Quote:
Originally Posted by TheSweetener
First of all. This Eq sounds simply GREAT!
Sory for being stupi but, can perhaps someone explain the System 1000, 2000 and 5000 thing on their website?
I simply did not understand it. What do these algorithms do?
First off, it is great to see David releasing some of his work into the general plug-in pool. Kyma users appreciate his contributions over the years. Personally, I like his his take on the Neve Masterpiece the best and his limiters are quite good along with his filters. While I agree that his website could certainly use an overhaul and the GUI isn't particularly sharp, his DSP chops are first rate.
A long time ago he talked about the idea behind the System series, so the following is based on 4 year old information. Without question it has been updated and tweaked over time. However, the basic principle is the likely still similar.
The System series is designed for those losing their hearing but find normal hearing aids disappointing in terms of listening to music. Most hearing aids do little but boost the sound in the voice range in a most indiscriminate way.
Basically, the concept is "Psychoacoustic Loudness Compression" (PLC) across phase-linear bandpass filters. The band are spaced 1/3 octave from 250 hz to 8k hz. Known as the critical bands it is the tested range generally, though newer test may also go higher. PLC is non-linear. The basic problem is most compressors work in amplitude (SPL), but we don't hear in SPL as the Fletcher-Munson curve illustrates (though that is for sine waves and doesn't translate quite so well for complex waves). PLC is similar to Dobly B and C encoding where preemphasis is applied only at the faintest levels in the sound.
To quote David in another thread talking about PLC:
"But unlike Dolby compression which sometimes uses a hard limiter in parallel with the direct signal, we use a compressor that has a negative compression slope of -1.67. That means that for every dB rise in signal level above threshold, the output level actually drops by 0.6 dB."
(btw, he is not talking about the System series here but a PLC example object he posted to the Kyma user group.)
"When you combine this negative compression in a mixer with a delay compensated direct signal you get the classical ski-slope shaped compression on your signal, but this time, we have the curvature of that ski-slope matched to our human hearing which carries an exponent of nonlinearity of around 0.6 for sounds above 40 dBSPL (most all of what we normally listen to is above that level)."
The compression ratios for each band is determined by your audiology report. You just plug in your audiology values and the program calulates the ratios (which have other factors as well). The ratios are generally quite mild when all is said and done.
I tested a very stripped down and modified version for the Kyma system with a music loving grandfather and am happy to say he was very pleased.
edit:
Ah, I just saw the link to David's explanation. It is clear they use far more bands than discussed above (please see my disclaimer
) as well as model for more than I covered, but hopefully, I added a bit of context.
The No.1 Website for Pro Audio
Latest
Trending
Not exactly the best point of reference.... I don't like Renaissance EQ at all!
