Altec Lansing 4048A SIGNAL PROCESSING, Manual

Page 1: ...c Lansing Pr Altec Lansing Pr Altec Lansing Pr Altec Lansing Professional ofessional ofessional ofessional ofessional 1000 W Wilshire Blvd Suite 362 Oklahoma City OK 73116 USA A division of Altec Lansing Technologies Inc Milford PA 18337 0277 Made In USA ...

Page 2: ...O TEC LANSING MAESTRO TEC LANSING MAESTRO SOFTW SOFTW SOFTW SOFTW SOFTWARE ARE ARE ARE ARE 8 7 7 7 7 7 GETTING ST GETTING ST GETTING ST GETTING ST GETTING STA R A R A R A R A RTED TED TED TED TED 9 8 8 8 8 8 OTHER SOFTW OTHER SOFTW OTHER SOFTW OTHER SOFTW OTHER SOFTWARE FUNCTIONS ARE FUNCTIONS ARE FUNCTIONS ARE FUNCTIONS ARE FUNCTIONS 15 9 9 9 9 9 TROUBLESHOOTING TIPS TROUBLESHOOTING TIPS TROUBLES...

Page 3: ...to alert the user to the presence of uninsulated dangerous voltage within the product s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE COVER NO USER SERVICEABLE PARTS INSIDE REFER SERVIC ING TO QUALIFIED SERVICE PERSONNEL TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK DO NOT EXPOSE THIS APPlIANCE TO...

Page 4: ...ess appearance After unpacking please inspect for any physical damage Save the shipping carton and all packing materials as they were carefully designed to minimize the possibility of transportation damage should the unit again require packing and shipping In the event that damage has occurred immediately notify your dealer so that a written claim to cover the damages can be initiated The right to...

Page 5: ...D becomes lit when an output channel is turned off through software control 4 3 Preset Indicator This display indicates the currently selected preset number 1 18 for the 4048A This display also indicates the following operating conditions within the 4048A Firmware revision number is displayed during power up and when a factory reset is aborted Factory reset countdown which occurs by pressing and h...

Page 6: ...ut trim adjustments on the 4048A therefore all the processing including gain is done in the digital domain As a consequence of this design philosophy it is important to feed the processor with the proper nominal signal level to achieve good signal to noise performance as well as headroom before clipping The 4048A is designed to clip at signal levels above 20dBu 7 75Vrms which places the noise floo...

Page 7: ...es may be used where the trigger event is the transition from open to closed for a given circuit Closing a circuit will automatically override any previously recalled presets Up to eight switches can be used with all switches sharing a common ground connection Each pin number above the contact closure connector corresponds to the number of the preset which will be recalled when that switch is clos...

Page 8: ...computer A standard D Sub nine pin female to male connector cable is used to connect the PC to the 4048A If the PC lacks a nine pin RS 232 port an active USB to RS 232 converter can be purchased at computer stores Following are the suggested steps for connecting the 4048A to a PC 1 Plug the RS 232 cable into an available serial port on the PC 2 Plug the other end of the cable into either the front...

Page 9: ...the Options menu The default configuration options are 1 4 x 2 way Crossover 2 2 x 3 way and 2 Aux 3 2 x 3 way mono sub 4 2 x 4 way Crossover 5 1 x 5 way and 3 Aux 6 Mono Distribution 7 Stereo Distribution 8 LCRS with mono subs 9 4 x 4 Processor 10 Muted Flat Start up 7 2 Metering Options The front panel LEDs on the 4048A indicate signal present 20dBu 0dBu inputs only or clip 20dBu For more detail...

Page 10: ... filter position to its starting position c Cut Active Filter z Zero Active Filter Ctrl c Cut Master Gain Ctrl z Zero Master Gain 7 3b Mute The 4048A allows the user to mute all inputs or outputs When muted an input or output s red Mute LED is lit To mute or unmute all outputs simultaneously click on the Mute menu heading and select the Mute all or Unmute all option Inputs can be muted or unmuted ...

