Film-Tech Forum ARCHIVE: SDDS eq

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Posted by Antonio Marcheselli (Member # 373) on 03-01-2003, 04:53 PM:

Hi everyone

Since I'll work in the near future with an SDDS unit, I've just downloaded the manual and the setup software just to understand the basics of the decoder.

I recall I've read on this forum a message from Brad (if I'm not in mistake) where he says that SDDS eq is too "digital", and that it would be fantastic to have the chance to try SDDS sound using CP500 equalization.

But I've read that SDDS can be connected both after and before Dolby, disabling the SDDS' equalization. I'm talking about 6 ch setups, of course.

Did I correctly understand?

Bye
Antonio

Posted by Dave Macaulay (Member # 813) on 03-01-2003, 07:26 PM:

well, mostly yes.
The 2000 or 2500 can be connected either after the 500, acting as the cinema controller then as the SDDS EQ & volume will be set only from the 2000/2500. It can also be set up as a 6-channel digital/aux input to the 500 and use the 500 EQ and volume control although there isn't a way to disable the SDDS volume knob.
Wiring it after the 500 is normal as this is the easiest way to get auto fallback to SRD/SR if the SDDS drops out - although it means doing house EQ twice. You also won't have the full SDDS 8 channels available if you go into the 500.
The 3000 is a complete cinema analog + SDDS processor and normally you won't have a CP500 as well as a 3000. It is still feasible to install it as a 500 input but I'm not sure there is a way to get a fallback signal out of it to tell the 500 to go to SRD/SR if SDDS drops out.

[ 03-02-2003, 10:21 AM: Message edited by: Dave Macaulay ]

Posted by Christopher Seo (Member # 7) on 03-02-2003, 03:31 AM:

Antonio,

The CP500's EQ is done in the digital domain as well, so this probably wouldn't be a useful test unless you want to compare one DSP EQ to another.

Posted by Michael Schaffer (Member # 1204) on 03-02-2003, 03:54 AM:

I don`t want to start another SDDS vs. Dolby discussion here, but - I am not sure what Brad meant, in my eyes (or ears), the SDDS EQ is vastly superior to the CP500. I can ask Brad at ShoWest what exactly he meant, but I suppose he just wasn`t used to the sound of the DFP-D3000 which has a far clearer sound than the CP500 which is also way noisier. Many people react to clear sound in the higher frequencies negatively, because they are not used to it. The diffuseness that a lot of equipment has in the higher frequencies is often perceived, or rather mistaken, as "warmer sound".
I have had a setup where the SDDS processor was installed as a source into the CP500, I reconnected it to come after the CP500, and it was much, much, much better.
I also had setups with a CP500 as input to the DFP-D3000 which is the better way to do it.
Antonio, which SDDS processor will you be using?
Whichever it is, download the SDDS tech-notes. Among them you will find two which specifically address how to connect to CP500, both variations.

Posted by Brad Miller (Member # 2) on 03-02-2003, 04:07 AM:

The SDDS internal pink noise generator is high frequency deficient. So assuming you EQ a Dolby vs. a SDDS the same, the SDDS will always sound "brighter" or "cleaner" when A/B compared because the tech turned up the high frequencies trying to get a desired response on his RTA. If you like your sound trebly and bright, then go for it. I don't. If you take (for example) a dts or SRD track played back through a CP65, and then switch in and out to an SDDS player with it's own internal calibration, the same SPL also is much "louder" appearing and harsh. It's those frequencies which brings about complaints. This is why most every tech I know when setting up an EQ internally in a SDDS processor calibrates the levels at 75db, not 85db. You just have to play SDDS lower because of that treble boost or customers will complain. With the DFP-2000 only having a fader 10db down from reference, MANY theaters simply couldn't turn it down low enough when calibrated at 85db. However that same track plays well at 85db (or close to it) on a Dolby processor (particularly the older ones with cat64B cards).

I've set up two SDDS units in my screening room "double stacked". One was EQ'd inside the SDDS processor and the other was left "flat" and ran through the Dolby's EQ. Both were calibrated to have as close of a response and level to each other as possible. In the end though, every single person I gave an A/B test found the one EQ'd by the Dolby processor to sound superior to the internal SDDS EQing. Do the test for yourself.

