Summary of Contents for TDM-Audio 24CX-2
- Page 1 ELECTRONIC CROSSOVER OWNER’S MANUAL TDM AUDIO INC. 7270 BELLAIRE AVE. NORTH HOLLYWOOD, CA 91605 (818) 765-6200 TDMAUDIO.COM A U D I O 24CX-2 24CX-3 24CX-4...
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Page 2: Read Before Using
MPORTANT *** Read Before Using *** CAUTION: The following must be observed to prevent malfunctioning and/or possible equipment damage. • Before plugging the unit into the main AC line, make sure that all of the equipment following the crossover output lines is turned off or all of the inputs are turned down. -
Page 3: Table Of Contents
MOUNTING THE UNIT IN A RACK...10 ...10 SING THE ECURITY OVER HOOKING UP THE CROSSOVER...11 ’ ...11 ...11 AKING DAPTER ABLES ...12 ASIC (24CX-2 PERATION (24CX-2 HREE PERATION (24CX-3) ...13 HREE PERATION AY OR PERATION OPERATING THE CROSSOVER...14 ...14 RONT ANEL... -
Page 4: Introduction
Introduction hank you for purchasing the TDM 24CX series electronic crossover. These units are made from the finest components and engineered to exacting standards. Precision components are used in all critical circuitry for the finest sonic quality and performance. To get the most out of your new crossover, please take a few minutes to review this manual and familiarize yourself with the proper operation of the unit. - Page 5 Low Transducer Figure 1 - Typical Passive Crossover Configuration This kind of crossover is called a passive crossover because it does not use any power other than the power contained in the signal to accomplish its task. Passive crossovers have certain limitations that make them inappropriate for large systems, or systems requiring high fidelity at high sound pressure levels.
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Page 6: Crossover Terminology
• External Power: Passive crossovers are simply inserted between the amp and the speaker components. Active crossovers must be plugged into an electrical outlet in order to work. • Higher Typical Rolloff Rates: Passive crossovers typically roll off at rates from 6 to 12 dB per octave. -
Page 7: How Crossovers Work
result in a greater overall efficiency of the system by making sure a band of frequencies is always reproduced by the speaker components that are most efficient at reproducing it. How Crossovers Work To divide a range of frequencies into two or more smaller ranges, a crossover uses filter circuits. A filter is simply a circuit that lowers the levels of unwanted frequencies in a signal. - Page 8 To make a 2-way crossover, we feed the same signal into a high-pass filter and a low-pass filter with the same cutoff frequency. This is called the crossover frequency. The output of the high- pass filter is the high output of the crossover. The output of the low-pass filter is the low output of the crossover.
- Page 9 The crossover frequency of 1000 Hz is where the two lines on this graph cross over each other. In crossovers with three or more output bands, there are two filters for each of the middle bands. A low-pass filter rolls off frequencies above a certain cutoff point. A high-pass filter rolls off frequencies below a certain cutoff point.
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Page 10: Mounting The Unit In A Rack
If you want to use the security cover on a 24CX-2 or a 24CX-4, make sure all of your settings are correct, then install the cover. There are two holes in the face plate of the crossover—one on either end. -
Page 11: Hooking Up The Crossover
TDM 24CX series crossovers have many possible configurations. For example, if you are connecting a 24CX-2 for stereo 2-way use, you need two cables to feed your stereo signal source into the two channel inputs, and two cables for each channel (for a total of four) to feed the low and high outputs to your amplifiers. -
Page 12: The Basic Hook-Up
The 24CX-2 provides one channel for Three-way operation. The 24CX-4 provides two channels for three-way operation. In the 24CX-2 the two channels are combined to make a single three- way channel. In the 24CX-4, channels one and two are combined to make one three way channel, and channels three and four are combined to make another three-way channel. -
Page 13: Three-Way Operation (24Cx-3)
channels to link them together and form one three-way channel. This switch may be found on the rear of the unit between the channels. It is recessed into the chassis through a small, square hole, and you might need to use a small screwdriver to press it. When it is in the in position, the channels are linked. -
Page 14: Operating The Crossover
24CX-2 has only two. The 24CX-3 has two channels, each of which is set up for dedicated 3-way operation. All channels are identical, so you only need to understand how a single channel works. Here is a list of the controls for a single channel of the 24CX-2 or 24CX-4. -
Page 15: Adjusting The Crossover Frequencies
If your unit has range switches (24CX-2 or 24CX-4), make sure they are in the correct positions for the desired frequencies. -
Page 16: Checking The Hookup
Checking the Hookup It is critical that the crossover is connected and adjusted correctly before use. To avoid speaker damage, we recommend checking your hookup and settings using the following method. 1. Make sure the input level and all output levels on the crossover are down. Adjust the crossover frequencies according the recommendations of your speaker manufacturer. -
Page 17: Adjusting The Output Levels
Adjusting the Output Levels Start with the input levels at 0 dB (unity gain). After the rest of the system has been dialed in (amplifier gains and output levels), the input levels can be fine tuned. Feed a lower-than-normal level signal from your signal source into the system. You want to make sure that you set it up so you have room to spare. -
Page 18: Tdm Option Cards
TDM Option Cards he TDM 24CX series crossovers have internal connectors for option cards. A variety of different option cards is available from TDM. Plugging a card into the connector inserts the circuitry on the card between a crossover section output and the output of the unit. The most common card to use for this application is the high-pass filter card. -
Page 19: Optional Output Limiters
Optional Output Limiters he TDM 24CX series crossovers can be ordered with output limiters. These let you set the maximum level for each crossover output. Limiters are used to help protect speaker components and ears from damage by excessive levels. Levels above the preset threshold are reduced automatically by the limiter circuit. -
Page 20: Troubleshooting And Support
Troubleshooting and Support his section details various problems that you might encounter when using your crossover, and the possible causes and solutions. It also tells how to contact TDM when you need service or support for your 24CX series crossover. No Signal Output If you are getting a signal from some of the frequency bands, but one or more of them is not working, check the cables and hookups for the band(s) in question. -
Page 21: Excessive Noise
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. -
Page 22: Contacting Tdm
two different grounds. The problem is most often caused by a single piece of equipment grounded to two different power sources that are located some distance apart. For example, a mixing console is plugged into a grounded outlet at the back of an auditorium, and the power amplifiers are plugged into a different outlet 100 feet away at the stage. -
Page 23: Specifications
Maximum Voltage Gain 6 dB Constant-Directivity Correction +3 dB @ 3.5kHz rising at 6dB/octave to 22.5 kHz 24CX-2, 24CX-4 Frequency Range Hum and Noise (20 Hz-20 kHz) Av = 0 dB, fc = 800 Hz Low Frequency Section Output @ 0 dB...