I-Tech 4x3500 HD DriveCoreSeries I-T 4x3500 HD Operation Manual Obtaining Other Language Versions: To obtain information in another language about the use of this product, please contact your local Crown Distributor. If you need assistance locating your local distributor, please contact Crown at 574-294-8000. This manual does not include all of the details of design, production, or variations of the equipment.
I-Tech HD DriveCore Series Power Amplifiers Important Safety Instructions Wichtige Sicherheitsinstruktionen Importantes Instructions de Sécurité Instrucciones de Seguridad Importantes 1. Read these instructions. 2. Keep these instructions. 3. Heed all warnings. 4. Follow all instructions. 5. Do not use this apparatus near water. 6. Clean only with a dry cloth. 7. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions. 8.
I-Tech HD DriveCore Series Power Amplifiers DECLARATION of CONFORMITY Harman International ISSUED BY: Harman International 1718 W. Mishawaka Road Elkhart, Indiana 46517 U.S.A. FOR COMPLIANCE QUESTIONS ONLY: Sue Whitfield sue.whitfield@harman.
I-Tech HD DriveCore Series Power Amplifiers Table of Contents Important Safety Instructions .............................................................2 7.3 Presets.................................................................................... 27 14.8 LevelMAX Tranducer Thermal Limiters................................... 57 Declaration of Conformity...................................................................3 7.4 List of Pop-Up and Descriptions............................................
I-Tech HD DriveCore Series Power Amplifiers 1 Welcome I-T4x3500HD 2-ohm 2.7-ohm 4-ohm 8-ohm 4-ohm Bridge 8-ohm Bridge 70Vrms Direct 100Vrms Direct 20 Hz - 20 kHz 1 kHz 20ms Burst 2,100W 2,200W 2,400W 1,900W 4,200W 4,800W 2,100W 2,300W 3,500W 3,800W 4,000W 1,900W 7,000W 6,000W Minimum power in watts with 0.35% THD, all channels driven. The Crown® I-Tech HD DriveCore Series offers amazing power, light weight and ease of use for touring sound applications.
I-Tech HD DriveCore Series Power Amplifiers 2 Setup 2.1 Unpack and Install Your Amplifier Please unpack and inspect your amplifier for any damage that may have occurred during transit. If damage is found, notify the transportation company immediately. Only you can initiate a claim for shipping damage. Crown will be happy to help as needed. Save the shipping carton as evidence of damage for the shipper’s inspection.
I-Tech HD DriveCore Series Power Amplifiers 2 Setup 2.2 Connecting to AC Mains WARNING: The third (ground) prong of the supplied AC power cord connector is a required safety feature. Do not attempt to disable this ground connection by using an adapter or other methods. 2.3 Wire Inputs and Outputs 2.3.1 Wiring basics • Always use shielded wire for input wiring. The higher the density of the shield (the outer conductor) the better. Spiral wrapped shield is not recommended.
I-Tech HD DriveCore Series Power Amplifiers 2 Setup 2.3.2 Choose Input Wire and Connectors Crown recommends using pre-built or professionally wired, balanced line (two-conductor plus shield), 22-24 gauge cables and connectors. Use 3-pin male XLR connectors. Unbalanced line may also be used but may result in noise over long cable runs. Figure 2.5 shows connector pin assignments for balanced analog wiring or AES3 digital wiring.
I-Tech HD DriveCore Series Power Amplifiers 2 Setup 101-150 ft. 151-250 ft. 8 AWG 6 AWG CAUTION: Never use shielded cable for output wiring. Channel 2 Channel 1 2.3.4 Stereo Mode Wiring Typical input and output wiring is shown in Figure 2.9. IMPORTANT: Turn off the amplifier and unplug its power cord. INPUTS: Choose one of these options: • Connect analog input wiring for all channels. • Connect AES3 digital signal to the AES3 connectors.