I've never been a fan of digital EQing. It's hard to put into words, but there is a certain harshness, almost metallic sound to it. A SDDS ran into a CP200 or CP65 will have much better sound than an SDDS signal calibrated inside a CP500 or inside the SDDS player itself. (One of these days I've got to get my hands on a Panastereo and play with it.)

Another test you can do is to take a CP65 with a properly calibrated reverse scan reader and compare the SR track to the SDDS (calibrated inside the Sony processor) track. The discreteness isn't there, but it certainly is easier to listen to. Digital is not always better.

Posted by Antonio Marcheselli (Member # 373) on 03-02-2003, 06:50 AM:

Michael,

I believe 2500 since the theater is already equipped with CP650. I agree with you that many people do not like too much high frequencies, that's why many people prefer Dolby vs DTS, IMHO.

However Brad is not saying this. I will be curious to make an A/B comparison with my ears. But will not the tech note the lack in high frequencies in SDDS' pink noise? If the PN is HF deficient he/she will note that HF controls has to be boosted rather than Dolby ones, isn't it?

More: has anyone ever connected the SDDS' outputs directly to the RTA and check if the PN is flat?

If I correctly understood, you can also use the SDDS eq for Dolby sound too. If you left flat the DOlby EQ and check the "use eq" box on SDDS for aux format, you should achieve the goal. But I'm not familiar with the SDDS. Am I wrong?

Bye
Antonio

Posted by Steve Guttag (Member # 268) on 03-02-2003, 09:34 AM:

I stumbled upon the SDDS pink noise issue when setting up a 2000 with a CP-200 using and SA-10 Surround-EX adapter. Since the SA-10 only has a partial joke of a full-octave EQ...I set up some RANE 1/3-Octave constant-Q eqs outboard. Thus everybody had to share the surround EQ and have their internal EQs bypassed or set flat.

So after tuning the CP-200 first...I checked with the SDDS on the surrounds....low and behold...the HF appeared to be rolled off...thus if one were to use the SDDS internal pink noise, they would artificially boost the HF of the system.

I have not confirmed this on the 3000 or 2500. And yes, you can verify this on an analyzer plugged straight to the various processors.

Steve

Posted by Michael Schaffer (Member # 1204) on 03-02-2003, 01:48 PM:

Brad, thanks for explaining that. It will be interesting to talk about this in more detail at ShoWest. It is no secret to the members of this forum that I am a big fan of the SDDS process. I indeed like the SDDS bright sound because it is gives better definition to details which comes from more clarity in the high harmonics.
That does not mean that I like the brighter sound generally better. If I listen to old magnetic soundtracks, I like the mellowness of the sound too. It sounds kind of "homely". And it fits the recording style of the era as that was sensitively adapted to the properties of the technology available.
But for modern sound equipment, I think crisp, clear sound is much better. You can still use soft, round sounds on the soundtrack if you like. The SDDS process will not brighten them up. But some other equipment will mellow all sounds and therefore limit the range of reproducable tone colours.

Antonio, yes, you can use the 2500 internal EQ for external input sources. If you want to do that is up to you. However, you should install the equipment with the DFP coming after the CP650. If you set it up with the DFP as external input for the CP650, I will come to Italy and set your beard on fire.
And please, read the manuals and tech-notes carefully. In my experience, the SDDS equipment works very well, but many technicians have not not read the documentation carefully, and that is the cause of many problems with the equipment.

Posted by Antonio Marcheselli (Member # 373) on 03-02-2003, 02:18 PM:

Steve,

If I'll have the opportunity, I'll check the SDDS outputs directly with an RTA.

Michael,
"Set your beard on fire"? [Smile]

Wouldn't it work? As I told you I'm not familiar with an SDDS, I'll never try to set up by myself and as I wrote!! [Smile]

Bye
Antonio

Posted by Michael Schaffer (Member # 1204) on 03-02-2003, 02:32 PM:

It would work but the DFP is simply the superior sound processor so it wouldn`t make sense to channel it through the CP650. It would just be a waste of the unit.
Who is setting up the DFP? As I said, many technicians are not familiar with the SDDS hardware even though there is plenty of literature and I have seen very strange things done by technicians who had no clue what they were doing.

