Interfaces, ADC's and Dolby Encoding...

[MrG[UK]]

Hey all!!
(sorry if this seems like a repeat posting from another forum!)

Ive been trying to build a bit of a semi-pro surround sound mixing suite at home and have come into a few brick walls that i cant seem to get around/have very little expertise in.

My principle idea is to create a small home based surround mixing platform that i can work on minor surround projects to a relatively okay standard. Then take the project into a professional environment to tweak so that valuable studio time is not taken up.

Ive thought long and hard about the problems of surround sound at home and the only viable solution to it that i can see is going down the Dolby Headphone Technology route. To that end i've Equipped myself with a Pioneer SE-DIR2000C and ditched the wireless headphones for my high quality Wired Audio Technicas.

My question/ failing areas are....

1) do i encode to Dolby DTS in the box via plugins or do i route it via USB/Firewire to a new Audio interface that does the encoding for me. if so what Interfaces would you recommend for this (the higher quality the better).
2) do i buy a 2nd Audio Interface that accepts ADAT/ Analogue inputs up to 8 channels etc... and encodes to Dolby DTS?

My restrictions at the moment are that the Pioneer Unit only accepts Digital Optical and Coaxial. it cannot run multiple inputs at one time. It accepts Dolby DTS, AAC and PCM data.


I am kind of on a budget...
But the advantage of the 1st option is less DAC and ADC conversions(cheaper), disadvantage is incompatability with Pro Tools.

Advantage of 2nd is compatability with Pro Tools, disadvantage being 2 DAC conversions and 1 ADC conversions(more expensive).

any advice/help would be greatly appreciated!

- note: looked at the highest encoding resolution on the Pioneers manual (thats in japanese) and its up to 48kHz, so no 192kHz AD/DA Converters needed! btw this is encoding just for confidence monitoring and mixing, not final mixdown to master :P

[MrG[UK]]

wow cheers for so much help guys! I truly am overwhelmed by the comradeship, the sense of helpfulness and overall community spirit!

you do realize criticism can be constructive too! people learn from the errors in their ways and all that jazz. but hey, pardon me for not being perfect.

[Geert van den Berg]

Your reaction is very exaggerated.

If you'd did a search on this forum, you might be able to find all the answers to your questions, we've had similar questions like this before.

But to answer in short. There's no such thing as doing surround on a budget.

What you intend to do is couple semi-pro audio gear with a consumer receiver, this won't work!

You can do surround pre-production at home, but you have to skip the encoding fase. What you need is:
-Software that can route tracks / pan over 5.1 outputs and busses.
-An audio interface with at least 6 outputs.
-A multi-channel monitor controller
-5 speakers + sub.

If you do want to encode the material you either need an expensive hardware solution from Dolby or one of the slightly cheaper software offerings and then you'd still need to have the gear to quality check/decode.

Apple Compressor or the offerings from Minnetonka are the cheapest options. It will encode and do a decode to PCM files again which you can then play over your system to check.

[MrG[UK]]

i understand that completely! ive just been racking my brain wondering if theres some semi pro application to dolby headphone technology or if it will always be considered consumer only.

I know that the digital revolution has opened many gates to higher quality home recording/production projects, and that niche markets in some places do still exist (eg. mastering), i had just wondered if there was a way to use the good work dolby had come out with to make home 5.1 mixing a feasable reality to people that dont have the perfect asymetrical room decoupled from all surroundings and diffused to the nth degree.

dolby headphone seemed to be a (possible) viable option but i suppose as i dont know anyone/ havent seen any paper written detailing a comparison of true 5.1 vs dolbys virtual system, it ended up a preverbial stab in the dark.

still... i like the idea... even if its just to save on $$$ 5.1 studio time setting things up to a relatively okay dynamic mix, then tweak once ur in there with the clock ticking at an ever more expensive rate!

a jumping off platform for a more open ended discussion perhaps?

G

[Geert van den Berg]

Just as with any mixing, mixing on headphones isn't advisable. It's good for editting and extra quality checking.

Look after the smallest 5.1 A Blue Sky monitoring system. It won't break the bank.
Blue Sky

The encoding part isn't that important while mixing when doing a mix intended for Dolby Digital/AC3, because the channels are discrete, meaning there's no matrixing happening that can cause weird side effects on decode. Left goes to Left, Right goes to Right, Centre goes to Centre etc.

Dolby Surround is another subject, but for that you might be able to find some encoders and decoders 2nd hand. But I wouldn't make such a big deal out of this if your intention is to finish the production at a professional studio anyway.

[philper]

Originally Posted by MrG[UK]

wow cheers for so much help guys! I truly am overwhelmed by the comradeship, the sense of helpfulness and overall community spirit!

you do realize criticism can be constructive too! people learn from the errors in their ways and all that jazz. but hey, pardon me for not being perfect.

I see you are calling from the UK. It's been a big holiday weekend here in the USA (Thanksgiving) so many people won't be back on the forums until Monday.

Philip Perkins

[MrG[UK]]

ahhh now i understand!! sorry if it seemed like i had a short fuze. completely forgot about the whole thanksgiving holiday over there! my apologies!