I-Tech HD DriveCore Series Power Amplifiers 2 Setup AES Analog Table 1 and Figure 2.10: Wire one Speakon® cable connector to two speakers. Insert the Speakon® cable connector into the amplifier’s top Speakon® connector. 2.3.5 Bridge-Mono Mode Overview: Turn on the amp, enable Bridge-Mono mode using the LCD Control Screen, turn off the amp, wire it, and turn it back on. 1. Be sure that no cables are connected to the amplifier. Turn on the front-panel power switch. The LCD Control Screen will light up.
I-Tech HD DriveCore Series Power Amplifiers 3 HARMAN GreenEdge -Going ‘Green’ without compromise 3.1 Going ‘Green’ 3.3 Green Savings Going ‘Green’ is no longer an option – it’s a necessity. Protecting the world we live in against adverse climate change is a major objective of socially responsible governments, businesses and individuals everywhere. Reducing energy consumption is fundamental to the reduction of greenhouse-gas emissions and is likely to impact various elements of our lifestyle.
I-Tech HD DriveCore Series Power Amplifiers 4 Integrated DriveCoreTM Technology Class D and Class I amplifiers are notable for extraordinarily high efficiency and being well suited for driving difficult reactive loads such as subwoofers. Crown engineers developed DriveCore™ Technology – a proprietary hybrid analog-digital integrated circuit (IC) developed with Texas Instruments that drives the “front end” of the Class D or Class I output stage.
I-Tech HD DriveCore Series Power Amplifiers 5 Powered by Crown This I-Tech HD Series amplifier is compatible with the Powered by Crown app. For more information visit: http://www.crownaudio.com/mobileapplications/index.htm iPad iPad The New System Control App from Crown, Available at the Apple App Store.
I-Tech HD DriveCore Series Power Amplifiers 6 Operation 6.1 Protecting Your Speakers It’s wise to avoid clipping amplifier signals at the input and output. Not only does clipping sound bad, it can damage loudspeakers. To prevent clipping, use System Architect software’s Level Max suite to enable or display the peak voltage limiter and average power limiter in your amplifier’s built-in DSP. That way, no matter how strong a signal your mixer produces, the amplifier output will not clip.
I-Tech HD DriveCore Series Power Amplifiers 6 Operation 6.4 Front Panel Controls and Indicators Many of these functions can be disabled using Blackout Mode (a selection in the Advanced Menu, Section 7.2). A. Cooling Vents Front-to-rear forced airflow through foam dust filter B. LCD Control Screen Integrated 4.3” color touchscreen LCD with backlight, controls amplifier setup and operation.
I-Tech HD DriveCore Series Power Amplifiers 6 Operation 6.5 Back Panel Controls, Indicators and Connectors operation off of one connector, the bottom NL8 speakon connection is for four way operation off of one connector. A. Fans Provide front-to-back forced airflow for cooling. D. Binding Post Output Jacks One pair per channel of high-current, 60A color-coded binding posts. Accepts banana plugs, wire or spade lugs. OUTPUTS SECTION C.
I-Tech HD DriveCore Series Power Amplifiers Menu Tree As a handy reference, Figure 7.2 shows the menu structure of the LCD control screen. Starting from any Menu screen, press an Encoder knob to go to the first selection in the Menu. You can loop through a menu’s selections using the Next and Prev buttons. The Menu/Exit button returns you to the previous screen.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.2 Operation Examples 7.2.1 Basic Selections Operation Example 1 How to set the CH1 input sensitivity using the LCD Control Screen: 1. After power-up, when the default display screen appears, press Menu/Exit. 2. Press Next twice to reach the Advanced Menu, press the encoder wheel to select. 3. Press Next once to reach the Analog Input Sensitivity menu, then press the encoder wheel to select. 4.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation Sample Rate: Starting from the Attenuation screen, press Menu/Exit to go to the Sample Rate screen in the advanced mode. The sample rate of the amplifier’s DSP is displayed. It can be modified only in System Architect software because FIR filter settings will need to be recalculated as a result of the change. Please refer to its Help files. When you route a Cobranet input, the sample rate displayed here must match the Cobranet source.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation Attenuator Limits: You can set the maximum attenuation from 0 dB to –100 dB. This feature allows you to set a limit on the attenuators. Once set, attenuation cannot be adjusted beyond this level. NOTE: The attenuator setting must be below the attenuator limit that you are trying to set. For example, if the attenuator is set at –3 dB, you cannot set the attenuator limit below –3 dB unless you decrease the attenuator level.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation AES Input Status: “Lock” indicates that an AES cable is plugged in and the amplifier is receiving (and locking to) the AES phase logs logs. “No Lock” means that the amplifier is not receiving, or is not locking to the AES clock pulse. Bandpass Gain: In each channel of the I-Tech HD’s DSP, just before the output limiter and after the preceding filter, is a gain block (not shown on the Signal Path block diagram).
