So the first order of business was to see how flat the response of each cable was.

First I generated a 40 second clip of white noise , I saved this as a Wav file and ran it through a spectrum analyser,

this is the reference point.

Then I burned the sample to CD and tested each of my CD players by playing it back and recording the analog

output to find the one most like the reference in shape and overall level. I settled on a Denon DCD910 analog

output which had the lowest deviation from the reference from 20 - 20K using stock cables.

Now I set about more critically measuring the response for the 4 cables I bought plus my own 77c specials.

To do this I played back the white noise sample and recorded it to my PC. To cater for random variations

I did each recording with each cable **10** times.

Each resulting wav file (70 of them, I tested the AQ cables aligned by the arrows and unaligned to test for the claimed directionality) was clipped to exactly 24.003628 seconds, each file is precisely

4.03 MB (4,234,284 bytes) all white noise. Due to careful editting ( the same protocol used for each file)

no wav file can differ from any other wav file in alignment by more than 1/1000th of a second.

Each file was then run through a spectrium analyser with 1024 sample points. Each spectrum was exported as a text file.

Then I started up Excel and I loaded each set of ten trials into a separate worksheet. This allowed me to see the Min, Max and Average levels for any frequency. Also it allowed me to see how much variation there was in any set of trials.

For instance the biggest difference between any two trials for any frequency with the Stock cables was 0.056db, the average difference between the max and min value for all frequencies for stock cables was 0.032 db.

Tartan cable 0.032 and 0.014

BlueJeans 0.047 and 0.016

AQ G-Snake Not Aligned 0.061 and 0.016

AQ G-Snake Aligned 0.038 and 0.013

AQ Sidewinder Not 0.050 and 0.014

AQ Sidewinder Aligned 0.044 and 0.014

The way that the recording was set up meant that each recoding was always at a slightly lower absolute level than the reference. Thus the best cable by definition at any frequency would have the highest value or the lowest attenuation from the reference. This made life easy.

In no case did any cable boost any frequency above the reference level.

Each set of 10 trials for each cable was averaged and the results fed into the worksheet with the reference values.

The maximum difference found between any two cables at any frequency point was 0.029db. The average difference between the best and worst cable across all frequencies was 0.012db. Note that the identity of best and worst cable did differ between frequencies.

Two of the cables I purchased are supposed to be directional. I recorded samples using the Audioquest G-Snake and Audioquest Sidewinder both correctly aligned and incorrectly aligned. I recorded 10 samples with each of the 4 combinations.

The G-Snake correctly aligned was in fact measurably different from the G-Snake incorrectly aligned. When I fed the results into SPSS the result was significant.

the maximum difference at any frequency was 0.022db and the average difference was 0.001db. For the Sidewinder the maximum difference was 0.011db and the average difference at all frequencies was 0.002db.

Do any of these cables roll off any more than any others. I tested the differences in level between 1K and 20K, 2K and 20K, 3K and 20K, 4K and 20K, 5K and 20K, 6K and 20K, 7K and 20K, 8K and 20K, 9K and 20K, 10K and 20K, 11K and 20K, 12K and 20K, 13K and 20K, 14K and 20K , 15K and 20K and finally between 16K and 20K.

The maximum difference in roll-offs between any two cables for any two frequencies was 0.016db

Stock(77c) vs Sidewinder ($60) , max diff 0.020db, ave difference 0.009 db

Stock(77c) vs G-Snake ($35) , max diff 0.013db, ave difference 0.003 db

Stock(77c) vs Blue Jeans($26.75), max diff 0.014db, ave difference 0.004 db

Stock(77c) vs Tartan ($5) , max diff 0.009db, ave difference 0.003 db

Tartan ($5) vs Sidewinder ($60) , max diff 0.014 , ave difference 0.006db

Tartan ($5) vs G-Snake ($35) , max diff 0.009 , ave difference 0.003db

Tartan ($5) vs BJC ($26.75) , max diff 0.007 , ave difference 0.002db

BJC($26.75) vs Sidewinder($60), max diff 0.011 , ave difference 0.005db

BJC($26.75) vs G-Snake ($35), max diff 0.012 , ave difference 0.004db

Sidewinder vs G-Snake max diff 0.018 , ave difference 0.009db

I just loaded my dataset up into SPSS and ran a repeated measures ANOVA with cable type as a covariate and some ANOVAs between cables.

The results show that for these cables there was no significant effect on changing cable, no cable was significantly different from any other. Frequency also did not alter the result, no cable was significantly different at any frequency.

The other result was that there was much more variation between trials than between cables, this is entirely predictable as a cable is a passive device and and ADC is not, so my decision to average 10 trials was justified. Amusingly the repeated measures variation was significant. Remember this was a variation of no more than 0.056db between any two trials for any given cable at any frequency, but when you have 4600+ data points little differences become statistically significant.

