I don't believe cables make a difference, any input?

[IanHarvey]

Originally posted by gpapag

I do not have the gear to measure L and C.
I do not have the time to calculate L and C.

Basic frequency-response type measurements can be done really simply, if you have a multimeter with a tolerable bandwidth AC range, and a test CD (or computer+sound card+software).

The basic procedure is to put on a test tone at a given frequency, measure the AC voltage across the amplifier output terminals, and then across the speaker terminals. Divide one by the other, take the log & multiply by 20 and you have a loss figure in dB.

This won't tell you the cable L/C/R directly, but it will give you an idea whether they are having an obvious effect (i.e. on the frequency response). Well worth the 20 or 30 pounds it'll cost.

Cheers
IH

[gpapag]

That they want more beers?

Frank, I think you are missing something. Not only they want more beers, they are asking for Chetos potato chips as well.

Are you saying that your friends won't give them back ?.
If so what did they say about the cables that they prefer ?.

Eric, what i can understand is that they like the appearence of the cables a lot, their "sound" a bit less, but most of all they are very satisfied with them, because it didn't cost them anything.

This won't tell you the cable L/C/R directly, but it will give you an idea whether they are having an obvious effect (i.e. on the frequency response). Well worth the 20 or 30 pounds it'll cost.

Ian, thank you for the advice, but the intent of the exercise was to construct some cables with same materials but different geometry in order to see if they "sound" different. Six ears said yes and this is enough for me, since we had no particular preference for any cable initially. The implication is that the "WHY" comes after and it doesn't go away easily. I know that the geometry sets the C and L of the cable (for the C, dielectric constant of the insulator as well). So suppose that we measure these. Does this LCR pad inserted between the o/p - i/p impedances demistifies everything? I doupt it, but i will try to help it. For now, i did some rough capacitance measurements (with my multimeter, i am sure this is not the accepted way of doing this, but it is the only i can do. In any case, accuracy will be worse than +/- 10 %). Results:

Pair 1:
+++++++++++++-------------
Capacitance: 75 pF/m


Pair 2:
-+---++----++++----++---+-
Capacitance: 295 pF/m

Pair 3:
+-+-+-+-+-+-+-+-+-+-+-+-+-
Capacitance: 650 pF/m

In addition to this and for confirming the validity of the above figures,, i measured the capacitance of adjuscent strands of the 26 strands ribbon, each time strands number increasing by one, up to 13 strands X 13 strands (configuration of "pair 1")Results:
Strands No Capacitance/m (pF/m)
1x1 15
2x2 21
3x3 26
4x4 30
5x5 32
6x6 34
7x7 39
8x8 43
9x9 47
10x10 53
11x11 62
12x12 67
13x13 75

All these measurements do show something, but the full picture is not clear yet. I will search beneath the paper piles in my room for some equations that combine R,C,L,Characteristic impedance and Geometric factor. This way i may get the L that i am not able to measure.
With the same multimeter, just for comparison and out of curiosity, i measured the capacitance of some more cables that were lying around.

Flat lamp cord 0.75 mm^2 multistrand, centers 2.5mm appart : 38 pF/m
Flat speaker cable 3mm^2 multistrand, centers 4mm appart :65 pF/m
Telephon cable 0.2mm^2 solid, centers 2mm appart, loosely held in PVC outer cover : 60 pF/m
Coaxial interconnect ("PROFIGOLD"), screen diameter=8mm, center conductor diameter=0.7mm :22pF/m
Normal Screened cable, screen dia=2.5mm, center multistrand conductor dia=0.25mm :150 pF/m
RG 154 coaxial cable, screen dia=2.5mm, center multistrand conductor dia=0.25mm :85 pF/m
RG 59/U coaxial cable, screen dia=4mm, center solid conductor dia=0.5mm :75 pF/m
RG 62/U ("ALPHA WIRE") coaxial cable, screen dia=4mm, center, hollow dielectric, solid conductor dia=0.5mm :30 pF/m
Twisted (4 twists/cm) pair, , 0.5mm^2 multistrand, centers appart 1.3mm):40pF/m

I am just wondering. 2 days are common practice?

jh6you, nothing is common practice. I just wanted to make sure that i treat all cables in the same way (that's for burning in). 2 days under broadband noise (FM interstation noise) is enough for my purpose.

Regards
George

[gpapag]

How can i present table data properly?
Regards
George

[fdegrove]

Hi,

Why the "quote" - "/quote" trick does not work anymore? What can i do instead?

I don't know what you did before but check the following:

When you post a reply you can select the portion of text from a previous post and copy that to your clipboard.

Now push the QUOTE button from the menubar and paste in the text from the clipboard by using either ctrl+v or right mouse button,paste.

Click on O.K. and the text should now appear in your reply between html square brackets the first with just word QUOTE inbetween, the closing one with a slash / preceding the word quote.
In that way you can do it manually as well, a bit of a PITA but it works.

This is how I do it anyway.

Cheers,

[gpapag]

Frank, thanks, i fixed it. But i can not still print tables.
Regards
George

[fdegrove]

Hi,

But i can not still print tables.

If I understand you correctly you probably mean the the spacing in the table gets lost, right?

The only way I know of to solve this to turn that texttable into a picture.

Just create an empty gif file set for a max size of 100Kb and IIRC to 800*600 frame size, past the table into that and save the picture.

Note that you'll often have to redo the spacing of the data within the pic as well but one it's done you can at least post it to the web without it changing anything.

Hope that helps,

[britonk]

Hi,

Having read all your posts I would like to add a little input.

I have always been a believer in high quality cables - I don’t think they make a HUGE difference but I do believe they make a minor difference HOWEVER please read on about an experience I had about 6 months ago.

I purchased a new widescreen Philips TV and decided that it was silly to spend so much on a TV without buying a decent SCART lead to connect to my Sky digital receiver. I spend UK £40 on a decent SCART cable and when I got home I plugged it all in and had great picture and sound FANTASTIC.!

ABOUT A MONTH LATER I noticed the picture had gone slightly blurred in areas and after a few swaps of cables identified the expensive SCART cable to be the culprit. I took it back and got a replacement (assuming the cable to be faulty). Interestingly the same thing happened again. To start with great picture and sound then after a while it went blurry.

I got a refund on the cable and started using a bog standard UK £ 2 SCART and it has worked perfectly since.

What do you cable lovers think of that?

[Stew320]

Usually people hear differences when they change over cables, but if you change them back the sound 99% of the time stays the same, I recon it's because a fresh connection has been made. I have noticed this a few times.

It's never usually the wire itself that alters the sound, it's just the connection.

As long as a speaker wire is of adequate gauge and made from copper (or other material that is as good a conductor) then it wont change the signal.

It's the same with interconnects, as long as it's a fresh connection and the IC is adequately shielded and constructed there is no room for changes to the signal.

Lets face it, we are all susceptible to placebo, it affects the way we hear, see and think, like it or lump it, that’s the way it is.

Stew

[analog_sa]

we are all susceptible to placebo

Probably, but the deaf (audio related deaf ) appear to be a lot more susceptible.

[Pan]

"As long as a speaker wire is of adequate gauge and made from copper (or other material that is as good a conductor) then it wont change the signal. "

Have you been sleeping thru this thread?

/Peter