It *cannot* just be about 1's and 0's - surely?

[Mazza]

Yes, USB cables are a contentious subject but bear with me please! ?

 

So, I have just swapped my 3m USB cable for a 1.5m USB that I have on loan. Same manufacturer, but 'higher-up' in their range. The USB is the link between my server and my speakers which have built in DACs and AMPS.  I wasn't expecting any noticeable change but I was wrong; the change was very noticeable:

 

 - first: it was a immediately obvious that the output volume on my speakers increased. So I checked this by swapping cables and measuring dbA levels on a sine-sweep test track that I use to calibrate levels. I was right and there was just under a 2dB vol increase when using the shorter, 'higher grade' cable over the longer 'lower grade' cable. I checked this 4x by swapping between the cables and had to adjust the pre-set on my speakers for the loaner cable.?

 

- second: there was a tangible/significant improvement in the sound by using the the shorter, 'higher grade' cable by whatever subjective assessment that I used. It was readily and easily discernible. 

What I don't get is *how* the playback volume can increase when all I am doing is shifting 1's and 0's over a 5v/3.6v cable and secondly, if the improvement in sound quality is say attributable to better rejection of EMI/RFI from my source to the DAC, or control of jitter, can it *really* be so significant over a length of 1.5m?

[Mazza]

1 minute ago, Fokus said:

 

Either that cable multiplied all data with 1.258, or it made the individual 1s and 0s 1.258 times heavier.

 

 

?

[Mazza]

3 minutes ago, davide256 said:

 

Think of the 2db as an average... of greater transient peaks.  Like increasing the contrast on your video monitor.

 

Not sure if that is what it is ...... I used three constant test tones/files ..... 100Hz, 1kHz and 2kHz....each 10 secs long and the increase in volume on any file was approx 2dB. So no transients, just constant tones.

[Mazza]

52 minutes ago, davide256 said:

Clocking accuracy  matters. Clocking degradation damages harmonic structure integrity and dynamics.  You could also try the Lush 2 cable if you want a real treat,  its Faraday cage like shielding mechanism works for improving USB audio. But you may be happy with the AQ Diamond you have ?

 

Thanks davide256: the AQ Diamond you refer to is what I am changing to and is what is giving me the big changes; it uses a 72vDC diaelectric-something-or-other (I don't claim to understand it)....maybe that is contributing to the faraday effect you mention

[Mazza]

7 minutes ago, crenca said:

As to your experience, the most likely explanation is your missing something unobvious but nevertheless not related to the cables at all except maybe ancilar way, like how you bump the volume control when you change cables ?

 

Yes, but it's puzzling as to what it could be, certainly it is not bumping the volume control, because I am measuring the volume of the sound using a Behringer mic. My ref isn't just some notches on a volume dial.

[Mazza]

10 minutes ago, Archimago said:

Mazza,

If this is true that an AQ Diamond is able to cause a 2dB volume difference over the USB digital interface (I assume this is to your Kii THREE system), doesn't this speak poorly of the Kii's digital design?

 

If this is true, does the company then warn people in the manual that the USB cable can make quite a significant impact on the sound because for whatever reason it's remarkably sensitive to timing or noise!? Maybe list a few "optimal" cables to purchase? Perhaps they should then have included a USB cable with the package to ensure that end-users are not ending up with inferior sound. Who knows, if this is true, then different cables might have even more effect - +/-3dB? +/-6dB with 15' cables anyone?

 

Kinda sucks to purchase a Kii system if this is true. [Which I highly doubt.]

 

Thanks Archimago: On the contrary, Kii are pretty laissez-faire about the influence of cables and quite rightly so. After all everything is in the digital domain, no analogue interfaces (except some internal ones to the speakers). I don't know if it is the cable length that is making a difference, it's just that those are the two cable lengths I have.

 

Of course, the volume change is academic except that I have been careful to ensure that the perceived improvement in SQ is not down to volume change. That is something I was a keen to correct before I did the extended listening around.

 

I have to say the Kii's are stunning and I have nothing but praise for them....everything I do to my system just seems to bring out more and more musicality and resolution out of them.

