Telex ISP-100 manual

User s Manual ISP -100 INTEGRA TED SIGNAL PROCESSOR[...]

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i General Information PROPRIET AR Y NOTICE The Merlin product information and design disclosed herein were originated by and are the property of Telex Communications, Inc. Telex reserves all patent, proprietary design, manufacturing, reproduction, use and sales rights thereto, and to any article disclosed therein, except to the extent rights are ex[...]

ii 10 July 1998 ANY AND ALL IMPLIED WARRANTIES, INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY ARE LIMITED TO THE DURATION OF THIS EXPRESS LIMITED WARRANTY. NEITHER TELEX NOR THE DEALER WHO SELLS MERLIN PRODUCTS IS LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND. CUST OMER SUPPORT Technical questions should be directed to: Customer Se[...]

iii General Information End-User License Ag reement for T ele x® Softwar e IMPORTANT – Please read this document carefully before using this product. THIS DOCUMENT STATES THE TERMS AND CONDITIONS UPON WHICH TELEX COMMUNICATIONS, INC. (the “COMPANY”) OFFERS TO LICENSE THE INSTALLED SOFTWARE OR PROGRAM (the “SOFTWARE”) FOR USE WITH THE PRO[...]

iv 10 July 1998 Table of Contents INTRODUCTION .................................................................... 1-1 An Overview of the ISP-100 ................................................................................................ 1-1 About this Manual ....................................................................................[...]

v General Information Table of Contents LowPass Filter ........................................................................................................... 4-2 HighPass Filter .......................................................................................................... 4-2 AllPass Filter .........................................[...]

vi 10 July 1998 Table of Contents INST ALLING VUE-IT ........................................................... 5-1 Minimum System Requirements ......................................................................................... 5-1 Identifying a Serial Port ..................................................................................[...]

vii General Information Table of Contents OpenDevice Status Panel on Error ............................................................................... 7-4 Display QuickMAP Pop-Up names ................................................................................ 7-4 Display Filter Bandwidth in “Q” ........................................[...]

viii 10 July 1998 Table of Contents Polarity Control (+/-) ...................................................................................................... 8-3 Mute Control (M) ........................................................................................................... 8-3 Bypass Control (master) ...............................[...]

ix General Information Table of Contents Bypass Control (master) .............................................................................................. 8-28 Filter .................................................................................................................................. 8-29 Filter Bands .............................[...]

x 10 July 1998 Table of Contents Familiar Controls ......................................................................................................... 8-46 Unfamiliar Controls ...................................................................................................... 8-48 Notes on Operation of the Limiter ..........................[...]

1-1 Introduction INTRODUCTION An Overview of the ISP-100 Thank you for choosing the ISP-100™ for your signal processing needs. The ISP-100 is the first in a line of high quality signal processing products from TELEX Communications, Inc.’s Merlin division. The ISP-100 represents a continued commitment to understanding and meeting our customers n[...]

1-2 10 July 1998 closures. This interface allows users to change system settings directly and/or scroll through various settings. About this Manual This manual is covers the installation and operation of the ISP-100’s hardware and software. The ISP-100 has been designed to be as user-friendly as possible. However, this manual should be read befor[...]

2-1 Setup & Installation SETUP & INST ALLA TION Introduction This section details the setup and installation of the MERLIN ISP-100. Information is provided on the following: front and rear panel features, physical requirements, installation of expansion cards, signal connections for audio, data, and control. Unpacking The shipping carton is[...]

2-2 10 July 1998 Rear Panel Features (see Figure 2-2) Figure 2-2 ISP-100 rear panel features. 1. AC Power—Connects to mains via an IEC type AC power cord. 2. RS-232 Port—Links the PC to the unit via a RJ-45 connector. 3. External Sync—Precision frequency reference input to the unit. 4. GPI—Provides a General Purpose Interface for the user. [...]

2-3 Setup & Installation Card Installation Procedure Figure 2-3 Battery/module tool. Figure 2-4 Card being inserted. 1. Ground yourself using a wrist strap and anti-static mat. 2. Turn off the ISP-100. 3. Remove the screws securing the module slot cover. 4. If you are not replacing an existing card please proceed to step 6. 5. Use the battery/m[...]

2-4 10 July 1998 Cable Diagrams Analog Audio (MIM-1, MIM-2, MOM-1) Figure 2-6 Analog inputs. Balanced Input from Balanced Output Connect the positive (+) side of the line to pin 2 of the male 3-pin XLR connector and the negative (-) side of the line to pin 3 of the connector. In keeping with standard wiring practices, the shield should not be conne[...]

2-5 Setup & Installation Balanced Output to Unbalanced Input Connect the “hot” wire to pin 2 of the 3-pin female XLR connector and the shield wire to pin 1 of the connector. To avoid a 6 dB drop in level, connect pin 3 to pin 1 of the connector. See Figure 2-7 for more information. Digital Audio (MDM-1 Cards) Figure 2-8 AES/EBU inputs. AES/[...]

