Z Systems rdq-6 Instruction Manual

Summary of rdq-6

  • Page 1

    Rdq-6 instruction manual z-systems audio laboratories 1 rdq-6 instruction manual rdq-6 instruction manual.................................................................................................................................................... 1 introduction...................................

  • Page 2

    Rdq-6 instruction manual z-systems audio laboratories 2 including room correction, speaker matching, speaker compensation, or tonal shaping. Additionally, the rdq-6 allows the user to control master volume, individual channel volume offsets and dither all in the digital domain. With the rdq-6 in the...

  • Page 3: Physical Layout

    Rdq-6 instruction manual z-systems audio laboratories 3 physical layout • front panel controls figure 2 shows the front panel in normal operating mode. Below, you will find a description of all of the front panel controls on the rdq-6. F igure 2 1. Display. 4 row by 40 character. 2. Signal valid ind...

  • Page 4: Rear Panel Layout

    Rdq-6 instruction manual z-systems audio laboratories 4 7. Control knobs. The three large knobs on the front panel are used to change parameters shown in the display. All three knobs may not always be active. To aid in understanding this, the illustrations in this manual will have the knobs "greyed ...

  • Page 5: Operational Guide

    Rdq-6 instruction manual z-systems audio laboratories 5 operational guide • input selection the rdq-6 has three independent digital processor cards, left/right front, left/right surround, and center/sub. Each of these cards has two digital inputs and two digital outputs. The rdq-6 allows you to sele...

  • Page 6: Stereo-Linked/dual-Mono Mode

    Rdq-6 instruction manual z-systems audio laboratories 6 • stereo-linked/dual-mono mode the left/right front and left/right surround digital processor cards can be configured to run in either stereo-linked or dual-mono modes. In stereo-linked mode, the controls and displays pertain to both the left a...

  • Page 7: Volume Control

    Rdq-6 instruction manual z-systems audio laboratories 7 the rdq-6 allows you to set different output wordwidths and dither settings for each of its three processor cards so that you can use different dacs for each channel pair. The majority of dacs today use 20-bit digital-to-analog chips as their c...

  • Page 8: Individual Volume Offsets

    Rdq-6 instruction manual z-systems audio laboratories 8 f igure 7 how to do it. With the rdq-6 in normal operating mode, press the volume button. The display will change as shown in figure 7. To change the master volume, turn the center knob until the desired value is shown on the display. You can a...

  • Page 9: Channel Selection

    Rdq-6 instruction manual z-systems audio laboratories 9 f igure 8 • channel selection the rdq-6's display is only large enough to display the complete set of filter parameters for one channel at a time. The purpose of the channel selection button is to scroll between the filter parameters for each o...

  • Page 10

    Rdq-6 instruction manual z-systems audio laboratories 10 volume is left unchanged. When in bypass mode, none of the rdq-6’s controls are functional; you must press bypass again to return to normal mode. F igure 10 a special note on performing a/b comparisons the italicized text above makes it clear ...

  • Page 11: Transparent Tone Control

    Rdq-6 instruction manual z-systems audio laboratories 11 transparent tone control for a thorough discussion of equalization, please refer to appendix a. There, you will find a complete explanation of concepts such as center frequency, bandwidth, gain, boost, bell filters, and shelving filters. The r...

  • Page 12

    Rdq-6 instruction manual z-systems audio laboratories 12 f igure 11 how to do it. With the rdq-6 in normal operating mode, the display will show all of the parameters for the low shelf filter, filters 1, 2, 3, 4 and the hi shelf filter across the screen from left to right. These parameters are organ...

  • Page 13: Memory Functions

    Rdq-6 instruction manual z-systems audio laboratories 13 press the button corresponding to the filter of interest in order to display its parameters and bring the focus of the knobs to that particular filter. It is important to realize that the display will change whenever you change which channel i...

  • Page 14: Load Preset

    Rdq-6 instruction manual z-systems audio laboratories 14 • load preset f igure 14 how to do it. Now that we know how to store presets, what about recalling them? Assuming we are in the normal mode of operation, press the system button and select the load submenu. The display will appear as in figure...

  • Page 15: Equalization

    Rdq-6 instruction manual z-systems audio laboratories 15 appendix a: equalization and dither • equalization the ttc consists of two types of filters: bells and shelves. These filters derive their names from their frequency-domain shapes. The bell filter is characterized by three parameters: the cent...

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    Rdq-6 instruction manual z-systems audio laboratories 16 slope of 1 giving the widest bandwidth, and a value of 12 giving the narrowest bandwidth. Figure 15 illustrates this relationship clearly -- as we increase the slope parameter, the 3-db points will gradually move toward 1000 hz from the left a...

