BSS FDS360 Manual 电路图.pdf

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1、1 FDS 360 User Manual RadioFans.CN 收音机爱 好者资料库 2 This equipment has been tested and found to comply with the following European Standards for Electromagnetic Compatibility: Emission Specification:EN55013(1990)(Associated equipment) Immunity Specification:EN50082/1(1992)(RF Immunity, Fast Transients a

2、nd ESD) Mains Disturbance:EN61000/3/2(1995) For continued compliance ensure that all input and output cables are wired with cable screen connected to Pin 1 of the XLR. The input XLR Pin 1 on BSS equipment is generally connected to chassis via a capacitor to prevent ground loops whilst ensuring good

3、EMC compatibility. V3.0JMK14 October 1996 We have written this manual with the aim of helping installers, sound engineers and consultants alike get to grips with the FDS-360 and obtain its maximum capability. If you are new to BSS products, we recommend that you begin at the start of the manual. If,

4、 however, you are already familiar with the intended application, and just want to get the unit installed without delay, then follow the highlighted sections. We welcome any comments or questions regarding the FDS-360 or other BSS products, and you may contact us at the address or World Wide Web sit

5、e given in the warranty section. RadioFans.CN 收音机爱 好者资料库 3 Contents Contents 1.0What is a Crossover?5 2.0The difference between Active and Passive Crossovers6 3.0Other advantages7 4.0The Linkwitz-Riley advantage8 5.0What is special about BSS Crossovers?9 6.0Unpacking9 7.0Mechanical Installation12 8.

6、0Mains Power Connection13 9.0Input Connections14 9.1XLR Plugs.14 10.0Output Connections14 10.1XLR Plugs14 11.0Controls16 11.1Mode Switch16 11.2Level Control16 11.3Mute Switch16 11.4Polarity Switch17 11.5Mono Low Switch17 11.6Phase Control17 11.7Limiter Threshold Switch18 11.8Signal LEDs18 12.0Freque

7、ncy Cards19 Card Location for Four Way System19 Card Location for Three Way System19 Card Location for Stereo Two Way System19 13.0Rear Barrier Strip20 13.1Limiter Cancel20 13.2Auto Mute Cancel20 13.3Limiter Threshold Reference20 13.4Band Insertion Points20 4 Contents 14.0Modes of Operation21 14.1Mo

8、no Three Way with Extra Full Range Buffered Output21 14.2Operating a Sub-Woofer system from an Effects Send21 14.3Mono Low between separate units21 15.0Limiter Adjustment22 Adjustment for A22 Adjustment for B22 16.0Phase Adjustment24 17.0System Diagrams and Descriptions25 17.1Full unit25 17.215Hz Su

9、bsonic Filter Change25 18.0Filters and Frequency Tables27 18.1Standard Filters27 18.2Full Range Frequency Card27 19.0BSS Supported Options30 19.1Output Balancing30 19.2Security Cover30 20.0FDS-360 Equalisation Options31 20.1Introduction31 20.2FDS-360D Installation31 20.3Circuit Description31 20.4Fil

10、ter Design33 20.5Application Notes35 20.6Application of the FDS-360D to a system36 20.7FDS-360 E Installation38 21.0Electronic/Chassis Earth Link39 22.0Transient Suppressor Replacement 39 23.0Troubleshooting40 24.0Glossary41 25.0Specifications44 26.0Warranty Information45 Index49 User Notes51 Spare

11、Parts Information 5 1.0What is a Crossover? Crossovers Crossovers are a necessary part of sound reinforcement systems because the loudspeaker drive-unit which can produce clear reliable high SPL (sound level) over the full audio bandwidth has yet to be invented. All real-world drive units work best

12、when they are driven over a limited band of frequencies, for example: Low, Mid and High. Any crossover aims to provide the division of the audio band necessary, so each drive unit receives only the frequencies it is designed to handle. In a high power, high performance sound system, the crossover sh

13、ould also reject unsuitable frequencies to avoid damage and poor quality sound. Fig 1.1 Stereo 2-way Crossover setup Fig 1.2 Mono 3-way Crossover setup 6 2.0The difference between Active and Passive Crossovers Passive crossovers divide the frequency spectrum after the signal has been raised to a hig

14、h power level. They are generally heavy, bulky and inefficient. Active crossovers utilise ICs and transistors, and divide the frequency spectrum at line levels, immediately ahead of the amplifiers (See Figure 2.1). An active crossover does the same job as a passive crossover, but with more precision

15、, flexibility, efficiency, and quality. Fig 2.1 Active and Passive Crossovers Crossover frequencies can be more readily altered to suit different driver- horn combinations. The level balance between the 2 or 3 frequency bands (brought on by differences in driver and amplifier sensitivity) can be rea

16、dily trimmed. Inside an active crossover unit, line-driving, signal summing, driver equalisation, system muting and polarity (phase) reversal facilities can all be incorporated at small extra cost. 7 Crossover advantages 3.0Other advantages The drive-units in sound reinforcement systems utilising ac

