Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Nov 20, 2020 4:54:40 GMT
|
|
|
Post by macca on Nov 20, 2020 8:45:35 GMT
Cable mismatch is one reason why listeners cannot tell the difference between CD and high-resolution music. The other major reason is that external vibration is blurring the sound.
just interested to know if you have any research that backs this statement up? It's pretty controversial.
|
|
|
Post by misterc on Nov 20, 2020 8:45:35 GMT
Cue Simon and Macca...........
|
|
|
Post by macca on Nov 20, 2020 8:45:52 GMT
Beat you to it
|
|
|
Post by misterc on Nov 20, 2020 8:52:10 GMT
You can also use a VNA and TDR to obtain very accurate impedance analysis results as well plus you have the ability to de-embed the various components along the transmission line itself.
Transmission line being EVERYTHING in the circuit pathway from traces on the circuit boards, cables, inductors, capacitors and resistors. X/overs wiring and board tracks, drivers the whole shooting match. By achieving the ability to measure each section of the TL you can gain very accurate results as to which components are causing the impedance mis-match as well as how well the basic conductor / dielectric performs in the cables not just the insertion loss.
Max why not place this on Amir's site where the rabit dogs of DBT will enjoy it immensely
|
|
|
Post by misterc on Nov 20, 2020 15:30:19 GMT
To help you get to grips with the term transmission line in the context of any electronic circuit not just audio he is description of the basic premise
"Every interconnect, from the 1 mm long leads in an IC (Integrated circuit) package, to the 10 km long coax cables buried underground distributing cable TV, and everything in between are transmission lines. In most modern products, the electrical properties of interconnects are important and can make or break a product. Success will depend on the design and final verification (characterisation) of the interconnects as transmission lines."
"All interconnects are transmission lines, always, no exceptions. A transmission line is composed of two conductors, a signal and a return path. Always, no exceptions. The properties of a transmission line depend as much on the return path as the signal path."
The bottom line is the entire pathway matters no matter how long or short!"
So the audio term interconnect just purely refers to cables that connect one box to another say a dac to a pre amplifier, where as here we are stating it is the entire signal pathway that counts as the interconnect from inception to completion (Tx<>Rx) This is referred to as a transmission line.
Here is the real killer in terms of transmission line theory in relation to both RF and high speed digital signal analysis :
"Signals interact with interconnects based on their electromagnetic properties."
|
|
|
Post by sq225917 on Nov 20, 2020 18:44:46 GMT
Id print that out and have a read of it when I'm on the toilet, but I can only handle one load of Sh#t at a time.... ;-)
I thank you...
One should first perform a blind AB/x test to ensure their are audible differences, of course.
|
|
|
Post by karma67 on Nov 20, 2020 18:58:22 GMT
Id print that out and have a read of it when I'm on the toilet, but I can only handle one load of Sh#t at a time.... ;-) I thank you... One should first perform a blind AB/x test to ensure their are audible differences, of course. lol brilliant!
|
|
|
Post by misterc on Nov 20, 2020 19:31:12 GMT
Normal service resumed then
|
|
|
Post by sq225917 on Nov 20, 2020 20:57:59 GMT
Natch.
I'm just not a cables guy.
|
|
|
Post by macca on Nov 20, 2020 21:20:41 GMT
If you combine the Spotfire interconnects with the NVA LS5 speaker cable and play something with a lot of mid-bass you get weird distortion artefacts.
Ollie will vouch for this as we tried it on his system too. Obvious artefacts too, not 'Did I just hear that or not?' stuff.
So something is happening there and they are not weird cables, no boxes on them or anything and both low capacitance. If that can happen then it's possible that so can more subtle effects, it seems to me.