2-6 10 July 1998 Figure 2-10 AES/EBU output. AES/EBU Output Figure 2-11 DB-9 to DB-25. Figure 2-12 DB-9 to DB-9. Connect the positive (+) side of the line to pin 2 of the 3-pin female XLR connector and the negative (-) side of the line to pin 3 of the connector. In keeping with standard wiring practices, the shield should be connected at this end; [...]

2-7 Setup & Installation Figure 2-13 RFI choke data. RFI choke such as Steward PN: 28B2025-0A0 should be used at the ISP-100 end of the cable. See Figures 2-13 and 2-16, and Table 2-1 for more information. Rear Panel RS-232 Figure 2-14 RJ-45 to DB-25. Figure 2-15 RJ-45 to DB-9. The serial port selector switch should be set in the up position. I[...]

2-8 10 July 1998 Table 2-1 RS-232 signal pinouts for RJ-45, DB-9, and DB-25 connectors. Figure 2-16 Connector pinouts. The RS-232 standar d is very common to computer controlled devices . T able 2-1 and Figure 2-16 can help you decipher the RS-232 interfaces of many devices .[...]

2-9 Setup & Installation General Purpose Inputs (GPI) Figure 2-17 GPI connector pinout. Figure 2-18 BNC cable example. Synchronizing to an external clock source requires RG-58 or other suitable 50 Ω cable terminated with a BNC connector. A precision (±5 ppm) clock source of 12.288 MHz, 6.144MHz, or 3.072 MHz is supported. The Master Clock In[...]

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3-1 Troubleshooting TROUBLESHOO TING > > > CAUTION < < < NO USER SERVICEABLE PARTS INSIDE. HAZARDOUS VOLTAGES AND CURRENTS MAY BE ENCOUNTERED WITHIN THE CHASSIS. TO AVOID ELECTRICAL SHOCK DO NOT PERFORM ANY SERVICING OTHER THAN THAT CONTAINED IN THESE OPERATING INSTRUCTIONS. User Modifications Modifications to Merlin products are [...]

3-2 10 July 1998 Diagnostics Table 3-1 LED diagnostic messages. The ISP-100 was designed with built-in diagnostics that activate when power is applied to the unit. During the power-up cycle, the ISP-100 performs several self-checks. The ISP-100 also will report problems, as they happen, while the unit is running. The diagnostic messages are communi[...]

3-3 Troubleshooting Figure 3-1 About VUE-IT dialog Retrieving Version Numbers Figure 3-2 Properties dialog. Clicking on the star icon in the Project Manager and then clicking on the Properties button will reveal the ISP-100’s serial number. See Figure 3-2. Application, OS, and DSP version numbers can be obtained by clicking on the Help menu and t[...]

3-4 10 July 1998 Changing the Fuse The universal switching power supply in the ISP-100 adapts to input voltages from 90 to 264 VAC, 50/60 Hz. To reduce risk of fire, replace only with same type fuse. The fuse holder is located under the security cover on the front panel. The fuse is a standard 20mm X 5mm European type. The values used are as follow[...]

3-5 Troubleshooting Caution: Use only the tool attached to the inside of the security cover to change the battery. The tool is black anodized so it will not short out the battery or anything else. DO NOT under any circumstance use pliers to grip the battery. Doing so could cause damage. See Figure 3-3. Replace the battery with a Renata CR2450N batt[...]

3-6 10 July 1998 Technical Support Technical questions should be directed to: Customer Service Department - Merlin Telex Communications, Inc. 9600 Aldrich Avenue South Minneapolis, MN 55420 U.S.A. Telephone: (612) 884-4051 Fax: (612) 884-0043 Helpful Information Be prepared to provide the following information (if possible): 1. A detailed descripti[...]

3-7 Troubleshooting Shipping to Manufacturer for Repair or Adjustment All shipments of Merlin products should be made via United Parcel Service or the best available shipper prepaid. The equipment should be shipped in the original packing carton; if that is not available, use any suitable container that is rigid and of adequate size. If a substitut[...]

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4-1 Specifications SPECIFICA TIONS Components Compressor Property Range Default Fine Coarse Bypass in/out out n/a n/a Threshold -60 dB to 0 dB 0 dB .5 dB 3 dB Compression Ratio 1.2:1 to 24:1 1.2:1 n/a n/a Attack Time 20 msec to 50 ms 20 msec .02 ms 1 ms Release Time 20 msec to 5 sec 5000 ms 1 ms 100 ms Detection Window 20 msec to 5 sec 50 ms 1 ms 1[...]

4-2 10 July 1998 Limiter Property Range Default Fine Coarse Bypass in/out out n/a n/a Threshold -60 dB to 0 dB 0 dB .5 dB 3 dB Attack Time 20 msec to 50 ms .02 ms .02 ms 1 ms Release Time 20 msec to 5 sec 5000 ms 1 ms 100 ms Detection Window 20 msec to 5 sec 50 ms 1 ms 100 ms Crest Factor 0.00 to 1.00 .70 .01 .0 5 Knee hard/soft hard n/a n/a Sidech[...]

4-3 Specifications PEQ Property Range Default Fine Coarse Center Frequency 20 Hz to 20 kHz 20 1/12 Oct. 1/3 Oct. Boost/Cut +12 dB to -12 dB 0 dB .1 dB 1 dB Bandwidth 0.08 to 3.0 octaves 1.0 1/12 Oct. 1/3 Oct. Combine Property Range Default Fine Coarse Channel “1” Entry Gain +0 dB to -96 dB 0 dB .5 dB 1 dB Channel “1” Entry Polarity +/- + n/[...]

