I don't know if the circuit _is_ cheapo but the microphone does seem to be, the triangles don't look equilateral when looking at the picture.
But, hey, I found a site with someone who actually experimented with Ambisonic recording experiments in different places(with the Canadian NFB), but it's in french.
http://www.er.uqam.ca/nobel/k24305/memoire.html (Chapter 5)
You can *try* to read it with a translator if you don't understand french. I found systran.com to be the easiest to read after a fast look.
They told that they found the decoder are somewhat limited :there's no distance compensation in decoders, just gain compensation, there's often 4 channel output and they haven't been able to find one with a Z input.
Yup, I actually started to understand "clearly" what is Ambisonic.
Hehe, web translators always give ± good results. Systran/Altavista Babelfish is one of the best. Reverso (reverso.net) gives also pretty good results, often completely different from Systran, but the site translator is telling "Temporarily not available...". Using the copy - paste box should work too, but it's max. 300 characters.
Actually, only a few people know how to write french without errors.
I think it's the language with the most exceptions. Even objects are male/female, so web translators often give you strange results like "She is a table"
DragonMaster said:
The big difference with 15 years ago is the move from hardware encoders/decoders to software ones. It's that move that kept Ambisonic alive.
When I wrote my Master's thesis, only Anthony Morris (AGM Digital) had a software solution, now there's quite a few:
http://www.digenis.co.uk/ambi_au.html
There's a list in there, still not complete as far as I remember, but it gives an idea.
- Kewl
A DSP can do things impossible with analog solutions, but if you listen to an ambisonic LP, software decoders introduce losses in definition, detail, and sound quality.
About every multimedia hardware built now is a DSP with some code running on it. You could modify the software in your DVD to play ambisonic in the 6 channel analog outputs.
About every multimedia hardware built now is a DSP with some code running on it. You could modify the software in your DVD to play ambisonic in the 6 channel analog outputs.
Me, no, but someone who knows VisualDSP or Linux programming could make one. In the Digital section, someone is working(in his free time) on a DVD-A/AAC/MP3/WAV/OGG/CDA player based on a DSP and a computer DVD reader. DSPs are quite powerful. The one that is going to be running the CDP is running at 500MHz I think.
DragonMaster said:
Do you state that from personal experience or from what you have read on Ambisonic?
Two of the last analog hardware decoders that were "widely" available were from Minim in England and were not that good according to Dave Malham. He works with Ambisonic day in, day out, and from my correspondence with him, I would tend to believe him.
Any "losses in definition, detail, and sound quality" would have to be due to bad programming, not enough internal resolution, etc, in the plug-in, app, or whatever, that is processing the signal.
But anyway, to rephrase my initial comment on the accuracy of the Ambisonic chapters in my thesis: since it was written mostly in 92-93, some (if not all) of the products taken as example do not exist anymore, so someone looking for them shouldn't waste to much time on that.
- Kewl
Kewl said:
Understanding real-time programing from previous experiences, the resolution, definition, and detail really depend on how programing is done and the sequencing of events. Not understanding how DSP programing is done, I somehow get a feeling that DSP programmers don't contral the sequencing of process, they just control functionality, and let a tool do the rest. I don't know if the calculation iteration rate, the sequencing of calculation events, etc can still be controlled. Many people who say DSP programming is different really don't explain the details, just some mathematical function. Therefore, the gap between the mathematical process and how it's mechanized exists.
Software decoders are digital, not analog. If you listen to an LP, you need to convert analog to digital, process it and then re-convert it to analog.
Hardware decoders can't give you an as impressive effect because of the precision loss : you can't have an exact resistor value, you're always stuck to use the nearest possible value, there's no delay adjustments with hardware decoders and gain is adjusted by ear instead of being adjusted by the DSP.
So, when using an analog source, hardware decoders sound better when using high quality components, but can't give you a good ambisonic decoding/impression. Software decoders are digital, so there is a need for two more conversion steps (A to D and D to A), lowering the sound quality, but giving you a lot better ambisonic effect.
For digital sources, software is the way to go: there's no sound quality loss, the source is already digital and the digital to analog conversion is always requiered, that you use a decoder or not.<
A DSP is a processor, it's just using a different instruction set as your x86 or your PowerPC. You should ask someone working with DSPs to know more about them.
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