Hi everyone.
recent purchased JRiver 20. very interested in the DSP capability. I really like the idea of having all the processing, xover, mixing done on the PC in high bit depth and only need a DAC and an amp down stream. An extremely simple and clean digital signal chain.
I wonder if there is a summary of how JRSS works (of course to the extend not to compromise JRiver proprietary IP). Sorry I was trained in a science major and currently work as an engineer, so I am very curious about what s under the hood and have the tendency to (over)analyze things.
1. downmixing. my understanding is that down mix is done by a predefined matrix, there might even be industry standard matrices for certain in/out channel settings. Can one override these matrices? Is disable JRSS and enable channel copy with gains the right way to do that? Some software actually exposes the matrix to the user and one can just type in different numbers into the cells. A very interesting but dangerous practice, I got some very funny effects out of those.
2. But what about upmix. I guess it could be just a simple copy surround to rear for 5.1 to 7.1 but that is a separate option so I assume JRSS does more even in this case. Then an upmix of 2 channel to 5 or 7 necessarily involves decorrelation of LR otherwise the stereo image is destroyed by having location specific signals going into the center. Presumably the surround and rear need to be delayed, attenuated (frequency dependent). So on this front, how does JRSS differ to other alogorithms like, say, Dolby Pro Logic?
3. To push this further, I currently finishing my basement. To keep up with the tide, I m contemplating install a pair of front-wide to form 9.1. When fed with 5.1 or 7.1, would JRSS be able to perform the ambisonics that generates artificial reverberation into the front wide speakers? I m not even sure how to tell JRSS those are front-wides, not heights etc etc, so I m not confident the feature is available. In the same token, I don't know how JRSS works when, say, output to "12 channels" is selected, it does not even know the location of those speakers.
If JRiver can do artificial reverbs, then it opens up the possibility to treat the listening room on the dead side (e.g. with low RT60) and use JRiver to simulate controlled ambiance. A whole new level of "room correction".
4. Now this leads to the Effects menu. This does indicate some ambisonics capability in JRiver, in that it can emulate certain reverb profiles ("Environment"). What does "Surround Field" do? Tried it but the difference seems subtle. My assumption is that it also generates reverberation signals but only for the fronts? How do these two features interact with each other when both selected?
5. Why is the sub default to cross at 60Hz in output menu while the THX calls for 80Hz? It is user selectable, just curious whether there s any thought put into the 60Hz default that users could benefit by knowing about. My guess is that it might be a preference for music?
Author
Topic: general question on JRSS etc (Read 1749 times)