Interesting phenomena I'm not sue I can explain about cable behavior

[PHD]

Hi

I have two Amphenol RCA cables of the same length but from different models/colors. Both seem to work fine when used to hook AVR subwoofer out to the subwoofers.

But, when I connect RCA one cable from the subwoofer's LFE input and then touch the signal lead on the other end, I hear a loud 100Hz hum, which is expected.

But, when I replace the RCA cable with the second one (same length) and repeat the same test, the hum is much weaker and at a higher frequency.

What could explain such behavior? Better shielding on the low hum cable? Or perhaps the low hub is faulty with some sort of attenuation?

Thanks

 

[Speedskater]

How about trying some other brands of RCA cables.

 

[Doodski]

Hi

I have two Amphenol RCA cables of the same length but from different models/colors. Both seem to work fine when used to hook AVR subwoofer out to the subwoofers.

But, when I connect RCA one cable from the subwoofer's LFE input and then touch the signal lead on the other end, I hear a loud 100Hz hum, which is expected.

But, when I replace the RCA cable with the second one (same length) and repeat the same test, the hum is much weaker and at a higher frequency.

What could explain such behavior? Better shielding on the low hum cable? Or perhaps the low hub is faulty with some sort of attenuation?

Thanks

The hum is either 50Hz or 60Hz dependent on your location in North America or maybe Europe etc. It is possible that you have a cable that is more prone to picking up the EMF from the air. Don't worry about it this is normal and use the cable that works.