John Dunlavy On "Cable Nonsense"

My suggestion is just to confirm your measurements. If there are differences with the RS acoustic meter you will also see differences with a voltage meter. A 2dB bass hump due to cabling is unexplainable and unreasonable. Are you using music as a source? You state the measuments we taken at the same time during each trial. I hope you can try with a test cd with tones.

thanks for the help

leme

I was using the Stereophile Test CD 3 bass decade 1/3 octave warble tones track. I agree the 2 dB hump really threw me also, since I had always believed that wire was wire and once you got a big enough one it didn't matter anymore. I was using the digital meter so under just the right circumstances it could have been a 1.1 dB difference.

There was a difference in the length of the cables, the Monster was 12 foot while the other brand was 8 foot, but I have never seen a calculated result showing that this should have made the difference in the SPL I measured. Even if it did make a difference, I would have expected this to have been consistent across the board, not varying by frequency.

Lets pretend (cause it probably will not happen in real life) that your speaker has a strong impedance dip and drops from a nominal 8 ohms to say .25 ohms. If both cables were of simular guage then the longer ones could have a little more resistance in them and not deliver the exact same current to the speaker that the shorter one did at the frequency of the impedance dip. This type of situation is where the difference could be frequency selective.

I am impressed with your testing method. Three identical measurements with test signals would imply valid results. I for one feel that the differences are very large and would like to have others see if they can find results of this magnitude. Was the test conducted while only one speaker was playing? That would help to remove some reflection problems and the effects of the other speaker. Chris

Yes those were recorded with only one speaker driven as you suggest. I should have mentioned that. I tried both methods and found that there was more than enough bleedthrough from the second speaker to skew the results so I stopped it.

Well I'm impressed by your diligence. Thank you very much for sharing your results and for taking the time and putting in the effort to do this. Here I am conjuring up all kinds of digital computer measurements, and you just go out and do the obvious test. Bravo!

Since I've heard big differences in midrange performace from cables, I can easily believe a 1db difference from cables. Frankly, from what I've experienced in the difference between the cheapest and some of the best silver cables, I'm surprised it isn't closer to 3db difference in the 3k-5khz band.

Gpalmer, you rule.