From: Andy Sheen <sheen@src.bae.co.uk>
          Thu, 27 Aug 92 10: 23:05 BST
Subject: Philips DSS
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Thu, 27 Aug 1992 13:04:26 GMT
          id <g.24791-0@ben.uknet.ac.uk>; Thu, 27 Aug 1992 10: 47:48 +0100
          id <7313-0@eros.uknet.ac.uk>; Thu, 27 Aug 1992 10: 47:46 +0100



Haakon.Lie@nta.no wrote to this newsgroup asking about the Philips DSS 
speakers. Well, last month's (Aug 92) "Audiophile" had a 6 page article
on this very speaker and for those interested I thought I'd quote some
stuff from the article:

Technical items first:

Connections on the back:
Power on/off switch
3 position for selecting which speaker pair this speaker belons to (yes-its a
multi room/speaker system :-)
3 position switch to say whether this speaker is the left/right or a mono 
system
Coaxial SPDIF input
Digital SPDIF output.

On the front:
Selected Philips "Isophase" tweeter - is an isodynamic type with a 
non-inductive foil pattern etched on a thin, flat polyamide diaphragm.
(I think that means its a ribbon tweeter :-)
Pair of 5.25 inch polypropylene coned drivers. Above 650Hz, the lower driver
is rolled off leaving the upper unit to handle freq. upto the xover of 4kHz.

The digital SPDIF is first converted from SPDIF to I^2S (I squared S)
bus (Philips internal serial data standard) then passed to a Motorola
DSP (doesn't say what type DSP56000???) that implements a 85 tap FIR
filer + 5 biquads for the bass- mid channel and a 21 tap FIR + 3 biquad
for the treble channel.  These flatten the amplitude response
(50Hz-20KHz +/- 1.5dB), ensure linear phase 350Hz - 19kHz (+/-20deg)
and provide 6th order xover filtering.

After processing by the DSP, the digital signals are converted by two
SAA7350GP bitstream DAC's operating in differential mode. Then fed to
the amps. Treble amp is nominally a 20 watt design, peaking at 110W
for 0.2sec (includes soft clipping), bass-mid rated at 80W but can
supply 450W for short term peaks.

Cabinet has a speaker volume loading the bass units of 13litres and an
IR remote rx. window at the bottom of the front of the speaker for volume 
etc.

Cost 1300 GBpounds, and the reviewer (Alvin Gold) thinks it sounds
pretty good (the performance graphs look prety impressive). He does
have reservations particularly with regard to the amps used, although
the general thrust of the article seems to suggest the DSP overcomes
some of this. In fact he says "the good qualitatively outweighs the bad
many times over in this case".


The other box that is talked about is the DSC950 sound controller,
since without it all you can do is play 1 digital source thorugh the
system. Cost, 400GB pounds. To be fair, any control box/pre-amp with
digital output *should* do the trick though (my comment).

As usual, I have to make the disclaimers - I have no connection with
Philips or anything to do with the review/reviewer.

If anyone does listen to this (or any other active digital
loudspeaker), perhaps they could keep this group informed of how much
better/worse they are than other, more conventional speakers.

Andy Sheen                                 Email: sheen@src.bae.co.uk
FPC 267, British Aerospace PLC,            Tel:   +44-272-363547
P.O. Box 5, Filton,                        Fax:   +44-272-363733
Bristol. BS12 7QW                          #include <disclaimer.h>



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