[danijel]

Originally Posted by MrG[UK]

1) do i encode to Dolby DTS in the box via plugins or do i route it via USB/Firewire to a new Audio interface that does the encoding for me. if so what Interfaces would you recommend for this (the higher quality the better).
2) do i buy a 2nd Audio Interface that accepts ADAT/ Analogue inputs up to 8 channels etc... and encodes to Dolby DTS?

My restrictions at the moment are that the Pioneer Unit only accepts Digital Optical and Coaxial. it cannot run multiple inputs at one time. It accepts Dolby DTS, AAC and PCM data.

AFAIK, there is no real-time unit that will encode your DAW output, so that you can pass it on for the receiver to decode. When you are mixing surround, you have to have 6 discreet outputs, and 6 speakers. If you're on a budget, go for a 2-speaker stereo setup, and then later buy more speakers.

BTW, Dolby and DTS are two different things, there's no such thing as 'Dolby DTS'.

[MrG[UK]]

ohh right! sorry for the screw up in definitions... im sure u know what i ment tho.

the only units ive found that does real time encoding are genuine dolby rack units, theres a dolby digital encoder and decoder but they are amazingly expensive new, and very rare to find on ebay. plus all the digital outpus are digital BNC's which would be rediculously hard to try and convert to optical Toslink.

Decided to look around for a v small blue sky surround system (fingers crossed), thinking about renting out an earthworks mic for pink noise calibration and then save corrective EQ settings to use over main outs when mixing... then pulling it off, bouncing channel stems and then using apples compressor to encode it to dolby 5.1 with pictures and play it through my dolby headphone encoder to see how its fairing.

any thoughts??

(btw my mixing room leads a lot to be desired!)

[danijel]

Originally Posted by MrG[UK]

the only units ive found that does real time encoding are genuine dolby rack units, theres a dolby digital encoder and decoder but they are amazingly expensive new, and very rare to find on ebay. plus all the digital outpus are digital BNC's which would be rediculously hard to try and convert to optical Toslink.

There were some consumer audio cards (maybe from Creative) that could live-encode AC3 for use in home-theater applications, but I doubt they are ASIO-capable.

[danijel]

Look what 'realtime AC3 encoder' search on google returns:
» redocneXk released - Realtime 5.1 ac3 Encoder

Maybe that is a handy tool for your headphones?

[MrG[UK]]

it would be if it was coded for CoreAudio and not ASIO :(

my PC seriously isn't a music production computer, plus every tool i have for music production is centered on my mac. I know the analogue fiends on this board would have quite a bit to say but without your own place big enough and without a pretty decent amount of cash you have to resort to digital solutions.

still searching but its not soo much of a necessity as compressor will do what i need... just not immediately as i would have liked, but you cant have it all your own way now can u!

btw.. thanks for all your replies!

[grimepoch]

I thought that the encoder on this page:

Dolby - Dolby Surround & Dolby Pro Logic II Products for Broadcast & Pro Audio

Was real-time. But at $4k, well, thats pretty expensive for low-budget

I'd like to reiterate the problems with working in headphones as I've experimenting with this quite a bit. I wrote a bit of an article for myself when I was working on it here:

The Axis of Music » Blog Archive » Mixing and Monitoring in Headphones

To sum up the biggest point, the problem with headphones is there is no cross-feed of audio from the opposite speaker to your ears. Couple this with reflections in a room and you quickly can see why things sound SO different between both.

There are plugins I used to simulate loudspeakers with headphones, and honestly, they did okay. It was still not the same. Out of all the experimentation I learned that if something sounded good on the loudspeakers, it sounded good in the headphones. The reverse was NOT true. Even with the Panorama5 plugin I used, I could still get mixes that sounded great in the headphones and fell apart out loud.

Granted, I was MUCH closer to what I wanted.

Now, I too am preparing my studio for surround work. I would absolutely not even bother trying to mix in a set of headphones. From most of the surround headphones I have seen, they take a 5.1 field and fold it down into stereo with processing to simulate what a speaker would sound to your ears from two speakers. Given the proximity of the drivers to your ears, it's not that this sounds horrible, it does sound neat, but you are absolutely not listening to an actual surround mix.

To make matters worse, it depends what you are mixing surround for. If you are doing a theatrical release, from what I have read, using FULL RANGE monitoring is much better with an LFE channel. If you are mixing for broadcast or DVD, you can use systems with bass management and channel bass to the subs from what are probably near field monitors that lack bottom end.

I am ramping up for both broadcast, theatrical and DVD work for two projects in my pipeline. Similar to you, I will be doing most of the mixing at my studio in 5.1 and then sending it off to another house to do the sound stage mix and final work. For me, this is ideal.

I am using 5 ADAM A7 nearfields as I love their sound and 2 subs, Sub8 and a Sub12 for the low end. I am probably going to use a MultiMax with a ManagerMax from Martinsound to do the speaker management and using PTLE 8 to drive it (through a 003).

As mentioned, the Blue Sky stuff will not break the bank and I absolutely agree with the poster that this is the path you should look at if you have financial considerations (who doesn't) for this work. The better you make the system you are working on in your studio, the less you are going to discover at a better setup that has to be fixed. One way or another, you are going to spend that money! It just depends if you want to spend a little more up front, or spend it later over and over again.

That's my two octaves anyways!

Rick
Asylum Studio Productions