Calculating Final Impedance
02-09-2007, 12:56 PM
#1
2000 Watt CAFz'r
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Join Date: Jan 2001
Posts: 2,026
Calculating Final Impedance
When connecting Speakers in Parallel (All positive voice coil wires connected together to the positive on the amp & all negative voice coil wires connected to the negative on them amp) Follow this formula:
Y= Number of voice coils
X= Impedance of each coil
Take the impedance of each coil (X)
Turn it into a fraction (X/1)
Then reciprocate the fraction (1/X)
Take all of the fractions and add them together (Y/X)
Then reciprocate the facrtion again (X/Y) THis is your final load.
A Practical examples:
6 coils @ 4 ohms each.
4
4/1
1/4
1/4 + 1/4 + 1/4 + 1/4 + 1/4 + 1/4= 6/4
4/6 = 0.6666 ohms
3 coils @ 6 ohms each
6
6/1
1/6
1/6 + 1/6 + 1/6 = 3/6
6/3 = 2 ohms
When connecting the speakers in series (+ from Amp to Coil + Coil - to next coil + ect until the last coil negative returns to the amp)
Very simple. Add all of the voice coil impedance values together.
Using Series and Parallel together. There is no set formula that can be applied here because several combinations can produce different results.
Example:
3 Dual 4 ohm Voice Coil Speakers (6 coils at 4ohms each)
Series first: (4 + 4) (4 + 4) (4 + 4)
Parallel next: (8) (8) (8)
8/1
1/8
1/8 + 1/8 + 1/8 = 3/8
8/3 = 2.666
or
Series first (4 + 4 + 4) (4 + 4 + 4)
Parallel Next: (12) (12)
12/1
1/12
1/12 + 1/12 = 2/12
12/2 = 6 ohms
Or
Parallel first (3 pairs):
4/1
1/4
1/4 + 1/4 = 2/4
4/2 = 2
Series next: 2 + 2 + 2 = 6
It is important to note that each sub needs to be treated equally when combining series and parallel. If the wiring is imbalanced on any individual sub, the output will be adversely affected - The coils on one sub cannot be wired in series and while the coils on another are wired in parallel. This will cause a massive power imbalance between subs. In the above three examples, the subs were treated equally.
These generic formulas can be adapted to fit any application.
Y= Number of voice coils
X= Impedance of each coil
Take the impedance of each coil (X)
Turn it into a fraction (X/1)
Then reciprocate the fraction (1/X)
Take all of the fractions and add them together (Y/X)
Then reciprocate the facrtion again (X/Y) THis is your final load.
A Practical examples:
6 coils @ 4 ohms each.
4
4/1
1/4
1/4 + 1/4 + 1/4 + 1/4 + 1/4 + 1/4= 6/4
4/6 = 0.6666 ohms
3 coils @ 6 ohms each
6
6/1
1/6
1/6 + 1/6 + 1/6 = 3/6
6/3 = 2 ohms
When connecting the speakers in series (+ from Amp to Coil + Coil - to next coil + ect until the last coil negative returns to the amp)
Very simple. Add all of the voice coil impedance values together.
Using Series and Parallel together. There is no set formula that can be applied here because several combinations can produce different results.
Example:
3 Dual 4 ohm Voice Coil Speakers (6 coils at 4ohms each)
Series first: (4 + 4) (4 + 4) (4 + 4)
Parallel next: (8) (8) (8)
8/1
1/8
1/8 + 1/8 + 1/8 = 3/8
8/3 = 2.666
or
Series first (4 + 4 + 4) (4 + 4 + 4)
Parallel Next: (12) (12)
12/1
1/12
1/12 + 1/12 = 2/12
12/2 = 6 ohms
Or
Parallel first (3 pairs):
4/1
1/4
1/4 + 1/4 = 2/4
4/2 = 2
Series next: 2 + 2 + 2 = 6
It is important to note that each sub needs to be treated equally when combining series and parallel. If the wiring is imbalanced on any individual sub, the output will be adversely affected - The coils on one sub cannot be wired in series and while the coils on another are wired in parallel. This will cause a massive power imbalance between subs. In the above three examples, the subs were treated equally.
These generic formulas can be adapted to fit any application.
02-09-2007, 01:11 PM
#2
thats a lot of math lol. I use this Woofer Enclosures - Fraction to Decimal - Parallel - Series - Port Length and Volume Calculators
The links for those with minimal math skillz like me.....
The links for those with minimal math skillz like me.....
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