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation LED Meter Display Type : Here you can set the LCD bar meters to display average or peak levels. Turn the Encoder knob to select the option, then press the knob to confirm your selection. LevelMax - RMS Voltage Limiter: Limits the output rms voltage to an amount that you set, either OFF or 1 to 500 volts, for each channel. Press the Encoder to turn on the Limiter. Once it’s on, turn the Encoder to set the voltage.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.2.2 MONITOR MENU This menu lets you monitor the status of the amplifier. Load Monitoring: Press a channel icon to turn speaker load monitoring on or off for a channel. When load monitoring is on, the load connected to the amplifier output is displayed. The text below the reported load indicates whether the value is within the limits set in System Architect. OFF means load monitoring is off. LOW means the load is below limits.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation Low Limit Load Errors: This screen lets you view low-load errors without using the control software. A low limit load error occurs if the load impedance falls below the value set with the Low Limit spin control on the Amplifier Settings page in System Architect. When an error occurs, the count displayed in this screen is incremented, and the operating time since the error is displayed. To clear this screen, press a channel icon.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.2.4 NETWORKING MENU This menu has screens for setting up audio network parameters. Push an Encoder knob to see the selections in the Networking Menu. HiQnet Node Address: This screen lets you set the HiQnet address of this amplifier (a node in the network). Tap icon, then turn an Encoder knob to set the address, then press the knob to save your setting.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.2.5 COBRANET MENU To access the CobraNet Menu from the Attenuation screen, press the Encoder knob, then press Prev. This menu has selections for setting CobraNet parameters. Press an Encoder knob to access the CobraNet Menu selections. See Section 12 and the System Architect Help files for more on CobraNet. CobraNet Tx: Tap the icon then turn the Encoder knob to adj.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.3 Presets We will describe each type of preset in detail. 7.3.1 Introduction Your I-Tech HD amplifier has a wide variety of onboard Digital Signal Processing (DSP). Some applications for this DSP are speaker configuration (setting the drive levels, frequency bands, delays and limiting for your particular speakers), EQ, filtering, compression, and much more.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation Lockout “Lockout” is displayed when front panel lockout has been enabled from either the software or front panel. It prevents any changes from the display. 7.4 List of Pop-Up Boxes and Descriptions USB Lockout “USB Lockout” is displayed when USB lockout has been enabled from the software. It disables all USB functions. Invalid Subnet An invalid subnet mask was selected. Invalid Address An invalid IP address was selected.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.5 Digital Audio Options (AES3 and VDrive) Digital audio inputs allow you to keep the amplifier input signals in the digital domain. Keeping the input signal digital reduces the number of Digital-to-Analog and Analog-to-Digital conversions. This provides better sound quality and reduces pickup of electrical interference. The AES3 connector provides a widely accepted format of digital audio transmission.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.1 Amplifier DSP Selection Screen On the left of this screen is the Input and Output Signal Level Monitor (explained later on this page). On the right side are rows of DSP selection buttons for each channel. When you double click on a button, a control panel opens for that button’s function.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.3 Input Level, Fades, Mute, Link, I/O Level Meters, and Indicators This panel is on the left side of the I-Tech HD’s main control panel shown above. Channels 1, 2, 3, and 4 Level Controls set the input signal level of each channel. Each channel can be muted, and both faders can be linked with the Link button. Input Signal Level Meter (green) The measurement range is from 0dBFS to –40dBFS with 0.5dB resolution.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.4 Input Signal Router Each channel of the I-Tech’s signal processing has an Input Signal Router that lets you choose the audio signal that will be used by the channel. Choose one of the following configurations: • Analog Audio: This is the audio input from the audio connector on the back panel of the amp. Choices for the Analog Audio input are Channel 1, Channel 2, or a sum of Channels 1, 2, 3, 4, or a sum of 3 and 4.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.5 Source Configuration In this screen you can configure the levels and settings of the analog, AES and CobraNet inputs. The input signal of each channel can be independently muted. The I-Tech HD amplifier can be set to work as a fixed gain amplifier: any input signal is given a fixed amount of gain, either 26dB or 32dB. In addition, you can set the input sensitivity to determine how much gain is provided. See Section 4.8.
