
Speaker Wiring/Loading Examples

5/98 (Updated 04/99, 08/02, 12/03, 01/04, 09/04, 05/05 and 05/12)  Jens Moller 
http://www.colomar.com/Shavano/spkr_wiring.html
NOTE: I get a lot of people asking how to
wire 2 speakers up together and maintain the same impedance as one of the
speakers, for example taking 2 8 ohm speakers with the end result as an 8 ohm load.
It is impossible  your only options are to wire 2 8 ohm speakers in
parallel and get a 4 ohm load, or 2 8 ohm speakers in series and get a
16 ohm load (please note that things of this nature are possible with
crossover networks, however, only if the 2 speakers will be responding to
different frequencies). It is possible to maintain the impedance with
4 speakers, but not with 2. 3 speaker and 6 speaker systems are discussed
at the end of this document.
Can I use a Resistor in place of a speaker to even out the impedance?
Yes, but its a very bad idea, here is why:
 Anything going thru the Resistor becomes Heat  you are throwing away signal 
all you do is put load on the power amp that accomplishes
nothing for your volume levels.
 Resistors give off heat  you need to size the power rating 200% above the
amplifiers RMS rating  too small and you have created a fire hazard.
 Almost all power resistors are wire wound  they are inductors. As inductors
they alter the low freq roll off of a speaker  this will compete with any passive
crossover that you are using  in general it makes things sound very poor.
Its your speaker cabinets, so you can wire them anyway you want, however you rarely accomplish anything
of value trying to subsitute a Power Resistor in place of a real speaker just to balence up
impedance  my advice is to get a real speaker  it will sound better. I have no other advice
on the topic beyond not doing it.
There are noninductive power resistors  they are used for tuning power levels to
individual speakers in crossover networks  in this case, they are being used in the same
manner as LPads  this is done frequently on horns and tweeters. Thats a totally different use.
Parts Express sells noninductive resistors for this purpose.
Using Midrange Speakers/Horns with Woofers
If you are building a speaker system with a midrange Horn or other frequency specific
speakers, each speaker (or set of speakers) that will operate in its own range needs
a crossover network of some sort to limit its frequencies to those that they are capable
of operating at. See:
First Order Crossover Networks to have a look at how to do this.
When setting up a crossover network, all the frequency devices need to be the same impedance. By this,
I mean that if you have 2 16 ohm woofers in parallel, giving you 8 ohms, and you want to add a midrange
horn, it should be 8 ohms so that the crossover for both the high pass and low pass filters are for 8
ohms. Don't mix impedances in crossovers, its a bad idea.
If you use a crossover, and it splits low pass and high pass at the same frequencies, then when you put
the Woofer and the Horn together, their impedances do not contribute to each others load  This is because
each section only conducts its frequency range and the impedance is consistantly the same for all
frequencies. More info can be found here:
2 Way/3 Way Passive Crossover Networks.
If you are using Piezo horns, you do not need a crossover network.
Dual Voice Coil (DVC) Speakers
If you have Dual Voice Coil (DVC) Speakers, please see: Dual Voice Coil
Speaker Wiring first to figure out how you might be using the individual speakers.
Speaker wiring (using all the same type of speaker)
The following 'speakers' could be speaker cabinets that you are
trying to wire up into a network and balance the loads
appropriately. Each element shown in the drawings is represented
as a speaker symbol. Each speaker symbol counts as a load.
In the case of dual voice coil SubWoofer drivers, they appear
(electrically) as if they are 2 speakers. Use the 2 Speakers  (In Phase)
information to figure out how to wire them up if both coils are to be
connected the the same power amplifier.
Shown are 1, 2, 4, 6, 8, 12 and 16 ohm loads (voice coil impedance or total
cabinet impedance). These are the most likely combinations of wiring
that you will run into.
2 Speakers  Series Wiring; In Phase
NOTE:
If you have a dual voice coil
speaker and you want to use both voice coils to drive the same signal,
you would wire it like this. The impedance results are noted below.
 1 ohm loads  total load = 2 ohms
 2 ohm loads  total load = 4 ohms
 4 ohm loads  total load = 8 ohms
 6 ohm loads  total load = 12 ohms
 8 ohm loads  total load = 16 ohms
 12 ohm loads  total load = 24 ohms
 16 ohm loads  total load = 32 ohms

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

2 Speakers  Series Wiring; Out Of Phase
NOTE:
Never wire a speaker cabinet Out Of Phase
unless it requires a PushPull/Isobaric
alignment. Dual Driver SubWoofers would
use this (not single drivers with Dual
Voice Coils).
 1 ohm loads  total load = 2 ohms
 2 ohm loads  total load = 4 ohms
 4 ohm loads  total load = 8 ohms
 6 ohm loads  total load = 12 ohms
 8 ohm loads  total load = 16 ohms
 12 ohm loads  total load = 24 ohms
 16 ohm loads  total load = 32 ohms

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
The Red Speaker is the
one that is Out Of Phase.