Posted by Brad Miller (Member # 2) on 03-02-2003, 02:46 PM:

quote:
The SDDS process will not brighten them up. But some other equipment will mellow all sounds and therefore limit the range of reproducable tone colours.

Nope, you've got it backwards. Because the SDDS has defective P/N, the reproduction of SDDS is NOT what was intended to be heard. This is the same thing as people to get a graphic EQ and make a "V" out of it even with relatively flat speakers because of personal preference.

And speaking of that, why does SDDS not offer course bass and treble on their EQ? That makes a huge difference when calibrating to get things as close as possible before jacking with the individual controls. Any processor that does not have this will never sound as good as one that does because the individual controls end up being slid further to try and get the desired response.

I must also disagree with you regarding the CP650. I have found them to sound quite good, probably the best processor on the market (that I have tuned) that does processing in the digital domain.

Antonio, remember if you place the SDDS *after* the Dolby, you also lose control of your formats. That meaning that anytime SDDS is detected, that format will literally take over and play SDDS in the auditorium. I have always had a huge beef with that. I want control of what is to be played in the auditorium, not some machine that assumes what I want to be played! [Mad]

In my screening room I have a CP200 as well as a DFP-3000. The 3000 does nothing but reproduce SDDS. It does a fantastic job of this and I would not have it any other way. Because I have an Aux rack, I still get the full 8 channel sound.

Posted by Michael Schaffer (Member # 1204) on 03-02-2003, 03:30 PM:

If you have a 2000 or 2500, you can simply switch it off when you don`t want SDDS. With the 3000 you have all the format control options that you have with other processors, plus a few more. You can define multiple fallback chains, individual dynamic offsets for all formats etc and also easily suppress SDDS playback if you don`t want it at any given moment.
The unit is also very remote-controllable.

Posted by Brad Miller (Member # 2) on 03-02-2003, 03:54 PM:

Yes Michael, but if you want to run something in SDDS, then something in SR or another format, then go back to SDDS, the 2000 and 2500 cannot be controlled without major wiring issues. It's on or off and that sucks.

Also, since the P/N does not match, anytime the digital drops out, the tone of the room will be altered and the revision becomes obvious. Had Sony just sat down and made a DA20 kind of SDDS player, the format would be MUCH more saturated in the market. Instead they came along too late and were too pricey because of all the unnecessary circuitry and that is what is killing them. The format will not be around in the long run.

I will agree the 3000 was well thought out. There are still issues with it though. Let's say you want SDDS to be the primary format and you have a dts player hooked into AUX 1. When the SDDS drops out and switches for a few moments into dts, there is a literal drop out in sound for a few milliseconds which is not acceptable. There is a newer board that can be used in the unit that offers cross-fading to cover this up, but most everyone with a DFP-3000 has the older board with the dropout.

In my screening room, SDDS is my preferred format (but only because of the way I have it wired). Even with that being said, I rarely run it because even after having the Sony techs personally calibrate my readers, I still have that obnoxious BUUUzzzzUUUzzzUUUzzzUUUzzz from the sprocket on the reader that is so loud you can hear it in the auditorium. With the older 2000 series readers you could thread one perforation less tension and assuming it was calibrated to be threaded like that would track flawlessly. There is no way to get around the reader noise with the 3000. Even assuming the projection room wall was 100% soundproof and the audience could not hear the reader noise, it's enough to drive a projectionist insane. If Sony would fix just one thing, I really wish they would find a way to quieten down their reader!

Posted by Antonio Marcheselli (Member # 373) on 03-03-2003, 07:24 AM:

More, if you have CP650 with EX decoding, to have EX applied to SDDS too, you'll have to connect the SDDS before dolby, right? I believe there isn't another way to have SDDS-EX without an SA-10.

Bye
A

Posted by Steve Guttag (Member # 268) on 03-03-2003, 08:00 AM:

So Brad...on your SDDS set up...did you place it in the JM-11/JM21 loop? If so, how are you switching it in and out...that is...how do you select SDDS and how does it handle digital drop outs?

Oh and the DFP-D2500 is no more...on our most recent sale...we were told we got the last units.

Steve