KVR Audio

ScottAxxe · Post by **ScottAxxe** » Tue Jul 04, 2017 3:59 am

Section 2.1 states
"The CPU bar shows in real-time the percentage of available CPU power being used by the synthesizer."

You might want to clarify that this is usually the percentage of power being used by a single core of the cpu not the entire system. Less technical users might see 50% or more and think Fathom is dragging their whole system down.

guvnor_p · Post by **guvnor_p** » Tue Jul 04, 2017 8:59 am

Maybe I'm just being an idiot but I purchased the pro version but almost all of the presets are monophonic. It seems as if the presets that are initially set to have polyphony of 1 can't be changed, even when changing the polyphony value. For sounds that have a default of more than 1, such as the keyboard instruments, the polyphony value works fine. So all the pads that I've so far played are monophonic.

Is this a bug or am I missing something?

Scrubbing Monkeys · Post by **Scrubbing Monkeys** » Tue Jul 04, 2017 10:40 am

guvnor_p wrote:Maybe I'm just being an idiot but I purchased the pro version but almost all of the presets are monophonic. It seems as if the presets that are initially set to have polyphony of 1 can't be changed, even when changing the polyphony value. For sounds that have a default of more than 1, such as the keyboard instruments, the polyphony value works fine. So all the pads that I've so far played are monophonic.

Is this a bug or am I missing something?

Most of the leads are mono. Also check your glide setting. At one point if glide was on it forced the synth to mono. I dont know if that has been changed or not.

guvnor_p · Post by **guvnor_p** » Tue Jul 04, 2017 10:56 am

Yup, having glide on forces it to mono, thanks for that.

FathomSynth · Post by **FathomSynth** » Tue Jul 04, 2017 1:55 pm

Yes, that's correct, glide always changes it to mono.
I realize this can be confusing.
I will try to fix this in the near future so it can also do a polyphonic glide.

ScottAxxe, Good find in the manual regarding the CPU bar,
I will update that shortly.

ScottAxxe · Post by **ScottAxxe** » Wed Jul 05, 2017 1:02 pm

Polyphonic glide would get you that much closer to MPE compatibility.

Scrubbing Monkeys · Post by **Scrubbing Monkeys** » Wed Jul 05, 2017 8:07 pm

My, you have been busy.

The keyboard underlay is brilliant on the KB tracking page. Its nice to hear the filters cut out. I also realized that you had subtly included my next feature request. It has probably always been there. I am speaking of knowing which modulator goes with which osc or component. The componet changes from grey to black ( just as when you click on it directly ). I know, obvious right?

So many times had I clicked up and down the modulator list trying to remember what was going on and where. I was so focused on the parameter being modulated I never noticed the changing color.

I love it it keeps the GUI clean and now I know its there its a breeze to use.

Musical Gym · Post by **Musical Gym** » Wed Jul 05, 2017 10:11 pm

I prefer to be notified of updates via email. Is that doable?

ScottAxxe · Post by **ScottAxxe** » Thu Jul 06, 2017 3:07 am

Getting a little bit more time to actually play with Fathom and getting a feel for its powerful capabilities. it's really turning into quite a machine!

A couple suggestions, or simply tell me what I missed.

- Add Sample & Hold and continuous random shapes to the LFO. I was trying to create a standard auto-filter effect earlier and found it tedious/difficult to try and get a random-sounding filter cutoff with a sequence when a S&H LFO would do the job quickly.

- That brought up another idea. The ability to initialize a sequence with random values would be handy as well. It could certainly be used for wacky effects but also to subtley humanize an already modulated destination by adding just a bit more randomness to the modulation.

FathomSynth · Post by **FathomSynth** » Thu Jul 06, 2017 10:29 am

Musical Gym, Yes, I will put you on the list for email updates.

Scrubbing Monkeys, Thanks for noticing that, its true, clicking on the mod slat
highlights the audio object in the signal flow. I forgot that myself, so I just added
it also to the user's manual to make it more obvious.

