Review and Measurements of NAD T758 V3 AVR

[Blumlein 88]

I have the UMIK-1 measurements vary wildly in the 9 Dirac positions and when moved even an inch.
These devices are sensitive in ways that our ears/brain are not.

These efforts led to the conclusion that REQ/PEQ is best left to the below 150Hz in my room.
View attachment 33185

The dips at 800Hz and 1.5kHz were not confirmed using the OminMic2. Since the Salon2s are reasonably flat, this is due to reflections and as Dr. Floyd Toole has pointed out. Attempted correction is not recommended for a well designed speaker.
I'll try Dirac and PEQ again when I get my next processor.

- Rich

I find the ERB smoothing above 500 hz to fit well with what we hear or 1/6th smoothing. 1/3 is too smooth for what we hear.

 

[Blumlein 88]

I wonder if some of this relates not to our potential mechanical, physical hearing differences but more our more likely than not similar acoustic environments we experience growing up.

If we took ten people from a pre industrial environment, say the rain forest and tested them.. then again how much of our hearing is based on past evolutionary events and comes pre programmed in our genes. This being so maybe we would have more in common with a pre industrial people's than we would assume.

Who knows .

Stanislas Dehaene
Look for papers by this guy. I've recommended his book Reading in the Brain here before. He has other books I've not yet read. You can find research articles by him if you look.

In regard to reading he made a pretty good case that genetically controlled pattern matching capabilities influenced the kind of written languages we came up with by fitting with pre-existing visual genetically coded patterns of brain acitivity. Some of those relating to the environments humans evolved in. One of the reasons most written script is taller than wide. Also that it appears to have influenced a fine tuning of those filters over generations of people with a written language. It is likely the same things in general would apply to spoken language filters and hearing. How much we have varied from rain forest hunter-gatherers I don't know. My guess is again maybe some fine tuning, but likely 95% the same built in pattern matching.

Harman research seems to indicate people of different cultures and languages have the same basic hearing capacity and share a preference for the same kinds of loudspeaker performance.

 

[Blumlein 88]

Like I said before, we need to put the two Doctors, Toole and Dirac Live's in the same room and have a good debate on that one. From what I could understand, they will agree on measuring/EQ'ing above the room transition frequency may not be always reliable as the results may not be consistent, but Toole advised not to do it whereas Dirac (actually Anthem too) would want people to try and see how what happens, in other words, it may work out well too. So no definite answer on that, I am doing some tests now and hopefully to find out which way I prefer.

I feel pretty sure that a speaker that varies far from optimum can be helped by fixing upper frequencies. I've heard it on several speakers (Dirac and others), and haven't run into the situation where it hurts. Some say it does end up being a negative, but I've not found that. Yet most speakers I've done it to aren't of the good controlled directivity kind (like ESL panels).

I've used and like Tact as have others I know, ditto for Dirac, and everyone I personally know are anywhere from iffy to not at all liking Audyssey. Not sure how their approach differs and it has gotten better. It too often ends up far too bright in my opinion and those I know. I've heard the Anthem ARC briefly and it didn't seem badly done, but it was a brief listen.

 

[RichB]

I don't know we really know which doctor is right, not in this kind of stuff. And I am sure if you and I are interpreting what Dr. Toole said 100% correctly. Can he be contacted via email?

If you register on AVS, you can PM him.

There is a huge thread on AVS started by Kevin Voecks "How to Choose a Loudspeaker -- What the Science Shows".
Dr. Toole has practically written a new book. on this thread.

https://www.avsforum.com/forum/89-speakers/3038828-how-choose-loudspeaker-what-science-shows.html

Here are some relevant posts I found that were most recent from Dr. Toole:
https://www.avsforum.com/forum/89-s...aker-what-science-shows-104.html#post58249910

Sorry I missed your point. Above about 500 Hz steady-state room curves are not very informative unless one has elaborate anechoic data on the loudspeakers. Any detailed EQ in this frequency range needs to be based on anechoic data, although broadband tone-control spectral balance adjustments can be useful.

EQ can only compensate for frequency-response irregularities (mostly resonances), not inconsistency in directivity: a very common problem, or non-linear distortion/power compression: a less common problem.

It is impossible to translate such corrections into $$$$$. In the Revel product line and the high end JBL monitors resonances are not problems, and directivity is well controlled, so the main differentiation is in visual aesthetics ($$$) low frequency extension, and power output capability ($$$), none of which are related to EQ. The essential timbral neutrality is comparable among many of the products, and although small differences may be perceived in direct comparisons, experience has shown that these end up being statistically insignificant because of variations in program material. Readily accessible tone controls are a better investment.

