Is there evidence that digital filters like those used in digital speakers and room correction devices are free of "deleterious" effects on audio signals ?

It is hard to prove a negative. Is there any evidence that digital filters cause "deleterious" effects on audio signals?

Is there evidence that digital filters like those used in digital speakers and room correction devices are free of "deleterious" effects on audio signals ?

Early digital recordings suffer from harshness too, due to primitive filters. After painstaking research, Meridian developed a special filter [...] cleaning up the effects of early filters.

Quote from: julf on 2014-11-25 13:54:21

It is hard to prove a negative. Is there any evidence that digital filters cause "deleterious" effects on audio signals?

Yes. In the Best Peer-Reviewed Paper under discussion conclusion no.1 is:
FIR filters that emulate downsampling for sample rates of 44.1 kHz and 48 kHz can have a deleterious effect on the listening experience in a wideband playback system.

I was just wondering if it was a good thing to test the effect of (steep) digital filters by using a playback system that apparently contains several digital filters. The specifications of the playback system are:
192 kHz D/A convers, wide frequency response (up to 40 kHz), very low differential group delay and compact impulse response with insignificant ringing.
There is quite some anecdotal evidence about audible effects of digital filters, so to me an all analogue path after the DAC would make more sense. Perhaps a reason could be that Meridian doesn't have any non-digital speakers ?

Is there evidence that digital filters like those used in digital speakers and room correction devices are free of "deleterious" effects on audio signals ?

Let's start:  "how do you even imagine that one can hear a difference between two systems, one with noise 98 dB down and the other 146dB down, when the level is set to peak at 96dB?"

How do you (Amir) explain how "obviously difference" fails to show up in even the worst kind of ABX test? (unless it is the unsupervised, Windows pc, online cheatable variety, which are worthless and unrelated to the anti-ABX BS paper)

I have yet to see a whit of evidence that "high-rez" matters for final presentation to a listener.  Have you any, bearing in mind that citing non-blind-testing proves nothing but the incompetence, the complete and total incompetence, of the person citing it as evidence.

Bear in mind the hard evidence for the persistance of loudness memory while you're at it.

08-01-2014, 10:07 PMjj_0001 avsforum
I have my doubts that SACD or DVDA are much, if any, of an improvement, but the test is just blisteringly hard to run, and more likely to respond to artifacts, either positively or negatively, than it is to actual differences. Time alignment, level alignment, frequency response in-band can all throw it positive, lack of training, bad test environment, bad time alignment, etc, can also cause false negatives. Subject verification, likewise, is an important issue.

So, I remain undecided, but I note that I own a lot of CD's and not a single SACD or DVDA, except for some people have sent me.

In comparison testing I have done, switching amplifiers using the classic class D configuration always sport incredible low frequency control and power. They beat out linear class AB amplifiers almost regardless of price. What they give up though is high frequency fidelity which I find somewhat harsh. The distortion is highly non-linear and challenging to spot but it is there. The Mark Levinson No 53 is the first switching amplifier I have heard which does not have this compromise. Its bass is amazingly authoritative: tight and powerful. Yet the rest of the response is absolutely neutral and pleasant.

If you have not heard these unique amplifiers, I highly encourage you to come into our showroom for a listen.

Even if you could show "deleterious" effects of real-world filters, it doesn't seem to matter, because as Meridian writes:

Quote

Early digital recordings suffer from harshness too, due to primitive filters. After painstaking research, Meridian developed a special filter [...] cleaning up the effects of early filters.

(Let's ignore the fact that this is partly false, because aliasing is virtually impossible to remove from any sampled piece of inadequately filtered music. In other words if the A/D conversion is crap, you cannot un-crap it.)

Also see #539 for a demonstration.

There is a lot of vagueness in the statement "Early digital recordings suffer from harshness too..."

This ‘apodising’ filter is so effective that it can correct problems further up the chain – even including fixing faults in the original recording.

In the most characteristic "subjective audiophile" fashion I am having a strong audio gut feeling that you purpously misquoted Meyer and Moran. They mean exactly the oposite of what you are saying since 2007.

...

That is a very illogical affirmation. It should have said it sounded diferent (not better). it s that from a scientific paper??!!
...

Dynamic range compression does not depend on audio format. It is a choice made by the recording technician. Didn't Meyer and Moran know that?! I don't think they said that. I don't think you can be trusted as a source of information. Can you show some evidence?

A Note On High Resolution Recordings
Though our tests failed to substantiate the claimed advantages
of high-resolution encoding for two-channel audio,
one trend became obvious very quickly and held up
throughout our testing: virtually all of the SACD and
DVD-A recordings sounded better than most CDs—
sometimes much better. Had we not “degraded” the sound
to CD quality and blind-tested for audible differences, we
would have been tempted to ascribe this sonic superiority
to the recording processes used to make them.

Plausible reasons for the remarkable sound quality of
these recordings emerged in discussions with some of the
engineers currently working on such projects. This portion
of the business is a niche market in which the end users are
preselected, both for their aural acuity and for their willingness
to buy expensive equipment, set it up correctly,
and listen carefully in a low-noise environment.

Partly because these recordings have not captured a
large portion of the consumer market for music, engineers
and producers are being given the freedom to produce
recordings that sound as good as they can make them,
without having to compress or equalize the signal to suit
lesser systems and casual listening conditions. These recordings
seem to have been made with great care and
manifest affection, by engineers trying to please themselves
and their peers. They sound like it, label after label.
High-resolution audio discs do not have the overwhelming
majority of the program material crammed into the top 20
(or even 10) dB of the available dynamic range, as so
many CDs today do.

