Hollywood 24CX-3, 24CX-4, 24CX-2 owner manual Excessive Noise, Hertz Hum or Buzz

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is the cause of the distortion. If none of the signal processing units in the chain is causing the distortion, then either it is present in the signal source, or there is a problem with your speaker system, amplifiers, or crossover.

If you determine that the TDM 24CX series crossover is the cause of a distortion problem, make sure that the unit is plugged into a proper power source. Read the back panel of the unit for the correct supply voltage and frequency (US models are set up for 110 VAC at 60 Hz). Using a unit designed for 220 volt operation with a 110 volt outlet can cause distortion.

One of the most common causes of distortion is improper gain staging. That means that some piece of equipment is operating at much lower than unity gain (the signal coming out of it is a lot lower than what is being fed in). Under these conditions, there is often some piece of equipment that must provide a very hot signal output to compensate. This can cause distortion in the output stages of this unit, or in input stages of the unit that it is driving.

If the unit is plugged into the correct power source, the signal feeding the unit is clean, your gain staging is normal, and you are still getting distortion, contact your vendor, or call TDM for support and/or service (see Contacting TDM).

Excessive Noise

TDM 24CX series crossovers have an excellent signal to noise ratio. If you hear excessive noise in your system, try to determine its origin systematically. Remove each piece of processing gear from the signal chain one at a time until you hear the noise go away. If none of the signal processing units is the cause of the noise, then the noise is probably present in your signal source.

If you suspect that the TDM 24CX series crossover is the cause of your noise problem, make sure the unit is plugged into the correct power source. Read the rear panel of the unit to determine the correct voltage and frequency (US models are set up for 110 VAC at 60 Hz). Using a unit designed for 220 volt operation plugged into a 110 volt outlet can cause very noisy operation of the unit.

Make sure your gain staging is correct. If some unit in your system is running at a very low gain, or if your signal source is weak, you may be running some other unit at a very high gain to compensate. Some audio equipment produces excessive noise when running at gain levels higher than unity.

If you check all of these possible causes and you still can’t resolve the problem, contact your vendor, or call TDM for support and/or service (see Contacting TDM).

60 Hertz Hum or Buzz

60 Hertz hum or buzz in a system can be extremely difficult to track down because it is usually not a problem with any one piece of equipment. It is usually caused by how the entire system is connected and grounded.

To fix a hum or buzz in a system, suspect any piece of equipment that gets a ground connection from more than one place. These problems are called “Ground Loops” and the technical explanation of why they cause problems is that there is actually a voltage difference between the

© 2003 TDM Audio, Inc.

Electronic Crossover Owner’s Manual

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Contents TDM Read Before Using Table of Contents Crossover Fundamentals IntroductionSignal Source Power Amplifier Passive Crossover Crossover Terminology Shows a typical active crossover configurationFilter Frequency Response Curve How Crossovers Work24 dB per Octave Filter Curve Three-Way Crossover Response Mounting the Unit in a Rack Using the Security CoverHooking Up the Crossover What You’ll NeedMaking Adapter Cables Basic Hook-Up Two-Way Operation 24CX-2 or 24CX-4Three-Way Operation 24CX-2 or 24CX-4 Four-Way or Five-Way Operation 24CX-4 Three-Way Operation 24CX-3Front Panel Controls Operating the CrossoverThree-Way Control Meanings Adjusting the Crossover FrequenciesChecking the Hookup Using the CD Horn BoostAdjusting the Input Levels Adjusting the Output LevelsTDM Option Cards Optional Output Limiters Troubleshooting and Support No Signal OutputDistortion Hertz Hum or Buzz Excessive NoiseContacting TDM 24CX-2, 24CX-4 Specifications