17、tive crossovers benefit because: Steep rolloffs are readily attainable. The -24dB/OCT rolloff in the BSS FDS- 360 active crossover rapidly discharges out-of-band energy. At one octave below the crossover point power received by the driver has dropped to less than % (or 1/200th) of full power. The re

18、sult: Bad sound resulting from out- of-band resonances are effectively masked immediately beyond the crossover frequency (See Figure 3.1). This contrasts markedly with passive crossovers, where slopes in excess of -12dB/OCT are rarely achieved, and power rolloff is 4 times less rapid, per octave. Fi

19、g 3.1 Crossover Terminology If one frequency range is driven into clip, drive-units and horns in other frequency ranges are protected from damage, and distortion is kept to a minimum. Direct connection of drive-units to the power amplifier cuts out loss of damping factor, normally inevitable thanks

20、to the appreciable resistance of the inductors in passive crossovers. Amplifiers benefit too from the use of active crossovers. Because they do not handle a full-range signal, clipping produces far less harmonic and intermodulation distortion. The results: Momentary overdrive sounds less harsh. Also

21、 the amplifiers dynamic headroom is generally higher, and heatsink temperatures can run lower. 8 Linkwitz-Riley Alignment 4.0The Linkwitz-Riley advantage There is an additional set of advantages exclusive to active crossovers made by BSS, and other manufactures using the Linkwitz-Riley alignment (Se

22、e Figure 4.1). Fig 4.2 Radiation Pattern Frequency showing excellent on- axis symmetry Zero Phase difference at crossover: The phase difference between drivers operating in adjacent frequency bands is close to zero degrees at the crossover frequency. Phase alignment in this manner prevents interacti

23、ve effects (i.e.: High and Low drivers fighting each other), over the narrow band of frequencies around the crossover point; this is where the units from two adjacent frequency ranges are contributing near equal amounts of sound pressure. More predictable sound dispersion: By providing in-phase summ

24、ation at the crossover point(s), the Linkwitz-Riley alignment provides for more cogent sound dispersion - it provides on-axis symmetrical radiation patterns. (See Figure 4.2). Invisible slopes: The absence of electrical phase difference close to the crossover frequency helps to make the steep -24dB/

25、OCT slope effectively inaudible,. Response peaks and dips are negligible and inaudible given the correct polarity (phasing) of the speaker connections. The same is not true of the shallower (-6, -12 or -18dB/OCT) rates or rolloff, in other crossovers. Fig 4.1 Linkwitz-Riley filters 9 BSS Crossovers

26、5.0What is special about BSS Crossovers? The FDS-360 is an electronic crossover system, and incorporates all the latest technology and facilities that are required for todays high powered loudspeaker systems. This frequency dividing system (FDS) is substantially more than a basic crossover, combinin

27、g a high degree of sophistication which enables accurate control of loudspeaker power, dispersion and acoustical summation around the critical crossover region. The FDS-360 features the following: Stereo two-way mode, or switchable three/four way mono mode. Separate frequency band limiters matched t

28、o the precise band of frequencies controlled. Separate polarity switching for each band. LED signal level monitoring. Band insertion points for interfacing external equalisation and time delay units. Band-edge phase adjustment allowing 360 degrees of control. Crossover filter programming via plug-in

29、 frequency cards allowing any frequency, choice of 12/18/24dB/OCT slopes and filter responses to be specified. 24dB/OCT Linkwitz-Riley responses are supplied as standard. Internal equalisation option. Every FDS-360 is manufactured to the highest professional standards with a robust steel case, high

30、quality circuit boards and ICs, and high quality components to provide reliable performance under the most demanding conditions of the global sound-reinforcement environment. In common with all other BSS equipment, the FDS-360 is subject to stringent quality control procedures throughout the manufac

31、turing process. Components are tested against demanding acceptance criteria. Every completed unit is tested both by measurement and in a listening test carried out by trained audio professionals. To positively ensure reliability, all units are burnt-in for fifty hours, before being tested. Unpacking

32、 As part of BSS system of quality control, this product is carefully inspected before packing to ensure flawless appearance. After unpacking the unit, please inspect for any physical damage and retain the shipping carton and ALL relevant packing materials for use should the unit need returning. In t

33、he event that damage has occurred, please notify your dealer immediately, so that a written claim to cover the damages can be initiated. See Section 26. 6.0Unpacking 10 Getting to know the FDS-360 11.2 11.411.5 11.8Fig 6.1 Front Panel Fig 6.2 Rear Panel FUSE 5x20mm 240 .51 ON OFFWA .51 ON OFFWA 10.0