Our test results indicate that all of these recordings
could be released on conventional CDs with no audible
difference. They would not, however, find such a reliable
conduit to the homes of those with the systems and listening
habits to appreciate them. The secret, for two-channel
recordings at least, seems to lie not in the high-bit recording
but in the high-bit market.

The fact is that the market for 'hi rez' in and of itself -- as for all 'audiophile'  niches -- is tiny relative to all audio content sales.

And sales arent always about the 'resolution'.  I've bought quite a few 'high rez' releases myself in the past few years....because they included 5.1 mixes and bonus tracks and 'flat transfers' of original masters, which are what I *actually* cared about and *obviously* make a difference.  I had to buy the 'high rez' edition to get them.

Even so, if that changes -- if hi rez becomes the norm, if the industry somehow decides to replace all the most popular forms of profitable audio delivery content (currently CD and  lossy compressed downloads and streaming) with 'hi rez' as the default ...

Unless they commit at the same time to 'old school' mastering, it won't matter to those who actually understand the differences.

The average consumer might 'believe' they got 'better sound' that 'even your wife could hear',

Tap dancing CD Fearmongers need to STOP saying we need hi rez to get good sound.  That's a lie.  We don't.  We need good recording and mastering, and good listening setups

How would you "understand" the difference if all you have in your hand is a CD and compressed MP3/AAC?

The only way you would know there is or is not something better is to get the upstream stereo mix.

One of two things will then happen:

1. It is the same master in which case it may or may not demonstrate a small incremental fidelity.

2. It is a better master in which case the merit is obvious and something we all violently agree we want.

By making a case against high resolution you are throwing the baby with the bath water.

"
Our test results indicate that all of these recordings
could be released on conventional CDs with no audible
difference. They would not, however, find such a reliable
conduit to the homes of those with the systems and listening
habits to appreciate them. The secret, for two-channel
recordings at least, seems to lie not in the high-bit recording
but in the high-bit market.
"

I don't know all the details about the Meridian speakers, but the fact that the Meridian supplied frequency response curve only goes up to about 40 KHz suggests that they may be based on 96 KHz sampling.

1x balanced digital (AES/EBU) input on RJ45; 32kHz–96kHz sampling rates at up to 24 bit; MHR support. RJ45 input also carries RS232 and trigger.

I think Amir you're a little guilty of wishful thinking.

Audiophile record labels create great sounding hi-res releases. They create great sounding CDs too.

Meanwhile mainstream-ish content, when it makes it out in hi-res, is a real mixed bag. I don't have a feeling for the proportion of good vs disappointing releases out there, but of the few I've tried, most have been disappointing. In a few cases a great SACD from an audiophile company has eclipsed an old and ropey mainstream CD. Without SACD, the same company would have put out an audiophile CD.

I'll happily give credit where a new master, released in hi-res, beats all available CD issues. I just can't join in with this fiction that the improvement in sound quality is due to the number of bits.

As for the price...
http://www.amazon.co.uk/After-Midnight-Nat...e/dp/B004C6QCXM

Then don’t.  My argument is the former.  That is why I say all of this technical discussion, listening test, etc. are moot.

That is why I say all of this technical discussion, listening test, etc. are moot.  We have a path to get better masters.

Quote from: amirm on 2014-11-25 16:50:40

2. It is a better master in which case the merit is obvious and something we all violently agree we want.

The implicit false claim here is that the only way to obtain a better master is to up the sample rate and/or word length. That has long been disproven by means practical examples.

Let's see, argument ad populum, red herring, fear mongering..... 

Bieber being released straight to MP3, oh the horror, the horror.

Now, about this BS paper....

Quote from: krabapple on 2014-11-25 16:11:55

"
Our test results indicate that all of these recordings
could be released on conventional CDs with no audible
difference. They would not, however, find such a reliable
conduit to the homes of those with the systems and listening
habits to appreciate them. The secret, for two-channel
recordings at least, seems to lie not in the high-bit recording
but in the high-bit market.
"

So what do the second and third sentences mean?

That audiophiles are less likely to purchase a well mastered recording if only available on a CD or CD format (44/16) download?

Is the CD well that poisoned by unnecessarily bad product?

The only relevant discussion relates to the CD.

It was simple science.

(1) I created a suite of recordings of music and high bandwidth natural sounds @ 24/96 using microphones with 40+ KHz bandpass.

(2) Using myself and friends as guinea pigs I ABXed them with downsampled/upsampled versions of themselves.

None of us could hear a difference.  This was > 14 years ago when my hearing was much more sensitive to subtle differences.

Quote

Fortunately, the above speculations are not true.  With complex music signals the limit of audiblity is more like 16 KHz due to masking, and that is more than plenty far enough away from 44.1 KHz with modern digital filters.

Ah yes.  I recall you saying this before:

Quote

I've done experiements with sliding brick wall filters down to lower and lower frequencies. Usually, they start being barely audible around 16 KHz.

Can you please outline those tests?  Were they double blind or sighted?  And was the person performing the tests had his hearing tested to make sure they could hear above 16 Khz?

And a reference to masking of everything above 16 KHz would also make for great bedtime reading for me .

I did what I said in the previous post. I made recordings of live  musicans in an exceedingly quiet and non-reverberent room @24/96 using 1/4" measurement mics that had strong content > 20 KHz, even 30 KHz.

I set up an ABX between the 24/96 files with a 16 KHz brickwall filter, and with full bandpass. I used speakers and amps with strong response > 30 KHz and put the listeners on axis of their supertweeters.

Quote from: Amir on AVS link=msg=0 date=

Were they double blind or sighted?

both

The training sequence was files brick walled at lower frequencies such as 9 KHz, and working up in logical steps.

Quote from: Amir on AVS link=msg=0 date=

And was the person performing the tests had his hearing tested to make sure they could hear above 16 Khz?

Yes.