4-4 10 July 1998 Gate Linkwitz-Riley 3-way Crossover Notch Filter Parametric Equalizer Filter Peaked HighPass Filter Shelving Filter AP is a trademark of Audio Precision, Inc.[...]

4-5 Specifications System Measurements System Frequency Response System Noise Floor System THD+N AP is a trademark of Audio Precision, Inc.[...]

4-6 10 July 1998 MIM-1 & MIM-2* Analog Input Modules Power Symbol Description Minimum Typical Maximum Units V A18P positive analog supply voltage 17.50 18.00 20.00 volts V A18M negative analog supply voltage -17.50 -18.00 -20.00 volts VD5P positive digital supply voltage 4.75 5.00 5.50 volts IA18P positive analog supply current 77(43.7) 81(46.0[...]

4-7 Specifications MOM-1 Analog Output Module Power Symbol Description Minimum Typical Maximum Units V A18P positive analog supply voltage 17.50 18.00 20.00 volts V A18M negative analog supply voltage -17.50 -18.00 -20.00 volts VD5P positive digital supply voltage 4.75 5.00 5.50 volts IA18P positive analog supply current 92 96 100 milliamps IA18M n[...]

4-8 10 July 1998 MDM-1 AES/EBU Digital I/O Module Power Symbol Description Minimum Typical Maximum Units V A18P Pos Analog Supply V oltage 17.50 18.00 20.00 Volts V A18M Neg Analog Supply V oltage Not Used V olts VD5P Pos Digital Supply V oltage 4.75 5.00 5.50 V olts IA18P Pos Analog Supply Current 8 9 10 mA IA18M Neg Analog Supply Current Not Used[...]

4-9 Specifications Performance (Sample Rate Converter bypassed) Symbol Description Minimum Typical Maximum Units F s Sample Rate for Digital TBD 48 96 kHz Input Data 19 THD+N T otal Harmonic Distortion 0.00002 % plus Noise 20 (RELA TIVE) IMD Intermodulation Distortion 21 0% (SMPTE 4:1) Jitter in Output Clock 415 pS T olerable Jitter in Inp[...]

4-10 10 July 1998 Notes 1 Per Analog Devices AD1890 data sheet, where applicable. 2 With 6.144 MHz MCLK/2 input. 3 20 Hz to 20 kHz, full-scale input, through sample rate converter , to output via passthrough. 4 From input, through sample rate converter , to output via passthrough. 5 When installed in ISP-100. 6 When installed in I[...]

5-1 Installing VUE-IT INST ALLING VUE-IT Minimum System Requirements CPU: Pentium® processor . OS: Microsoft® Windows 3.1x, Windows 95, or Windows 98 Memory: 8MB RAM Hard Drive: 5MB of available space (beyond swap file needs) Disk Drive: 3.5 inch high-density Monitor: 640X480, 256 color Pointing Device: mouse or other Windows compatible poi[...]

5-2 10 July 1998 Figure 5-2 OS download request dialog. Figure 5-1 OS mismatch dialog. Updating the ISP-100’ s Operating System The updating of the operating system contained in the ISP-100’s flash memory is usually required after loading a new version of VUE-IT on the computer . A dialog box such as those in Figures 5-1 and 5-2 usually indicat[...]

5-3 Installing VUE-IT 5. Download the OS software file you need via the application when prompted. See Figure 5-3 for more information. The default location for OS files is “ c:program filesvue-itisp-100 ”. Figure 5-3 Open OS file dialog. Figure 5-4 Download progress dialog. 6. The lights will continue to rotate with only brief pauses. Y [...]

5-4 10 July 1998 Configuring the Software Turn on the ISP-100. The power switch is located at the far right under the front access panel. This is accomplished by placing the switch in the down position. See Figure 2-1 for the location of the power switch. Check to make sure that the LEDs light in a percentage complete fashion. Launch the VUE-IT app[...]

5-5 Installing VUE-IT Figure 5-8 ISP-100 not detected dialog. If a dialog box like the one in Figure 5-8 appears in place of the one in Figure 5-7, the cable connecting the computer to the ISP-100 should be checked. If no problem is found there, try selecting a different serial port. Figure 5-9 Communications error dialog. If a dialog box simila[...]

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6-1 Getting Started GETTING ST ARTED Starting VUE-IT Figure 6-1 VUE-IT workspace. When VUE-IT is started, you will see a screen similar to the one in Figure 6-1. The window displayed in Figure 6-1 is the basic environment in which all interactions with VUE-IT take place. There are six key features of this window that users should be aware of: 1. Me[...]

6-2 10 July 1998 Starting a New Project Figure 6-2 Create new project dialog. T o start a new project select New Project from the File menu. A panel similar to the one in Figure 6-2 will appear . Y ou are allowed to select a name of up to eight characters for the project, assign a path for the project to be stored, and create a new subdirectory if [...]