34、 8.011.1 11 11.3 11.6 All numbers in bubbles refer to Section numbers. .51248dB ON OFFWATS560B4H .51248dB ON OFFWATS560B4H .51248dB ON OFFWATS560B4H .51248dB ON OFFWATS560B4H 11.713.0 9.0 12 7.0Mechanical Installation A vertical rack space of 1U (1 / 10mm) deep is required. Ventilation gaps are unne

35、cessary (See Figure 7.1). If the FDS-360 is likely to undergo extreme vibration through extensive road trucking and touring, it is advisable to support the unit at the rear and/or sides to lessen the stress on the front mounting flange. The necessary support can generally be bought ready-built, as a

36、 rack tray. As with any low-level signal processing electronics, it is best to avoid mounting the unit next to a strong source of magnetic radiation, (for example, a high power amplifier), to help keep residual noise levels in the system to a minimum. Installation Fig 7.1 Unit dimensions. Fig 7.2 Ra

37、ck dimensions. 13 Connecting to Power 8.0Mains Power Connection Voltage: The FDS-360 operates on supply voltages between 95 and 125V AC. It must not be plugged into 220, 230 and 240V AC outlets. If the unit is accidentally connected to an AC supply giving in excess of 132V AC, refer to section 23, (

38、See Figure 8.1). Frequency: Both 60Hz and 50Hz are acceptable. Fig 8.1 Mains fuse on rear panel. FUSE 5x20mm 240 Grounding: The FDS-360 must always be connected to a 3-wire grounded (earthed) AC outlet. The rack framework is assumed to be connected to the same grounding circuit. The unit must NOT be

39、 operated unless the power cables ground (earth) wire is properly terminated - it is important for personal safety, as well as for proper control over the system grounding. If the electronic 0V has to be separated from the chassis and mains power earth, refer to section 23. Connections: The AC power

40、 cable has a moulded 3-pin utility plug attached to the free end to facilitate the correct and proper connections. AC Power Fusing: The incoming line power passes through a 200mA (for 240V only) anti-surge (T) fuse, accessible from the rear panel (The fuse is rated at 250mA for 120V). If the fuse bl

41、ows without good reason, refer to section 23. Always replace with an identical 20mm x 5mm T rated fuse for continued protection from equipment damage and fire. Also see section 22 for information on replacing blown transient suppressors (if applicable). Power ON: Before turning on the power, it is w

42、orth checking that the three frequency cards are installed correctly. Loosen the captive screw securing the small cover plate on the lid of the unit, and inspect the cards. The slope and frequency information is recorded on each of these cards, and it must be ensured that all cards are fitted, regar

43、dless of whether they are required. Refer to sections 12 Rfa, Rfb, Cfa and Cfb, and is given by the following equation: Fc =1/6.28 (R*fa/b . C*fa/b),where R is in ohms, C is in Farads, F is in Hz. For symmetrical and normal responses note that Rfa = Rfb and Cfa = Cfb, and the equation reduces to: Fc

44、 =1/(6.28 x Rf x Cf) Such that for Rfa = Rfb = 10k and Cfa = Cfb = 16nF than Fc = 1kHz. Design limits for Rf should be within the range 2k to 100k ohms. There are no limits for Cf apart from physical space on the circuit board. 2. Q and dB Boost/Cut: Both of the parameters Q and dB are set by a sing

45、le resistor, Rq and RdB respectively. To some extent they are interactive and it is therefore easiest to obtain their values from a set of graphs (See figure 20.10 and 20.11). These allow for ranges of Q from 0.2 to 3.0 and for a range of boost/cut of up to 16dB. For further information on deciding

46、on the values of these filter variables, refer to section 20.5. Fig 20.4 First Order Sample Response 20501002005001k2k5k10k20k40k 5dB Bell ResponseRQ values, 0 , 1k , 4k7,= 12.5dB Frequency (Hz) 8 Fig 20.5 Parametric Equaliser Sample Response Equalisation Options 35 20.5 Application Notes 100Hz Notc

47、h to reduce mains related interference The design specification for this would be: Fc= 100Hz Q= Maximum possible dB cut= Maximum possible Using the Fc equation given earlier, and selecting Cf = 220nF gives a value for Rf = 7.23k ohms. Using the graph for Rq will indicate that for a maximum value for

48、 Q, the value of Rq should be also be a maximum. In this circuit we can allow Rq to be infinite, so the design value for Rq would be open circuit, and no resistor would be fitted in this position. Using the graph for RdB will indicate that a minimum value for RdB is required for a maximum value for

49、boost/cut. In this circuit we can set a minimum value for this of 10k ohms. (Ensure this resistor is fitted in the cut of C position on the circuit board). Notch depths of up to 50dB can be achieved, however this depends on the close matching of the frequency determining components. An example of this notch circuit is shown below in Figure 20.6. 20501002005001k2k5k10k20k40k 10dB Notch Response RQ =, Rcut = 10k, Fc = 960Hz Frequency (Hz) 8 Shelving Filter: Utilising the parametric section and selecting a very low Q value will achieve a standard shelving type response