As shown in the book, resonances need to be below the threshold of detection, not necessarily eliminated, and this is achievable in popularly priced products.

https://www.avsforum.com/forum/89-s...aker-what-science-shows-162.html#post58538632

Your post is good advice. However, I question the above remark based on what I have experienced.
I have one of the most powerful and expensive multichannel processors on the market, widely praised for its processing power and complicated signal processing. It is enormously flexible, clearly designed by smart people in the math and DSP categories, but equally clearly these people did not understand the acoustics and psychoacoustics of loudspeakers and rooms - my speciality. The result is that, in its self-calibration mode it does things that should not be done.
I won't go into the details of my history with this unit, but it began with a setup procedure, using their proprietary microphone, spatial averaging with weighted mic locations, and allusions to combined IIR and FIR processing promising a very special result.
It was indeed special, because the superb sound of my Revel Salon2s was clearly degraded. Measurements I made with REW disagreed with the unit's displayed result, but agreed with my ears. With help from a product specialist, manual EQ overrides were able to restore the essence of good sound.
Some subsequent fiddles have taken it to the point that I can enjoy programs, but only by overriding or disabling some of the internal processes.
I know that there are other digital equalizers with problems. All originate with clever math/DSP engineers doing things that may make academic sense, but that pay insufficient attention to the peculiarities of human perception. At professional audio gatherings I have had extended discussions/arguments with some of their engineers. It has always come down to opinion, not fact, and the opinions are inclined to enhance the customers' perceived value in the product. It is part of a mighty struggle to be different or distinctive in a product that delivers something that nowadays many people can do for themselves with off-the-shelf DSP, free measurement software and a $100 mic.

None of these processes are supported by published double-blind subjective evaluations. Tell me if I am wrong.

The universal availability of "room EQ" is now a kind of "disease" in audio. People place trust in these devices that is misplaced. As I have stated several times, when the operating manual of the "calibration" device basically states that if the customer does not like the sound from the default target curve, then change the target curve. At this point it becomes a subjectively guided tone-control exercise, not a calibration. The "circle of confusion" for whatever program used during the tweaking is now permanently installed in the system.
All that said, equalization is part of the necessary treatment of room modes in bass. There is no escape from that, but even there, something that should be simple is sometimes compromised. Chapter 8 in the 3rd edition.
Toole, F. E. (2015). “The Measurement and Calibration of Sound Reproducing Systems”, J. Audio Eng. Soc., vol. 63, pp.512-541. This is an open-access paper available to non-members at www.aes.org http://www.aes.org/e-lib/browse.cfm?elib=17839

Dr. Toole's research and experience are well known and reasoning impeccable, to me anyway.
I think I heard a mic drop

- Rich

 

[peng]

If you register on AVS, you can PM him.

There is a huge thread on AVS started by Kevin Voecks "How to Choose a Loudspeaker -- What the Science Shows".
Dr. Toole has practically written a new book. on this thread.

https://www.avsforum.com/forum/89-speakers/3038828-how-choose-loudspeaker-what-science-shows.html

Here are some relevant posts I found that were most recent from Dr. Toole:
https://www.avsforum.com/forum/89-s...aker-what-science-shows-104.html#post58249910


https://www.avsforum.com/forum/89-s...aker-what-science-shows-162.html#post58538632



Dr. Toole's research and experience are well known and reasoning impeccable, to me anyway.
I think I heard a mic drop

- Rich

I have read a lot of his articles, papers and watched at least one YouTube video, did buy his book though. Almost every time I read what people quoting him I had to think about if I came away with the same interpretation. May be I focussed too much on the technical side, the logic behind, and/or over thinking in general.

Thank you for the links, that should keep me busy this weekend.

 

[RichB]

I have read a lot of his articles, papers and watched at least one YouTube video, did buy his book though. Almost every time I read what people quoting him I had to think about if I came away with the same interpretation. May be I focussed too much on the technical side, the logic behind, and/or over thinking in general.

Thank you for the links, that should keep me busy this weekend.

There is nothing wrong with tone-controls, but running global REQ with a speaker that is well engineered with flat frequency response and smooth off-axis performance is likely to compensate in a way to compromises the on-axis response and perceived response.

It comes down the early and late reflections. You will not find a consensus even between Toole and Voecks on their efficacy.

Personally, I find impulse response goal a bit far-fetched given the wave-length and varied seating positions.
It seem to me your head would have to be in a vice.

Edit: A long time ago I decided to buy the best performing speakers that I could afford. Later, I upgraded components to make better use of them. I am not relying on REQ and will continue to try various REQ/PEQ solutions, focusing on room modes.

- Rich

 

[Blumlein 88]

Stanislas Dehaene
Look for papers by this guy. I've recommended his book Reading in the Brain here before. He has other books I've not yet read. You can find research articles by him if you look.

In regard to reading he made a pretty good case that genetically controlled pattern matching capabilities influenced the kind of written languages we came up with by fitting with pre-existing visual genetically coded patterns of brain acitivity. Some of those relating to the environments humans evolved in. One of the reasons most written script is taller than wide. Also that it appears to have influenced a fine tuning of those filters over generations of people with a written language. It is likely the same things in general would apply to spoken language filters and hearing. How much we have varied from rain forest hunter-gatherers I don't know. My guess is again maybe some fine tuning, but likely 95% the same built in pattern matching.

Harman research seems to indicate people of different cultures and languages have the same basic hearing capacity and share a preference for the same kinds of loudspeaker performance.