6-3 Getting Started used to create the QuickMAP . The QuickMAPs can be sorted by Name, I/O Configuration, Creation T ime, and Modification Time. T o sort the QuickMAPs, click on the heading button of the property you wish to sort by (i.e. Name , I/O Configuration , etc.). The first click of the mouse will sort the QuickMAPs in ascending order and t[...]

6-4 10 July 1998 Archiving Projects T o save a project for archival purposes do the following: 1. Exit VUE-IT . 2. Save the project directory and the four files mentioned previously to the archival media (i.e. floppy disk, zip™ disk, tape, CD, etc...). The directory name will usually be the name you assigned the project. Mounting Projects T o ins[...]

7-1 Using VUE-IT Using VUE-IT VUE-IT has a variety of commands available to the user . These commands are accessible via the menu items along the top of the VUE-IT workspace window . File (see Figure 7-1) Figure 7-1 File menu. New Project - Creates a new project file. Open Project - Loads an existing project. Save - Saves a project. Save as. .. - S[...]

7-2 10 July 1998 Edit (see Figure 7-2) Figure 7-2 Edit menu. Cut - Removes the selected item(s) and places them on the clipboard. Copy - Places a copy of the selected item(s) on the clipboard. Paste - Inserts item(s) from the clipboard. T ools (see Figure 7-3) Figure 7-4 Options menu. Preferences - Allows the user to setup preferences available wit[...]

7-3 Using VUE-IT Figure 7-5 Windows menu. Cascade - Arranges panels in overlapping layers. Tile - Arranges panels side-by-side. Arrange Icons - Arranges minimized panels side-by-side. Help (see Figure 7-6) Figure 7-6 Help menu. About - Lists the current application software version, OS version, and DSP version if an ISP-100 is connected and online.[...]

7-4 10 July 1998 there is when changing between QuickSET s or using a GPI mute. The total time for ramp-up and ramp-down is twice the time specified. (i.e. If 50 ms of time is specified, the ramp-down will be 50 ms and the ramp-up will be 50 ms. Thus, the total time between the start of the ramp-down to the end of the ramp-up is 100 ms.) Display re[...]

7-5 Using VUE-IT QuickMAP Library This is the directory under which QuickMAP templates are stored. T o modify the path, click on the Modify ... button located to the right of the directory path entry . Company Name This entry is reserved for possible future use in documenting projects. Y ou can enter the company name, but it currently will not be s[...]

7-6 10 July 1998 able to access ISP-100 statistics such as free memory , number of QuickSET s, etc. Properties for the ISP-100 Figure 7-10 ISP-100 properties dialog. Properties for the ISP-100 (see Figure 7-10) reports statistics on the ISP-100. It is accessed by double clicking on the entry next to the star icon (see Figure 7-9), or by clicking on[...]

7-7 Using VUE-IT Project Properties Figure 7-1 1 Project properties dialog. Project properties (see Figure 7-1 1) provides the user with information on the name of the project, project location, and notes related to the project. It is accessed by double clicking on the project name entry , or by clicking on the project name entry and then clicking [...]

7-8 10 July 1998 Configuration , etc.). The first click of the mouse will sort the QuickMAPs in ascending order and the second click will sort them in descending order . See section 6 for the location of the QuickMAP directory . QuickMAP Properties Figure 7-12 QuickMAP properties dialog. QuickMAP Properties (see Figure 7-13) appear by clicking on t[...]

7-9 Using VUE-IT Clicking on a component (i.e. Cut , Compressor , Limiter , etc.) in the Project Manager (see Figure 7-9) and then clicking on the Properties button displays the properties for the selected component. Component Properties allow the user to name the component and enter notes related to that component. See Figure 7-14. Component Expor[...]

7-10 10 July 1998 Component Import Figure 7-16 Component import dialog. T o import component settings from the Project Manager , click on the desired component entry in the project manager (see Figure 7-9) and then click on the Import button. Y ou will then see a dialog box like the one in Figure 7-16. The Import Component dialog displays currently[...]

7-11 Using VUE-IT The QuickSET Manager (see Figure 7-17) allows the user to develop and manage multiple groups of component settings. The QuickSET Manager is opened when a component is opened. Creating New QuickSET s The user can name a group of settings by clicking on the New button and then entering the name in the pop-up window and clicking on t[...]

7-12 10 July 1998 will appear , and the proper command can be selected from the list by clicking on it. The list displays the following options: Empty - No command assigned to input pin. Mute Combo - The initial contact closure causes the outputs to mute. The subsequent contact closure causes the output to un-mute. Mute Enable - Contact closure cau[...]

7-13 Using VUE-IT QuickMAP Figure 7-20 QuickMAP panel. Double clicking on the QuickMAP (name) entry or by clicking on the entry and then clicking on the Design button can access a graphical representation of the selected QuickMAP (see Figure 7-20). Clicking on the green input triangles in the QuickMAP will open the I/O Properties dialog (see Figure[...]

7-14 10 July 1998 I/O Properties (see Figure 7-21) Figure 7-21 I/O properties dialog. Input The Input Function controls the levels entering the unit. This function can be accessed in any of the following three ways: 1. Clicking on the green input triangles. 2. Right clicking on either the green input or green output triangles and selecting Properti[...]

