Meyer Sound MPS-488HP Manual Do Utilizador

13

The Limit LED turns solid yellow when its heat sink tempera-
ture reaches 65° C (145° F), indicating the unit is reaching its 
maximum heat dissipation and a reduction in SPL is recom-
mended. While the MM-10XP will continue to operate while 
the LED is yellow, the limiter threshold is lowered to a safe 
level (causing the output level to be lowered by 6 dB) to pre-
vent the subwoofer from overheating. When the temperature 
of the heat sink cools to 50°C (122°F), the LED changes 
from yellow to green and the limiter threshold returns to nor-
mal.

The Limit LED flashes red when its input signal causes the 
amplifier to overload. If the LED flashes red continuously, the 
subwoofer is severely overloaded and a reduction in the 
input level is recommended.

If the Limit LED turns solid red and 

the subwoofer continues to output audio, 

though at reduced levels, the subwoofer’s voltage 
may have dropped below 25 V DC. When these con-
ditions are encountered, operation of the subwoofer 
should cease and its power supply and cabling 
should be verified.

Each MM-10XP subwoofer draws a maximum current of 
3.31 A average and 3.45 A peak from the 48 V DC output of 
the MPS-488HP. The current draw for the MM-10XP is 
dynamic and fluctuates as operating levels change. The 
cabling between the MM-10XP and the MPS-488HP adds 
resistance and hence causes a voltage drop at the sub-
woofer. Because lower DC voltages compromise amplifier 
performance (peak SPL), and in some cases frequency 
response, cable resistance should be kept to a minimum.

For long cable runs, you can use a large 

cable gauge for DC power and a separate bal-

anced audio cable for audio.

When connecting an MM-10XP to an MPS-488HP channel 
output, you can use cable lengths of up to 150 feet with only 
1 dB of peak SPL loss using 18 AWG wire. Longer cable 
lengths are possible with heavier wire gauges (see Table 1 
and Table 2).

When connecting an MM-10XP to an 

MPS-488HP channel output, the total cable 

resistance should not exceed 2 ohms.

The maximum cable length for an MM-10XP can be calcu-
lated with the following formula:

maximum length = 2 ohms / 2 * cable resistance

For example, the maximum length of an 18 AWG cable with 
a resistance of 0.00636 is 157.2 feet (2 / 2 * 0.00636).

/ft)

12 AWG

0.0016

600 ft

14 AWG

0.00253

375 ft

16 AWG

0.00402

237 ft

18 AWG

0.00636

150 ft

20 AWG

0.01008

87 ft

/m)

2.50 mm

2

0.0052

157 m

1.50 mm

2

0.01076

87 m

1.00 mm

2

0.02087

45 m

0.75 mm

2

0.03307

27 m