I'm in the process of revamping the wiring to my home theater system. I'm installing a wall jack, as I do have speaker wire hidden inside the walls. I'm planning on using a single gang outlet box that will have banana clip ports.
From the research I've done, it appears using banana clips helps prevent oxidation on the wires. I'm not exactly sure why, but I'm guessing it's because there is less air contact (almost none) where the wires are "flanged" out to touch the metal before the screw cap is placed, etc. I don't want to screw in bare wire behind the wall plate... as that will defeat the purpose of preventing oxidation. So my plan is to banana the back (behind the plate). Also, to banana the front (in front of the plate). And also to use banana at the outputs of the receiver/amp.
So far so good? Or is there a preferred better way of doing the above steps? Some prefer to use spade lugs (I will get to that in a moment). I'm also not sure if the banana clips will have insulation at the grabbing point to prevent accidental cross-touching in case the amp gets turned on and any of the wires are outside the sockets.
Secondly, I would also like to do something at the speaker terminals. One set of speakers DOES have the banana clip option - so I plan to use them there. But my center channel (and others) do not! I have seen "pin" style banana clips, but I do not like those. I think they "wiggle" too much, and I have the old push-down tab style on the back of the speaker.
So currently what I do is just do a twisted thread of bare wire on the speaker points. But about every 2-3 years I need to take my wire strippers... cut off the existing points... and rethread a new 1/2" twisted thread to remove any oxidation. I find there is a VERY slight difference in performance when there is a dark coating on the bare wires, but more importantly the added resistance tends to "tax" my receiver/amp.
I was curious what the AVS'rs do to help prevent oxidation at the speaker level. Is there some kind of anti-corrosion material I can brush on the wire threads? Can you use spade lugs instead of the skinny pin-prong banana style clips? As I said before, the thin prong tends to move around too much, and I also fear the metal may touch the other speaker wire and short out the receiver. I have seen some banana style clips that have a plastic separator to make sure the two leads never touch! That's a great idea, and I wouldn't mind using those. But I still don't like the long pin prongs.
Can the bulging banana style also work inside the push tab (older) style speakers?
What do the folks here on AVS like to do in this situation?
And does everything look okay on the top section?
The best way to prevent copper wire from oxidizing is to "tin" it; that is to flow solder onto the wire applying rosin flux to the copper first. Clean excess flux away with rubbing alcohol and a small brush when finished. When soldering, use a soldering iron that is around 60 watts. Dip the stripped bare wires into a can of rosin flux and then flow the solder into the point where the wire touches the iron tip. Apply heat and flow solder until the solder can be seen to flow onto all surfaces of the wire and no copper is visible. A shiny tinned surface should result. The smallest-diameter rosin-core solder works best (.030" to "050").
Bare wire that has been "tinned" can be inserted into binding post holes. Untinned bare copper wire will oxidize quickly.
I would advise you to buy blank wall plates, drill holes in them for 3-way binding posts and attach the spade lugs to the back by nuts on the threaded rear stud.
You may be able to find wall plates with binding posts already installed; preferably gold-plated ones. Monoprice #106707 is a very nice one that has labels and posts for all 7 channels.
The speaker wires will then be held by the thumbscrew of the binding post.
You may have to use banana plugs where the binding posts are too close together for spade lugs; just be sure to use only gold-plated ones, and that they fit snugly when inserted.
It is good practice to put color-coded heatshrink tubing over the shank of the spade lug to avoid any possibility of shorting.
The Audioquest spade lugs are not terribly expensive and are good quality.
PartsConnexion sells them for $1.25 each.
The various anti-oxidation compounds on the market have been found to create long-term problems; I recommend you not use them.
Gold does not oxidize. Gold-to-gold contact is the best long-term insurance against poor connections.
Banana plugs and pin connectors don't work any better than bare wire, they're just more convenient. They don't prevent oxidation, you want to put Caig on the wire that goes into them as well.
The Laws of Physics aren't swayed by opinion.
Hello again everyone,
I would like to use the wall plate and banana clips for convenience. There will be times when I may need to pull the receiver away from the wall, and having the convenience of these easy snap on plugs will be nice and look organized & professional. I will take very special care to make sure each banana plug is assembled correctly.
On all speakers that do NOT support banana plugs, I plan on taking the board's advice and just use the direct raw twisted wire connection. I looked on Amazon and found this very well rated CAIG "nail polish" product:
It seems to work much better than the sprays (most of the spray gets lost & wasted), and it looks like you can really "target" that 1-2 drops per speaker. I'm assuming it not only cleans off oxidation but also puts a helpful "coat" to protect oxidation in the future. As it is, I'm finding that I need to re-strip the wires every 2-3 years. But with this bottle I'm hoping I can get away with 5+ years before needing to do another service.
I should also probably place one tiny drop on the surfaces that are contacting with the banana plugs.