[Mazza]

2 minutes ago, crenca said:

 

I have not explanation of your UFO experience Mazza.  The most likely is that you are an astroturfer here to give yet another Audiophile cable tent testimonial.  In other words, you are lying.  OR perhaps your an oddball who likes throwing the forums into a frenzy.  OR perhaps you are experiencing something and wrongly focusing on the cable change (missing the real cause entirely).  

 

 

Thanks for the supportive words.

 

I am not trying to push any cable agenda, in fact if you go back to my OP I deliberately didn't mention cable or equipment so to avoid any fanboy accusations. There is merely a phenomena which I don't understand which I put to the forum to ask if anyone knows better.

 

I can hardly imagine the forums are going to get into a frenzy over this small matter!!!!!

 

But thank for your contribution

[Mazza]

3 minutes ago, crenca said:

 

Well, there is your explanation.  In the audiophile art of system tweaking, everything leads to more "musicality", more "resolution", more (where is Ralf Arnott when you need him).

 

What are you selling?

 

Here we go, the insults start. I am not selling anything, I merely asked if anyone knows why I got an odd result

[Mazza]

6 minutes ago, crenca said:

Until then, it's a UFO sighting...

 

Yep, maybe you are right. Odd that I can make this UFO re-appear again and again with these two cables. Just don't know why. ??

[Mazza]

Thanks @mansr and @crenca .... you might have something there, the OS on the transmitter end and on the receiver ends are just a 'black box' with no user configurability, but the Kii's do a lot of DSP, so maybe that is where it is?

[Mazza]

1 hour ago, Archimago said:

 

While a 2dB reduction is not a big deal when we're listening to modern hi-res devices with plenty of resolution, it does still imply something has changed which presumably should not. And since the playback "system" includes the DAC which you're connecting and in this case your active speakers, you need to look at what's going on there rather than focus on the cable itself. Time to ask Kii why this is happening.

  

You are absolutely right.  Per se, I don’t really give a hoot  the vol change other than it surprised mand the volume thing has peaked my curiosity. I think your point and the same by mansa and Franca, that it  is more likely to be something with the Kii’s is a more likely explanation than cable properties. 

[Mazza]

37 minutes ago, Jud said:

It's a well known effect that louder sounds better, and though you may think you can somehow mitigate the subjective SQ improvement by some mental feat like intense concentration, it really isn't so.  That's just how our ear-brain system is wired.

 

You are right Jud. That’s why I was careful to equalise the volume before I did my listening. 

[Mazza]

24 minutes ago, crenca said:

 

Is this the USB cable (that is obviously more than a cable) the OP is using?

 

Looks like it could be, there are two in the range that have this. 

[Mazza]

30 minutes ago, crenca said:

 

His speakers have amps and DAC built-in so there are no speaker terminals that he can use.  So the USB cable is going directly into one speaker, and then perhaps a proprietary connection from one speaker to the other.... Firedog probably clear this up.

 

Thanks @crenca, yes you are correct. No speaker terminals. So I used a Behringer mic on tripod, REW software to measure. Test tones played off a file on server. 

 

USB cable connects to digital controller of the Kiis. This connects to the two speakers by cat 5 cable. 

 

@esldude: don’t use phone for measurements. No options for test meter etc etc because no speaker terminals

[Mazza]

12 minutes ago, crenca said:

 

Does the one your using have this?

To clarify... my original AQ cable (cinnamon) does not have this, the new AQ cable (Diamond) does.   They fit it to a number of their various cable range inc analogue cables. It is some form of dialelectric bias system. Don’t claim to understand how it works. 

 

[Mazza]

Thankyou all for the suggestions about further measurements. I have ordered a plain vanilla 3m and 1.5m cable from Amazon and a USB A-B adapter. I’ll report back. 

[Mazza]

14 minutes ago, STC said:

 

Why do you need the AB adapter?  

 

One of the suggested measurements I take is a data checksum 

[Mazza]

The speakers and mic were constant. I moved around of course and there were small variations each time I did measurements... type around 0.5 dB but on the whole reasonably consistent