OK, I'm more of a 'Let's make it sound good', sort of a guy than a 'Tech Head' but I was amused when I received the following quote from a professional audio supplier about Super Live Audio monitors:


"Where digital processing is required, KV2 Audio use 20MHz High Resolution Sigma Delta A-D Conversion technology. This Super Digital design offers significantly improved dynamic range, very high sound quality even at low volumes (-80dB) and very low harmonic distortion, but more importantly, non-harmonic distortion.

KV2 Audio’s new Super Analogue technology exhibits low levels of non harmonic distortion and a very high dynamic range due to incredibly fast settling times of <1us. This is coupled with a large signal frequency response of 200kHz, being the minimum requirement to correctly and accurately reproduce high frequency dynamics"


Firstly I thought dynamic range was determined by bit depth, not sample rate, but perhaps this is different when referring to the resolution of the converter quality, happy to be corrected there...........

-80dB is indeed quiet if we're talking dB SPL - there's no other reference........

And it's news to me that 200kHz is now the minimum requirement to correctly and accurately reproduce high frequency dynamics, I'll have to just take their word for that one and tune into my nasal hair vibrations..............

I wonder how they actually sound?

Bob

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www.bickerton.co.nz

That blurb doesn't even make sense. It's typical Bad Science.

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madtheory creations
Synths and pianos for Kontakt

neither does your bicycle!

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http://soundcloud.com/richie-royale
http://www.mixcrate.com/richieroyale

Yes, I would say it is mostly Round Objects.

I have long been a champion of systems that have bandwidths commensurate with the input signal. There are a few mics that go to 50kHz but most don't even make 20.

A bandwidth of 200kHz implies a "transit time" of 5microseconds. This stuff gives me a headache but CAN you have a "settling" time 5x faster than the system response time?

And almost everyone agrees that old analogue kit sounded good and if you got a mic>tape>speaker up to 15kHz you were doing well!

Dave.

Quote narcoman:

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neither does your bicycle!

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That's like a duck.

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madtheory creations
Synths and pianos for Kontakt

Quote Tomás Mulcahy:

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Quote narcoman:

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neither does your bicycle!

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That's like a duck.

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Give it to a fish.

Dave.

I wonder if they are describing a one-bit system along the lines of DSD?

FWIW, you can trade off bit depth (resolution) and sample rate. Suppose you take two samples. You can report each sample as it comes, in which case you've got your normal resolution at this sample rate. Or you can report the average of the two samples, at which point you've now got a number with a resolution of half a bit (suppose one sample reported 125 and the other reported 126, the average will be 125.5), so effectively you've doubled your resolution. There's a bit more devil in the detail, but that's the basic idea. If they're sampling at 20MHz and reporting data at 200kHz, that's a shade under 7 extra bits worth of resolution.

Whether the speaker is capable of responding this fast and at this accuracy might be another issue...

KV2 stuff generally sounds awesome...even if the marketing blurb is a little wordy...

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www.exaviormusic.com
www.manninmusic.com Music Teacher, Isle of Man

Just about all audio convertors work this way nowadays - but if you want to reproduce the full audio band from DC to 200kHz you will need to decimate the 20MHz rate down to more than 400kHz and the bit depth will be reduced compared to a convertor outputting a more sensible rate.

James.

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JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net

Er... I would surmise, as Sam suggests, that they are trying to talk up the benefits of using a delta-sigma conversion technique.

There is a direct trade off between word length and sample rate and one can be exchanged for the other while maintaining audio quality.

DSD used in Super audio CDs uses this technique, and so do virtually all A-D and D-A converters in modern use.

However, most delta-sigma converters actually work with something between 3 and 5 bit wordlengths, rather than single bit, becuase it has long been argued that 64x the base sample rate (~2.8MHz) as used in standard DSD is insufficient for accurate capture and rendition of high amplitude high level signals.

I know of systems that run at 12MHz... but 20MHz is seriously fast. I wonder if they are employing video converter technology?

Regardless, assuming they are talking about a very high sample rate one-bit system, their claims and statements do make some sense and are vaguely credible.

Quote Bob Bickerton:

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Firstly I thought dynamic range was determined by bit depth, not sample rate

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It is a combination of the two when working with oversampled systems.

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-80dB is indeed quiet if we're talking dB SPL - there's no other reference........

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If we're talking SPL, then it would be 80dB below the threshold of hearing... which is indeed very quiet! I would presume they are talking about 80dB below the full scale maximum digital amplitude the systenm can accommodate.

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And it's news to me that 200kHz is now the minimum requirement to correctly and accurately reproduce high frequency dynamics

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It does seem rather high, but mots decent analogue gear has an internal bandwidth that extends to 100 or 150kHz, so it's not that mad, and if they are using video converters maybe this number is what falls out as a side effect of the technology they have decided to use.

Hugh


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Technical Editor, Sound On Sound

Edited by Hugh Robjohns (29/06/11 09:16 AM)

Quote narcoman:

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neither does your bicycle!

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http://madtheory.bandcamp.com/track/avez-vous

Maybe now it makes sense?



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madtheory creations
Synths and pianos for Kontakt

I tried to build one just like it !!

Quote Tomás Mulcahy:

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That blurb doesn't even make sense. It's typical Bad Science.

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Typical marketing I'd say.

Quote narcoman:

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I tried to build one just like it !!

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Did you remember the philange?

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madtheory creations
Synths and pianos for Kontakt

darn..... THAT's why it smelled funny.......

At first glance I thought it was speaking of a Class D power amplfier.(all the rage at the moment).

I have read Super Analogue somewhere before.

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