I just tested the Sidewinder vs the stock cable using a cymbal crash with lots of harmonics and transients.

Originally Posted by **nick_charles**

Stock and Sidewinder

Complex set of square waves from 10hz to 10000hz, maximum difference 0.027, average diference 0.0028

-------------------------------------------------------

Max difference 0.102340db average difference 0.003539db

Average overall signal

Stock------------ Sidey ------------ difference

-37.743888 ******-37.742651 ****-0.001237

This graph shows the stock cable with the sidewinder dropped by 20db so you can see the patterns

For the Anoraks - the distribution of differences against frequency

And finally difference vs signal level

The max variation was 0.08db at 129hz and -54db, the average difference is 0.001408db.

These were done using a five second sample of digital silence and recorded back via the ADC. I ran the tests ( 10 trials) for both stocky and the Zu Oxyfuel.

Average Noise levels Stock -95.7975db.........Zu Oxyfuel -95.8598db

This is quite close to the theoretical noise levels for 16 bit systems

Low frequency noise pattern

---------------------------

I also did a few tests on my $2.11 Monoprice and the $60 Sidewinder. Interestingly each cable has a distinct noise pattern with specific low level spikes at different frequencies.

To place these noise figures in context, here is the noise juxtaposed against the cymbals crash.

In absolute terms the stock cable is the worst for noise with three low frequency spikes between -78 and -76db ,- Monoprice is as good as the most expensive cables for noise, but I will need to run 10 trials.

This text is between a DH labs BL-1 Series II Silver Plated Copper cable and the solid copper Sidewinder with the cymbals sample.

Maximum difference is at 19488hz where the difference is -75.3254db to

-75.3695db i.e a difference of 0.0441db, average difference from 20 to 20K is 0.0014 db. See graph below

-------------------------

Maximum difference at any frequency = -0.00436 db , the Monoprice cable has less attenuation at all frequencies, the average difference = - 0.00266 db.

No graph posted, no point , impossible to see the deviations.

For these tests I made a slight change to my protocol I used a 16K FFT analysis which translates to 7K sample points. Since I have all the original wav files I may redo them with a smaller FFT later if it is a bust.

Noise differences ranged from

Freq (Hz)SilverCopperdiff

1418-101.0146-92.8366-8.1781

1421-100.8319-95.2206-5.6112

1416-100.7780-95.2324-5.5456

541-99.8670-96.9008-2.9662

15111-97.3906-95.1398-2.2508

538-99.8972-97.7621-2.1351

to

Freq (Hz)SilverCopperdiff

721-79.8842-95.098515.2143

301-80.4885-95.816915.3284

299-79.8153-95.577015.7617

719-79.4283-95.246215.8179

121-65.8202-82.408316.5881

600-79.7158-96.373216.6574

118-66.7071-83.371416.6642

363-80.7216-98.865118.1435

358-73.5922-99.016525.4243

361-70.9139-98.449627.5356

Silver Average Noise level = -97.8339 db

Copper Average Noise level = -99.5085 db

Average difference = 1.6746 db

silvercopperdiff

-35.1717-35.19860.0269

Range of differences from

Freq (Hz)silvercopperdiff

10864-31.2361-31.1511-0.0850

12037-34.3904-34.3113-0.0791

19598-64.2617-64.1956-0.0661

17821-60.0233-59.9590-0.0643

18050-53.2547-53.2003-0.0544

19668-64.8693-64.8172-0.0521

to

Freq (Hz) silvercopperdiff

17870-58.5000-58.59830.0983

12029-32.1039-32.20500.1011

19679-68.4469-68.55140.1045

19663-66.2487-66.38070.1321

121-53.2967-53.58550.2888

118-55.8897-56.20280.3131

Differences vs frequency

Silver copper diff

-12.2418-12.26050.0188

Range of differences

Freq(Hz)Silvercopperdiff

19237-12.7538-12.76280.0090

19902-13.4680-13.47800.0100

19862-13.2093-13.21950.0102

19657-13.5434-13.55390.0105

to

Freq(Hz)Silvercopperdiff

12880-12.7116-12.73470.0231

16422-13.0786-13.10170.0232

8454-12.6774-12.70070.0233

8064-11.8652-11.88850.0233

18594-13.4783-13.50170.0234

17286-13.2584-13.28180.0234

11666-13.2417-13.26540.0237

7580-11.4654-11.48910.0237

19113-13.3649-13.38870.0238

10933-12.7789-12.80300.0241

Differences vs frequency

-----------------------

Pattern of Frs against Frequency

Edited by nick_charles - 3/1/11 at 3:56pm