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Old 2007-03-24, 03:07
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Soulinsane Soulinsane is offline
Pirate Lawd
Join Date: May 2004
Location: Hanger 18
Posts: 6,520
Fast and easy Cab wiring mod.

This mod is for any speaker cabinet. This mod will help add clarity and frequency response to your tone; mostly in the low mid to bass range. For simplicity, I will explain these instructions as if I were performing this mod on a closed-back 4x12 speaker cab, but is only the example. This mod can be performed universally on absolutely any type of speaker cab.

Important note: These instructions will only cover what the cab is wired with and not change its wiring schematic (or change how it is wired). Basically, when finished, you cab should be wired the same but with better wire material.

First step is to assess if your speaker cab needs this upgrade. The focus here is to determine what wire gauge diameter ( AWG ) is currently being used in the cab. Most cabs use a small diameter wire because it is very economic when manufacturing a large number of cabs. Better wire adds a huge cost when you have to wire hundreds if not thousands of cabs. The AWG of a wire can be found written somewhere on the length of the wire or you could just measure the diameter of the conductor to get a close guess. Small wire diameter will result in poor signal transfer from the amp to the speakers for many reasons to detailed to post about here. Anything 15 AWG or higher AWG will need to be replaced.

FYI: The bigger the AWG # the smaller the wire diameter. The smaller the AWG # the bigger the wire diameter. Keep in mind stranded core wire will seem to measure larger in diameter than solid core wire due to cross reference parallax error. Higher frequency signals travel better near the surface of a conductor and stranded core wire was invented to accommodate those frequencies. It was designed as one wire with a lot of surface area carry high frequency traffic far better than solid core wire.

Materials needed:
Soldering iron
Electronics solder ( not plumbing solder )
Female spade push-on connectors ( that will accept you new wire AWG )
Pliers to crimp the spade connectors
Wire strippers ( a knife will work if your careful ) wire.

The new wire will need to be STRANDED COPPER WIRE with an insulated wrapping to help keep it oxygen free. Stranded copper wire is ideal to carry high frequency signals without problems. Do not buy solid copper wire or any type of aluminum wire. Stranded copper wire is the best you can buy. Ignore "speaker wire" as it really isn't designed for use inside a speaker cab and will have a measured capacitance even in short lengths. It is better to keep single insulated wires ( stranded core ) in a cab separated about an inch apart to prevent capacitance from building up and ruining the signal. There room inside a cab so use it.

The new wire also needs to be at least 14 AWG. I would not use anything large than 12 AWG unless you really are good with soldering. I used 10 AWG in my cab as overkill but it also very hard to work with. I purchased 10 feet of 10 AWG stranded copper wire at a Home Depot hardware store for $0.40/foot.

12-14 AWG stranded core copper wire is perfect the prefect mod.

The Work:
Draw out how your cab is wired on paper before you disconnect any of the old wire just in case you get confused later. Be very detailed. I will not cover wire schematics in this mod. The new wires should be connected to the same points as you old wires.

Measure out each length of wire you will need. The shorter the better but leave enough length to be able to move it away from other wires or things the wire might vibrate on.

Strip the insulation off the wire ends and twist the strands hand tight. With the solder iron tin all the twisted wire ends.

Next, depending on the cab, wire ends will now need to be soldered to the cabs input jack(s) terminals, but first you will need to desolder ( remove ) the old wires from the jack(s). This can be done by simply holding the solder iron to the where the old wires are soldered to the jack and lightly pulling on the wire at the same time. The solder will melt and the wire will pull free. Here's a nice soldering guide, but there are hundreds online to read.

Once the needed wires are soldered to the jack, put the female push-on spade connectors on the other tinned wire ends and crimp them on using the pliers.

Remove one of the old wires from the cab by pulling and wiggling the connector off. Replace it with the new wire by pushing and wiggling the spade connector onto the correct male speaker terminal. It should fit tight. Repeat this process one wire at a time until all the old wires are replaced by the new wires.

Advance Tip: If you are really good at soldering then add tinning on the female spade connectors and once pushed on the male speaker terminals, using the solder iron, apply just enough heat to remelt the tinning on the female shade connector so that both the male and female terminals fuses together with solder. This will provide a rock solid connection but requires a lot of skill to know how and when to remove the solder iron. What makes this hard is the speaker magnet. The magnet will pull very hard at the solder iron and could take it out of your hand and put the hot end through the speaker cone. I seen it happen once so be very careful.

Once everything is connected, make sure none of the wires length contacts anything or comes within a inch of the other wires. This will prevent the wires from rattling or building a capacitance.

The wires should look like this when finished.

And this, but ignore trying the foam mod until I post it.

Once everything is back together you should notice an improvement in tone. Mostly in the low range frequencies. The improvement comes from the lowered resistance of the bigger gauged wire, better frequency attenuation of the stranded copper core, and removed capacitance due to careful wire placement. However little difference this new wire compared to the old wire makes on short lengths measured by a multimeter, this mod does make a real difference when measured on a O-scope. Musical tone is noticeable to the point that even a untrained ear will hear it.

This is an easy and cheap mod. The key phase is, "Bigger gauge, stranded copper wire is better". No body should have much problem with this mod but post questions if you have them.

Good luck.
Authorized Mercury Magnetics tech/dealer
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