[bigshot]

How many trials did you do and how many of those were correct?

Are there measurements of the Chord that show where the difference might be?

I’m guessing the Chord would be the one that is colored, because the Apple dongle has been extensively measured and is transparent by a mile. The funny thing is, we had someone in here who did a test with the Mojo and found it was transparent. That makes me think either your copy of the mojo is defective, or you had the toggle on some user definable filter engaged.

Are you very familiar with the Chord settings? The Apple dongle doesn’t have any settings.

Oh! One more question… did you amp the outputs?

 

[gregorio]

When I compared chord mojo 1 (linear) and apple dongle (minimum) preferred the dongle for sounding more spacious and natural compared to the thicker and sharper sounding chord. …. To me the dongle sounds more pleasant, they both measure well so I’m putting it down to the minimum phase filter.

When I compared a Ford Fiesta (metallic blue) and a Ferrari 430 (red), I preferred the performance of the Ferrari. They both measure well so I’m putting it down to the difference in colour, for me red cars perform better than metallic blue ones. Isn’t that pretty much the same argument/assertion? Obviously the Ferrari and Fiesta have some very significant differences, including massively different power outputs, just as the Apple Dongle and Chord Mojo have very significant differences, also including a massive difference in output, 0.5V verses 5V (or more). Is it any more rational to conclude your preference is due to the effect on performance between two different filters (both of which operate beyond the typical range of adult human hearing) than it is to conclude that my preference is due to the effect on performance between two different paint colours (which is also beyond the range of human senses)?

Yes I did

Did you actually match the levels or did you only make them somewhat similar (EG. By ear)? Reducing this obvious, massive difference to only a “similar” or even a very similar difference is still overwhelmingly the more likely cause, because even almost imperceptible differences in volume have been repeatedly demonstrated to affect our perception, while anti-imaging filters with properties (transition band, ringing, etc.) beyond adult hearing have not. Along similar lines, what exactly was your blind methodology? Isn’t it logical to precisely eliminate differences which are proven to affect perception before concluding a cause beyond human hearing thresholds?

anyway even if expectation bias or placebo played a big part in this then wouldn't it be for the far more expensive chord mojo over the £9 apple dongle?

Why, does price only ever bias humans towards the more expensive product? More importantly though, do you believe that a bias is only ever caused by one single thing or one thing at a time? Bias can be caused by any number of things, price is an obvious one of course but it can be caused by weight, colour, size, design, brand name, functionality, etc., as well as by anything you’ve picked up consciously or subconsciously from marketing, reviews, testimonials, videos, etc. Furthermore, a bias can be the result of a subconscious weighting/judgement between any or all of these things concurrently. So a bias towards a higher price could be outweighed by a bias towards some aspect of appearance, functionality, practicality, whether you like Tim Cook more than Rob Watts or pretty much anything else.

You appear to be inadvertently using all the same fallacies made by audiophile marketing/reviewers/etc for decades.

G

 

[bigshot]

If what he says is true and accurate, I think the Mojo is defective and is performing out of spec… or his test controls aren’t as tight as he thinks they are. I’ve seen reports of controlled listening tests and measurements that show both of those are audibly transparent.

 

[Digital Enigma]

Let’s put this blind testing to the side for a minute because it’s straying off the path of my original question, what does an apodizing fast linear phase actually do.

So far I’ve learned that it reduces/removes problems caused upstream during the recording and mixing process by cutting off early before the nyquist frequency but the filter it’s self is not free of producing its own ripple/ringing in the process. Correct me if I’m wrong.

 

[bigshot]

Is your question referring to audible ringing, or just measured? Because just about everything in life is a compromise under the right conditions, but the real question is, does it matter? That’s a pretty easy question to answer.

Perhaps a better question is, does it create more of a problem than an NOS DAC with a nice gradual (read: audible) roll off below 20kHz? That’s also a pretty easy question to answer.

It’s all relative. I consider switchable filters to be the audiophile equivalent of a child’s busy box- just buttons to have fun pushing. I just let the DAC manufacturer handle it and don’t worry about it. Gregorio know the ins and outs of this more thoroughly than I do though.