I-Tech HD DriveCore Series Power Amplifiers 4 Advanced Operation 7.7.6 CobraNet Advanced Settings In the CobraNet Advanced Settings screen you can set the parameters shown here. Indicators that are green can’t be modified. The latency on this screen is the CorbaNet transport latency or buffering. This latency must be set to the same latency as the source CobraNet device. The Foldback control panel lets you select the items to transmit via CobraNet.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.7 Input Signal Compressor An input signal compressor is available for each channel. Several parameters control this feature: On/off button: Enables or disables this function. Threshold: Sets the level, in dBu, above which the compressor begins to attenuate the input signal. This level corresponds to the input level meter reading.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.9 Input EQ and Output EQ These screens let you adjust channel equalization for up to 16 frequencies. You can select filter type, frequency, gain, and bandwidth in octaves or Q as set by the user preferences in System Architect. Changes to the equalizer’s frequency response can be done by typing in parameters or by click-dragging the response curve.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.10 Crossover Filters The Crossover section lets you use infinite impulse response (IIR) or finite impulse response (FIR) filters for the crossover. FIR advantages: FIR has a longer processing latency but has less phase artifacts compared to IIR. FIR allows for brickwall, 48dB/oct and 24dB/octave filters with zero phase shift. IIR advantages: FIR has one processing block per channel; IIR has one or more.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.11 LevelMax Suite This is a suite consisting of a peak voltage limiter, average power limiter, clip limiter and thermal transducer limiter. First you will set the mode to automatic or advanced: • Automatic mode: The software determines the best settings based on the signal characteristics. You can modify only the RMS threshold, Speaker Thermal threshold and time constant. Everything else is set automatically.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.13 Amplifier Settings The Amplifier Output Enable button turns each channel on or off. Error Reporting The I-Tech amplifier can detect four different error conditions per channel and errors in the AC line voltage. Each error type can be individually configured to report the error through the network. Network reported errors appear in the control software Event Log. The following describes each error source.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.14 Amplifier Information Information about the amplifier is stored in the software system inventory and is displayed on the software control panels. Information includes manufacturer, model, date code, and serial number. The green items can’t be edited. Channel Labels: Each amplifier includes two labels that you may edit for your own use. Simply type in the text areas. Use these labels to describe the channels of your amplifier.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.17 Preset Manager The control settings for all the functions can be stored as presets. Up to 50 presets can be saved in the I-Tech amp’s nonvolatile memory. Each preset can be named with a 30 character name describing its function, which is also stored in memory. • The Store Preset Control saves the current setting to the specified preset. • The Recall Preset Control recalls the specified preset settings.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation 7.7.18 Signal Generator All channels share a noise generator that allows noise to be mixed into the audio signal. This is useful for noise masking applications and testing. Each channel has the following controls: • Noise On/Off: Turns the noise generator on or off. • Noise Type: Selects full-spectrum white noise or pink noise. • Master: Sets the noise level with a fader.
