Hey all,
New Kasina owner/user here. FWIW I'm an experienced media/lighting/electronics engineer. I purchased the Kasina with a specific interest in creating my own music with SpectraStrobe component, as well as experiencing what others have achieved.
Creating my own has been a little challenging, as a lot of the software instructions seem to be somewhat out-of-date, but I managed to reverse engineer things to an acceptable level, and I've now moved into the stage of attempting to create content.
Here's the challenge I'm running into: I'm used to working with, and designing, audio/visual systems that give me complete control of all of the various signal chains (in their own lanes, so-to-speak). I understand the cleverness and convenience of encoding the LED controls into the frequency space of the audio content, but I'm finding that it is very unstable, not very precise, and full of "noise". For example, I setup a sample project that has the all of the SpectraStrobe tones, 18.2khz reference, with square wave LFO panning hard right/left @ 20hz, and then color tones at 18.7khz/19.2khz/19.7khz. The suggested tone level for best dynamics and headroom using the Audacity plug-ins seems to be about -39.483 db according to my calculations. When I run this project through the Kasina, all works as expected, it's detected as a SpectraStrobe signal and if I vary the volume of the color tones, the LEDs adjust output accordingly. Sweet!
Now I move on to adding some musical content. I'm simply adding a deep bass tone as a sine wave, at or below 200 hz. When I do this, and get the bass tone into the correct volume level, the LEDs shut off. I have a sharp 8th order Butterworth lowpass filter on the bass track to make sure I'm minimizing frequency bleed. I've also experimented with putting sharp bandpass filters on each of the respective SpectraScobe tone channels/tracks to try and minimize frequency "bleed". I've also removed all filters as well just to see. It seems as though even though the bass track isn't anywhere close to the SpectraStrobe frequency range, it's loudness is overpowering the signal and whatever filters are being used to pull out the SpectraStrobe content (FFT, IIR, frequency decoder IC - I'm not sure what's under the hood here) can no longer recover a stable enough frequency so the LEDs shut off. If I increase the volume of all of the respective SS tracks, they come back. But now I'm in a cat-and-mouse battle with the overall loudness and frequency content of the music itself relative to the SS tracks and signals. I haven't even begun to add any more musical content yet and my initial findings are not great based on what I was hoping I would be able to achieve.
Obviously there is some great music-based SS content out there. But now it's starting to seem probable that in order to achieve relatively clean SS control, within the scope of custom audio tracks or music, that some deep compromises are going to have to be made. Does anyone have any "best practices" or pointers on how to achieve this fine balance? I mean, even when I have no musical or audio content other than the SS reference tone, with all color tracks volume set to -INF db, I still get some flicker from the red channel (which red LEDs have a lower forward voltage so it sort of makes sense they would be the first one to go on based on "noise" in the signal) - but the only noise at this point is the SS ref tone track itself.
I guess it makes sense by choosing to encode the control signal in the audio there is going to be some noise and lack of precision... but having to relatively adjust overall tone volumes based on what the audio track is doing is pretty daunting. And look, I've got about as steep of a filter as I can get on the low frequency sine wave bass track, my spectral analysis shows clearly that it is only producing content in the low frequencies, and the SS ref/tones are quite isolated in the upper bands, and yet I'm still running into this issue.
For others who have successfully achieved a desired level of precision and control to their own music when making AS/SS tracks:
- First, is it possible to achieve and maintain precise SS control over dynamic audio?
- Second, what compromises to your music do you make to maintain enough control over the SS LED signals, or do you just sort of accept the audio signal is going to interfere with the SS signals and treat it as a "feature and not a bug"?
- Third, is it advisable to just keep musical content to a particular frequency space and and db level and/or not overly complicated? It seems like trying to master an SS track would play all sorts of havoc to it.
Looking for any guidance from those who have found the proper techniques to have creative freedom around the audio, but also precise (enough) control over the SS signals. I'm testing using the Kasina as a USB audio device, which has to be digitally transferred so there should be no "noise" on the line.
Thanks in advance for any tips or suggestions you have. I'd really like to find the balance to achieve my creative vision with this awesome tech!