 

[Digital Enigma]

Whether it matters or not it doesn’t hurt to be curious.

My question refers to audible and measurable.

 

[KinGensai]

Answer seems clear to me: use the filter that sounds best to you. They all address aliasing, and IME the effect of changing filters is almost imperceptibly subtle if your transducers don't have an IR lower than 2ms.

 

[Digital Enigma]

Answer seems clear to me: use the filter that sounds best to you. They all address aliasing, and IME the effect of changing filters is almost imperceptibly subtle if your transducers don't have an IR lower than 2ms.

But do they also suppress upstream ringing or is that just the “unique trait” of the apodizing?

 

[GoldenSound]

How many trials did you do and how many of those were correct?

Are there measurements of the Chord that show where the difference might be?

I’m guessing the Chord would be the one that is colored, because the Apple dongle has been extensively measured and is transparent by a mile. The funny thing is, we had someone in here who did a test with the Mojo and found it was transparent. That makes me think either your copy of the mojo is defective, or you had the toggle on some user definable filter engaged.

Are you very familiar with the Chord settings? The Apple dongle doesn’t have any settings.

Oh! One more question… did you amp the outputs?

Measurements available here: https://goldensound.audio/2022/05/26/chord-mojo-2-measurements/

Lower distortion/noise than apple dongle. Main difference would be the significantly better reconstruction filter (which is also linear phase) and significantly lower jitter

 

[KinGensai]

But do they also suppress upstream ringing or is that just the “unique trait” of the apodizing?

The idea here is that a linear filter creates spectral leakage (the ringing), so a window function is applied to the filter to allow some of that ultrasonic content past to reduce that artifacting. The consequence of course is the higher potential for aliasing if you are using DSP to mess with frequencies approaching the nyquist frequency.

It doesn't seem to me to matter upstream of the PCM to analog conversion if the track was mastered properly because the engineer uses higher sampling rates and a low pass filter of some kind to control aliasing.

IIRC of course, I'm not an audio engineer.

 

[KinGensai]

@gregorio
Actually, the cognitive biases that go into pricing dynamics is very interesting. An initial a priori analysis of fiscal decision making would indicate that a consumer's preference in pricing would logically be defined by a price to performance analysis, which makes sense in a situation where all the relevant information is available. Once assessment of quality is factored in though, the plot thickens. Consumers utilize a price to quality heuristic shortcut when making decisions with limited information, so they actually split into two groups: price conscious and prestige conscious. Like other prejudicial decisions, this heuristic often leads to poor decisions and is one of the most exploited marketing tricks in the book.

The evidence in this phenomenon points overwhelmingly to people perceiving higher price with better quality, with the question becoming the reasoning and personality traits that determine what a person will compromise on when making a choice between price and accessibility.

 

[bigshot]

Measurements available here: https://goldensound.audio/2022/05/26/chord-mojo-2-measurements/

Lower distortion/noise than apple dongle. Main difference would be the significantly better reconstruction filter (which is also linear phase) and significantly lower jitter

That looks audibly transparent. The measurements on the Apple dongle are audibly transparent too. I don’t see any reason they should sound different.

Either the Mojo being compared was defective, or the testing controls weren’t paid enough attention to. That’s what I suspected.

 

[GoldenSound]

That looks audibly transparent. The measurements on the Apple dongle are audibly transparent too. I don’t see any reason they should sound different.

Either the Mojo being compared was defective, or the testing controls weren’t paid enough attention to.

I don't think there is sufficient study to conclude an audible transparency threshold with regards to reconstruction filters yet.

In fact I have a video coming on this topic, where multiple people were able to successfully pass controlled blind tests of typical vs higher performance reconstruction filters. (testing done using identical hardware and software abx to eliminate additional variables)

 

[bigshot]

Answer seems clear to me: use the filter that sounds best to you.

how do you determine which one sounds best if they all sound the same? I think it’s better to just say, don’t use NOS DACs, because they aren’t audibly transparent.

 

[bigshot]

I don't think there is sufficient study to conclude an audible transparency threshold with regards to reconstruction filters yet.

You certainly can if the problems are all down below -50dB.