Page 11: ...ctory default is 1kHz but each filter s center frequency is adjustable from 19 7Hz to 21 9kHz in 1 96 octave steps Carefully sweeping a narrow bandwidth filter through a problem feedback area with just a slight boost is a quick way to find the exact frequency causing trouble Once the offensive frequency has been found cut the filter s level and then adjust the bandwidth as narrow as possible while...

Page 12: ...aking it necessary for the user to map out ahead of time which outputs will be used for the various frequency bands and set the overlapping filter frequencies and types accordingly Note The HPF determines the lower frequency limit of the signal while the LPF determines the upper frequency limit The frequency range for the high pass filter HPF is from 19 7Hz to 21 9kHz with an option to turn the fi...

Page 13: ...B oct Bessel filters One of the outputs must be inverted when using either 12dB oct or 18dB oct Bessel crossover filters or else the combined response will have a large notch Linkwitz Riley The 12 dB oct and 24dB oct Linkwitz Riley filters individually are always 6dB at the displayed crossover frequency however the 18dB oct Linkwitz filters individually are always 3dB at the displayed crossover fr...

Page 14: ...osest to the cluster front Using the location of the driver diaphragm farthest back as a reference point measure the distance to other drivers in the cluster and set the output delay for each accordingly with the driver diaphragm closest to the front getting the longest delay and the driver at the very back getting no delay at all The minimum adjustment is 0 02 milliseconds or about inch When appr...

Page 15: ... configurations repeat ing two times A preset file contains the control parameters of all four inputs and eight outputs For a written record of all parameters of a specific preset file click Print Channel in the File menu Since there are no user controls on the 4048A the only way to load channel presets is by using Altec Lansing Software to recall files saved on either the PC or the 4048A The exce...

Page 16: ...cated by a lower case r in the display followed by normal operation of the unit 9 TROUBLESHOOTING 9 1 Audio Troubleshooting Tips 1 No power Is the detachable AC cord fully plugged in Is the rear panel power switch on 2 Software controls don t work Is the RS 232 cable properly installed to the PC Is the software commu nications enabled Is the correct Comm port selected Check the security level sect...

Page 17: ...Boost Cut Range 15dB 30dB Parametric Filter Frequency Range 19 7Hz to 21 9kHz 1 96 Octave Steps Parametric Filter Bandwidth Four Octaves to 1 64 Octave All pass phase shift 0 deg at low freq 180 deg at selected freq 360 deg at high freq Delay Output Delay 0 682 milliseconds Crossover HPF and LPF Frequency Range 19 7Hz to 21 9kHz Off Available Filter Types 12dB Oct Butterworth 12dB Oct Bessel 12dB ...

Page 18: ...technical services at 405 848 3108 Fill out the information below for your records Serial Number______________ Dealer _______________________ Date of Purchase ___________ Dealer s Address _______________________________________________ Dealer s Phone _____________ Salesperson ____________________________________________________ Altec Lansing 4048A Digital Signal Processor 6 00 152 0 00 0 25 6 4 18...

Page 19: ...24dBLinkwitz Output Delay Output Gain Phase Invert Output Limiter Output Mute Limiter Threshold LED Software Output Meters D A Output Channels 1 8 Route Input Channels A D To Output Channels 1 8 in Any Combination Routing Limiter Link A 1 B Mute Gain EQ Route C Mute Gain EQ Route D Mute Gain EQ Route Altec Lansing 4048A Block Diagram Inputs Outputs Mute Gain EQ Route HpfLpf EQ Delay Gain Limiter M...

Page 20: ... Altec Lansing Pr Altec Lansing Pr Altec Lansing Pr Altec Lansing Pr Altec Lansing Professional ofessional ofessional ofessional ofessional 1000 W Wilshire Blvd Suite 362 Oklahoma City OK 73116 USA A division of Altec Lansing Technologies Inc Milford PA 18337 0277 Made In USA ...