Amplifier Power & Compatibility
Watts per Speaker
(Used for impedance calc if > 1)
Calculated Load Impedance (Per Channel): 8 Ohms
Recommended Amplifier Power (Per Channel): 200 Watts
Sam Ash Music Flash Deals
Speaker Impedance Calculator (Multiple Speakers)
Total Calculated Load Impedance: 4 Ohms
Diagram: Speakers wired in parallel. Connect all (+) terminals together to the amp (+), and all (-) terminals together to the amp (-).
Sound Pressure Level (SPL) Estimator
Watts RMS
dB @ 1W/1m
Meters
Estimated Peak SPL at Listening Position: 98 dB
(Reference: ~70dB Conversation, ~110dB Rock Concert)
Room Size & Acoustics Advisor
Power Recommendation Based on Room: Consider 50-100W RMS/Channel
Basic Placement Tip: For stereo, try placing speakers equidistant from each other and the listening position (forming an equilateral triangle). Keep them away from corners if possible to reduce bass boominess.

When selecting an amplifier, consider the following:

  • Power (Watts): This calculator gives you a great starting point. The goal is to provide enough clean power to your speakers without clipping (distortion) at your desired listening levels. The "3dB headroom" option is recommended because it provides double the power, which is ideal for handling dynamic peaks in music and movies without distortion.
  • Impedance Compatibility: Ensure the amplifier is stable at the load impedance of your speakers. If you wire multiple speakers to one channel, the total impedance changes. Our calculator determines this "final load impedance." Check the amplifier's specs to ensure it supports this value (e.g., "stable down to 4 Ohms"). Mismatched impedance can damage your amp or speakers.
  • Channels: How many speakers do you need to power? A standard stereo setup requires a 2-channel amplifier. For home theater, you'll need a multi-channel AV Receiver (e.g., 5.1, 7.1).
  • Features: Do you need Bluetooth, a phono input for a turntable, multiple inputs for different sources, or built-in streaming services?

Wiring multiple speakers to a single amplifier channel changes the total impedance load. Here are the two basic configurations:

  • Series Wiring: Speakers are daisy-chained. The (+) of the amp goes to the (+) of speaker 1, the (-) of speaker 1 goes to the (+) of speaker 2, and the (-) of speaker 2 goes to the (-) of the amp.
    • Effect: Impedances add up. Two 8-Ohm speakers in series create a 16-Ohm load.
    • Formula: R_total = R1 + R2 + ... + Rn
  • Parallel Wiring: All speaker terminals of the same polarity are connected. The (+) of the amp goes to the (+) of both speakers, and the (-) of the amp goes to the (-) of both speakers.
    • Effect: Total impedance decreases. Two 8-Ohm speakers in parallel create a 4-Ohm load.
    • Warning: Be careful! A very low impedance can over-stress an amplifier that isn't designed for it. Most home amplifiers are not stable below 4 Ohms.
    • Formula: 1/R_total = 1/R1 + 1/R2 + ... + 1/Rn

Our calculators handle these formulas for you, making it easy to see the final impedance load your amplifier will face.

As an Amazon Associate, AliExpress Affiliate, and Sam Ash Affiliate, I may earn from qualifying purchases. The "Find Amplifiers" buttons will generate a search link on these platforms using your calculated power and impedance. This comes at no extra cost to you and helps support the maintenance of this tool.