Dolby SA10

[Frank Raia]

Is there any benefit to add a Dolby SA10 to a CP500 if just using 6 channel in?

[Steve Guttag]

The SA-TEN is there to decode Surround-EX. So, if your content, even if using the 6-channel in has a Surround-EX soundtrack, then the SA-10 will work with that as well. The SA-TEN connects to the CP500 (or any sound processor) output, so it is source independent. The CP500 surround EQ are flattened and the output level is set to a fixed value so as to get the maximum S/N ratio without overloading the SA-TEN's inputs. You then calibrate the SA-TEN's outputs for both level and EQ. The SA-TEN will switch modes via the CP500 (EX or not) and what format is selected.

[Frank Raia]

great thank you Steve.

[Marco Giustini]

The SA-10 is a modded CP45 - more analogue signal manipulation on your sound! I've never worked with it but I understand a DTS-ES would be a better choice than the SA-10 and it works on Dolby Surround EX and DTS-ES - they-re the same thing.

Even SDDS can have Surround EX enabled.

Just one thing: Surround EX is ONLY to be enabled on Surround EX tracks. Dolby Digital had a flag, DTS had 5-digits serial numbers. Do not leave it on all the time. I've seen that so many times, whole multiplexes running everything in Surround EX. It won't make your sound better!

[Frank Raia]

Marco, I didn't get the unit yet but it is on its way!

[Steve Guttag]

The SA-10 is a modded CP45 - more analogue signal manipulation on your sound! I've never worked with it but I understand a DTS-ES would be a better choice than the SA-10 and it works on Dolby Surround EX and DTS-ES - they-re the same thing.

So, your logic is, since the CP500 (or whatever processor is ahead of the EX decoder) is outputting the sound analog, you are better off going through another set of A-D and then a D-A conversion, on top of the prologic decoding? If the movie was mastered using an SA10 or a Dolby decoder equivalent...whatever limitations of the unit are cooked into the mix. The same would be reverse if the DTS-ES decoder was used on the mix.

[Marco Giustini]

Another AD/DA conversion is not great indeed but I feel it's better than routing the sound through another analogue unit and another set of CP45-style equalisers. Not to mention that the DTS-ES will allow the installer to EQ the surrounds in quadrants as the CP650 does. If memory serves, it also carries two separate EQs, one for "stereo" and one for "ES"?

That said, I do not know how good the AD/DA of the DTS-ES is. Those are... 1997? units and DSPs were expensive back then.

The main point of my post was to clarify that either the SA-10 or the DTS-ES will work. Back in 1997 I remember talking to a lot of people who opted for the SA-10 because "I don't get many DTS features here".

[Steve Guttag]

What I don't think you have established is why a DSP representation of a 2:4 decoder, particularly in the technology of the day, will result in the same, if not superior result. Again, the SA10 was used as the reference decoder for when the film was being mixed. That is the sound you are trying to match...anything else is not what was recorded and has to be termed as "mistracking."

It would appear that DTS got it correct on the EQ front. That is, yes they have two sets of EQs...one for normal 5.1 and one for EX. No, the BSl and BSr are not EQed separately. The rear surrounds are EQed has they are grouped for each format. This would be a better method than what the SA10 used...which was the Ls and Rs EQ applying to both the 5.1 and EX mode.

We don't know the quality of the DTS-ES eq. It was full-octave, which was consistent for the surrounds of the era (e.g. CP500 only had full-octave...which was a bump up from prior EQ forms of earlier processors). Graphic EQs are more intensive in DSPs than Parametrics so they were probably working with what they had. This isn't esoteric stuff and Dolby set the upper price limit for equipment. Nobody would be able to sell non-Dolby equipment for the same price as Dolby, let alone more so DTS would have been on a strict budget. One could only adjust the EQ in 0.5dB increments. The SA10 used full-octave EQ as well (instead of that goofy 2/3rd octave thing on the CP45) but with 7 bands to the DTS' 9. The omitted bands were the dubious 63Hz and 16KHz...of little value to a typical surround speaker, and covered by bass/treble controls.

In short, I just don't think you've established that there is some sort of inherent sonic benefit to the DTS-ES unit. The only improvement I can see, from a design perspective, is that they have truly separate EQ for 5.1 versus EX modes. Particularly in the era that we're talking about (as scary as it might sound...a ¼ of a century ago), digital was not inherently superior to analog and the digital equipment used at these price-points is not going to be at the upper-end of digital.