Speaker Wiring - Series and Parallel

11/98 - Jens Moller - http://www.colomar.com/Shavano/spkr_wiring_sp.html

See Speaker Wiring/Loading Examples for loading considerations.

1) 2 or 4 Standard Speaker Cabinets - 1 or 2 Serial Patch Boxes
Use this if you already have production speaker cabinets with a jack on the back, or you plan to build speaker cabinets in this configuration.
2) 2 or 4 Cabinets - Extra Jacks built into the Speaker Cabinets
Consider this if you are building your own speaker cabinets, and want to build serial/parallel patch boxes into them.

1) 2 or 4 Standard Speaker Cabinets - 1 or 2 Serial Patch Boxes

If you power amplifier already has 2 speaker cabinet jacks on the back of it, creating a parallel circuit, you can build 2 series Patch Boxes (see Patch Boxes; Multi-Purpose Audio Adapters) and use one with each of the power amplifier output jacks.

The Wiring is quite simple, however you need to make sure that the jacks don't short each other out - I advise mounting them on something other than metal.
To connect 4 speakers together, you need 2 Serial Patch Boxes. You will need a total of 6 cables.
The big advantage is that you can connect any stock pre-wired Speaker cabinet up using this process, and you can reconfigure your speaker system as needed, anytime you need to - you don't require anything special to make it work.

Some suggested cable lengths per Series Adapter are:

2 short (10 feet long or less) power amp audio cables - for Out 1 and Out 2.
1 long (30 feet long or longer) power amp audio cable - for the connection to the Series Adapter Input and the audio power amplifier speaker jack.

If your speakers will be grouped in 2's on either side of the stage:

Take the long cables, plug one end into the Input of the Series Adapter and the other end into one of the 2 power amplifier speaker cabinet jacks. Do this for both Series Adapters. Run one Series Adapter over to the cabinets on the right hand side of the stage behind the speaker cabinets, the other to the left hand side behind the speaker cabinets. The, one each side of the stage, plug a cable into the Series Adapter Out 1, and the other end into one cabinet, and then plug a cable into the Series Adapter Out 2 and the other end into the other cabinet. Do the same on the other side. All of 3 of the jacks on each of the Series Adapters must be connected in order for it to work. This completes the wiring.

If your speakers will be placed anywhere on the stage (floor monitors are a typical example):
Take the long cables, plug one end into the Input of the Series Adapter and the other end into one of the 2 power amplifier speaker cabinet jacks. Do this for both Series Adapters. Run one Series Adapter over to the middle of where you will place 2 speaker cabinets. Do the same with the other Series Adapter. Plug a short cable into each of the speaker cabinets and then connect the other end into either Out 1 or Out 2 of the Series Adapter. All of 3 of the jacks on each of the Series Adapters must be connected in order for it to work. This completes the wiring.
If you are only wiring 2 speaker cabinets in Series
Its really the same process, except you only connect one Series Patch Adapter Box using 3 cables as shown here.
Repeat for each side of the stage if using 4 speakers.

2) 2 or 4 Cabinets - Extra Jacks built into the Speaker Cabinets

If you need to be able to wire up a set of cabinets in either Series or Parallel with each other, and don't want to carry around any special cables, you can do it by wiring the cabinets with a few extra sets of jacks.
You'll have to pay attention to how you connect the cables up, and you may want to print out this Web Page to assist you in figuring out the proper way to do this when setting up for performance.
If you use a road crew, or other members of the band occasionally help in the setup and tear down, you may want to number the cabinets (on the back) and have a diagram of how to wire the system properly that they cab work from. Color coded cables (at least on the Plugs) will help during setup.
PLEASE NOTE: You cannot use a metal mounting plate to hold the Jacks - the Series In/Out will short out the speaker wires if you do, which will severely damage your power amplifier. Use plastic, Masonite (compressed fiber board) or thin plywood to mount the Jacks on.

Each cabinet is wired in this fashion - This could be a 2 way or 3 way cabinet (with passive crossovers). A single driver is shown to keep the concept simpler to manage.

2 Cabinets - Parallel Wiring

The impedance decreases. The equation is
Total Load = (S1 x S2) / (S1 + S2)
Where:
S1 = the impedance of Speaker load # 1
S2 = the impedance of Speaker load # 2

2 Speakers - Serial Wiring

The impedance is additive. Add up all the
loads to figure out the total load value.
Add up all the series loads:
Total Load = S1 + S2
Where:
S1 = the impedance of Speaker load # 1
S2 = the impedance of Speaker load # 2

4 Speakers - 2 in Series, 2 in Parallel

you will be doing a combination of both of the above examples. You would wire it in the following way:

Label your cabinets 1, 2, 3 and 4 (it makes no difference which is chosen for each individual position).
Connect The Parallel Segments first
Parallel-In of Cabinet 4 goes to Parallel-Out of Cabinet 3.
Parallel-In of Cabinet 2 goes to Parallel-Out of Cabinet 1.
Connect The Serial Segments Next
Power Amp Audio Cable output connects to Serial-In of Cabinet 4.
Serial-Out of Cabinet 4 connects Parallel-In of Cabinet 1

Cabinet 4 will have 3 cables plugged in to it. Cabinet 1 will have 2 cables plugged into it. Cabinets 2 and 3 will have one cable plugged into them.

Or, to simply have a single speaker in a cabinet, where you want to have either a prewired series or prewired parallel connection for your add on speaker cabinet:

For 1/4 inch (and 1/8 inch) phone jacks, you need to verify which solder tabs go to the + and - connections, 1/4 (and 1/8) inch phone jacks have no standard for which of the solder tabs goes to what. Open cased Jacks are easy to verify - just look at it. In an enclosed Jack, you may need to use a VOM/Digital Multimeter to check which connection goes to what.

The + and - relate to how the speakers are connected. The speaker should have a colored dot on it to indicate + or it will be marked with a +.

NOTE: We do not work on Home or Car Audio. We work only with Pro-Audio applications. We cannot help you with Home or Car Audio questions.

Questions? Comments? .

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