2 Speakers  Parallel Wiring; In Phase
NOTE:
If you have a dual voice coil
speaker and you want to use both voice coils to drive the same signal,
you would wire it like this. The impedance results are noted below.
 1 ohm loads  total load = .5 ohms
 2 ohm loads  total load = 1 ohm
 4 ohm loads  total load = 2 ohms
 6 ohm loads  total load = 3 ohms
 8 ohm loads  total load = 4 ohms
 12 ohm loads  total load = 6 ohms
 16 ohm loads  total load = 8 ohms

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
Another was to define this is:
1/Total Load = 1/S1 + 1/S2

2 Speakers  Parallel Wiring; Out Of Phase
NOTE:
Never wire a speaker cabinet Out Of Phase
unless it requires a PushPull/Isobaric
alignment. Dual Driver SubWoofers would
use this (not single drivers with Dual
Voice Coils).
 1 ohm loads  total load = .5 ohms
 2 ohm loads  total load = 1 ohm
 4 ohm loads  total load = 2 ohms
 6 ohm loads  total load = 3 ohms
 8 ohm loads  total load = 4 ohms
 12 ohm loads  total load = 6 ohms
 16 ohm loads  total load = 8 ohms

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
The Red Speaker is the
one that is Out Of Phase.

4 Speakers  Serial Wiring; In Phase
 1 ohm loads  total load = 4 ohms
 2 ohm loads  total load = 8 ohms
 4 ohm loads  total load = 16 ohms
 6 ohm loads  total load = 24 ohms
 8 ohm loads  total load = 32 ohms
 12 ohm loads  total load = 48 ohms
 16 ohm loads  total load = 64 ohms

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 + S3 + S4
Where:
S1 = the impedance of Speaker load # 1
S2 = the impedance of Speaker load # 2
S3 = the impedance of Speaker load # 3
S4 = the impedance of Speaker load # 4

4 Speakers  Parallel Wiring; In Phase
 1 ohm loads  total load = .25 ohms
 2 ohm loads  total load = .5 ohms
 4 ohm loads  total load = 1 ohm
 6 ohm loads  total load = 1.5 ohms
 8 ohm loads  total load = 2 ohms
 12 ohm loads  total load = 3 ohms
 16 ohm loads  total load = 4 ohms

The impedance decreases. The equation is
1/Total Load =
1/S1 + 1/S2 + 1/S3 + 1/S4
Where:
S1 = the impedance of Speaker load # 1
S2 = the impedance of Speaker load # 2
S3 = the impedance of Speaker load # 3
S4 = the impedance of Speaker load # 4

4 Speakers  Series/Parallel Wiring; In Phase
 1 ohm loads  total load = 1 ohm
 2 ohm loads  total load = 2 ohms
 4 ohm loads  total load = 4 ohm
 6 ohm loads  total load = 6 ohms
 8 ohm loads  total load = 8 ohms
 12 ohm loads  total load = 12 ohms
 16 ohm loads  total load = 16 ohms

The impedance is the result of the
series load being wired in parallel.
Add up all the series loads:
SL1 = S1 + S2
SL2 = S3 + S4
Then Figure out the Parallel load
Total Load = (SL1 x SL2) / (SL1 + SL2)
Where:
S1 = the impedance of Speaker load # 1
S2 = the impedance of Speaker load # 2
S3 = the impedance of Speaker load # 3
S4 = the impedance of Speaker load # 4
SL1 = the impedance of Speaker load # 1 + 2
SL2 = the impedance of Speaker load # 3 + 4
If you have Dual Coil SubWoofers, or
separate cabinets with 2 speakers in them
You can wire this way (where both of the
loads are shown as 2 speakers)  the resulting
load is same as above.

8 Speakers  Series/Parallel Wiring; In Phase
This is simply a variation of everything else here.
2 sets of 4 speakers wired in parallel, with those
sets wired in series.
 4 ohm loads  total load = 2 ohm
 8 ohm loads  total load = 4 ohms
 16 ohm loads  total load = 8 ohms


Oddball Configurations
3 Speakers
This is usually a very poor combination if all the speakers are the same impedance
and I strongly reccomend against it. A lot of people ask me about a 3 speaker combination  I'm
not sure why anyone would go out of thier way to use this combination (2 or 4 speakers are much better
when all the speaker impedances are the same)  If you get a cabinet
that is designed for 3 speakers, I suggest that you get with the person or company who
designed it and ask for their wiring reccomendations.
NOTE: It is very easy to put together 3 speaker combinations that
can damage your power amp because of too low of a load impedance  make sure that you
choose your configuration carefully.
Some options are:
 All 3 speakers in series:
 For 4 ohm speakers, you get a 12 ohm load.
 For 6 ohm speakers, you get an 18 ohm load.
 For 8 ohm speakers, you get a 24 ohm load.
 For 16 ohm speakers, you get a 48 ohm load.


 All 3 speakers in parallel:
 For 4 ohm speakers, you get a 1.33 ohm load.
WARNING: Very few power amps can drive a 1.33 ohm load
 For 6 ohm speakers, you get a 2 ohm load.
WARNING: Power amp must be able to drive a 2 ohm load
 For 8 ohm speakers, you get a 2.67 ohm load.
WARNING: Power amp must be able to drive a 2 ohm load
 For 16 ohm speakers, you get a 5.33 ohm load.
NOTE: Works well with power amps designed for 4 ohm loads


 Possible 3 speaker mixes that work quite well:
 2  4 ohm speakers in series (8 ohms)
then wired in parallel
with an 8 ohm speaker = 4 ohms


 2  8 ohm speakers in series (16 ohms)
then wired in parallel
with a 16 ohm speaker = 8 ohms


6 Speakers
This is sometimes a poor combination if all the speakers are the same impedance
and I strongly suggest against it, however if your power amp can drive these loads,
it will work. Some options are:
 2 sets of 3 speakers in series, with those 2 sets in parallel:
 For 4 ohm speakers, you get a 6 ohm load.
 For 6 ohm speakers, you get an 9 ohm load.
 For 8 ohm speakers, you get a 12 ohm load.
 For 16 ohm speakers, you get a 24 ohm load.


 2 sets of 3 speakers in parallel, with those 2 sets in series:
 For 4 ohm speakers, you get a 2.67 ohm load.
WARNING:Power amp must be able to drive a 2 ohm load
 For 6 ohm speakers, you get an 4 ohm load.
 For 8 ohm speakers, you get a 5.34 ohm load.
 For 16 ohm speakers, you get a 10.66 ohm load.


 Possible mixes that work OK, but speaker loading may not be optimal:
 4  4 ohm speakers in series (16 ohms) then wired in parallel
with 2  8 ohm speakers in series (16 ohms) = 8 ohm load


 4  8 ohm speakers in parallel (2 ohms) then wired in series
with a 2  4 ohm speakers that are wired in parallel (2 ohms) = 4 ohm load
Warning: the 4 ohm speakers will see 2 times the power
that the 8 ohm speakers will see. Make sure they can handle it.


 4  16 ohm speakers in parallel (4 ohms) then wired in series
with a 2  8 ohm speakers that are wired in parallel (4 ohms) = 8 ohm load
Warning: the 8 ohm speakers will see 2 times the power
that the 16 ohm speakers will see. Make sure they can handle it.


12 Speakers
Not a very common set up. but I have been asked how to wire 12 speakers many times.


If you can't get all the loads totally the same
This happens. Your goal is usually to load your power amplifier
somewhere between 4 and 16 ohms (refer to your power amplifiers
documentation to be absolutely certain of its limitations and
never provide a load lower than the system was designed for).
Some can handle 2 ohms. I'm not aware of any that can handle 1
ohm or less.
If, for example, you have a 8 ohm and a 4 ohm cabinet that need
to be connected together  you will need to wire them in Series
and create a 12 ohm load. The 4 ohm driver may be louder than the
8 ohm driver (provided the SPL ratings are the same), but not
necessarily. The important thing to do is to balance the load
as equally as possible and never overload your power amplifiers.
How Much Power is Going to Each Speaker?
If all of the loads are initially the same, then the power is spread
equally across all loads. For example, if you have 2 speakers wired
in Series, both rated at 8 ohms, and you apply 100 Watts to the
load, then the power is equally distributed among the 2 speakers  in
this case, each will absorb 50 watts of power. The same holds true
for speakers wired in Parallel  if the loads are the same, then the
power will be distributed equally  2 speakers wired in Parallel with
100 watts of power applied to them will have 50 watts applied to
each individual speaker driver.
The same holds true for 4 speakers wired in Series, Parallel or
Series/Parallel.
If the different speakers have a different impedance, the lower
impedance load will have more power delivered to it. Its a good
idea to make certain that any given driver can handle the power
you plan to apply to it. I suggest that you build or buy your systems
where all of the cabinets have the same impedance (it will greatly
simplify dealing with them if you suddenly scale up the number of
cabinets that you use).
If you have a different combination of speakers/loads to wire up,
see:
Speaker
Wiring; Impedance Calculator.
This may help you figure out the effects of various speaker system loads.

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 ProAudio applications. We cannot
help you with Home or Car Audio questions.
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