Cerwin-Vega P1800SX, P1500x manual Troubleshooting, Bad cable connections

			CERWIN-VEGA! PROFESSIONAL
Troubleshooting (continued)
Bad Sound Equipment		settings	∙ Check the meters on the external mixing console to ensure that the signal is
	are not set	properly	not being clipped by the mixer, if the levels from the mixer are too hot
	causing distortion		correct the gain structure of the console; first by lowering the pre-amplifier
			trim (input sensitivity), if this does not lower the signal level sufficiently then
			lower the channel fader, and if the level is still too hot then lower the master
			bus (but most likely a clipped input is the source of the distortion). It is
			important to check every active input channel on the console to ensure that
			each input trim is set correctly for each source.
			∙ If the signal sources are plugged directly into the P1500X make sure that the
			input level knobs are not turned up too high. If the signal indicator LED is
			turning RED on any channel that means the input on that channel is clipping
			and the input level needs to be lowered. It is also possible that the source
			level will need to be lowered. If distortion is still audible after lowering the
			source level and input level knob then lower the master volume knob on the
			P1500X.
			∙ Check that the audio source and/or mixer do not have excessive bass or
			treble added to the mix, overdriven EQ’s can clip causing audible distortion.
	Bad cable connections		Verify that all connections are good. Verify the connectors are clean and free of
			any residue build-up. Verify the insulation jacket on all cables has not been torn
			or crushed.
	Rattling Sounds		Be sure the rattling sounds do not come from the caster wheels (subwoofer
			only), loudspeaker stands or any furniture or fixtures located near the system.
	Bad AC mains cable		Avoid using an AC power source that is connected to a light dimmer. Use an AC
	location		filter box or use a different AC circuit.
			Avoid routing the audio signal cables along other power cables, transformers
			and signal cables to prevent interference.
	Ground loop ‘hum’		Turn all volume and input levels to the minimum setting to verify there is no
			‘hum’ coming from the connected audio equipment. If the ‘hum’ is still present,
			than remove all audio cable connections and if the ‘hum’ disappears than there
			is a potential ground loop problem. Ground lifting the signal cable (with a direct
			box or coupling transformer) is the safest way to eliminate ground loops within
			sound setups. Plug all audio equipment AC power connections into the same
			outlet which shares a common ground (make sure the outlet is capable of
			supporting the equipment to avoid overloading the circuit). Verify that the
			distance between AC power source and common ground is as short as possible.
	Equipment ‘hiss’		Use a balanced connection (instead of an unbalanced connection) to take
			advantage of the best noise rejection.
			Plug all audio equipment AC power connections into the same outlet which
			shares a common ground (make sure the outlet is capable of supporting the
			equipment to avoid overloading the circuit).

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