Some time ago I needed to look into how electrical connections are made and should be made. I investigated soldered connections, as in RCA plugs, and crimped connections, as in spade lugs used with terminal strips or even binding posts.

Looking into manufacturers' literature, the consensus was that the best connection would be one where the metals were arranged (soldered, for instance) or so tightly crimped that oxygen could not get between the two surfaces and cause corrosion. AMP crimp connection systems, for one, guaranteed that their crimpers and connectors squeezed so hard that there was actually cold flow of the metal, and quite a bit of metal-to-metal contact where oxygen could not penetrate. And for speaker connections, you want quite a bit of cross-section at the connection point to carry the current without heating.

But now I look at banana plugs, gold or otherwise, and find that four little springs push out from the shaft of the connector, thereby making contact with the inside of binding posts (in most instances). The occasional connector that allows an actual increase of pressure by rotating the connector or by some other means AFTER making the connection does not fit into this discussion.

So, in a banana plug connection, the analog of the twenty pounds that I exerted to make a crimp with the AMP tool, magnified by leverage to at least a hundred pounds, is represented by, what, five? ten? two? pounds of pressure on the binding post from each little spring. And the surface area of the banana plug that contacts the binding post has GOT to be way less than the thickness of the wire! Now, if this happens to heat, that will weaken the spring, lessening the pressure, increasing the heating effect....

You can occasionally see this kind of effect in a light bulb socket, where the little piece in the center has been heated and is not as easy to connect to without cranking the heck out of the bulb. Remember now how massive the crimping tools are, used by electricians, to terminate wires that carry current.

Because of this, I never use bananas. I take the speaker wire, slip it into the hole in the side of the binding post, and tighten it up very well. I find that the copper reshapes, or flows, slightly, and after about five minutes another tightening can be done.

I know that gold bananas are a very good profit source, but can someone other than Noel Lee tell me some reasons that they are a good approach for high fidelity speaker connections?

I can think of one reason: they are easily removable. In some installations, this is a drawback, of course.

I can't, mainly because I mostly agree with you. I hook and tin (in that order) my speaker wire ends.

I would not use them for high-fidelity speakers, I use spade lugs myself.

I always fall back on the fact that a system is only as good as it's weakest link (and even more than that, a great system never made a bad movie or crummy music less pathetic).

Sometimes in the real world, the banana plugs are the only way we can get to a system, good or bad. Otherwise we'd prefer to connect the wire directly to the binding posts. On a side note, If you wiggle the wire a little after the first tightening, the strands will seat and then you can then retorque the binding post. I've seen quite a few loose and disconnected speaker wires over the years.

In Arizona, we call it a "dry heat". As I understand it, oxidation is brought on by moisture among other things. Is there another reason why I need to connect with a gold plug especially if you pop the top of a $2000 amp and find nothing but tin solder?

Anyone soldering the wire directly to the binding posts? Beat that connection!

noel lee...

This message was edited by Steve Garn on 06/27/05 00:35 ET.

For a while there, Rotel was making binding posts that had no holes, and were very small... There was no choice but to use something, and bananas were usually close at hand. After a few months, they started shipping with bananas - must have been a lot of calls to make THAT happen!

Otherwise, bare wire...

I prefer not to connect a connector to a connector!

Adding another potential problem is not in my game plan!

It could add a few $ to the bottom line but, it's not worth it if you factor in the 'warranty'service calls!

Larry, you are correct on all of your points except using bare wire through the binding post. Bare wire no matter how tight the connection will still oxidize over time leading eventually to a corroded speaker wire and poor sound quality. You also run the risk of over tightening the binding post leading to breakage of the speaker wire which leads to less surface contact (at best) or a loose speaker wire(at worst) leading to a short. Even Noel will tell you the spade is the best speaker connection Monster offers. The 2nd best would be flex tips and the last is bananas. If you have to use bananas or any other type of termination for bare wire make sure they also have a tight fitting set of cable pants to minimize the oxygen getting to the wire (DON'T use the gold plated adapters with the hole like a binding post - that's only for a quick and easy connection - there is NO performance benefit at all).

As you said earlier it has to do with the actual amount of wire making contact with the binding post. The spade has the largets surface area of the different types of connections (just a pain in the ass connection to work with somtimes - like the manufacturers that put there binding posts to close together!).

Sorry Ernie, after years of lurking you would think I would'nt confuse you and Larry. Must be that super member status, makes me nervous:-)

The ONLY reason for gold connectors is they won't oxidize or corrode providing you with a better connection. Silver would be the better conductor of course but it oxidizes easily so gold plated connectors are just a compromise. Selling gold plated connectors to use on your lower end systems (without gold plated rca jacks or bining posts) will offer no benefit (other than less oxidation assuming speaker wires have some sort of cable pants and line level connections have heat shrink tubing at the connection point)

Actually, silver-oxide is a better than non-oxidized silver as a conductor.

Well I guess I'm on the opposite end of this. I won't use banana connectors for a true hi-fi system but I don't see many of those anymore. I solder banana connectors onto the majority of my home theaters. It may not be the best connection but there are worse things in life and I am DONE with trying to cram bare wire into the back of these 7.1 receivers. IMO it makes for a cleaner install and much easier to service.

why does everyone dispell mercury as a conductor metal?

It may have something to do with the slight case of death after use! :)

I just have to think the thought and out it comes from Ted's keyboard. I have forgotten to order more in and the last few jobs have used bare wire. Lord, help me if those amps ever needs service.

Alan

Couldn't agree more.

The monster Quick Lok banana plugs are one of my favorite connectors. You can clamp the to your wire very very tight and they hold very tight in binding posts.

We use more of these than any other Monster product.
( If MIT made a good banana we'd use theirs - but they don't)

[Link: monstercable.com]