Yes I am so pitiful I reply to my own posts.

https://www.sciencedirect.com/science/article/pii/S0896627312007635

Here is an article showing that blind people use built in brain filters for vision when reading via braille. So kind of interesting.
https://www.sciencedirect.com/science/article/pii/S0896627312007635

This one is about how the brain processes a single sound anomaly vs how it responds to several successive anomalies in audible sounds.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0085791

This one is behind a pay wall. It shows that existing brain filtering is improved by the acquisition of literacy. The visual processing is enhanced, and related processing areas are altered to take over different tasks. Visual processing of letters becomes more localized in a visual center of the left brain and as a result pattern matching for human faces becomes more localized in the right hemisphere. Interesting stuff at least to me.
https://www.nature.com/articles/nrn3924

 

[Sal1950]

I received a reply to my NAD Support query today,
About what I expected, no comment.

Bob Moran (NAD Electronics) Sep 13, 4:08 PM EDT Hello Sal,

Thank you for considering the M17 V2 as an upgrade to your Marantz Marantz 7703 processor.

NAD does not comment on forum reviews of our products.

Our best advise is to listen to the M17 V2 in person and let your ears decide.

Kind Regards,

Bob Moran
NAD Support Specialist

Sal1950

Sep 8, 5:01 PM EDT

Dear Sir,
I have been considering purchasing a M17 V2 as an upgrade to my current Marantz 7703 processor. Unfortunately my friends at Audio Science Review just did a detailed measurement lab test on your T758 receiver and the results were very disturbing.
https://www.audiosciencereview.com/...iew-and-measurements-of-nad-t758-v3-avr.8912/
I'm wondering why the digital tests showed such high noise and distortion numbers from a DAC chip that specs at near state of the art? I would love to move into a M17 for it's Dirac DSP but afraid it would mirror the poor performance of the T758. Maybe this unit was defective and if so the lab at ASR should be contacted to get a properly performing one. I would love to hear your response to the issue either personally or on the ASR website. Operator Amir would be glad to revisit the issue you.
Thanks
Sal1950

 

[digitalfrost]

BNAD: "You're on your own. Good luck."

 

[Sal1950]

NAD does not comment on forum reviews of our products.

I bet they'd be crowing and linking the review if it was a rave.

 

[peng]

Wow, that's very different than Marantz approach to forum review related questions. Good thing I only have one NAD product. I can understand why they wouldn't respond to all or any forum reviews, but they should be open minded enough to at least take a look and make a reasonable assessment of the apparent credibility/quality of the said review, instead making it a general blanket rule.

 

[digicidal]

"Let your ears decide" - because we all know those are impossible to trick right?

 

[amirm]

I received a reply to my NAD Support query today,
About what I expected, no comment.

That's what they told the owner.

 

[Sal1950]

That's what they told the owner.

Is the M17 you mentioned in the queue now?

 

[Hugo9000]

I bet they'd be crowing and linking the review if it was a rave.

Even if they didn't link it, they might not have been so dismissive and called it a "forum review" as if it were just the rambling impressions found in the middle of any old thread in an audio forum or on reddit.

lol

 

[RichB]

The dealer audition of my friends Revel F206's used a NAD integrated amp. He kept turning up to 1:00 and I kept turning it down to 11:00. Thankfully, I knew that Revels could not sound that bad and assured him that it was the NAD. Dealers seem to pair products by price range and markup. Not very scientific.

At his home, the F206s rock using the Oppo BDP-105 and Parasound A21.

- Rich

 

[RichB]

I received a reply to my NAD Support query today,
About what I expected, no comment.

Bob Moran (NAD Electronics) Sep 13, 4:08 PM EDT Hello Sal,

Thank you for considering the M17 V2 as an upgrade to your Marantz Marantz 7703 processor.

NAD does not comment on forum reviews of our products.

Our best advise is to listen to the M17 V2 in person and let your ears decide.

Kind Regards,

Bob Moran
NAD Support Specialist

"Forum reviews", the pain the pain
I like BenchmarkMedia's responses better.

- Rich

 

[Dj7675]

I should have mentioned that their official line is to not comment on any outside reviews or measurements. At Amir's suggestion, I asked if they could provide their detailed measurements of the device.
Unrelated, but it gave me a laugh out loud moment.. a guy in the AVS T758 thread referred to Amir as a known online agitator. At first my response was that isn't fair... but the more I think about it, as poor as the measurements have been for NAD and Anthem, maybe the audio world needs a little agitation I kind of like it... Amir the Agitator. Has a nice ring to it!

 

[Jimster480]

Amazing how poor the performance has been with AVR's... such high noise floors and poor resolution.

 

[NTK]

I should have mentioned that their official line is to not comment on any outside reviews or measurements...

But they have no problem putting out press releases when reviewers said good things about their products
https://nadelectronics.com/nad-m17-v2-wins-2019-top-pick-award/

[Edit:] An even more relevant one.
https://nadelectronics.com/nad-elec...eiver-by-worlds-most-prestigious-hi-fi-press/