I-Tech HD DriveCore Series Power Amplifiers 7 Advanced Operation Maximum analog input Fixed gain Low +21 26/32 dB Hi +15 32/38 dB Low +21 dBu (0 dB) High +15 dBu (+6 dB) Analog input AES input trim Analog input sensitivity Source select Output attenuator Fixed gain compensation AES input Limiters Amplifier Cobranet input trim Cobranet input Figure 7.3 The Various Gain Settings in the I-Tech HD 7.7.
I-Tech HD DriveCore Series Power Amplifiers 8 Troubleshooting CONDITION: Power indicator is off and power switch is not illu minated. POSSIBLE REASON: • The amplifier has lost AC power. • The amplifier is not plugged into the power receptacle. CONDITION: Thermal indicator is on. POSSIBLE REASON: • The amplifier is becoming too hot for safe operation. Allow amplifier to cool. Check for loads less than 2 ohms, and for excessive input levels. Check for proper ventilation. • Rear-panel breaker is off.
I-Tech HD DriveCore Series Power Amplifiers 8 Troubleshooting CONDITION: No sound, even though the amp has power. Power LED is on without flashing and the amp is receiving an input signal. Signal indicator is on or flashing. CONDITION: Data indicator not flash ing, even though host computer software is active. POSSIBLE REASON • Cable between computer and amplifier is broken or not connected. • Speakers not connected. • Open circuit due to speaker failure.
I-Tech HD DriveCore Series Power Amplifiers 9 Specifications Minimum Guaranteed Power 20 Hz - 20 kHz with 0.35% THD, all channels driven 2-ohm 2.7ohm 4-ohm 8-ohm 4-ohm Bridge 8-ohm Bridge 70Vrms Direct 100Vrms Direct Performance Input Sensitivity (volts RMS) for rated output Voltage Gain for full rated power at 8 ohms I-T4x3500HD 20 Hz - 20 kHz 1 kHz 20ms Burst 2,100W 2,200W 2,400W 1,900W 4,200W 4,800W 2,100W 2,300W 3,500W 3,800W 4,000W 1,900W 7,000W 6,000W I-T4x3500HD Adjustable in 0.
I-Tech HD DriveCore Series Power Amplifiers 9 Specifications Performance I-T4x3500HD Damping Factor (8 ohms): 20 Hz to 100 Hz > 5000 Crosstalk (below rated power, 20 Hz to 1 kHz) > 80 dB Common Mode Rejection (CMR) (20 Hz to 1 kHz) DC Output Offset (Shorted input) Input Impedance (nominal) Load Impedance (Note: Safe with all types of loads) Stereo Bridge Mono > 55 dB, typically > 70 dB < ± 3 mV 20 kilohms balanced, 10 kilohms unbalanced 2-4-8-16 ohms, 70V/100V 2-4-8 ohms, 70V//100V Required AC Mai
I-Tech HD DriveCore Series Power Amplifiers 9 Specifications Charts Figure 9.1 Typical Frequency Response (1W) page 48 Figure 9.2 Typical Crosstalk vs.
I-Tech HD DriveCore Series Power Amplifiers 9 Specifications Figure 9.3 Typical Damping Factor vs.
I-Tech HD DriveCore Series Power Amplifiers 10 AC Power Draw and Thermal Dissipation I-Tech 4x3500HD AC Current Draw and Thermal Dissipation: I-Tech 4x3500HD AC Current Draw and Thermal Dissipation: Pink noise 12dB crest factor, bandwidth limited 22Hz to 22kHz. Pink noise 12dB crest factor, bandwidth limited 22Hz to 22kHz. Typical lineimpedance impedance used. Typical line used. Data basedononallall channels driven. Data based channels driven.
I-Tech HD DriveCore Series Power Amplifiers 11 Advanced Features 11.1 Protection Systems Your Crown amplifier provides extensive protection and diagnostic capabilities, including thermal level control, fault indicators, high-pass filtering, DC protect, AC under/over voltage protection, inrush limiting, and variable-speed fans with tachometer feedback. Microprocessor monitors fans, and signals an error via System Architect if fans are not operating. 11.1.
