|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
99.227.108.37
In Reply to: RE: The Gauntlet has been thrown down! posted by cpotl on September 17, 2014 at 20:40:28
Some minor information;
I have a dedicated listening room.
Isolated sub-panel, independent ground, one feed off one side, and one off the other.
One receptacle feeds my BPT isolation transformer (source components), with another receptacle feeding a Torus Power station (amplifiers).
All connections have a conductive paste (similar to Walker SST) to prevent my theoretical micro arc-ing. Even in the sub-panel.
Midrange measurements first.
The first picture is with multi-strand speaker wire, with the second picture using solid core.
There appear to be fewer spikes which touch the 0.1 line with solid core.
Next post is for the tweeter
Follow Ups:
I think that trying to extract meaningful results for the relative distortion caused by stranded versus solid core speaker wires by means of acoustic measurements in the listening room is a process fraught with too many measurement uncertainties. Any effect, if there at all, is going to be tiny, and is liable to be "lost in the noise" (literally!).
As a start, it would be good to compare several of your distortion vs frequency plots for the *same* wire configuration, to get some feel for how much variation there is between one run of the distortion measurements and the next one.
But in any case, if the object of the exercise is to measure the distortion caused by a length of stranded wire and compare with a length of solid core wire, then the precision and reliability of the experiment would be greatly increased if the measurements were made purely on the electrical signals in the two cases.
Chris
You might get into trouble with the differences being too hard to measure if you limit the scope (no pun intended...) of the exercise.
IOW, it is easier to see the differences (and hear) them when the change is a bit more global- such as building an entire preamp or amp with a certain brand of resistor, rather than just one resistor changed in one spot.
One thing that led us to solid core was skin effect- which (depending on the circuit impedances) can get down below 80KHz if the wire gets too small. In theory the skin effect could manifest as a differing impedance depending on frequency. Never really chased it down though.
We did do a set of measurements using a TDR we leased way back in the early 1980s, that showed that there was more noise associated with stranded wire than solid core. Of course, the TDR was operating at RF frequencies, but if you think about how you might have more RFI in the circuit due to the choice of wire... we all know that RFI can affect the sound of a circuit. Again, inconclusive as we didn't chase that one down, but we did find that there is a correlation at audio frequencies with the measured characteristic impedance of the speaker cables we tested on the TDR. Although this is all circumstantial, they were real world measurements and do point to the possibility of a difference between solid core and stranded.
I think Billy is on the right path- we often hear things but struggle with the bench measurements to confirm what we hear- but if we put a mic in the same room where we hear the difference, and measure **that**, then we have some substance to work with.
"You might get into trouble with the differences being too hard to measure if you limit the scope (no pun intended...) of the exercise.
IOW, it is easier to see the differences (and hear) them when the change is a bit more global- such as building an entire preamp or amp with a certain brand of resistor, rather than just one resistor changed in one spot."
Personally, I will stick with the tried and proven scientific method. If you want to test the assertion that multi-stranded wire creates more distortion than single-core wire, then do a clean experiment that simply measures one against the other. Don't introduce extraneous factors like running the signals through a loudspeaker and thereby introduce confounding factors associated with acoustic measurements.
Chris
I agree more with cpotl on this issue, but I do commend Cousin Billy for his attempt to understand why he hears what he (and I) hear. That said, the posted data could equally as well be interpreted as "proof" of a slight superiority of stranded wire vs solid core wire, as the converse. Note that at certain frequencies or groups of frequencies, distortion is very slightly (probably inaudibly) lower for the stranded wire, but to say so would make it seem as though I endorse the methodology; I do not.In my earliest days of moving over to solid core wire, I was told by Pierre Sprey of Maple Shade not only to use solid core but also to choose the thinnest possible gauge of solid core. My own experiments suggested that he was "right" (or at least that my ears and brain work the same as his). In fact, and paradoxically perhaps, I found that extreme low bass response seems to improve with very thin solid core wire vs thicker solid core wires of the same material. I tell myself that this has something to do with skin effect, but I have read too many articles positing that the skin effect is essentially irrelevant at audio frequencies.
Edits: 09/19/14
The following are tweeter measurements.
Similar results to the midrange measurements. With the solid core in place, there appear to be fewer spikes which touch the 0.1 distortion line.
All measurements where done twice.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: