HP/IEM cables and SQ

Basically, yeah. Or at least we must be able to predict, using our knowledge of the physics involved, that the change would be measurable if only our measuring devices were better (e.g., if they had higher resolution, lower noise, better sensitivity, etc.).

As it happens, though, we already have tools that can measure the relevant quantities much more precisely than necessary.

The implication is that the frequency-dependent delay will affect imaging (because the low frequencies will seem to originate from further away than the highs, or the phase change will confuse your HRTF) or maybe timbre (because high-frequency harmonics will be out of phase with their low-frequency fundamental).

Ok, so let's use that paper's worst-case numbers and slightly odd choice of cable to examine what the effect will actually be.

First, all the math:

Speed of light (C): 300,000,000 meters/second
Speed of sound under standard conditions: 343 meters/second

Cable: Belden 9515 interconnect, 1 meter (selected by the paper's author)
Propagation speed through the cable, 20KHz: 0.42C (provided by the paper's author)
Propagation speed through the cable, 20Hz: 0.01C (provided by the paper's author)

Time for the signals to travel through the cable:

20kHz: 1 / (300000000 * 0.42) seconds = 8 nanoseconds
20Hz: 1 / (300000000 * 0.01) seconds = 333 nanoseconds
Difference: 325 nanoseconds
​

Distance that sound travels through air in 325 nanoseconds:

325 ns * 343 nm/ns = 111000 nanometers, or 0.111 millimeters
​

Wavelength and distance/degree for a 20Hz signal:

Wavelength: 343 meters / 20 = 17.15 meters, or 17150 millimeters
Distance/degree = 17150 mm / 360 degrees = 47.6 mm/degree
​

Phase change (relative to a 20Hz signal) over 0.111 millimeters:

0.11 mm / 47.6 mm/degree = 0.002 degrees
​

So the imaging effect of the frequency-dependent delay will be as though low frequencies were produced from 0.111 millimeters behind the high frequencies. And therefore the lowest-frequency signals will be out of phase with the highest by 0.002 degrees.

Does that matter? Maybe. But 0.111 mm is only 1/5 the diameter of the thinnest violin string -- or less than half the thickness of a playing card -- so probably not.

And remember, this isn't the only source of timing error in the system. A frequency-dependent propagation delay occurs across ALL the wires and traces (and components) through which the audio signal travels -- on the recording side and the playback side. And for all you know, that delay might already be (accidentally, perhaps) compensated for in the system design. Not that any system has the resolution to even demonstrate it: A 325 ns delay is tiny -- barely more than 1% of the time between two consecutive 44.1KHz samples on a CD.

But if you somehow believed that the frequency-dependent delay through that interconnect cable might be audible -- and if you also believed that absent the delay, somehow all the frequencies would be arriving at your ears exactly simultaneously -- then you could correct it by just tipping your speakers back so the tweeters were about half a playing card's thickness behind their original position.

[EDIT: Explicitly noted that the Vprop numbers are from the paper under discussion. I have not verified them.]

 

I'm very curious how you calculated Vprop

 

I uncritically accepted the numbers from the Iconoclast Cable paper that @bilboda referenced here: https://www.superbestaudiofriends.org/index.php?threads/hp-iem-cables-and-sq.11029/#post-349136

The paper is here: https://iconoclastcable.com/techpapers/vpandimpedance.pdf

 

I will have a read when I have more time. I worked for 25 years for a company that overlapped with Belden. They are very good at what they do, and I have no doubt their work would have been rigorously reviewed before release.
I know there is a transition area where a cable ceases to be a transmission line and becomes a lumped element. It does not immediately occur to me why that affects Vprop, but I'll read the papers you linked, thanks

 

Do you mean large gauge copper cables or just OCC copper with more strands? This AliExpress cable cable can be customized for iem use with an esrhook even. It’s fat for an iem cable but very flexible.

I’m curious if it would add some warmer tonality to the OG Solaris. I tried the CA copper litz cable and it didn’t sound any different from the SPC.

16 Core 99％ 7N OCC Earphone Cable
https://a.aliexpress.com/_mLW5po5

 

Just regular large gauge multi-strand wire with thin individual strands. The more the better. An 8-core cable made with the same wire has a fatter, more impactful sound than the 4-core version. I suppose the same gauge cable made with fewer but thicker strands might sound different, but that would result in a stiffer cable overall, which goes against my personal preference for supple, easy-handling cables.

I haven't heard the CA copper Litz (didn't know they had one). With OG Andromeda, I went from the stock CA SPC Litz to a PW Audio No. 5, and then to a Han Audio Zen which handled better.


I forgot to mention that I've also played around with Deulund solid-core pure silver wire and silver/copper hybrid cables (not SPC). I didn't choose solid-core on purpose, but this was the least expensive high-quality pure Ag wire I could obtain locally. In general terms, pure silver sounded a touch brighter and more detailed, but lacked the fat pure copper bass that I prefer. The silver/copper hybrid provided the best of both worlds: that silvery detail + phat copper bass. But considering cost/performance, I don't think the silver wire is worth the extra that it brings.

This is my temporary unbraided pure silver cable:

And this is the final silver/copper hybrid cable I made:

 

How does that AliExpress cable look to you? Do you have a better suggestion?

thanks!

 

I added this in as an edit, possible after your reply.

These two are reasonably priced cables and had a similar warming effect with Andromedas compared to the stock SPC Litz cable, for me. There are tons of IEM cables out there, some costing ridiculous amounts, as I'm sure you know. If you don't want to spend that much, then I'd just try the highest gauge cheap chi-fi cable I could find and see what it sounds like. Somebody here mentioned picking something up on Amazon, but I can't remember what or where I saw it.

 

Paging Yoda @Armaegis

 

I checked with my IEM guru who said,

So maybe better to try cheaper OFC than OCC.