Cable Pathways Between Audio Components Can Affect Perceived Sound Quality

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2 hours ago, Kal Rubinson said:

Pretty clear:

"(A) a Straight-Wire Virtuoso higher-end (retail price ~$500 for 0.5 m) 0.5 m long balanced XLR-to-XLR cable with polytetrafluoroethylene insulation and (B) a MonsterCable11 Interlink 400 entry-level (retail price ~$50 for 2 m) 2 m long RCA-to-RCA cable with polyethylene insulation."

Yup.

 

DAC = Berkeley Alpha DAC Series 2.

 

A lot of work to do what amounts to basically a test of balanced XLR vs. single-ended RCA output from the DAC.  I'm not even sure how much of this has to do with the cables themselves which are also of different lengths! Notice the balanced cable is only 0.5m long while they hampered the RCA performance with a much longer 2m cable! 

 

Is this seriously new knowledge, or a slow day at the lab? 

 

The part about the "phonemic-restoration" in musicians is interesting though.

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20 minutes ago, The Computer Audiophile said:

I wish the author would jump in here to explain his rationale. 
 

I’m no scientist but I would’ve probably done a more apples to apples type thing. 

 

Yup, I'm sure you have Chris.

 

I'm also wondering why Figure 5 has frequency in MHz. I think it would simply be interesting to see 20Hz-20kHz audio frequency of what kind of grunge and hum the RCA is picking up in their test setup being sent to the amp.

 

Weird that AES would publish this unless we're missing something profound here... Would have been more interesting and of significance if he found differences in digital cables going to the DAC in a blind test 😄.

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15 minutes ago, The Computer Audiophile said:

I still have an open mind about it but more questions the more I read. 
 

I found it very interesting he used Spectral amplification. Spectral “requires” using MIT cables and has ultra wide bandwidth. Great stuff, but perhaps not idea for such a test?

 

Would you say he really tested for a difference between a single ended route and balanced route, rather than a difference in cables per say?

 

Dunno Chris. Interesting observation about the Spectral. Never played with them so that's interesting.

 

14 minutes ago, fas42 said:

... And all the excuses start spilling out ... when there's an agenda, never let a single thing past, just in case it could do some damage to one's magnificent edifice of thinking, 😉.

 

What are you talking about man?

 

Yes, XLR vs. RCA output from a DAC can be audible depending on what noise there is or if there's a change in the tonality using the different outputs of course. So I agree with the findings totally. What I don't understand is what's so special about that to deserve publication in the AES in 2021???

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52 minutes ago, fas42 said:

Note,

...

The author says, in the introduction,     Therefore, doing the carefully controlled test to verify this, and publish the results, is fully justified.   As I implied earlier,we now have adequate research, that is the first step. Next step, don't change the

 

Let's get into the details Frank.

 

Yes, the author sets out to find a difference in audibility between 2 cable paths. One with a 2m RCA cable and the other with a 0.5m XLR cable. Both plugged in simultaneously as far as I can tell to the same Berkeley Audio Alpha 2 DAC.  Both cables connected to the same Spectral DMA-250S Amplifier.

 

Potential causes of differences between the RCA and XLR outputs:

1. The Berkeley DAC may perform differently between the single-ended and balanced outputs - distortion levels, frequency response can be different. Even as output level controlled.

2. I didn't see a measurement of the output impedance of the Berkeley DAC and the input impedance of the Spectral amp; I assume they're OK for both balanced and unbalanced operation.

3. Odd that RCA cable longer than XLR. Unbalanced cables obviously more susceptible to noise which is what they found. No surprise. (And no surprise that this could be audible.)

4. Even more strange, why did he choose an expensive $500 XLR short cable vs. $50 RCA long cable?

 

If we give the benefit to the Straight Wire Virtuoso cable as better built with better connectors since it is 10x the price for 1/4 the length, then he's totally stacking the listening test against the RCA output! And guess what, the RCA output path sounds worse with more noise which he concluded as "However, the electrical measurements conducted here indicate that noise levels may be one determining factor of sonic performance".

 

"May be"!? Why doesn't he just show us an FFT of the noise floor from the RCA output vs. the XLR from 20Hz-20kHz? Let's see the level difference between the 60Hz hum for a start... 

 

What exactly is the new "scientific" finding here or the uniqueness of this experiment?

 

35 minutes ago, fas42 said:

 

Well, two different ways of connecting the component parts of an audio chain are audible - demonstrated in a rigorous trial. Which counters the usual cry of objectivists, "Well, I just connected my audio stuff together with very ordinary, cheap cable - because that's all that's needed; fancier stuff will make no audible difference".

 

The result is not surprising to "objectivists" or any audiophiles, period! It still doesn't mean he could not have replaced that $500 XLR cable with a $20 Monoprice XLR and found that this still sounds better than the $50 RCA, right?

 

Actually, I want to see Kunchur try that and tell us whether the RCA wins in that experiment 🤨.

 

Might as well keep another post-grad student busy and get another paper under his name to tell the University of S. Carolina that he's working hard doing science.

 

By the way, here's the measurable difference between three 10' XLR cables - 2 Monoprice and generic SRADIO vs. short 4' Amazon Basics RCA cable:

 

 

Check out the noise level (and small amount of crosstalk difference). This is the noise difference coming out of the outputs from my RME ADI-2 Pro FS as DAC. As you can see, I even stacked it against the XLR cables with more than twice the length versus RCA... (Original article here.)

 

Yes. This difference is audible with appropriate conditions. You honestly think "objectivists" don't believe cable types (and balanced vs. unbalanced operation specifically in this case) make a difference?

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28 minutes ago, fas42 said:

 

Thanks for the solid response.

 

 

Great. So there's no problem, right? Everything's pretty clear?

 

28 minutes ago, fas42 said:

 

The uniqueness that it's now a published paper  - rather than rule of thumb thinking. I thought that's the point in science: someone publishes findings, which allows others to confirm or refute, or extend - or have I got it wrong, 🙂?

 

As @pkane2001said, balanced cabling was designed to reduce susceptibility to noise. Kunchur presumably proved it with this paper (other variables still possible because the research design wasn't great).

 

28 minutes ago, fas42 said:

So why do they just throw in the comment, "A cable that happened to be lying around was plugged in, and was fine - of course!"

 

Alright all you "objectivist" jokers... Which one of you said: "A cable that happened to be lying around was plugged in, and was fine - of course!" just so @fas42 could quote this???!!! Hope I didn't say that over the years... 🤣

 

Got a reference/link to that comment there Frank?