7-15 Using VUE-IT Output The Output function controls the output levels from the unit. Using the Stereo Control This button controls the tracking of the Gain/Attenuator levels. If the LED is gray , then the two channels do not track each other . If the LED is blue, then the channels will track each other . Clicking on the button will toggle the set[...]

7-16 10 July 1998 Status Information Figure 7-22 Digital I/O status panel. Status information can be obtained for card slots 1 and 2 by clicking on the Status button in the desired slot. See Figure 7-22. Sample Rate Converter On indicates that the sample rate conversion option is selected on the card. The card cannot be selected as the clock master[...]

7-17 Using VUE-IT Device Status Panel Figure 7-23 Device status panel. Clicking on the entry next to the star icon (see Figure 7-9) and then clicking on the Design button in the Project Manager opens the Device Status Panel. See Figure 7-23. The device status panel has five simulated LEDs: Clock Sync (red) The main board cannot lock to specified lo[...]

7-18 10 July 1998 Output Meters Figure 7-24 Output meter panel. The Output Meters (see Figure 7-24) provide monitoring of the outputs of the DSPs before digital-to-analog conversion. T o activate the Meters, click on the green output triangles in the QuickMAP , or click on the Meter Bank entry in the Project Manager and then click on the Design but[...]

8-1 Processing Components PROCESSING COMPONENTS The components used in the VUE-IT interface have a wide variety of controls for adjusting settings. Each component description begins with a full explanation of the component including all of the parameters that can be adjusted. In some areas the explanations may go into more depth than the average us[...]

8-2 10 July 1998 Combine The Combine component (see Figure 8-1) adds multiple input signals together and sends the sum to a single output. In QuickMAPs, 2-to-1, 3-to-1, and 4-to-1 combines may exist. The combine’s default attenuation is set so that the combine’s output level is unity. In every case the attenuation applied to each input channel [...]

8-3 Processing Components - Combine Fine (F) or Coarse (C) Control This button determines the increment/decrement associated with the UP/DOWN arrows. Fine produces small steps in value, while Coarse provides large steps in value. Clicking on the button will toggle the setting. Polarity Control (+/-) This button determines the polarity of the signal[...]

8-4 10 July 1998 Compressor Figure 8-2 Compressor component. A compressor (see Figure 8-2) is used in situations where the input signal has a greater dynamic range, or ratio of loudest to softest, than is desired in the output signal. Compression is accomplished by preventing the output signal from changing in level as much as the input signal, and[...]

8-5 Processing Components - Compressor threshold value, no compression takes place and the change in level of the output signal exactly matches the change in level of the input signal. When the input signal level is above the threshold value, compression is used and the change in level of the output signal is less than the change in level of the in[...]

8-6 10 July 1998 2.5 dB below the input level at the threshold. The divergence continues to increase gradually until approximately 6 dB above the threshold, beyond which the output level rise is dictated solely by the selected compression ratio. There is a smooth, gradual transition from no compression below the threshold to compression above. The [...]

8-7 Processing Components - Compressor Crest Factor Sensitivity A signal’s crest factor is the ratio of a its peak level to its average level. The signal having the lowest possible crest factor is the square wave, whose peak and average levels are equal and whose crest factor is therefore 1.0. The peak level of a pure sinewave tone is 1.414 times[...]

8-8 10 July 1998 input signal was going to be, then the Crest Factor Sensitivity control would ideally be set to: Signal Input of Factor Crest 1 Since this quantity is not generally known, it is best to experiment until satisfactory results are obtained. Metering The compressor meter shows the attenuation applied to the signal passing through the c[...]

8-9 Processing Components - Compressor not its compressor control settings. If multiple compressors utilize the same channel as their sidechain sources, then all controls on all compressors must still be configured. Meter The meter located at the left of the component indicates the amount of attenuation taking place in dB. Threshold The Threshold c[...]

8-10 10 July 1998 Using the UP/DOWN Arrows To increase the level, click on the up arrow. To decrease the level attenuation, click on the down arrow. The amount of increase or decrease is controlled by the fine/coarse control. Fine (F) or Coarse (C) Control This button determines the increment/decrement associated with the UP/DOWN arrows. Fine produ[...]

8-11 Processing Components - Crossover Crossover Figure 8-3 Two-way crossover component. Crossovers (see Figure 8-3) are used to divide the audio signal into multiple bands appropriate for different types of loudspeakers or loudspeaker elements. In QuickMAPs, 2-way, 3-way, and 4-way crossovers may exist. Each of these crossovers may be implemented [...]

8-12 10 July 1998 The lowpass filter LP 1 and the highpass filter HP 1 may each be independently configured as: Bessel 6 dB/octave (1 st -order) Bessel 12 dB/octave (2 nd -order) Bessel 18 dB/octave (3 rd -order) Bessel 24 dB/octave (4 th -order) Butterworth 6 dB/octave (1 st -order) Butterworth 12 dB/octave (2 nd -order) Butterworth 18 dB/octave ([...]

8-13 Processing Components - Crossover Two-way Linkwitz-Riley Crossovers Linkwitz-Riley designs constitute a special, even-order in-phase class of two-way sum-to-allpass response crossovers, and they must be configured in accordance with very strict phase and polarity requirements. A properly implemented 2-way, 12 dB/octave Linkwitz-Riley crossover[...]

