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© 2003 TDM Audio, Inc. 

Electronic Crossover Owner’s Manual 

Page 16 

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. 

2. 

Turn on the amplifiers and raise their gains about halfway up (leaving the levels on the 
crossover all the way down). 

3. 

Feed a program signal such as pre-recorded music into the system. At this point you 
should hear nothing because the levels at the crossover are all the way down. Adjust the 
signal level so you are feeding about -20 dBm into the system. If you don’t have meters 
to verify this, just set the level a bit lower than normal. 

4. 

Start with the 

highest 

frequency band for a channel. Raise the output level of that band up 

about ¼ of the way.  

5. 

Slowly raise the input level of the crossover until you just begin to hear the high 
frequencies. 

6. 

Walk over to the speaker cabinets and put your ear right up to the high-frequency 
components (usually the horns) and verify that the high frequencies are coming out of 
these components. This is to make sure you haven’t accidentally plugged the high 
frequency output into the wrong amplifier input or hooked the high frequency speaker 
cable to the wrong speaker input. If you have more than one high frequency speaker 
component on the same channel, check them all. If something is not hooked up right, stop 
and fix it before continuing. 

7. 

Once you are satisfied that the high frequencies are being reproduced by the correct 
components, raise the crossover output level a little bit and listen to the sound. If you are 
inexperienced, it may take a little practice to get used to what the various frequency 
bands usually sound like. Make sure that the crossover points are correct. For example, if 
you forgot to press in the range switch, you will hear some lower frequencies that 
shouldn’t be coming from the high frequency speakers. Correct any problems before 
continuing. 

8. 

Go back to the crossover and turn the high frequency output all the way down. Bring up 
the next lowest band until you can just hear it. Repeat steps 6 and 7 for each band from 
highest to lowest. 

Using the CD Horn Boost 

If you are using constant directivity (CD) horn designs for your high frequency speakers, your 
system may require a CD horn boost. Consult your speaker manufacturer to determine if this is 
the case for your system. If you need a CD horn boost, press the CD horn boost switches 

in 

for 

the channels on which you need the boost. These switches are found on the rear of the unit next 
to the input connectors. They are recessed into the chassis so you may need a small screwdriver 
to press them. Pressing the switch 

in 

applies the correct boost to the input near which it is 

located. This should be done before setting the output levels. 

Summary of Contents for 24CX-2

Page 1: ...24CX 2 24CX 3 24CX 4 ELECTRONIC CROSSOVER OWNER S MANUAL TDM AUDIO INC 7270 BELLAIRE AVE NORTH HOLLYWOOD CA 91605 818 765 6200 TDMAUDIO COM TDM A U D I O...

Page 2: ...are turned down Never change the frequency range switch from the x10 to x1 position or vice versa with the crossover output levels passing signal Transients can result and speaker damage is possible...

Page 3: ...RATION 24CX 2 OR 24CX 4 12 THREE WAY OPERATION 24CX 2 OR 24CX 4 12 THREE WAY OPERATION 24CX 3 13 FOUR WAY OR FIVE WAY OPERATION 24CX 4 13 OPERATING THE CROSSOVER 14 FRONT PANEL CONTROLS 14 ADJUSTING T...

Page 4: ...roduce only a portion of the audible frequency spectrum A speaker system is made up of a collection of speaker components each of which can reproduce some part of the spectrum The crossover s role is...

Page 5: ...his makes them impractical for high power systems Fidelity The nature of the way passive crossovers work makes it difficult to design them with high fidelity in mind The kinds of components used in pa...

Page 6: ...f would be reproduced equally by both the low and the mid speakers Rolloff Rate A crossover s rolloff rate determines how sharp the transition between one set of speakers and another will be Higher ro...

Page 7: ...the output If you answered No you were correct In fact a signal at 999 Hz would be virtually as loud at the output of this filter as a signal at 1000 Hz Signals that are above or near the cutoff freq...

Page 8: ...over frequency Because the cutoff frequency of a filter is the point at which the output signal is 6 dB below the input signal which means that it has half of the amplitude of the input signal the cro...

Page 9: ...cies below a certain cutoff point This leaves a band of frequencies in the middle These middle bands have two different cutoff points Figure 6 shows the responses of the three bands of a three way cro...

Page 10: ...Using the Security Cover The security cover is used to prevent unwanted tweaking of the crossover settings If your crossover will be installed permanently for one particular purpose and will be set up...

Page 11: ...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 lo...

Page 12: ...connections are made and you are ready to operate the unit The normal way to connect a crossover is between your sound signal source and your amplifiers For each channel the output of the signal sour...

Page 13: ...re using the second half of the 24CX 4 to the input of your mids amplifier Connect the low output of channel two or four to the input of your lows amplifier Three Way Operation 24CX 3 The 24CX 3 provi...

Page 14: ...nel of the 24CX 2 or 24CX 4 Input Level This lets you adjust the overall level of the channel By turning this level up or down you can adjust the volume of all speakers for a single channel simultaneo...

Page 15: ...Output Mute This button mutes the low output of the channel Mid Output Level This lets you set the mid frequency output of the channel Mid Output Phase Pressing this button reverses the phase of the...

Page 16: ...gh frequency speaker cable to the wrong speaker input If you have more than one high frequency speaker component on the same channel check them all If something is not hooked up right stop and fix it...

Page 17: ...est to have a little more than you need because you can always turn it down at the source if it is too loud If you cannot get enough volume with the output level all the way up raise the input level u...

Page 18: ...from the output This helps remove stage rumble and wind noise and also helps prevent speaker damage Another popular option is the parametric equalizer card Each card has two fully parametric equalize...

Page 19: ...miting As you turn the trimmers clockwise you lower the limiting threshold thus reducing the maximum output signal for a given crossover output Set up and adjust the crossover for normal operation the...

Page 20: ...s to be working correctly try plugging it into some sound reinforcement equipment that is known to work such as a monitor system If you do this and there is still no signal the problem is that the sig...

Page 21: ...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 process...

Page 22: ...pecially if this piece of equipment is installed publicly Another common cause of ground loops is direct input or DI boxes These let you plug an instrument such as a guitar or bass directly into a mic...

Page 23: ...itch Led indication 24CX 3 Frequency Range Low Mid 80 Hz to 920 Hz Mid High 800 Hz to 9 2 kHz Hum and Noise 20 Hz 20 kHz Av 0 dB fc 230 2 3k Hz Low Frequency Section Output 0 dB 98 dBu Mid Frequency S...

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