But I'm not a fan of the 'bullshit baffles brains' approach.
|
|
Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,399
Member is Online
|
Post by Bigman80 on Nov 20, 2020 21:48:27 GMT
If you combine the Spotfire interconnects with the NVA LS5 speaker cable and play something with a lot of mid-bass you get weird distortion artefacts. Ollie will vouch for this as we tried it on his system too. Obvious artefacts too, not 'Did I just hear that or not?' stuff. So something is happening there and they are not weird cables, no boxes on them or anything and both low capacitance. If that can happen then it's possible that so can more subtle effects, it seems to me. But I'm not a fan of the 'bullshit baffles brains' approach. Yes, I remember that well. Never been able to recreate that over blown/distorting midbass with any other cable combination I have ever had available. Strange stuff, cables.
|
|
|
Post by misterc on Nov 21, 2020 10:46:26 GMT
|
|
Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,399
Member is Online
|
Post by Bigman80 on Nov 21, 2020 14:37:53 GMT
Yes, let's not forget this forum is an open forum and if one doesnt agree with the statement of a member, it is totally ok to discuss it but not to dismiss it. The "Sh#t" post isn't constructive. Rather, why not explain why the offered white paper is not applicable to you or anyone else sq225917
|
|
|
Post by macca on Nov 21, 2020 14:59:16 GMT
|
|
|
Post by sq225917 on Nov 21, 2020 15:31:55 GMT
Because it provides no measured proof of blind tested difference, or that measured difference extends beyond lump LCR.
I like Max a lot, he's a proper gent. But the scientific method is first to identify a difference, exclude confounding variables and then move to identify causality.
There's no point using high frequency square waves to look for effects within the audioband if they don't exist as significant noise in the system.
|
|
|
Post by misterc on Nov 21, 2020 15:58:14 GMT
Martin
I feel what Max was illustrating was the of a measurement criteria to demonstrate quantifiable differences between several types of cable geometry and construction techniques.
The fact that TA cables were used is quite possible one of the reasons he did the experiment to point out that fact imho
|
|
Bigman80
Grandmaster
The HiFi Bear/Audioaddicts/Bigbottle Owner
Posts: 16,399
Member is Online
|
Post by Bigman80 on Nov 21, 2020 16:37:28 GMT
Wow.....this white paper got absolutely savaged over there.
Wow
|
|
|
Post by sq225917 on Nov 21, 2020 22:03:41 GMT
Savaged, thats mild peer review...
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Nov 24, 2020 9:57:23 GMT
The main reason for the test in the first place was to find a simple measurement that quantified the difference between different geometries. The easiest way is to see what the voltage drop was across a single conductor. There is no sleight of hand or skullduggery going on here. I am an engineer and engineers only work with the truth, because everyone can see when your bridge falls down. (doctors bury their mistakes, lawyers suggest better luck next time, accountants can come up with any figures they like). What fascinates me, is the imagination of the trolls who don't want to know. I know there is a difference between cables and the is not down to a slight frequency variation at 20kHz, there is something more going on and I have tried to identify it. Please participate in the Zoom call at 6 PM GMT 5 Dec 2020. Details to follow.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 4, 2020 9:23:25 GMT
Townshend is inviting you to a scheduled Zoom meeting. Time: Dec 5, 2020 18:00 GMT Topic: Townshend cable measurements Demo + Q&A. To demonstrate that characteristic impedance matters in the case of speaker cables. Forum questions regarding voltage and oscilloscope timebase settings will be addressed. The session will have the following format: A brief overview of the paper. Introduction of the test set-up. A live repeat of the experiment. An opportunity to discuss the theory and test practices. To facilitate preparedness, should you have any specific questions, please feel free to pre-submit them to us. This is not a requirement. Open section for ad hoc or any further questions concerning cable testing. Join Zoom Meeting zoom.us/j/93569703283?pwd=Q3hHOStzU0dENnArY0lGV2F3ZGJFZz09Meeting ID: 935 6970 3283 Passcode: JYzH2K The session will be recorded.
|
|
|
Post by sq225917 on Dec 4, 2020 18:47:50 GMT
Will the tests be limited to audio bandwidth?
|
|
|
Post by rexton on Dec 5, 2020 20:22:22 GMT
Did anyone go to this?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 9, 2020 14:28:43 GMT
|
|