8-14 10 July 1998 implementation of Linkwitz-Riley crossovers, for which the ISP-100 has been optimized. The filters marked optional in Figure 8-5 will be explained in the Linkwitz-Riley Crossover section, below. The lowpass filters LP x (except for the optional LP 2 ) and the highpass filters HP x may each be independently configured as: Bessel 6 [...]

8-15 Processing Components - Crossover In the ISP-100, 3-way Bessel and Butterworth crossovers are implemented as shown in Figure 8-6. Bessel crossovers utilize Bessel filters. Bessel filters are designed for maximally-flat group delay, meaning that they have nearly linear phase and excellent transient response. Their amplitude response is not as f[...]

8-16 10 July 1998 band and LP 2 lowpass filter in the low band. The inclusion of these filters is mandatory for proper implementation of the 3-way Linkwitz-Riley crossover; they ensure that the phase shift and magnitude response in each band match those of the other bands to maintain the fundamental Linkwitz-Riley sum-to-allpass quality. A detailed[...]

8-17 Processing Components - Crossover Four-Way Crossovers Figure 8-8 Four-way crossover implementation. In the ISP-100, 4-way crossovers are implemented as shown in Figure 8-8. This parallel structure was selected over the more common binary- tree structure for its suitability to the distribution of filters among multiple DSPs. The parallel struct[...]

8-18 10 July 1998 The attenuation in each band is continuously variable from -96 dB and 0 dB, plus mute. The polarity in each band is selectable as + or - (in-phase or out-of- phase). Each band may be bypassed, in which case all of the crossover filters in that band will be bypassed while the crossover filters in the other bands will not be affecte[...]

8-19 Processing Components - Crossover Four-way Linkwitz-Riley Crossovers Figure 8-10 Four-way Linkwitz-Riley crossover implementation. In the ISP-100, 4-way Linkwitz-Riley crossovers are implemented as shown in Figure 8-10. Linkwitz-Riley designs constitute a special, even-order in-phase class of 2-way sum-to-allpass response crossovers, and they [...]

8-20 10 July 1998 A properly implemented 2-way, 12 dB/octave Linkwitz-Riley crossover is characterized by: •2 nd -order Linkwitz-Riley (Butterworth-Squared) lowpass filter, -6 dB magnitude response at crossover frequency •2 nd -order Linkwitz-Riley (Butterworth-Squared) highpass filter, -6 dB magnitude response at crossover frequency • polari[...]

8-21 Processing Components - Crossover depending upon whether 12 dB/octave or 24 dB/octave filters are used, respectively. The following sections will show this sum-to-allpass trait to hold true for the ISP-100 Linkwitz-Riley 3-way and 4-way crossover implementations. Three-way From Figure 8-6 Summed Response = LP 1 LP 2 ± HP 1 LP 2 ± θ 1 HP 2 =[...]

8-22 10 July 1998 Class To change settings, click on the arrow next to the number in the text box. A selection list will appear. The list may or may not be scrollable. To make a selection click on the desired entry. Cutoff Frequency The Cutoff Frequency can be adjusted three ways: Using the Knob Click on the indicator on the knob and while continui[...]

8-23 Processing Components - Crossover Fine (F) or Coarse (C) Control This button determines the increment/decrement associated with the UP/DOWN arrows. Fine produces small steps in value, while Coarse provides large steps in value. Clicking on the button will toggle the setting. Polarity Control (+/-) This button determines the polarity of the sig[...]

8-24 10 July 1998 Cut Figure 8-11 Cut component. The Cut (see Figure 8-11) can apply as much as 96 dB attenuation, or mute completely, and invert polarity. Attenuation and Polarity Application of attenuation is accomplished by multiplying each data sample by a number whose absolute value lies between 1.0 (0 dB) and 0.000015625 (-96 dB). Muting is a[...]

8-25 Processing Components - Cut Fine (F) or Coarse (C) Control This button determines the increment/decrement associated with the UP/DOWN arrows. Fine produces small steps in value, while Coarse provides large steps in value. Clicking on the button will toggle the setting. Polarity Control (+/-) This button determines the polarity of the signal. A[...]

8-26 10 July 1998 Delay Figure 8-12 Delay component. Delay (see Figure 8-12) is used to compensate for differences in the physical alignment of loudspeakers or loudspeaker drivers. In the ISP-100, the delay in each output channel is adjustable in the range 0 – 2,500 milliseconds (depending on QuickMAP used) in 20.833 microsecond (single sample) i[...]

8-27 Processing Components - Dither Dither Figure 8-13 Dither component. Dithering (see Figure 8-13) is used when shortening high resolution digital audio data words to a lower resolution; for example, when sending 24-bit ISP-100 audio data to 20-bit D/A converters, or directly to a 16-bit Digital Audio Tape recorder through a digital interface. Si[...]

8-28 10 July 1998 numbers between 16 and 24 bits, inclusive. The bit level of the dither signal should be set to the bit resolution of the destination for the data. The resulting dither signal will have an amplitude equal to ±1.0 quantization level (peak-to-peak) at the selected Bit Level. Using the examples, the bit level for the dither signal sh[...]

