Filter type(s) of the good ol' Soundblaster Live

[Orchidius]

Fellow Earthicans!

Is there any knowledge about the kind of the filter model used in the soundblaster live? I mean if it's more svf, diode, ladder (this one surely not ... )

I am converting some old projects from back in the days, trying to get away from .sf2 to mostly Kontakt. I recall the filter had a very nice, but disctinct sound where e.g. it let pass through some transient material even if the cutoff was close to 'closed'.

I am aware that there was the EMU10K1 on it, but that led to nothing, because (if I get this right) technically one could implement any filter type you like, of course limited to the dsp power of the chip.

I am also aware of sfz as well as many other soundfont players finding they're all not the real deal...

And yes! I really should just go by ear, take whatever sounds best...so if it's just out of curiousity I'd really like to know what kind of filter it might be...

Thanks you!

[synthgeek]

It wasn't really an analog-modeled filter in the way you might be thinking. It's described in documentation as simply a "resonant digital filter" of a "two-pole low-pass design," there's a description and diagram here:

https://web.archive.org/web/20140302033 ... /m2049.pdf

You can find the paper that doc references (which seems to be where the "special sauce" is) here:

https://ieeexplore.ieee.org/document/634131

[Orchidius]

I kind of expected something like that, but it's cool to actually have the math of it available as a starting point...it will take some time to look into it I guess

Thank you!

It wasn't really an analog-modeled filter in the way you might be thinking. It's described in documentation as simply a "resonant digital filter" of a "two-pole low-pass design," there's a description and diagram here:

https://web.archive.org/web/20140302033 ... /m2049.pdf

You can find the paper that doc references (which seems to be where the "special sauce" is) here:

https://ieeexplore.ieee.org/document/634131

[synthgeek]

You're welcome!

[Essent]

You can measure it yourselves by running some white noise through it. I did it and measured it to be a 18 dB filter. However it is already some time ago and I could have made a mistake.

[Orchidius]

You can measure it yourselves by running some white noise through it. I did it and measured it to be a 18 dB filter. However it is already some time ago and I could have made a mistake.

Cool, I actually never thought about this. How does one do that? I assume you run the noise through a filter sweep with at least two different Q-values...and then?

[Essent]

You can measure it yourselves by running some white noise through it. I did it and measured it to be a 18 dB filter. However it is already some time ago and I could have made a mistake.

Cool, I actually never thought about this. How does one do that? I assume you run the noise through a filter sweep with at least two different Q-values...and then?

1. Just get or create a .sf2 file with a white noise sample.
2. Disable the filter modulation envelope (set to filter cut off = 0).
3. Set filter to say something between 1000 - 4000 Hz.
4. Playback the sound (a long note) and record it.
5. Analyse the recorded sound using a spectrum analyzer. My DAW is Logic, which has a good spectrum analyser (in the EQ)

Don't forget to analyse the Q as well.

I might be in the same boat as you. Got some legacy stuff (SoundBlaster Live / AWE64) with some crucial sounds / instrument, they really are a boaster to some of my (dance) tracks. So I definitely need them.

[Essent]

It wasn't really an analog-modeled filter in the way you might be thinking. It's described in documentation as simply a "resonant digital filter" of a "two-pole low-pass design," there's a description and diagram here:

https://web.archive.org/web/20140302033 ... /m2049.pdf

You can find the paper that doc references (which seems to be where the "special sauce" is) here:

https://ieeexplore.ieee.org/document/634131

If it is a 2 pole filter, according to that article, then it must be a 12 dB filter.