Thanks for the advice & help. One quick question... should I thoroughly wipe & dry with a paper towel (or something) before inserting the bare wire in these connections?
Nice tip on the Deoxit, I have a project tonight.
Banana plugs and jacks for this application are terribly old school. The best solution for this particular application is Speakon connectors:
I say this because:
(1) Speakon connectors are purpose designed for exactly the job at hand - hooking up speakers. For the record banana jacks were designed for general lab work, and their now traditional application to speaker wiring is incidental.
(2) In this application you control both sides of the connection. In pro audio the speakers and amps come with Speakons, but not so with consumer audio.
Copper like Aluminum corrodes almost as easily and quickly as steel except that when it corrodes the corrosion formed tends to protect it from further corrosion. This is unlike steel where the corrosion tends to encourage more corrosion. Many of the products of the corrosion of copper in urban atmospheres are semiconductors. That means that they pass audio signals but they can add significant nonlinear distortion, or even block the passage of current entirely in severe cases.
When you tighten down a screw on a copper wire the screw tends to cut though any corrosion. Further, once tightened down, the joint tends to be protected from the atmosphere or is "gas tight".
Since almost all consumer amps and speakers generally come with banana jacks on them, we're pretty much stuck with them.
(1) One big problem with banana jacks is that they tend to come apart due to casual use.
(2) Another problem is that they go together with reversed polarity as easily as they go together with proper polarity. Inadvertent reversed polarity is pretty deadly to sound quality in a stereo or multichannel system.
(3) The third big problem is that when separated, banana jacks expose voltage on the plugs closest to the power amp.
(4) The fourth problem is that the wall connectors tend to stick out of the wall. The fifth problem is that you can only hook up one speaker at a time, and nothing keeps you from plugging the wrong speaker into the wrong jack.
Speakons make all that go away. And they aren't particularly expensive or hard to install.
Here's the inside of a Speakon:
Just twist the strands, stick into the little hole and tighten down the little screw!
This is an exploded view of a Speakon male plug:
The white thing is one of the strengths of Speakon plugs - the cable strain relief clamp. This means that the wires are relieved of stress when you pull on the cable. A very good thing!
And just to show that I practice what I preach:
If I pull on that cable without releasing the little silver latch, and I'm strong enough, I'll part the 12 gauge speaker cable. My wife loves these because I taught her how to release them and she never has to worry about putting it back bass-ackwards when she's cleaning. There are Speakons that will handle up to 4 independent speakers.
The Laws of Physics aren't swayed by opinion.
Those do look like very nice connectors, but I'm fine with the banana's. I'm very careful & anal about how I connect things, and they will only be removed once in a blue moon from the wall. And the bananas are color-coded to help me see which lines are red & black. They are going into an outlet wall jack, but the wall itself has a 3" recess to the rest of the wall. It should look very professional & decorative when finished.
Bill Fitzmaurice - thanks. That's what I will do then. I just don't like the long pointy-skinny prongs that move around. Overpriced MonsterCable has some flexible gold plated caps, but I think the much better value is this CAIG cleaner/coater stuff. At least this can be potentially used on other applications. The banana plugs should give me a really sharp look (and convenience) without detriment to the sound. The CAIG cleaner should allow the nice *solid* soft twisty-contact with the red & black tabs (so they don't move around and hopefully won't get oxidized for at least 2x-3x longer). I can definitely live with re-stripping every 5-7 years instead of every 2-3 I think. Heck, by then it may be time to re-edge the speakers too (lol).
Thanks again for the informative help.
I like the old fashioned banana plugs. I recently bought locking types and don't like them. Pain in the butt.
As far as tinning, I only tin the very tip of the cable (105 strands) on the cable behind my wall plates. Then apply Deoxit on the bare copper where I make my screw down connection.
(LCD - Sony KDL - XBR4) (Receiver - Sony STR-DA4ES)(Blu Ray - Oppo BDP-83) (PS3)( Dish Hopper DVR With Sling) Speakers (L & R - Paradigm Studio 20) (Center -Paradigm CC-470) (Surrounds & Back Surrounds - Paradigm SA-15R in walls) (Subwoofer 1 - Sunfire HRS-12) (Subwoofer 2 - Paradigm PW-2100)
I bought some wall plates with speaker binding posts and I can't seem to get sound now. I've tried banana into the front and out of the back of the plate as well as bare wire out of the back of the plate. No sound at all, any ideas ?
Did you try temporarily removing the wall plate and just connecting the speaker wire directly?
Not trying to cause any alarm, but if you have any metal connecting both sides together (either in front of the plate or on the back of the plate) it's possible you could have blown your amp. The AVR may still turn on, but the audio/amp portion may be blown. Hopefully that's not the case though. Is it possible the "A" / "B" speaker set buttons may have been accidentally pressed?