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Author Topic: Slate Virtual Microphone Claims  (Read 8785 times)

Piedpiper

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Re: Slate Virtual Microphone Claims
« Reply #15 on: January 27, 2014, 12:56:56 am »

extremely well said...
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row row row your boat...

Pied Piper Productions

didier.brest

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Re: Slate Virtual Microphone Claims
« Reply #16 on: February 06, 2014, 04:35:37 pm »

I hold against this bet  :)

They claim their plugin has zero latency, this is impossible with convolution or any other type of windowing process like FFT.
It's (almost) possible eg. with FIR or IIR filters.

Finite Impulse Response (FIR) filtering is convolution.

Quote from: Wikipedia page on FIR
The output y of a linear time invariant system is determined by convolving its input signal x with its impulse response b.

The zero latency claim, which means that there would be no (sensitive) delay between the signal of the actual microphone and the signal of the virtual microphone, is legitimate if the Slate Virtual Microphone is based on minimum phase filtering.

The impulse response may be made dependent on the level of the input signal, which is named dynamic convolution and allows for modelling the non-linear behaviour of the microphone to be emulated.
The Liquid Channel from Focusrite is quite good in doing this for vintage preamps emulation. I agree that emulating a microphone is more difficult than emulating a preamp because of the dependency of the impulse response of the microphone with respect to the direction. But good modelling of the response on the main axis might deliver interesting results at least in some cases (close miking of a voice ?). Who knows ? Not me. I would be interested in blind listening to samples comparing the original and the copy.
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Didier Brest

Kai

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Re: Slate Virtual Microphone Claims
« Reply #17 on: February 07, 2014, 01:07:53 pm »

Finite Impulse Response (FIR) filtering is convolution.
Sorry, I would have needed to be more precise:
I meant convolution based on real world impulse response, which is not as "finite" as one would like it to be for fast processing, not on (maybe simpler) mathematical filter functions.
To my knowledge and experience the computing of such takes too much processing power to be made in quasi realtime, except if you use dedicated DSPs.

In fact a real world impulse response covering the frequency range down to 20 Hz needs to be at least 50 ms long, practically (due to windowing) about double of that.
100 ms (4410 samples @ 44.1 kHz SR) is a lot of data to be convoluted with the input signal.
Now make this dynamic with several IR's blendet -

I would be very interested how they do it, maybe they found a shortcut?

I would be interested in blind listening to samples comparing the original and the copy.
That's exactly what I expect to do.
"All theory is grey".

Regards
Kai
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klaus

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Re: Slate Virtual Microphone Claims
« Reply #18 on: February 07, 2014, 03:43:16 pm »

Hello Kai,
Thanks for going into that much detail, but… you lose a lot of readers if these thoughts cannot be put into more simple, easier to understand terms. I will remove this request as soon as you have done so.

Best,
KH
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Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

David Satz

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Re: Slate Virtual Microphone Claims
« Reply #19 on: February 07, 2014, 11:14:49 pm »

I think that the presenter has a very convincing manner, but sometimes the ability to be convincing is inversely related to how well one really knows what one is talking about.
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klaus

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Re: Slate Virtual Microphone Claims
« Reply #20 on: February 08, 2014, 12:02:49 am »

Is this just a feeling, or can you give an example, where the information given by the presenter is inaccurate or misleading?
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Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

David Satz

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Re: Slate Virtual Microphone Claims
« Reply #21 on: February 08, 2014, 08:33:51 am »

?? I and some other people in this thread have been talking all along about ways in which this product can't possibly live up to all the technical claims that have been made for it, since they are logically contradictory. Having already done that, I wanted to make an observation about the persuasive quality of the video.

If postings based on feeling were banned, this forum would save about 80% on bandwidth and disk space, with your own postings being among those most affected. Fundamentally this forum is about esthetics; even the discussions about facts and science are ultimately governed by feeling.
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klaus

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Re: Slate Virtual Microphone Claims
« Reply #22 on: February 08, 2014, 12:52:31 pm »

(…) Fundamentally this forum is about esthetics

The discussion of audio esthetics is one of this forum's aspects, equal in weight to other subjects which participants are interested in to have the best possible understanding and usage of recording microphones.

What is sometimes perceived by others, and maybe you, too, as a forum void of, or hostile to, scientific examination of microphones, and audio products in general, is my strong skepticism towards the assumption that, if we cannot measure or quantify an aural phenomenon, it cannot possibly exist, and those who claim its existence are fools.

This attitude had led to decades of delay in the development of better sounding stored music, recording devices and musical instruments based on said storage, and it is still at the heart of the crux in most modern microphone designs: a prevalent attitude that "good" measurements are the key to good sounds and sales.
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Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Steven Slate

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Re: Slate Virtual Microphone Claims
« Reply #23 on: February 11, 2014, 02:31:11 am »

Thanks so much to Klaus for the discussion on the new VMS.

We have worked with some very talented microphone designers to develop two microphones that have an extremely high bandwidth and linear frequency response with a sufficiently high quality capsule.

Then the issue is measuring the reference microphone response.  It took us several months to develop a process that allowed us to capture enough complex measurements that were adequate enough so that we could develop an algorithm that was able to recreate the tone of the specific microphone.

I realize that there are a lot of physical properties involved in the way a mic capsule such as the M7 operates, but ultimately we found that the response was something that could be measured and then recreated algorithmically.

The polar pattern of our microphone shares a similar ratio of off axis frequency deviation to the classic Neumanns, which is aided by the sheer fact that the attenuation of high frequencies in off axis response makes it harder for the human ear to discern minute differences.

This is proven by the fact that when our 47 algorithm was about 80% accurate to the real 47 in its on axis response, it was already indistinguishable off axis.

The goal of this product is to offer another tool for music makers to help create their art, and we're very excited about the progress thus far.  Thanks again for the discussion,

Cheers,
Steven
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bodtbody

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Re: Slate Virtual Microphone Claims
« Reply #24 on: February 12, 2014, 05:53:08 pm »

You want to sell microphones , why don't you say so.
If this was serious , the software would accept any microphone in the input.
The software could then emulate a " toys are us" microphone to the very fine microphone you say you will sell.

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venlig hilsen JP

Jim Williams

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Re: Slate Virtual Microphone Claims
« Reply #25 on: February 13, 2014, 12:04:50 pm »

Antares has had that product out for years. It didn't seem to slow the sales of expensive mics, though.

For me, there are too many variables to include in a modeling stew, like capsule, internal wire selection, front end mic amp designs, front end capsule input impedance, output amplifier designs- solid-state or transformer- the mic cable itself, the preamp, the pre- amp's input impedance, the pre-amp's input design, s.s. or transformer, the converter, bit depth, sample rate and bandwidth, the converter's dynamic range and THD specs, on and on.

Then you can start the whole thing over again with the playback components. The DAC, sample rate, bit depth, clocking design, analog I/V design, analog filter design, power supply design, so on and so on.

Change just one of those factors and that reference is reset.
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