Matrix vs Discrete

[Owen Smith]

An alternative to HDMI out would be coax or optical digital putting out full rate DTS at 1.5 megabits. No HDMI licencing, and full rate DTS is pretty close to audibly transparent and anyway this is for legacy analogue sources which aren't perfect fidelity wise to start with. We'd need the option for it to add a silent centre channel ie 5.0 output for AVRs that mess up with 4.0, but that should be do-able. The question though is would it be possible to get a DTS encoder licence and at what cost for such a thing.

 

[JediJoker]

An alternative to HDMI out would be coax or optical digital putting out full rate DTS at 1.5 megabits. No HDMI licencing... The question though is would it be possible to get a DTS encoder licence and at what cost for such a thing.

Encoding to a lossy format increases complexity. I have to imagine DTS licensing, especially for encoding, isn't any cheaper than HDMI.

It's a shame S/PDIF can't do what ADAT can: eight lossless channels at 24-bit/48kHz or four multiplexed at 96kHz over Toslink.

 

[Owen Smith]

It's a shame S/PDIF can't do what ADAT can: eight lossless channels at 24-bit/48kHz or four multiplexed at 96kHz over Toslink.

Malcolm Lear's shadow vector decoder can send the decoded output using ADAT over toslink. I don't know what bit depth and sampling frequency, but given this is for legacy analogue formats I can't imagine there's any benefit going above 44.1 or 48kHz. Possibly even 32kHz would be sufficient to be honest. I appreciate 24 bit makes headroom for the ADCs and processing easier, but ultimately 16 bit over the output should be more than enough for legacy analogue formats if the levels are set correctly. And four lossless 24/48 fits in toslink bandwidth given that two 24/96 does.

The problem with ADAT over toslink is I'm not convinced any AVR can accept it as input. I've seen no mention of any of them accepting it.

 

[jimfisheye]

Encoding to a lossy format increases complexity. I have to imagine DTS licensing, especially for encoding, isn't any cheaper than HDMI.

It's a shame S/PDIF can't do what ADAT can: eight lossless channels at 24-bit/48kHz or four multiplexed at 96kHz over Toslink.

ADAT sure turned into a long lived standard! Very reliable too. Connect 30 year old devices with brand new units and it just keeps working.

Once you cross the line into an HDMI device, you're at the mercy of version mismatches and the copy protection gone wild stuff. If you can choose equipment and a setup that avoids HDMI or only use it for video display you can avoid some frustration.

There are these Magewell HDMI capture cards. It looks like they support capturing everything including audio. There are the more affordable Blackmagic HDMI cards that give you dropouts with video. I've seen the Magewell cards in action with video and they were solid. I have a friend who built a video switcher with a Mac Pro using these for 12 1080p cameras. Made for quite the fully programmable video switch! I have no idea what happens with trying to capture audio from some stand alone disc player or AVR. And these cards aren't cheap. Avoiding HDMI for audio is still the way to go.

ADAT and TOSLINK use the same lightpipe and devices with ADAT usually have a TOSLINK option with the same physical port. It's possible someone took advantage of a dual purpose chipset and hacked some firmware. Getting into some nuts and bolts there! There would need to be infrastructure to route 8 channels of audio once inside.

Meanwhile there are audio interfaces going back 30 years with ADAT ports. Plenty that can run at 96k (called SMUX in that mode with 4 ch per cable).

 

[DrKlahn]

Ah here it is and we compared:
View attachment 107485
We did it as an in house honest comparison to see how we racked up against the other formats available in 2009. It was not for media purposes.

Enjoy

Thanks for sharing. Never heard Involve. I have had a preamp with DPL II and the DTS modes though and I was never a big fan of either for music upmixing. It would be interesting to see how the latest algorithms stack up. I can't really compare them to any of the old modes since the equipment that had those options is long gone.

I still end up listening to 2ch music in 2ch most of the time. Movies in 2ch/5.1 I will switch on the Dolby upmixer if I think it will help. The DTS modes seem a bit overbaked vs Dolby.

 

[chucky3042]

Thanks for sharing. Never heard Involve. I have had a preamp with DPL II and the DTS modes though and I was never a big fan of either for music upmixing. It would be interesting to see how the latest algorithms stack up. I can't really compare them to any of the old modes since the equipment that had those options is long gone.

We did a similar study with test audience vs 5.1, its published in our other thread:
https://www.quadraphonicquad.com/forums/threads/all-tests-on-the-surround-master.32434/

 

[Asklia]

Ny MiniDSP has analog inputs, as you might see, since it is behind a fully analog Preamp from Bose, the 4401.

 

[JediJoker]

The problem with ADAT over toslink is I'm not convinced any AVR can accept it as input. I've seen no mention of any of them accepting it.

Definitely not. S/PDIF (and AES/EBU, too) is standard-limited to stereo for LPCM, despite having the bandwidth for 4 x 96kHz or 8 x 48kHz, and no consumer audio manufacturer has ever integrated nor will ever integrate ADAT into their products. So, no lossless multichannel over optical in the home market. HDMI is what we're stuck with and I wish some enterprising company (*hint hint* @chucky3042 ) would jump into the multichannel HDMI ADC space.

