SRS Gear

[Richard Fairbanks]

I want to throw in a couple of cents worth. I have not used SRS gear, so take this for what it's worth.

First, Dolby and DTS are de facto standards today, with Dolby dominating the matrix world. If you have mixed 4:2:4 you know very well how screwy the playback steering logic can be. Weird things happen sometimes, especially when some music mixes start sucking everything into the surrounds. I have no idea who, if anyone, holds patents for matrix surround technology. What I know is that Dolby, specifically Dolby, has put their matrix playback steering logic into nearly every receiver and DVD player on the market. It is the playback steering logic that so drastically affects playback image. I would not think about spending a penny until I could actually compare SRS playback to Dolby playback results.

Also, Pro Logic II (5:2:5) is a very different animal than Pro Logic (4:2:4). I do not think you can really mix in 5.1 and expect an automatically created matrix version to be very good. Pro Logic II is supposed to be backwards compatible with Pro Logic, but the surround channel(s) sound drastically different between the two modes. PLII uses full bandwidth surround channels, whereas PLI is mono limited bandwidth. During mixing it is easy to have too much ambience coming out of the PLII surrounds, yet the same mix will not have enough surround ambience with PLI! Dolby claims PLII was designed specifically for music, and in some ways the decoded playback matches your discrete 5.1 inputs better. PLII reveals even more of the infamous "magic surround" effect, and I have found it also reveals steering errors better. Also, when you add stereo surround channels together to make them mono for 4:2:4, this is being done with simple addition. I have noticed very obvious level differences in surround effects when switching between PLI and PLII modes, which can be corrected by panning surround elements to hard rearL or rearR and avoiding surround center.

I expect SRS will have the same or similar problems, which makes it even more important to know that what you hear while you are mixing is what will play at home.

[martian]

for sure for 4:2:4 it is essential to monitor thro encode-decode chain. I often found ambiences and music could whip your dialog away from center and it is very distracting.

but having used SRS to mix a fair number features I think the compatibility issue isn't a biggy.

I know one very reputable engineer who was working in Burbank for many years - and who always made my opticals sound good swore by ultra stereo encoders. despite the fact almost every cinema in existance has dolby cinema processor installed. And he had both dolby and ultra stereo encoders patched in and ready to go!

No disagreement on the 5.1 - absoluteley the best way to go is a tweaked mix for each playback system, but as an engineer who has been at war for a good few years I think you'll agree that you'd better get the front speakers carrying most of the mix- especially if time and budget don't allow you that luxury of different mixes.

The way I looked at it is that you are mixing SR- which presently has more market penetration - can be transmitted over cable etc. but actually only printing the DVD in AC3. So you can get the surrounds in stereo. But yes you are mixing to the limitations of standard SR. but it does work!! maybe it's a safer way to mix? phase cancellation can cause stuff in the surrounds to disappear when in mono. ( my parents' TV for instance is still mono). A budget thing really and a SR mix will playback nicely in on a stereo TV too. Ideally you will do a 5.1 mix for cinema release. ( even better was SDDS - dolby seems to lose a lot of HF detail when A-B'd to that. Couldn't comment on DTS as I haven't done that comparison in a large mix room/cinema.

Folding the left and right surrounds to mono will require some attenuation, and if you have the time to ride the faders then so much the better. Seems like a lot of studios fold down their SRD to SR in just that fashion.

I feel strongly about SRS circle surround because it really empowered my studio at a time when dolby wouldn't let us have an encoder!! ( even though our place compared favourabley with most of the studios in the area that were licensed.)

[dr sound]

Martian,
I can't agree about the "Ultra Stereo". This has not been my experience. I did a movie back in 97 and we started Printmastering through an Ultra Stereo box and it just didn't sound good to me. It really narrowed the spread. We imediatly switched to a Dolby SEU4/ SDU4 and it was much better.
Each and every format has it's sonic signature/ tradeoff. That's why I like discreet tracks.

[dr sound]

Richard,
On the SRS Plug In Encoder/Decoder it has a Dolby Pro Logic decoder on it so one can hear how it sounds to people at home with that type of decoder. I agree each format/box has it's own tradeoffs.
It comes down to what you the Mixer is most happy with(least amount of trade off).