  • Page 17

    Rdq-6 instruction manual z-systems audio laboratories 17 so far, we’ve only discussed bell-shaped parametric filters. We will now turn our attention to shelving filters. Whereas bell-shaped filters are used to emphasize or de-emphasize a range of frequencies in a bell-shaped region about a center fr...

  • Page 18: Dither

    Rdq-6 instruction manual z-systems audio laboratories 18 f igure 19 • dither in order to understand dither, we must briefly discuss the problems associated with quantization and re-quantization. First, quantization is the process whereby a continuous- valued analog signal is converted into a discret...

  • Page 19

    Rdq-6 instruction manual z-systems audio laboratories 19 internal result of the rdq-6’s volume control is, in general, 40 bits, whereas the cd source material feeding it is only 16 bits. Ideally, we would like to present the digital-to-analog converter (dac) with a signal having the proper bit-width...

  • Page 20

    Rdq-6 instruction manual z-systems audio laboratories 20 the truncated sine wave. Observe that there are harmonically related features all up and down the spectrum. When we listen to this signal, it will sound harsh and “buzzy,” like a square wave. This makes sense intuitively: -96 db undithered fro...

  • Page 21

    Rdq-6 instruction manual z-systems audio laboratories 21 most significant bits (msbs) of the dac. Roughly speaking, attenuating the signal corresponds to “shifting the bits” to the right. Those against digital volume control would argue that the loss of resolution begins to happen when the least sig...

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    Rdq-6 instruction manual z-systems audio laboratories 22 appendix b: the relationship between q and slope the relationship between slope and q is fairly straightforward but requires a bit of preliminary explanation. Appendix a gives some background on the unique digital filter structure that the rdq...

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    Rdq-6 instruction manual z-systems audio laboratories 23 appendix c: finite wordlength digital filtering two of the primary challenges facing designers of digital filters are dealing with quantization error and dealing with roundoff noise. Quantization error refers to a digital filter’s sensitivity ...

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    Rdq-6 instruction manual z-systems audio laboratories 24 digital signal processing when only small-wordwidth fixed-point processors were available and still holds true today, even for larger-precision floating-point processors. Other filter architectures, such as the wave structure, the cascade stru...

  • Page 25: Command Strings

    Rdq-6 instruction manual z-systems audio laboratories 25 appendix d: rdq-6 automation protocol in order to be seamlessly integrated with today's high-end home theater systems, the rdq-6 is controllable via an rs-232 or rs-422 serial signal. This appendix outlines the control protocol for the rdq-6. ...

  • Page 26

    Rdq-6 instruction manual z-systems audio laboratories 26 communication with the rdq-6. The table below describes the functions that the rdq-6 will perform. Function function word1 word1 word2 word2 main volume up 10h (none) main volume down 11h (none) lf / ch.1 offset up 12h (none) lf / ch.1 offset ...

  • Page 27

    Rdq-6 instruction manual z-systems audio laboratories 27 the input change command (1fh) switches the active inputs for the rdq-6. The following table shows the values for word2 for each combination of inputs. Word2 word2 l/r front l/r front input input l/r surround l/r surround input input center/su...

  • Page 28: Specifications

    Rdq-6 instruction manual z-systems audio laboratories 28 specifications • inputs: 1 aes/ebu (transformer-isolated, 110-ohm terminated on xlr), 1 s/pdif (transformer-isolated, 75-ohm terminated on rca) for each of 3 processor cards • outputs: 1 aes/ebu, 1 s/pdif for each of 3 processor cards • input/...

  • Page 29: Precautions

    Rdq-6 instruction manual z-systems audio laboratories 29 precautions the rdq-6 is equipped with two 800 ma slo-blo fuses. These fuses are adjacent to the power transformers on the power-supply circuit boards inside the unit. These fuses are in series with the ac power and disconnects the power suppl...

  • Page 30: Warranty

    Rdq-6 instruction manual z-systems audio laboratories 30 warranty if your z-systems audio laboratories product should fail to operate to specifications as a result of manufacturing defect, the problem will be corrected by z-systems audio laboratories without charge for labor, parts, or surface trans...

  • Page 31: Contact Information

    Rdq-6 instruction manual z-systems audio laboratories 31 systems has also released a two channel, 24 bit analog-to-digital convertor to allow our customers to bring in their analog sources into our tone control products. We also make a six channel, 24 bit digital to analog convertor to facilitate th...