Balanced cable definition?


I am getting some interference (using Focusrite Scarlett interface). There is no interference when I listen through headphones directly connected to the Focusrite. The Focusrite is connected to the speakers via a mixer which has RCA/phono outputs. I have 2 leads (L/R) running from the mixer to the (active) speakers. These are RCA to XLR connections - i.e. RCA at mixer and XLR at speaker.

I am assuming that no cable terminating in an RCA plug can be deemed as balanced? Is that correct?

The three wires (red, white & screen) are all connected within the XLR plug. In the RCA plug both red and screen are connected but I cannot see the white cable so I assume it is cut where the others emerge from their unifying black PVC shielding. Would such cable offer any additional protection from intereference whatsoever over (e.g.) an RCA to RCA cable with only two wires/connections?

Many thanks in advance.

That’s correct.

It would not provide additional protection from the additional wire.

Depending on size and construction, it “may” have slightly better screening than a typical RCA to RCA cable. Balanced “microphone” cables generally have greater diameter and (at least) braided shielding, whereas many RCA to RCA cables are rather thin with only a single layer of shielding wires spiralling around the signal wire.

OK thank you for the prompt reply Steve. It looks like I’ll have to connect direct from the Focusrite to speakers or use another mixer.

Thanks again.

[u]Here[/u] are some diagrams showing how to mix & match balanced & unbalanced connections. And [u]Here[/u] is a video about balanced connections. I don’t think I’ve watched the whole video (20 minutes) but I trust this guy (Amir Majidimehr).

Would such cable offer any additional protection from intereference whatsoeve

Short unbalanced connections are usually not a problem with line-level signals. If you’re getting noise interference it might be coming from somewhere else.

i.e. RCA at mixer and XLR at speaker.

If you have a true-differential balanced input I think it does help because it rejects common-mode noise. And I think it’s answered in the above video.