Banana plugs – how tight?

I have very little experience with banana plugs. I recently got a set of speaker cables with bananas at both ends. The plugs slip quite easily into the speaker binding posts. They don’t fall out, but they go in so easily that I wonder whether they are really making a solid connection. (Of course I wouldn’t want them so tight that it was a struggle to get them in.) Is this the way banana plugs are supposed to work with some equipment? It’s a different story with the BHK 250, where you have to loosen the binding posts, insert the bananas, and then retighten, which gives a nice secure connection.

I don’t know that you will find one answer. In my experience you should meet a some resistance but not have to push hard to insert- not nearly as hard as plugging a power cord into an outlet. Same with removing. It should take a bit of a tug but you shouldn’t have to pull hard.
I use locking bananas now and have only every used two cable brands with fixed bananas. One was a “audiophile” brand where the banana failed almost immediately. One of the springs collapsed and that plug would almost fall out. The other are from Media Bridge. I’ve had several pair but they’ve been plugged into lots of different speakers and amplifiers over the years and they all had a similar feel as I described, including PSA M1200’s.
I don’t have any experience with the BHK so can’t comment on the effect off loosening the binding post nut. This has no impact on how the bananas fit in my experience
It might help if you include both speaker and speaker cable manufacturer for those that have direct experience.
Good luck.

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I remember banana plugs on Monster cable, where the connectors had such a small diameter that they would just fall out and not stay in the speaker or amp, but had to be clamped in. I currently have Cardas speaker cables with banana connectors at the amp end (M1200’s) and spades at the speaker end (FR20’s). At the amp end, they fit perfectly, firm but not crazy tight, and of course the spades at the speaker end also fit nicely.

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FWIW, my Nordost fit very snugly into the speaker posts and firmly but not as snug into the posts on my amplifiers.

I suspect there may be variations in diameter on the male and female ends of things amongst manufactures of cables and kit.

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I would assume so (of course, it would be nice if things were better standardized). But the important question is how much does this matter? I am assuming, on a common sense basis, that a loose fit would result in a poor connection which in turn would lower SQ. But in audio “common sense“ doesn’t always apply; am I right to be concerned about this?

Some contact enhancer on the banana plugs will help. I use Furutech Nanoliquid. Caig Deoxit Gold also works, but needs to be wiped off and reapplied periodically for full effect.

How loose? If you have contact all the way around, so to speak, I am guessing everything is fine. OTOH, I think intermittent contact would be a problem.

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Good morning. Unfortunately, banana plug design and quality runs all over the place. I’ve not heard or seen a recommended or standard retention or pull-out spec on a banana. From the component side, the 5-way binding posts share a similar gambit of quality and most times offer little to help with the retention of a banana plug. The seizure points seem to vary quite a bit.

I bet most of us have heard of someone having a banana plug pop loose or come out of the binding post and causing a short, many times causing significant damage to their amplifier or receiver. I’ve seen extreme cases when a simple movement of a connected component or speaker cause a poor fitting banana plug to fall out.

Poor choices on bananas include those that use set screws and those that “crimp” to attach to the speaker wire and those that are sized for larger gauge wire (10-12 AWG,) that are then installed on smaller speaker wire (14-16 AWG.) Common sense comes to mind.

A properly soldered or ultrasonically welded banana plug as we do at BJC/Iconoclast Cable is the best choice for the mechanical connector to cable attachment. The all you have to worry about is the ability of the connector to provide a solid connection with an acceptable level of retention to ensure the connector stays in the port or post when components and/or speakers are adjusted or moved (within reason.)

We use an ultrasonically welded connection between the wire and connector. The connector itself is a “locking” design that on an almost universal level, provides an excellent connection of the cable to the component and to the speaker while providing the desired retention to the post. The rear nut on the connector is loosened before inserting the tip into the post. As the rear nut is tightened, a tension bar is moved forward spreading the 3-pronged tip until it is firmly attached. A great connection!

We don’t have an actual retention or pull-out spec since that will vary to some degree dependent on the port or post but in my experience it’s the best banana plug on the market. This is my personal connection of choice.

The question of connection quality, poor banana design and the possible risk of a banana fall out🤨 cause many audiophiles to choose a spade connection. Spades too have variables to consider. The actual post on a 5-way is not always the same size. We provide rhodium plated copper spades in 3-sizes. 6.3mm for WBT spec binding post, 7mm for a mid-point and 9.2mm for all the others. Rhodium is very soft and can provide a “gas tight” connection.

