Eventide Blackhole Algorithm?
- Thread starter lahatte
- Start date
Living Fossil
Senior Member
Sean Costello (the mastermind of Valhalla DSP) gave some valuable insights about the concept of Blackhole, which should be available online (involving keyword search in your favored search engine).
A good starting point is this one:
www.kvraudio.com
A good starting point is this one:
KVR Forum: Eventide BLACKHOLE Plug-in Officially Released - Page 5 - Effects Forum
KVR Audio Forum - Eventide BLACKHOLE Plug-in Officially Released - Page 5 - Effects Forum
www.kvraudio.com
Anders Wall
55°36'48.6"N 13°07'14.2"E
For those without search engines or for that matter internet access.
As written by Sean Costello:
"Blackhole is based on cascading a BUNCH of modulated allpass delays. Like 32 or so. The input is summed to mono, a bunch of allpasses process the input in series, and then the output of these allpasses is fed into 2 parallel allpass chains (one per output channel).
- A given output channel will go through 24 allpasses (due to the series->parallel structure).
- This produces a HUGE amount of echo density.
- Think about an allpass producing N echoes, where N depends on the allpass feedforward/feedback coefficient. Now raise N to the 24th power.
- Due to the laws of convolution, the attack and decay times of each allpass are also raised to the 24th power. So, if a given "average" allpass has an attack of A milliseconds and a decay of B milliseconds, the total reverb attack will be A*24 milliseconds, and the decay will be B*24 milliseconds.
- This brings up the tricky aspect of these massively cascaded allpass structures: The attack time and decay time are both intimately tied in with the allpass coefficients. And they are interrelated.
- For example, an allpass coefficient of 0.5 will have a slow fade in time, and will fade out at about the same time.
- To get a longer decay, the allpass coefficient needs to be at 0.7 or above. But this might still have a slow attack, due to the attack time of one allpass being raised to the 24th power.
- Coefficients of 0.827 to 0.91 and above will have a sharper attack. But the decay will be MASSIVE in this case.
- The chorusing of each allpass is essentially raised to the 24th power, which results in a very complex and rich modulation sound."
Best,
/Anders
As written by Sean Costello:
"Blackhole is based on cascading a BUNCH of modulated allpass delays. Like 32 or so. The input is summed to mono, a bunch of allpasses process the input in series, and then the output of these allpasses is fed into 2 parallel allpass chains (one per output channel).
- A given output channel will go through 24 allpasses (due to the series->parallel structure).
- This produces a HUGE amount of echo density.
- Think about an allpass producing N echoes, where N depends on the allpass feedforward/feedback coefficient. Now raise N to the 24th power.
- Due to the laws of convolution, the attack and decay times of each allpass are also raised to the 24th power. So, if a given "average" allpass has an attack of A milliseconds and a decay of B milliseconds, the total reverb attack will be A*24 milliseconds, and the decay will be B*24 milliseconds.
- This brings up the tricky aspect of these massively cascaded allpass structures: The attack time and decay time are both intimately tied in with the allpass coefficients. And they are interrelated.
- For example, an allpass coefficient of 0.5 will have a slow fade in time, and will fade out at about the same time.
- To get a longer decay, the allpass coefficient needs to be at 0.7 or above. But this might still have a slow attack, due to the attack time of one allpass being raised to the 24th power.
- Coefficients of 0.827 to 0.91 and above will have a sharper attack. But the decay will be MASSIVE in this case.
- The chorusing of each allpass is essentially raised to the 24th power, which results in a very complex and rich modulation sound."
Best,
/Anders
Living Fossil
Senior Member
@Anders Wall : if you have a closer look at my post you will find a direct link (at the bottom) to a thread where these (and many other) statements are expressed.
Anders Wall
55°36'48.6"N 13°07'14.2"E
Ah, sorry missed that.
Well there you go...
I copied that text a few years back just because I wanted to build something like that myself.
Seeing I missed your post it's not hard to understand I completely failed with my project
Ended up buying a H8000 ... and the plugin (they do sound different).
So sorry for the post, for more info please do see @Living Fossil 's link above my message.
All the best,
Anders
heisenberg
having uncertain feelings
Don't be sorry, Anders. Just be careful. That technical explanation was fascinating. Thanks for posting the info directly.
gsilbers
Part of Pulsesetter-Sounds.com
In kontakt 6 the new delay and reverb will get closer to that. Use the difusión setting and tweak the onboard settings.
Living Fossil
Senior Member
Seeing I missed your post it's not hard to understand I completely failed with my project
My issue with Blackhole is that i always have a memoryhole when it would be convenient to use it.
Happens all the time that i completely forget about it...i guess that's the downside of having too many options.
