Measurements and conclusion
Contents
Like the interlinks, we also subjected the Nordost Leif 3 speaker cables to some measurements…. We made a bodeplot (response and phase), made a measurement on a real speaker and of course did the well-known LCR measurements on the Sourcetronic LCR. You can see the results below.
Bottomplots
To make the bodeplot, we took the “black box” and terminated the cables with 0.3 Ohm output resistance and 8 Ohm input resistance. The Picoscope 5000-series sent a sweep through the cable.
You can clearly see gain and phase differences due to higher conductance. Each series higher shows better conduction toward higher frequencies.
Response
We grabbed a Teufel Definion 3 loudspeaker and a Bryston pro-series power amplifier for this measurement. The Prism dScope III sends out a sweep and then measures the response. We measure this at the speaker terminal to gauge the impact of the cable. So this is a comparative measurement to see the differences between the cables.
The differences are clear and confirm our earlier conclusion: the lower the impedance of a cable, the lower the impact on coloration. The Red Dawn – white line – has the lowest impedance. The White Lightning has the highest impedance and colors more in certain areas. For example, the difference between the 80 Hz peak and 300 Hz dip is 0.15 dBu with the Red Dawn. With the White Lightning, it is a little over 0.25 dBu, which is noticeable in certain accents that may or may not be turned on.
Know that we are only talking about frequency response here. That is only one part of the overall picture.
LCR measurements
The above picture (and the bodeplots) show the real-world results of what we measure here. Impedance in particular is important in speaker cables (we think). However, impedance is an interaction of conduction, inductance and capacitance. Especially low inductance is important to achieve solid results.
Now Nordost goes for low capacitance to keep velocity high and also to minimize variation in this velocity. And that is what we see here as well. A capacitance of 60pf (White Lightning) is insanely low. The Red Dawn with more conductors has 80 pf. That’s still incredibly low.
The downside is that the inductance is on the high side: between 1.8 uH (Red Dawn) and 2.2 uH (White Lightning). An amplifier must be able to deal with that (oscillation may occur). Our Pass had no problem with it. However, be careful with electrostatic or magnetostatic speakers and an amplifier with high feedback.
