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MQA The Truth lies Somewhere in the Middle


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2 hours ago, Archimago said:

I do hope that a representative for MQA is on hand to answer for some of these rather straightforward questions/issues even if a bit uncomfortable as they may arise!

One of the first things I did after conceiving the idea for this seminar was to invite Ken Forsythe from MQA to attend.   I have nothing to hide and am not out to take down MQA. I’m out to provide information. However painful that may be to some on all sides.

 

After all, if you have cancer you want the doc to tell you the truth so you can make an informed decision on whether or not you want to live with it or fight it. 

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@mansr, I think it's pretty clear what @The Computer Audiophile is trying to say: He's "not out to take down MQA," in the sense that he's doesn't have an agenda to try to kill MQA without regard for what the facts of MQA might actually be. He wants to promote and disseminate the facts at MQA and let the chips fall where they may.


If the facts about MQA were widely known, MQA likely would fail, yes - many of us here agree on that.

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5 minutes ago, Archimago said:

Cool. Hope Mr. Forsythe agrees to attend. Even better if he brings some information to present that might help us understand what we might be missing with this "elegant" codec.

I won't be surprised if the session is "mysteriously" cancelled at the last minute. Wouldn't be the first time.

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56 minutes ago, The Computer Audiophile said:

I’m out to provide information.

What's the format of your session?  Is it a presentation followed by Q&A, or a panel discussion or what?

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7 minutes ago, tmtomh said:

@mansr, I think it's pretty clear what @The Computer Audiophile is trying to say: He's "not out to take down MQA," in the sense that he's doesn't have an agenda to try to kill MQA without regard for what the facts of MQA might actually be. He wants to promote and disseminate the facts at MQA and let the chips fall where they may.

Do I need to explain the meaning of the word "troll"?

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30 minutes ago, The Computer Audiophile said:

Just me and a microphone and a slide show. 

So how does Ken Forsythe participate?  Or did you just invite him to see the presentation?

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2 hours ago, Shadders said:

Another question - is that it seems that Texas Instruments, Analog Devices, Cirrus Electronics et al, all have got it wrong with regards to ADC's. Has MQA notified these companies that their products have serious design flaws, and if not, why not ? Involving these professional companies in the discussion will ensure that MQA is assessed, and this may be of a benefit in exposing MQA as a false solution.

 

Regards,

Shadders.

 

Furthermore there are not many MQA ADC's - only one beta - while we have a lot of DAC's with MQA decoders!

It's like implementing end-to-end encryption where the focus is on selling decrypters, where you have a lot of different implementations all claiming to be authentic to the source (the master) and after decryption leading back the the plaintext before encryption, while you only have one encrypter ... (which is impossible when your codec is lossy).

The end-to-end claim was only invented not to loose the audiophile community because MQA is not lossless but lossy.

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15 minutes ago, mansr said:

Where is this stated?

Hi,

The MQA paper :

A Hierarchical Approach to Archiving and Distribution

http://www.aes.org/e-lib/browse.cfm?elib=17501

 

States that dispersion is blur :

"When considering the frequency and time responses of an end-to-end distribution channel, we must bear in mind that time dispersion or ‘blur’ can build up through a cascade of otherwise blameless components. Figure 3
illustrates the response of a cascade built up to eight stages, each with a 2nd-order roll-off at 30 kHz, possibly representing a microphone, preamplifier, mixer,....
"

http://archimago.blogspot.com/2018/02/musingsmeasurements-on-blurring-and-why.html#more

 

Deblurring is what is stated to be MQA's purpose.

 

Regards,

Shadders.

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29 minutes ago, Shadders said:

The MQA paper :

A Hierarchical Approach to Archiving and Distribution

http://www.aes.org/e-lib/browse.cfm?elib=17501

 

States that dispersion is blur :

"When considering the frequency and time responses of an end-to-end distribution channel, we must bear in mind that time dispersion or ‘blur’ can build up through a cascade of otherwise blameless components. Figure 3
illustrates the response of a cascade built up to eight stages, each with a 2nd-order roll-off at 30 kHz, possibly representing a microphone, preamplifier, mixer,....
"

They never state that their method fixes it.

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6 minutes ago, mansr said:

They never state that their method fixes it.

Hi,

OK- so all the discussion on deblurring is wrong ? De-blurring is a non-existent issue created by the press ?

 

If that is the case, and MQA does not deblur, and their (MQA's) non-linear phase filters add dispersion, then MQA is the cause of blur/dispersion, and not the end-to-end solution it is stated to be.

 

Therefore, the revised question would be, if MQA cannot deblur, and MQA filters are non-linear which introduce dispersion which is greater than linear filters, then MQA distorts the music rather than ensures it is accurate ???

 

Regards,

Shadders.

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We've been through this before. If not here then on another forum. What MQA call

'dispersion' is any widening of a channel's impulse response, be it linear phase

or not. They fight it by replacing all filters in the channel with slow roll-off filters,

in some cases even no filters, in order to obtain a more compact impulse response.

This happens at the cost of aliasing and imaging, something they claim to keep below levels

of audibility.

In principle they also provide for correction of ills of the original recording gear, but we all

know that this is not really done, and in the few cases where it is done, it amounts to

the sort of care anyone competent can (should?) apply in a restoration and remastering

project.

 

But this is off-topic and this discussion can better be held elsewhere.

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9 minutes ago, Fokus said:

We've been through this before. If not here then on another forum. What MQA call

'dispersion' is any widening of a channel's impulse response, be it linear phase

or not. They fight it by replacing all filters in the channel with slow roll-off filters,

in some cases even no filters, in order to obtain a more compact impulse response.

Hi,

Not sure what the point is you are making. Since we do not listen to impulse responses, and music should be band limited on a CD etc., any non-linear filter has a worse effect than a linear filter in regards to dispersion. By MQA using non-linear filters, although they may have little memory (taps), still does not stop them from being non-linear.

 

Regards,

Shadders.

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1 minute ago, Archimago said:

Yeah...

 

Whatever the hell MQA is doing in the time domain, it doesn't seem to work and should be taken as such until they prove something of value!

 

Where's Bob Stuart when we really need him?! ?

 

Dahn the pub...

 

(you have to say the above with a cockney accent).

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