FXpansion D-CAM: Synth Squad for sale now!

[rouge]

Hey andy those leads sound sensational - i'm curious - what samplerate are these generated at?

The high end is phenominal! Since i purchased my new audio interface i've discovered the beauty of (some) vsti's at 96khz - where synths such as fabfilter's Twin are *greatly* enhanced. Therefore, i would be greatly impressed if these sounds were *generated* at 44.1 or 48khz

+1 Good question

[andy-cytomic]

Hey andy those leads sound sensational - i'm curious - what samplerate are these generated at?

The high end is phenominal! Since i purchased my new audio interface i've discovered the beauty of (some) vsti's at 96khz - where synths such as fabfilter's Twin are *greatly* enhanced. Therefore, i would be greatly impressed if these sounds were *generated* at 44.1 or 48khz

The most recent examples are generated at the "realtime" oversample rate of x2 of the host sample rate, which in this case was 44.1 x 2 = 88.2kHz. There are two oversample amounts, one for realtime and one for render, and the synths can instantly switch between them for track freeze and bounce. The you can set either oversample amount to powers of 2 from x1 to x16. I'll put a simple demo together showing how much this helps for very driven patches.

Andrew Simper

[putte]

.. andrew, just wanted to congratulate you, and it was nice seeing you in those videos.

i wish you all the best with these synths.
cheers,

putte

[andy-cytomic]

(edit: I have added some dB values to put the drive in context, this is an extreme example to show how much of a difference oversampling has to the signal quality with heavy drive used)

I have some oversampling demos available, I have taken a pulse waveform and given it full drive (+36 dB) and into the filter and full drive into the amp (+36 dB) for a total of +72 dB of drive and plotted the results at x1 oversampling (ie none) and x16. Most guitar distortion pedals give you around 30 dB tops. I have low pass filtered the audio so as not to rip your ears off too much and just leave the lower frequency aliasing audible:


http://www.vellocet.com/SynthSquadAudio ... ple_x1.mp3


http://www.vellocet.com/SynthSquadAudio ... le_x16.mp3

Andrew Simper[/img]

[andy-cytomic]

...i wish you all the best with these synths.
cheers... putte

Thanks Putte!

[kritikon]

Yup, liked those leads too. Sounds like the filters will be quite musical higher up the keyboard. Unusual for most s/w (impOSCar being the main exception IMO - completely different filter sound though - apples and oranges).

So now I'm sold on Strobe and Cypher. Wouldn't mind hearing what the bit that sticks them together thing can do (sorry - forgot the name of it completely. Just got out of bed). Y'know, the thing with the sequencer and the layering and stuff...

[Amberience]

Fusor is a sort of stack 'em up utility, full of crazy modulation possibilities. You get LFO's, envelope followers, a sequencer, and the ability to load three synths at once, and process them individually with three effect slots per synth slot.

[fintain]

Not that it makes that much of a difference but there is some pretty heavy duty aliasing going on in both those plots.
Can you do something similar without driving the filter and the vca just to get a feel for the oscillators cleanness.

[BASSDRIVE]

I just wacked off right now.

[ckatrun411]

I have some oversampling demos available, I have taken a pulse waveform and given it full drive and into the filter and full drive into the amp and plotted the results at x1 oversampling (ie none) and x16. I have low pass filtered the audio so as not to rip your ears off too much and just leave the lower frequency aliasing audible:


http://www.vellocet.com/SynthSquadAudio ... ple_x1.mp3


http://www.vellocet.com/SynthSquadAudio ... le_x16.mp3

Andrew Simper[/img]

Hi Andrew,

I checked out these vibes, they seem really cool, but I'm afraid I've got some questions.

See I've been confused a little bit, by where the conversation has gone. Mainly cause I don't understand the whole oversampling, up-sampling thing.

I really keep things simple here. I do 24 bits, sample rate of 44100, when I do my homegrown masters, I switch to 16 bits.

Basically what I don't understand is: Are these synths fully anti-aliased? Do they alias? I mean, these are premium soft synths, with high quality algorithms, that have crystal clear highs, with oscillators that are anti-aliased right? And what do these pictures mean and all?


Cheers

[andy-cytomic]

Hi Andrew,

I checked out these vibes, they seem really cool, but I'm afraid I've got some questions.

See I've been confused a little bit, by where the conversation has gone. Mainly cause I don't understand the whole oversampling, up-sampling thing.

I really keep things simple here. I do 24 bits, sample rate of 44100, when I do my homegrown masters, I switch to 16 bits.

Basically what I don't understand is: Are these synths fully anti-aliased? Do they alias? I mean, these are premium soft synths, with high quality algorithms, that have crystal clear highs, with oscillators that are anti-aliased right? And what do these pictures mean and all?


Cheers

No problems about asking questions, always feel free to ask anything you want. If I can't answer it then the problem lies with me not you for having asked it!

All the oscillators are anti-aliased already in the synths. When you add non-linear drive from the filter and amp section this also needs to be anti-alised, and can be done by using oversampling.

Oversampling is where, if you are running at 44.1 kHz, you actually run the synths internally at a higher rate, for example x2 which is 88.2 kHz. But then you have twice the number of samples than your host expects, so you need to remove half of them which is called downsampling. All this is done for you, so you just get the synth sounding better in your host at whatever sample rate your host is running at.

The examples show a pulse oscillator being clipped by the filter and amp drive sections with +72 dB of drive, which is way more than most people use even for the most distorted guitar sounds. The first sound example is what happens with no oversampling (ie running at 44.1 kHz), and the second is with x16 oversampling (ie running at an internal sample rate to the synths of 705 kHz). You can clearly hear the improvement.

Oversampling is nothing new, and neither is switching between realtime and render quality, mostly it's been used in the past for samplers, not automatically done for you for synths.

Andrew Simper

[fintain]

hi andy,

Is there any chance you could do similar plots without driving the filter and the vca, you can count on the fingers of one hand the synths that do anti-aliasing properly and it would be great if these synths can join the club. Say a 10 khz saw tooth or 25-75 pulse.

[andy-cytomic]

Not that it makes that much of a difference but there is some pretty heavy duty aliasing going on in both those plots.
Can you do something similar without driving the filter and the vca just to get a feel for the oscillators cleanness.

Yes, you're right actually, there is more than there should be, I just checked and I had the anti-aliasing filters reversed! I've flipped them around and will post new demos

Andrew Simper

[andy-cytomic]

hi andy,
Is there any chance you could do similar plots without driving the filter and the vca, you can count on the fingers of one hand the synths that do anti-aliasing properly and it would be great if these synths can join the club. Say a 10 khz saw tooth or 25-75 pulse.

Definitely, I'm on it now. I'll also to sync sweeps, including sin and tri sync. The noise floor I've aimed for throughout the project is -120 dB (which means you get around -100 dB with edge cases).

Andrew Simper

[andy-cytomic]

Here are some basic sweeps put through the filter and amp sections at -12 dB gain (which is reasonably clean) then boosted back + 12 dB on the main outs all at x2 oversampling, which is the default "realtime" amount:

http://www.vellocet.com/SynthSquadAudio ... eps_x2.mp3

Andrew Simper