I-Tech HD DriveCore Series Power Amplifiers 12 Appendix A: Network and CobraNet Basics 12.1 HiQnet Networks Background: A Local Area Network (LAN) is a group of computers in a venue that share data, either through cables or via wireless transmission. Ethernet is a popular LAN communication protocol for PCs. An audio network is a Local Area Network made of audio devices and one or more computers. A subnet is a small network within a larger network.
I-Tech HD DriveCore Series Power Amplifiers MAC address: Short for Media Access Control, MAC is an address for an audio component that is burned into firmware in the component by its manufacturer, and cannot be changed. Every component in a network has its own unique MAC address. The MAC address is printed on a label outside the component.
I-Tech HD DriveCore Series Power Amplifiers 12.2 A Closer Look at CobraNet Licensed by Cirrus, CobraNet is a protocol, firmware and hardware that lets you transmit digital audio over a 100Base-T Fast-Ethernet network. This section provides an overview of CobraNet. Cirrus Logic has provided a number of technical papers that describe CobraNet in detail. These papers are available at: http://www.cobranetinfo.com. 12.2.1 Fast Ethernet (100Base-T) Fast Ethernet (100Base-T) runs at 100Mbps (Megabits per second).
I-Tech HD DriveCore Series Power Amplifiers In System Architect, you create audio connections between sending devices (transmitters) and receiving devices (receivers). For example, a mixer could be a transmitter, and a power amp could be a receiver. You assign each connection a Bundle number. The Bundle number indicates which devices are communicating with each other. Also in System Architect, you address each connection as Multi cast or Unicast.
I-Tech HD DriveCore Series Power Amplifiers 13 LevelMAXTM Limiter Suite The I-Tech HD LevelMAX™ Limiter Suite features three types of limiting: • • • Peak RMS Transducer Thermal and three modes of operation: • • • Auto Advanced Manual (OEM Factory Locked) The standard i-Tech HD LevelMAX limiter panel (Advanced Mode) is shown below: LevelMAX has been designed to limit accurately to the specified voltage thresholds.
I-Tech HD DriveCore Series Power Amplifiers 14 LevelMAX Limiters 14.1 LevelMAX Peak Limiter LevelMAX Peak limiting instantaneously limits the output voltage to not exceed the defined peak threshold voltage. 14.2 Peak Limiter Threshold (Vpk) In Auto mode, the peak limiter threshold value is automatically determined from the defined RMS threshold and the low pass frequency defined in the XOVER block. For a low pass frequency less than 100 Hz, the RMS to peak threshold ratio is 6 dB.
I-Tech HD DriveCore Series Power Amplifiers 15 Appendix B: Table of Parameters Modified by Each Mode with LevelMAX Limiter Suite Enabled Parameter Auto Peak Enable Peak Threshold Peak Attack Peak Release RMS Enable Advanced Visible in Main Panel RMS Threshold RMS Attack RMS Release RMS Detector Time Thermal Enable Thermal Threshold Thermal Attack Thermal Slope (Kp & Ki) Look-Ahead page 58 Operation Manual
I-Tech HD DriveCore Series Power Amplifiers SV Value Range Parameter Auto Peak max for each model (online) Auto Increment Parameter Auto Peak Threshold (See Below) 1-400V 1V I-Tech HD 5000 Peak Release 0.1ms-10s 1ms I-Tech HD 9000 217.6 RMS Threshold 1-200V 1V I-Tech HD 12000 233.4 RMS Attack 0-10s n/a I-Tech 4x3500 HD 217.6 RMS Release 0-10s 1ms RMS Detector Time 1ms-1s n/a Thermal Threshold 1-200V 0.
I-Tech HD DriveCore Series Power Amplifiers 16 Application of FIR Filters to Loudspeaker Crossovers Digital filters may be further classified into two general types: Infinite Impulse Response (IIR) and Finite Impulse Response (FIR). Fundamentally, IIR filters include feedback (recursion) in their implementation while FIR filters do not. The feedback in an IIR filter means that the impulse response of the filter theoretically goes on forever, thus the “Infinite” term in the name.