8-29 Processing Components - Filter Filter Figure 8-14 Filter component. Filters (see Figure 8-14) are used to modify the spectral balance, frequency content, or phase response of the signals upon which they operate. Filter Bands The filters in the ISP-100 are arranged in bands, each of which represent a single 2nd-order filter in the DSP code. Eac[...]

8-30 10 July 1998 All filters in the ISP-100 are derived from analog prototypes. The analog filters are approximated by the Bilinear Transform method, prewarped to match response at the critical frequency appropriate for the type of filter (cutoff frequency for LowPass/HighPass and Peaked HighPass; hinge frequency for LowShelf/HighShelf; center fre[...]

8-31 Processing Components - Filter In the ISP-100 highpass filters the passband slope is selectable from 6 dB/octave, 12 dB/octave, 18 dB/octave, and 24 dB/octave for the Bessel and Butterworth types, and from 12 dB/octave and 24 dB/ octave for the Linkwitz-Riley type. NOTE : Linkwitz-Riley filters are also known as Butterworth-Squared filters bec[...]

8-32 10 July 1998 The hinge frequency is defined as the frequency at which the magnitude of the filter response is changed by (approximately) 3 dB relative to the unfiltered signal. In the ISP-100 highshelf filters the hinge frequency is continuously variable from 20Hz to 20 kHz. In the ISP-100 highshelf filters the transition band slope is selecta[...]

8-33 Processing Components - Filter The EQ filters in the ISP-100 are full parametric. Each may be adjusted for center frequency, boost or cut, and bandwidth. Center Frequency The center frequency is the frequency at which the maximum boost or cut takes place. In the ISP-100 EQ filters the center frequency is continuously variable from 20 Hz to 20 [...]

8-34 10 July 1998 In the ISP-100 EQ filters the bandwidth is continuously variable from 1/12 octave to 3 octaves (which translates to Q between 17.3 and 0.404). Boost and Cut In the ISP-100 EQ filters the boost/cut is continuously variable from +12 dB to -12 dB. Peaked HighPass Filters The Peaked HighPass filter supplied with the ISP-100 is designe[...]

8-35 Processing Components - Filter Cutoff Frequency The cutoff frequency is the design frequency of the highpass filter, and is only approximately representative of the location of the magnitude peak. In the ISP-100 the cutoff frequency is continuously variable from 20 Hz to 20 kHz. AllPass Filters AllPass Filters shift phase without altering magn[...]

8-36 10 July 1998 text box without pressing the Enter key will cause the setting to return to the number that it was before a change was attempted. Alternatively, click and drag across the number in the box to highlight the number in it. Type the new setting and press the Enter key when finished. Using the UP/DOWN Arrows To increase the level, clic[...]

8-37 Processing Components - Filter Alternatively, click and drag across the number in the box to highlight the number in it. Type the new setting and press the Enter key when finished. Using the UP/DOWN Arrows To increase the level, click on the up arrow. To decrease the level attenuation, click on the down arrow. The amount of increase or decreas[...]

8-38 10 July 1998 Fine (F) or Coarse (C) Control This button determines the increment/decrement associated with the UP/DOWN arrows. Fine produces small steps in value, while Coarse provides large steps in value. Clicking on the button will toggle the setting. Isolate (Iso) Control This button allows the user to toggle between viewing either the com[...]

8-39 Processing Components - Gain Gain Figure 8-17 Gain component. Gain (see Figure 8-17) is the first function applied to all ISP-100 input data. The gain component performs many operations, including metering of raw input data (pre-fader), application of up to 18 dB gain, 96 dB attenuation, or full-muting, metering of data after the level has bee[...]

8-40 10 June 1998 to 0 dB and its polarity to positive (in-phase). Bypassing in a muted channel un-mutes it. Metering The meter located at the left of the component measures level in dBFS. The meter’s level will turn red 3 dB before clipping. The red clip light is located at the top of the meter. The green signal present light is located at the b[...]

8-41 Processing Components - Gain (i.e. after the master attenuator). A green LED indicates that the meter information is pre-fader. Clicking on the button will toggle the setting.[...]

8-42 10 July 1998 Gate Figure 8-18 Gate component. A gate (see Figure 8-18) is used in situations where the input signal is characterized by long periods of silence and a noticeably high noise floor, such as a signal taken from magnetic tape or from an open microphone. Gating is accomplished by attenuating the output signal during the periods of in[...]

8-43 Processing Components - Gate Closing Time A gate monitors the level of the input signal and controls the level of the output signal accordingly. When the average input signal level decreases from above threshold to below, a gate closes (applies attenuation) so that the output signal level is less than the input signal level. A gate generally s[...]

8-44 10 July 1998 Detection Window is adjustable in the range 20 µSec (one sample) to 5 Sec. Metering The gate meter shows the attenuation applied to the signal passing through the gate at any given moment in time. When the signal is below threshold and the gate is closed, the meter indicates negative values (gain less than 1.0). When the signal i[...]

