Electrical question - banana plugs (1 Viewer)

[BretWeaver]

I need a little help settling a debate between me and a friend. What we are trying to determine is if adding a banana clip on the end of your wire, instead of doing a bare wire termination, will increase the resistance of the sysytem. There are two points.

If you use banana clips: You fray the wire out into the clip, increasing the surface area of wire contacting the clip, which is made out of a more efficient conductor than the copper wire, and then it makes a higher surface area connection to the binding post on the speaker... thus it would not increase the resistance of the system.

Argument against banana clips: Anything you add to a wire system increases the impedence of the system. Therefore a bare wire connection will give you the lowest possible resistance in the system.

What do you guys think?? Any electrical engineers in the house?

 

[Kevin C Brown]

What's more efficient than copper? I will tell you: silver and gold and that is it. Copper is the best conductor most of us have easy access too.

Also, the contact that a banana clip has with the speaker post is usually not that robust. Think of how easy it is to unhook most banana clips. And, the surface area that a banana clip has in contact with the inside of the speaker post is pretty small actually. It's a bent triangle that is only contacting the inside of the post at that bend of the triangle. Banana clips are useful for convenience, but not much more IMO.

Usually the gist of discussions like these, is that bare wire is usually the best, followed by spades (much more surface area than bananas), followed by bananas.

 

[BretWeaver]

Are you sure about that? I was under the impression that aluminum was also a better conductor than copper as well as a number of other materials... Anyway the banana clips I was talking about are gold so I would assume they would be more conductive than copper wire.

 

[John Garcia]

Aluminum is definitely not a better conductor than copper. Gold is only used becuase it has much better corrosion resistance, it does not have considerably better conductivity than copper.

While using a banana plug is just one more connection in the chain, the difference between using or not using them is so negligible that it should not even be something to argue about.

Surface area is not a factor either, as the connectors and the binding posts saturate and still pass the same amount of current, which is relatively low in HT use.

 

[JeremyErwin]

silver tends to oxidize, as does copper. Gold, however, does not.
Conductivity of various metals. Oxidation, of course, reduces conductivity.

 

[Shane Harg]

John and Jeremy are right. Copper is a better conductor than gold, but gold doesn't oxidize as copper does, which is why you see it used on high-end electronics terminals.

 

[Kevin C Brown]

A few more thoughts: the oxide that copper and Al form are not appreciable films.

Has anyone ever changed a light switch? Wall socket? If Al or Cu formed a thick enough oxide, then you'd *have* to steel wool (or somehow else) the ends of tha bare wire to remove that oxide before making that connection, or else the connection wouldn't work. That is not the case.

Plus, remember that the bare Cu wires are attached to the banana plugs (or spades) somehow too. Obviously, solder is the best. But how many of us use crimp-on or those screw type connectors? No different than attaching bare wire to a speaker terminal.

I think it was Stereophile once that said bare wire is the best. But then once a year, undo the connection, steel wool the wire (or cut off to a fresh portion), and redo the connection.

 

[ScottCarr]

have you ever opened up your speakers and look at what the crossovers are made of?

It's not like the capacitors, filters, transformers or resistor wires/leads are gold plated or larger than 22awg.

bare wire:
if you twist it too tightly the strands may not flatten out reducing the amopunt of surface area coming in contact with the terminal.

end plug banana or spade. how many of the strands are coming into contact with the connector surface? my guess about the same amount found in the bare wire set up.

Now if the speaker terminal had a much larger hole which allows the cable to flatten out more then I would say bare wire. But then again the components in the crossovers are about 1/4 the size of the speaker wire.

Speaker cable to the terminals is like a 4 lane high way, into the crossovers is like a 1 lane road, then out of the crossovers to the speakers its another 4 lane highway.