MIM: Building A Speaker Wiring Harness

Written by
Logan Tabor
Published on
January 19, 2021 12:35:48 PM PST January 19, 2021 12:35:48 PM PSTth, January 19, 2021 12:35:48 PM PST
Welcome back, everyone!  This week on Make It Monday, we are going to go over how to wire up a 1x12 and 2x12 extension cabinet wiring harness.  This is a straightforward and simple project that will get you soldering, clipping wires, crimping terminals, and wiring up your own cabinets. 

Tools and Supplies

Before we dive in, let's go over the tools and supplies we will be working with today (Refer to Image 1A below).  We are using a Switchcraft J11 mono output jack, so we need one of those.  Next, we will need 2 or 3 feet of both black and white 18AWG stranded cloth covered wire (length will depend on your cabinet and how many speakers you are wiring up).  We highly recommend buying or borrowing a crimper or "crimping shrugs" to crimp down 1/4" female terminal fast-ons to the end of your wire -- this will make future speaker swaps much easier on you, where hard soldering to the speaker terminals will prove to be a much more frustrating connection in the end.  

After that, we need a set of wire cutters, a soldering iron and holder, and some solder.  


Step 1: Soldering the J11 Jack

Before anything else, let's make sure we have our cloth covered wire cut to the appropriate length.  To do this, run the black wire with your hands from the jack ferrule on the cabinet's backpanel, to the metal terminal on the speaker itself.  Now give an extra inch of slack, and cut the wire.  Repeat this step with the white wire.  Note: This will also depend on how many speakers are going into your cabinet and how they are being wired -- refer to Step 3: Wiring The Cabinet for more information.

Next, take a look at your J11 jack, you should notice two solder terminals; one is positive and the other is ground.  The ground terminal will be slightly inset and is connected to the metal sleeve that goes into the jack.  The positive terminal is the terminal that is all the way on the outer rim of the jack and is not connected to the metal sleeve (See Image 2A).  


We are going to start by wiring the black wire to the ground terminal on the jack.  To do this, get your jack in a stable position on your workbench, push back the cloth covering, twist the stranded wire together, and push it through the hole in the terminal (Image 3A).  Now that the wire will stay still on its own, you can solder the wire to the terminal.  You will likely have some excess wire hanging off of your connection, use your wire cutters to trim this excess (Image 3B).  Repeat the above with the white wire on the positive terminal of the jack.


Step 2: Applying 1/4" Female Fast-Ons

Now that we have the jack takern care of, we need to handle the other end of our wires.  Applying 1/4" female fast-ons will make for an easy and secure connection when it comes time to attach the harness to the speaker.  To do this, we need (2) of our fast-ons and our crimper.  

Here again, we need to push back the cloth covering on our black wire and lightly twist the wire.  Then, push the wire through the opening in the bottom of the fast-on (Image 4A), and then use the crimper to secure the fast-on to the wire (Image 4B).  Repeat this step for the white wire.


Step 3: Wiring The Cabinet

As I said in the beginning, we will be going wiring for both 1x12 and 2x12 extension cabinets.  Starting with a simple 1x12, we need to make sure that our speaker impedance matches our amplifier impedance.  Once this is confirmed, we will connect the white wire to the terminal on our speaker labeled with the plus symbol (+).  To do this, simply slide the female fast on over the corresponding speaker terminal -- you may have to wiggle it back and forth a bit to get it all the way on (See Images 5A and 5B).  Repeat this step for the ground/black wire on the speaker terminal labeled with the minues sign (-).  Note: Many speakers will not have the minus (-) sign on the ground terminal, but will instead be blank.  If this is the case with your speaker, just know the positive wire connects to the terminal labeled with the plus (+) sign and the ground wire connects to the unlabeled terminal. 


Lastly, all we have to do is secure the jack to the jack ferrule on the cabinet's backpanel.  To do this, remove the nut and washer from the jack, insert the threaded end of the jack through the ferrule, slide the washer back over the threads, and screw down the nut (See Image 6A and 6B). 


If you're a 1x12 cabinet kind of guy, you're all done!  However, if you are a 2x12 cabinet kind of guy, we need to go a bit further.  First, we need to determine the overall desired impedance of our circuit.  Let's say our amplifier is 8ohms.  We have two options:

Option 1 - (2) 16ohm speakers wired in parallel
Option 2 - (2) 4ohm speakers wired in series

In this case, we are going to use (2) 16ohm speakers wired in parallel for an overall 8ohm load (see speaker wiring diagrams at the end of article to determine best wiring configuration for your rig).  

Wiring in parallel requires you to run from the positive and ground terminals on your jack, to the positive and ground terminals on the first speaker.  From there, you will connect an additional set of wires from the positive and ground terminals on your first speaker, to the positive and ground terminals on your second speaker.  So, we need to prep another set of wires.  This time, we are going to apply 1/4" female fast-ons to both ends of each wire, but before we do that, we need to measure from the terminals on the first speaker to the terminals on the second speaker to determine how much wire we need (refer back to Step 2 if needed).  Once this is done, we need to push back the cloth covering on our wires, and attach the fast-ons (again, refer back to Step 2 if needed).  If desired, twist the wires together for a clean look (See Image 7A).


Finally, we will connected the positive and ground wires to the corresponding speaker terminals on speaker one, and then on speaker two (See Image 8A).


Last but certainly not least, connect this bad boy to your amp and listen to it scream!  Please take a look at the speaker wiring diagrams below to explore more ways to wire up your cabinet.  This will prove helpful when working with amps and speakers of varying impedances, and you will notice that there is almost always more than one way to wire a cabinet.  Thanks again for tuning in to this week's Make It Monday -- see you next time!