ScottAxxe, Thanks, Others have asked for a Random and Sample and Hold LFO also,
so I will try and move that up the list, but remind me exactly how you would like
the sample and hold LFO to work? It randomly chooses a value and then holds
it for a random amount of time?

Also, I just finished Keyboard Tracking on all the Filters for 1.0.9.

ScottAxxe · Post by **ScottAxxe** » Thu Jul 06, 2017 3:33 pm

For S&H the LFO would choose a random value and hold that value steady for the current period either tempo sync'd or not. For continuous random the LFO would select the random target value for the next period and basically be in a perpetual state of transitioning to the next value. Really, the random LFO is just S&H that avoids the sharp transitions by smoothing the path between random targets.

There's a nice diagram of S&H and arbitrary on this page.
http://www.embedded.com/print/4233780

BlackWinny · Post by **BlackWinny** » Thu Jul 06, 2017 4:12 pm

ScottAxxe wrote:There's a nice diagram of S&H and arbitrary on this page.
http://www.embedded.com/print/4233780

The book itself in its entirety is one of the best ever made on the DSP for beginners and for average level of technical knowledge. One of the best books. And piece on the cake it is also available in all the ebook formats (Epub, Kindle, PDF) as well as in paperback format. A must have among the books on the music, software as well as hardware.

Musical Gym · Post by **Musical Gym** » Thu Jul 06, 2017 6:42 pm

Thanks for putting me on the list.

ScottAxxe · Post by **ScottAxxe** » Mon Jul 10, 2017 1:03 pm

Regarding those LFO waveforms, the Sample & Hold is commonly used for things like auto-filters where the LFO drives the filter cutoff usually with a fair amount of resonance dialed in. This effect has been used countless times in popular music. When the filter variation is kept fairly subtle, it can still be a rather cool effect.

I hadn't really used a random/arbitrary LFO until recently when I purposely chose one to see what I could do with it. I started messing around with a default patch and the random LFO and accidentally walked into creating a pretty decent didgeridoo. I've always thought that was a very interesting instrument but never really tried to synthesize the sound. The didgeridoo is basically just a huge tube which means it creates a single drone note (very-low frequency standing wave) as the foundation of the sound. The player modulates the "filter cutoff and resonance" at the mouthpiece often in a seemingly random but rhythmic variation. This is done with smooth transitions which is why the random LFO, not the S&H, is useful for creating such a sound. In this case, actually having the choice of the random LFO changing targets with a fixed or random period might further enhance the effect. Obviously the random LFO has other uses but this is a good example of what you can do with it.

FathomSynth · Post by **FathomSynth** » Mon Jul 10, 2017 7:16 pm

SA, BW, thanks for the book reference, I took a quick look and
you're right it looks like a really good one.

Several people have asked for a random LFO with Sample and Hold,
so I will try to get that into an upcoming release soon.
Also drawable LFO's are high on the list.

******** DSP Question ********

Hey, I have a question for any of you DSP Guru's.
I sent this question to one of my book authors but he never replied,
so I don't think he knows the answer.

I need a closed form set of equations for an Elliptic Band Pass filter of variable order N,
such that I can input all the audio domain parameters, Cutoff Frequency in Hertz,
Band Width in Hertz, Ripple tolerance in Decibels and the filter order N.

And output the time domain transfer function coefficients.

Fc, BW, R, N -> H(t)

The reason I want the Elliptic is because it has the steepest roll off.
It would make some really cool sounds possible and I've never found
a synth with this filter anywhere.

The Elliptic Filter is similar to the Chebyshev except it has ripple in both the pass band and stop band.

I found a couple of good academic papers on the subject, but they only work the problem
down to its poles and zeros, not all the way to down the audio friendly parameters,
probably because they are not specifically targeting audio applications.

I would be so grateful if any of you have seen this solved somewhere before.

Fathom Synth Development Thread