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Speaker Impedance

Combine speakers in series, parallel or series-parallel and I compute the total impedance, the power each one receives and whether the load is safe for your amplifier (minimum stable).

How are they wired?

Parallel: impedance goes down (Z/n). Series: goes up (n·Z).

Ω

Nominal impedance of each speaker. Typical values: 4, 6, 8 or 16 Ω. All equal.

units

Total number of equal speakers connected to this amplifier output.

W

Power the amp delivers into the resulting total impedance. With equal speakers, each gets an equal share.

Ω

Lowest load your amplifier tolerates. Home units: 4 Ω. Robust / class-D amps: 2 Ω. Below this the amp may overheat or fail.

Examples
redzilla.cl — impedance
 
Total impedance
Power per speaker
Headroom over minimum
Z total
W / speaker
Config

Impedance by count

SpeakersZ totalvs minimum

your current configuration · in parallel the impedance drops as you add speakers.

How it is computed · series, parallel and safety

1. Series: impedances add up. Z = Z₁ + Z₂ + … + Zₙ. With n equal speakers of ZZ·n. Example: 2×8 Ω = 16 Ω.

2. Parallel: reciprocals add up. 1/Z = 1/Z₁ + … + 1/Zₙ. With n equal → Z/n. Example: 4×8 Ω = 2 Ω.

3. Series-parallel: you build G groups in parallel, each with N speakers in series. Zgroup = N·Z and Ztotal = Zgroup / G. Example: 4×8 Ω in 2 groups of 2 in series = (2·8)/2 = 8 Ω.

4. Power: the amp delivers P into the total impedance. The voltage across the load is V = √(P·Z). With equal speakers the power splits evenly: each one gets P / n.

5. Safety: if the total impedance falls below the amplifier's minimum stable load, current rises and the amp can overheat, go into protection or fail. Always keep the load the manufacturer's minimum.

Resistive model (nominal impedance, equal speakers). Real impedance varies with frequency; use the nominal value as a design reference.

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