 

[MidiMagic]

It would cost us and the guys at Shadow vector now around $25 K per year for the HDMI license.

Why patents and copyrights impede compatibility.

 

[chucky3042]

Why patents and copyrights impede compatibility.

I like stereo as the universal carrier!

 

[MidiMagic]

I like stereo as the universal carrier!

Me too. Matrix can even carry height.

And S/PDIF and Toslink can carry all of it.

 

[vinylguy4]

An alternative to HDMI out would be coax or optical digital putting out full rate DTS at 1.5 megabits. No HDMI licencing, and full rate DTS is pretty close to audibly transparent and anyway this is for legacy analogue sources which aren't perfect fidelity wise to start with. We'd need the option for it to add a silent centre channel ie 5.0 output for AVRs that mess up with 4.0, but that should be do-able. The question though is would it be possible to get a DTS encoder licence and at what cost for such a thing.

Creative Labs has the DTS-610 dts encoder unit, don't know about the bit rate. It outputs 44.1k/16 bit dts 5.1 on coax and optical in real time. Long out of production. I have 2 units that I use for analog -> dts digital. If no input on center or sub, will output silent center or sub.

 

[jimfisheye]

I want discrete channels. Lots of them! And just because we can.

Actually ADAT input would be a no-brainer to start including on AVRs. It's a pretty solid long lived format now and it's not going away any time soon. Nearly every audio interface that isn't just a little 2 channel job has one. Connect to stuff going back 30 years. The only thing that would hold that back would be very intentional demand of the copy protection madness built into HDMI.

Trying to hack ADAT into a TOSLINK input even if the chipset and protocol is already there to repurpose would still be a tall order! Probably have to write code and flash some chip. It's not a hack I see people just doing. Many interfaces with ADAT are in the affordable range and it just wouldn't be worth it. I suppose unless you worked in engineering on one of them and spotted an easy mod. And you have the factory programming tools and everything at your disposal.

 

[JediJoker]

Creative Labs has the DTS-610 dts encoder unit, don't know about the bit rate. It outputs 44.1k/16 bit dts 5.1 on coax and optical in real time. Long out of production. I have 2 units that I use for analog -> dts digital. If no input on center or sub, will output silent center or sub.

I have the DDTS-100 decoder/preamp. I wasn't aware they had ever made an encoder. Cursory search suggests it's going to be very hard to find one for sale.

 

[kfbkfb]

https://www.google.com/search?q=open+source+dts+encoder&sca_esv=458fc5d25ecd7a59

(I don't know the IP issues with DTS encoders, I didn't check to see if any patents have expired)


Kirk Bayne

 

[Owen Smith]

Creative Labs has the DTS-610 dts encoder unit, don't know about the bit rate. It outputs 44.1k/16 bit dts 5.1 on coax and optical in real time. Long out of production. I have 2 units that I use for analog -> dts digital. If no input on center or sub, will output silent center or sub.

I found an Amazon review saying you can feed the digital output straight into a CD recorder and blow a DTS CD, which agrees with the statement above about format. That's almost as good as DVD full rate DTS, about 1.4mbps rather than 1.5 if I recall correctly.

Don't seem to be any for sale anywhere I can find. I've set an ebay saved search to email me if one comes up, but I'm not hopeful. Shame because it looks like the most viable solution if you don't have multi channel analogue inputs.

 

[Owen Smith]

Trying to hack ADAT into a TOSLINK input even if the chipset and protocol is already there to repurpose would still be a tall order! Probably have to write code and flash some chip. It's not a hack I see people just doing. Many interfaces with ADAT are in the affordable range and it just wouldn't be worth it. I suppose unless you worked in engineering on one of them and spotted an easy mod. And you have the factory programming tools and everything at your disposal.

Arcam are a few miles away from me. Perhaps I should apply for a job (I'm an embedded programmer) and do it myself as a weekends and evenings project.

 

[jimfisheye]

Arcam are a few miles away from me. Perhaps I should apply for a job (I'm an embedded programmer) and do it myself as a weekends and evenings project.

Haha. Isn't there an internet story about some gamer that got a job with the game maker just to fix a bug that bothered him and then quit?

 

[atrocity]

I found an Amazon review saying you can feed the digital output straight into a CD recorder and blow a DTS CD

As long as your CD recorder doesn't resample everything like my Pioneer.

 

[MidiMagic]

That's an excellent question. The answer is very complicated but it's centered around ensuring the stereo encode does not suffer from image compression as the original QS did. Why compress ( via crosstalk) content with no or minimal surround.

Our encoder also is not a fixed parameter matrix it's a variable matrix that can have a cross talk component variable from 0.15 to 0.42 from memory dependent on the surround content in each band.And controversy the Chucky fact that the maximum separation that we can detect is 12 DB......it caused a lot of research on our part and some other magic numbers.

Again in tests no one can sense image compression in involve stereo. We still have a few encoder evaluation modules for usd$100 I think. The Suzanne Ciani record was made with one of these.

That sounds to me like the images would move about when on a QS decoder.