8-45 Processing Components - Gate Alternatively, click and drag across the number in the box to highlight the number in it. Type the new setting and press the Enter key when finished. Using the UP/DOWN Arrows To increase the level, click on the up arrow. To decrease the level attenuation, click on the down arrow. The amount of increase or decrease [...]

8-46 10 July 1998 Limiter Figure 8-19 Limiter component. A limiter (see Figure 8-18) is used in situations where the output signal must not exceed a given level, regardless of any increase in the level of the input signal. Limiting is often used for system protection purposes, such as the avoidance of amplifier clipping or the prevention of mechani[...]

8-47 Processing Components - Limiter Release Time A limiter monitors the level of the input signal and controls the level of the output signal accordingly. When the input signal level suddenly decreases, a limiter allows the output signal level to also decrease only as much as is appropriate, given the relationship between the new input signal leve[...]

8-48 10 July 1998 Unfamiliar Controls There are two controls on the ISP-100 limiter that are not available in traditional dynamic range limiters. These controls provide much greater flexibility and utility to this limiter than can be achieved with traditional limiters. Detection Window The detection window is the period of time over which the limit[...]

8-49 Processing Components - Limiter one. The two quantities are then compared and the larger is returned as the signal level. When the Crest Factor Sensitivity is set to 0.00 the ISP-100 limiter operates as a traditional limiter responding to average signal levels; when the Crest Factor Sensitivity is set to 1.00 the ISP-100 limiter operates as a [...]

8-50 10 July 1998 Computation of Average Level There are two common methods of computing average signal level; one is based upon RMS (Root Mean Square) calculations, and the other is based upon Absolute Value calculations. Each of these methods produces a slightly different value for signal level, and the difference depends upon the characteristics[...]

8-51 Processing Components - Limiter increase or decrease is controlled by the fine/coarse control. Attack, Window, Release, and Crest factor controls. All of these controls can be adjusted in three ways: Using the Knob Click on the indicator on the knob and while continuing to hold down the mouse button, move the mouse in an arc. The numbers in th[...]

8-52 10 July 1998 Select Figure 8-20 Select component. The select function (see Figure 8-20) allows you to set the source that feeds portions of a QuickMAP. The user is allowed to select from as many inputs as the QuickMAP allows. An entire QuickMAP can be fed from a single source or multiple sources depending on the settings of the Selects within [...]

A-1 Glossary GLOSSAR Y A to D Analog to Digital. Conversion of an analog signal to a digital representation. Amplitude factor See CREST FACTOR. Attack The rise of a musical note from zero to full volume. Attack time The time required for an applied signal that suddenly increases in amplitude to reach 1-(1/e), that is, 63.2% of its final, stable val[...]

A-2 10 July 1998 Cut To reduce a signal’s overall amplitude. D to A Digital to Analog. Conversion of a digital representation to an analog equivalent signal. dBFS Decibels with respect to digital full scale. The full scale amplitude (zero dBFS value) is the peak value of a sinewave whose positive or negative peak just reaches full scale. dBm dB r[...]

A-3 Glossary Gate A device or circuit which has no output until it is triggered into operation by one or more enabling signals, or until an input signal exceeds a predetermined threshold amplitude. Limiter A device or circuit whose output-signal amplitude remains at some predetermined level in spite of wide variations of input-signal amplitude. Lim[...]

A-4 10 July 1998 THIS P A GE LEFT BLANK INTENTIONALL Y[...]

B-1 Standard QuickMAPs ST AND ARD QUICKMAPS VUE-IT ships with eighteen standard QuickMAPs. These mappings were designed to be flexible enough to be applied in a wide variety of signal processing applications. This appendix provides drawings of the QuickMAPs for reference purposes. The drawings begin on page B-2. Identification of Slots and Conne[...]

B-2 10 July 1998 MONDOEQ.QMS[...]

B-3 Standard QuickMAPs 2X6CMBC.QMS[...]

B-4 10 July 1998 2X8COMB.QMS[...]

B-5 Standard QuickMAPs 3X6CMBC.QMS[...]

B-6 10 July 1998 2X8THRU.QMS[...]

B-7 Standard QuickMAPs 4CHAN.QMS[...]

B-8 10 July 1998 4X6CMBC.QMS[...]

B-9 Standard QuickMAPs 4X6THRU.QMS[...]

B-10 10 July 1998 3_2W.QMS[...]

B-11 Standard QuickMAPs 2WAYS.QMS[...]

B-12 10 July 1998 2_3WAY.QMS[...]

B-13 Standard QuickMAPs 2_2W_SUB.QMS[...]

B-14 10 July 1998 2_2W_FR.QMS[...]

B-15 Standard QuickMAPs 2_2W_2ST.QMS[...]

B-16 10 July 1998 4_2WAYS.QMS[...]

B-17 Standard QuickMAPs 4W_2FR.QMS[...]

B-18 10 July 1998 LCR.QMS[...]

B-19 Standard QuickMAPs MONO3W.QMS[...]

7/98 P/N: 38109-744 Rev. A Copyright © 1997—98 TELEX Communications, Inc. All Rights Reserved. Printed in USA 9600 Aldrich Avenue South Minneapolis, MN 49107 USA Ph. 612.884.4051 Fax 612.887.5588[...]