When choosing spades, you always want to unscrew the nut on the binding posts and look for 2-flat sides on the post itself. Many but not all binding posts offer the flat sides to allow the fork of the spade to lock on so that when the nut is tightened the spade does not want to turn with the nut when being firmed up. Calipers are helpful when determining the size or give your component or speaker brand a call to ask what size post they use. Alternatively, we offer a 3"x5" heavy stock card with notches for the 3-sizes that can be mailed to you. Handy to have in the audio tool box. Keep in mind that unlike the ultrasonically welded banana, a spade selection today might not fit your component or speaker of tomorrow.

Regardless of choice, chose “quality” of the connection, the connector and the one that fits your application the best.

Hope everyone has a safe an enjoyable Memorial Day Weekend!

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Long story short…

  • Gas tight connection to the cable stock.
  • Gas tight seal at the terminal. Tighter gets you there, looser farther away.

Use the banana pull-out value as high as is practicable. Locking, of course, can’t be pulled out when locked.

Best,
Galen

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Yes, contact enhancer is probably a good idea. I have the Caig Gold. I knew it has to be reapplied occasionally but didn’t realize it needed to be wiped off first (doesn’t it dry out?).

The cables sound good, so there must be a reasonable level of contact. But the obsessive audiophile in me wonders if a firmer connection would yield better SQ.

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Bob - how do I get one of these stock cards? Did not see it on your website
Mike

Thank you – this is really helpful! I had not heard of banana plugs coming loose and causing shorts; good to know now that I own these cables.

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Spades are The Way for an assured gas tight connection to a five way binding post. banana plugs are a convenience item, that can offer a gas tight connection, but IME many fall short for reasons listed above.

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I wipe off the Caig Gold from both metal surfaces (large foam swab for the binding post, lint free cloth for the plug) to remove any corrosion that has built up.

“ultrasonically welded banana”

You don’t hear that everyday. Lol.

My Monocle XL cables have a very well made “banana cincher” that tightens them up nicely. Not even sure what gas tight means, but there seems to be a very secure connection

The surface of a material is rough, and this allows “gas” to permeate between the surfaces. A gas tight seal fills in the gaps with various techniques. Solder, a softer metal like rhodium that displaces and fills in the cracks, or even “filler” compounds applied to block gas permeation.

The reason for gas tight is to prevent oxidation of a surface being in contact with the air. Most, not all, oxides are poor conductors. Copper oxide is worse than Silver oxide as an example.

Loose connections tend to get looser with the expansion and contraction of differing metal’s coefficient of expansion that pushes the bodies around the threads. A good connection needs to exceed the forces doing this.

The best current connection, not really new all all, is a soft sacrificial metal like rhodium plating on copper (rhodium/silver/copper usually) on a SPADE design. The softer metal displaces onto the crack and seals most of them and is a permanent seal left alone. A good spade post can be sufficiently tight to stay tight.

We looked at banana pretty closely and our choice eliminates most issues with them. They are ultrasonic welded to the BULK cable. The locking design applies sufficiently good pressure to be gas tight. We chose GOLD as Rhodium is too soft for banana with a more limited contact area and people tend to remove banana often so a more durable naturally oxidation resistant material like gold is best. But the POST material you use is still going to vary. Most are gold plated so we have like-like metals with oxidation resistance properties.

If we have no corrosion issues (gold to gold) we need a good low resistance contact, and gold is pretty good so not worrying about changes over time except if it is getting loose is nice. A super low DCR contact, like a race car, needs additional maintenance or expensive materials to be and remain the best.

There are compromises to any method we chose, so just be aware of what the connection is and act accordingly. Look at the connector plating, and the POST plating or material. One material or the other will drive the best method. Many use an oxidation resistant “filler” to coat the connection if it is a bare copper material against rhodium or gold. One surface can create the problem, not the other. Make sure bare copper posts or connectors are CLEAN before using them. Copper does oxidize over time in air.

Best,
Galen

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Now that was a dang good “Im glad Im on this forum” answer. Thank you. I now understand spade vs banana and the term “gas tight”

I dont think ill toss my cables but if i ever bought new, i may reconsider termination. I usually do have different technology amps. Like today ill be tryiing my speakers on a Gan fet vs tubes so a few times a year i do switch stuff out. Banana is a convenience but hardly necessary unless i did this type experimenting weekly.

Until today i figured both terminals were equal. Maybe close but not equal. Thanks again…

Mike, PM me your mailing address and one will appear in your mailbox at home. :mailbox_closed: