Shavano Music Online

    Speaker Wiring/Loading Examples

    5/98 (Updated 04/99, 08/02, 12/03, 01/04, 09/04 and 05/05) - 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 cross-over 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 cross-over 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 non-inductive power resistors - they are used for tuning power levels to individual speakers in cross-over networks - in this case, they are being used in the same manner as L-Pads - this is done frequently on horns and tweeters. Thats a totally different use. Parts Express sells non-inductive 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 cross-over 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 cross-over for both the high pass and low pass filters are for 8 ohms. Don't mix impedances in cross-overs, its a bad idea.

    If you use a cross-over, 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 cross-over 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 Sub-Woofer 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 Push-Pull/Isobaric alignment. Dual Driver Sub-Woofers 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 Push-Pull/Isobaric alignment. Dual Driver Sub-Woofers 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 Sub-Woofers, 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.

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

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