I-Tech HD DriveCore Series Power Amplifiers 16 Application of FIR Filters to Loudspeaker Crossovers 16.5 High Rolloff and Steep Slopes FIR filters can be designed to have extremely high stop-band rolloffs and exceptionally steep slopes which greatly minimizes crossover driver overlap. In a conventional analog or analog-based IIR crossover, driver overlap can extend over two or three octaves.
I-Tech HD DriveCore Series Power Amplifiers 16 Application of FIR Filters to Loudspeaker Crossovers 16.10 Filter Design IIR filters are typically based on an equivalent analog circuit. Because of this, the IIR design process is a straightforward matter of converting an analog filter frequency response specification into digital coefficients. In contrast, FIR frequency response is usually specified in terms of an ideal, though physically unrealizable filter, e.g. a brick wall lowpass.
I-Tech HD DriveCore Series Power Amplifiers 16 Application of FIR Filters to Loudspeaker Crossovers IIR Measurements A 4th-order Linquitz-Riley (LR) crossover with 24 dB/octave slopes at 3 kHz was chosen to demonstrate a typical well-designed conventional crossover. Although, in conventional terms, a relatively sharp 24 dB/ octave crossover slope is considered quite sharp. The crossover region spans a relatively wide two octaves.
I-Tech HD DriveCore Series Power Amplifiers 16 Application of FIR Filters to Loudspeaker Crossovers Level - dB 10 Figure 7 shows two graphs illustrating the measured frequency response magnitude (left) and phase (right of the 3.67 ms latency FIR 3 kHz crossover generated by the HD amplifier. The right graph shows the measured phase of the crossover with the phase rotation due to the latency and speaker-to-microphone transit time subtracted out.
I-Tech HD DriveCore Series Power Amplifiers 10 0 0 -10 Woofer Tweeter -20 -30 20 Level - dB Level - dB 10 100 1k Frequency - Hz 10k 20k 10 0 0 -20 -30 20 100 1k Frequency - Hz 10k 20k Fig. 16.8 Measured individual driver responses (left ) and overall summed on-axis response (right) of the two-way system of Fig. 5 driven with 3.67 ms latency 3 kHz FIR crossover filter generated by an I-Tech HD amplifier. Figure 16.
I-Tech HD DriveCore Series Power Amplifiers 17 Service Crown amplifiers are quality units that rarely require servicing. Before returning your unit for service, please contact Crown Technical Support to verify the need for servicing. Remember to transport the unit in the original factory pack. A list of authorized service centers in your area can be obtained from Crown Factory Service, or online from http://www.crownaudio.com/support/servcent.htm.
I-Tech HD DriveCore Series Power Amplifiers 18 Warranty UNITED STATES & CANADA SUMMARY OF WARRANTY 5 AR YE Crown International, 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown product, for a period of five (5) years from the date of purchase by the original purchaser (the “warranty period”) that the new Crown productis free of defects in materials and workmanship.
I-Tech HD DriveCore Series Power Amplifiers 18 Warranty 5 AR YE WORLDWIDE EXCEPT USA & CANADA SUMMARY OF WARRANTY WHAT THE WARRANTOR WILL DO Crown International, 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A.
I-Tech HD DriveCore Series Power Amplifiers PRODUCT REGISTRATION Online registration is also available at http://crownweb.crownintl.com/webregistration. Harman International 1718 W. Mishawaka Rd. Elkhart, IN 46517-9439 Phone: 574-294-8000 Fax: 574-294-8329 www.crownaudio.com Warranty is only valid within the country in which the product is purchased. When this form is used to register your product, it may be mailed or faxed.
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Crown Audio Factory Service Information Shipping Address: Crown Audio Factory Service, 1718 W. Mishawaka Rd., Elkhart, IN 46517 PLEASE PRINT CLEARLY SRA #: __________________(If sending product to Crown factory service.
