Monday, October 7 9:00 am 11:00 am
SESSION J: HIGH RESOLUTION AUDIO
Chair: Rhonda Wilson, Meridian Audio Limited, Huntingdon, Cambridgeshire, UK
J-1 DSD Processing ModulesArchitecture and ApplicationNathan Bentall, Gary Cook, Peter Eastty, Eamon Hughes, Michael Page, Chris Sleight, Mike Smith, Sony Broadcast & Professional Research Labs, Oxford, UK
As demand continues to grow for production equipment targeting the high resolution, multichannel capabilities of SACD (super audio CD), there is increasing interest in adding DSD capability to both new and existing systems. The prospect of researching and implementing the necessary algorithms from scratch can be daunting. The high data rates, coupled with the asymmetric multipliers often required by the algorithms, make conventional von-Neumann-type DSP platforms (where most developers traditionally have their DSP expertise) seem sub-optimal. Based on custom DSD audio processing engines and packaged in the very compact SODIMM form factor, the modules described in this paper can add high quality, real time, low latency DSD audio processing functionality to a system with a minimum of development time.
Convention Paper 5690
J-2 Multichannel Audio Connection for Direct Stream DigitalMichael Page, Nathan Bentall, Gary Cook, Peter Eastty, Eamon Hughes, Christopher Sleight, Sony Broadcast & Professional Research Labs, Oxford, UK
The development of large-scale multitrack production equipment for direct stream digital (DSD) audio will be substantially aided by the availability of a convenient multichannel interface. DSD is the high-resolution one-bit audio coding system for the super audio CD consumer disc format. Existing multichannel audio interconnection and networking protocols are not easily able to support the high-frequency sample clock required by DSD. A new interconnection type is introduced to provide reliable, low-latency, full-duplex transfer of 24 channels of DSD, using a single conventional office networking cable. The interconnection transfers audio data using Ethernet physical layer technology, while conveying a DSD sample clock over the same cable.
Convention Paper 5691
J-3 The Effect of Idle Tone Structure on Effective Dither in Delta-Sigma Modulation Systems: Part 2James A. S. Angus, University of Salford, Salford, UK
This paper clarifies some of the confusion that has arisen over the efficacy of dither in PCM and sigma-delta modulation (SDM) systems. It presents a means of analyzing in-band, idle tone structure using chaos theory and describes a fair means of comparison between PCM and SDM. It presents results that show that dither can be effective in SDM systems.
Convention Paper 5692
J-4 DC Analysis of High Order Sigma-Delta ModulatorsDerk Reefman, Erwin Janssen, Philips Research, Eindhoven, The Netherlands
A new method for the DC analysis of a sigma-delta modulator (SDM) is presented. The model used for the description of an SDM is adopted from Candys model for a first order SDM. However, where Candys model is exact for a first order SDM, it fails to be so in a higher order case. In our model, we deal with this by the introduction of stochastic behavior of the SDM and obtain the probability density distribution function of some variables which determine many of the characteristics of the SDM in the time domain. Comparison with simulation results shows that the assumption of stochastic behavior is rather good for SDM orders greater than 3, which display significant noise shaping. For lower orders (or less aggressive noise shaping) the approximation is less good. As an aside, the new model of sigma-delta modulation also clarifies why the time-quantized dither approach presented by Hawksford is much better compared to standard quantizer dithering.
Convention Paper 5693