Tip & How-To about Car Audio & Video

# How to calculate impedance in multiple speakers.

The ohms value is determined by the equation product /sum if the speakers are parallel,and addition if they are in series.
For example, you have two 4ohm speakers,and they are hooked up +to+ and _ to _. it will create a 2ohm load.The product or multiplication factor is 4x4 divided by 4+4.
16ohms divided by 8 equals 2 ohms.

A series configuration is different : if two 4ohm speakers are in series,where the _of one is connected to the + of the other,you have to add the two values hence 4+4 will make 8ohms. When you reduce resistance,you draw more current and create more wattage as long as the amplifier can deliver that current.A higher resistance draws less wattage,but will not shut down the amplifier.
Unless an amplifier is designed to drive a 2ohm load,it will shut down or burn out.Always follow the recommended speaker impedance.

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## Related Questions:

### i have a punch 1000 amp and 1 l7 15 and i need to find out how i can get it wired and adjusted to 2 ohms please

I am not familiar with "I7 15" but will assume it is a speaker. Please correct me if I am wrong. As for the amp setup:
The amp output impedance is not adjustable. The amp is rated at 1 ohm which means you can connect any amount of speakers onto the output as long as the sum total of the load you connect to the amp is not less than 1 ohm.
Speaker impedance is also not adjustable but the total load connected to an amp can be altered by altering the way the speakers are connected to the amp.
The formula for calculating impedance looks very complicated but is quite simple.
First you have to understand the difference between series and parallel connections.
See diagram.
Series: Connecting 2 or more speakers by using the negative on one speaker connected to the positive on the next speaker.
Parallel ( // ) : Connecting the positive of a speaker to the positive of the next and the negative of the speaker to the negative of the next.

Connecting speakers in series is handy when you have two 500 watt speakers for instance and want to run them off an 1000 watt amp. Connecting them in series will assure that you dont over power the speaker and damage it. When connecting speakers in series the total of the impedance of the speakers is the impedance of each individual speaker added together. In our example the total impedance will be 2+2+4=8ohm
The parallel connection impedance calculation is a bit more complex.
1/Rtotal = 1/R1 + 1/R2 + 1/R2
1/Rtotal = 1/2 + 1/2 + 1/4
Rtotal = 0.8 ohm

If you have Microsoft Excel installed in your computer you can enter the following formulae as shown into the spreadsheet. After entering the formulae you must enter the values of the speakers into fields A2, B2 and C2 and it will calculate the total impedance for you.
Using less speakers just remove C2 from the formula.
Using more speakers add for instance D2 into the formula
For your specific amp make sure the load you connect is not less than 1 ohm. It is safe to connect more than that but using less will result in the amp protection circuitry to be activated.
If you use one speaker only then there is no adjustment to be made.
Your particular amp can also connect to an additional amp( and speaker) by using the "PASS-THRU" connectors. This saves you from using an additional set of signal wires from the head unit.
I hope that you now have a better understanding of amp wiring.
If you like you can leave a comment with the specs of the speakers you want to use (wattage and impedance) and I will draw up a diagram for you to use when wiring the system.

Nov 12, 2010 | Car Audio & Video

### the resistance of 2 coils is 25 ohms when connected in parellel and 6 ohms when connected in series. determine the resistance of the 2 coils? (i nedd the working also)

equation for series R1 + R2 = 6 equation for parallel 1/R1 + 1/R2 = 1/25 substitute first equation for R2 in second equation: 1/R1 + 1/(6 - R1) = 1/25 I will leave the algebra solution to you.

Oct 01, 2010 | Cycling

### how do i install my L5 solo barics to a 2 channel amp if there is only one connection on the enclosure next to the vent? If I bridge the amp to 1x1000W will the power distribute evenly between both speakers?

Option 1 (parallel) = 2 ohm load
Speakers wired in parallel
Recommended Amplifier: Stable at 2 or 1 ohm mono
Option 2 (series) = 8 ohm load
Speakers wired in series
Recommended Amplifier: Stable at 4, 2, or 1 ohm mono
Option 1 (parallel/parallel) = 1 ohm load
Voice coils wired in parallel, speakers wired in parallel
Recommended Amplifier: Stable at 1 ohm mono
Option 2 (series/parallel) = 4 ohm load
Voice coils wired in series, speakers wired in parallel
Recommended Amplifier: Stable at 4, 2, or 1 ohm mono Option 1 (parallel/parallel) = 0.5 ohm load
Voice coils wired in parallel, speakers wired in parallel
Recommended Amplifier: Stable at 1/2 ohm mono
Option 2 (series/parallel) = 2 ohm load
Voice coils wired in series, speakers wired in parallel
Recommended Amplifier: Stable at 2 or 1 ohm mono
Option 3 (series) = 8 ohm load
All voice coils wired in series
Recommended Amplifier: Stable at 4, 2, or 1 ohm mono
Option 1 (parallel) = 2 ohm load
Speakers wired in parallel
Recommended Amplifier: Stable at 2 or 1 ohm mono
Option 2 (series) = 8 ohm load
Speakers wired in series
Recommended Amplifier: Stable at 4, 2, or 1 ohm mono
Option 1 (parallel) = 2 ohm load
Speakers wired in parallel
Recommended Amplifier: Stable at 2 or 1 ohm mono
Option 2 (series) = 8 ohm load
Speakers wired in series
Recommended Amplifier: Stable at 4, 2, or 1 ohm mono

Apr 09, 2010 | Kicker Solo-Baric L5 Car Subwoofer

### can i have more than one speaker coming from the same out output

Yes! The speaker outputs will have an impedance rating from 4Ʊ to 16Ʊ. If you have two speakers that are rated at 8Ʊ they can be wired in parallel for 4Ʊ total or in series for 16Ʊ total. You can even connect more speakers in a series-parallel circuit, say four to result in a sum of 8Ʊ, 16 speakers to result in 8Ʊ and so forth! Study Ohm's Law and you will see how the circuit looks. Series connection for example will have the + lead from one speaker to the - lead of the next then the + of that speaker back to the - of the first speaker. Parallel is just that + to + and - to -. Series parallel is just a combination of the two circuits. If you have a several speakers of the same size within a single cabinet that are all in phase it is like one giant speaker as it is the air moved that makes the sound. Bose speakers phased-arrays use a sophicated application of this principal to get awesome bass with less distortion than one big woofer. Do not go under or over the impedance rating or the amp could suffer. Fusing can help.

Nov 08, 2008 | Audio Players & Recorders

### help on 1 amp and 1 alpine srw-124d

You have dual 4-ohm coils. 2 coils per speaker.using one speaker, if you take and run the postive from one coil and connect it to the negative of the other coil, then take a wire from your bridge channel on your amp and connect the positive to the the remaining positive on the one coil and connect the negative to the remaining negative on the other coil you will create a 8ohm load on the amp in bridged mode.

now this is the important part. The bigger the load on the amp the greater the wattage output to the speakers. This sucks the wattage out of the amp. Careful not to overload you amp. The setup above is safe for any amp. The following is for 2ohm stable amps only. The lower the ohm value 2, 4, 8 and so on, the greater the load on the amp.

connect the positive of one coil to the positive of the other. connect the negative of one coil to the other negative of the other coil. then take a wire from your bridge channel on your amp and connect the positive to the the positive on one coil and connect the negative to the negative on the same coil and you will create a 2ohm load on the amp in bridged mode.

Series = add the two ohm value
parallel= halve the ohm value

you can play with series and parallel together using more than one speaker setup.

Jun 07, 2008 | Alpine Type-R SWR-1242D Car Subwoofer

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