.2 - 10 V
Low-pass filter
(Low Pass)	50 - 250 Hz
High-pass filter
(High Pass)	80 Hz
Bass boost	0 dB / 6 dB / 12 dB
Dimensions
W x H x D (mm)	184 x 52.5 x 183
W x H x D (")	7.25 x 2.1 x 7.2

Audio inputs (see Fig. 3)

You can select between 2 different audio inputs;

–Cinch (RCA)

–Hi level (loudspeaker connections)

Use only one of the audio inputs; otherwise, it may lead to audio interferences.

The preamplifier outputs are connected to the cinch (RCA) sockets 1via a shielded sound cable.

With control via the loudspeaker outputs, the input connec- tions of pos. 2/3are fed to the closest loudspeaker cables (front or rear) on the left and right. They are separated and connected to the input connections. The polarity of the

+or - connections must be observed. Bridge output stages (BTL) can also be connected directly without an additional adapter.

Plus / minus connection

–We recommend a minimum cross section of 6 mm2.

–Route commercially available plus cables to the battery and connect via fuse holder.

–Use cable glands for holes with sharp edges.

–Securely fasten commercially available minus cables to a noise-free earth point (chassis screw, chassis metal) (not to the minus pole of the battery).

–Scrap the contact surfaces of the earth point until they are bright and grease with graphite grease.

Integrated fuses (Fuse)

The fuses integrated in the amplifier (Fuse) protect the power amplifier and the entire electrical system in case of an error. If a replacement fuse is used, never bridge fuses or replace them with a type with higher current.

Connection examples

Connection of the voltage supply	Fig. 2
Audio inputs	Fig. 3
Loudspeaker connections	Fig. 4/5/6

+12V

Remote connection of the amplifier with switchable +12 V voltage source.

This allows the amplifier to be switched on and off using the on/off-switch of the radio device.

Level control

The Level control is used to adjust the input sensitivity of the power amplifier to the output voltage of your car sound system preamplifier output.

The adjustment range is from 0.2 V to 10 V.

If a car sound system of a third party manufacturer is con- nected, the input sensitivity must be adjusted corresponding to the manufacturer data.

A few important explanations in this context:

By turning the control clockwise, the input sensitivity of the amplifier and, therefore, also the volume increases. However, this is not a volume control; no further amplifier output can be achieved in the end position, even if it may sound like that at the beginning. The system merely increases the volume faster if the volume control of the car sound system is turned up.

Loudspeaker connections

(If the amplifier is to be jumpered, continue with the section "Bridged loudspeaker connections" at this point).

As with every audio component, the correct polarisation of amplifier and loudspeakers is of essentially importance for a good bass response. For this reason, ensure that the positive

(+)connection of the amplifier is connected with the posi- tive connection (+) of the loudspeaker; the same applies to the negative (-) connections. In addition, the left amplifier channel must be connected with the left loudspeaker and the right amplifier channel with the right loudspeaker.

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