What’s the difference of watts at different resistance (ohms)?

I’m new to car audio and I’m trying to find out if 500 watts at 4 ohms would produce the same sound levels as 500 watts at 2 ohms. Or would the same sound levels be produced if it was 500 watts at 4 ohms or around 900-1000 watts at 2 ohms? Also, do rms speaker ratings pertain to 4 ohms or any resistance?

5 Answers

  • NCA6.7
    Lv 5
    6 months ago

    Yes, it will sound the same but as your impedance drops lower you’ll be receiving higher current. Avoid cheap amplifiers because they lie about current output.

  • Anonymous
    6 months ago

    It WILL sound the SAME but it will NOT produce 500 watts at 2 ohms or 500 watts at 1 ohm if your amp is stable at 1 ohm.

    Lower impedance produces higher current.

  • 6 months ago

    The short answer is YES.

    500w at 2 ohms would sound basically the same as 500w at 4 ohms (if all other factors remain constant).

    There would generally be some subtle differences, but probably below or only slightly exceeding audible differences.

    Speaker power handling doesn't pertain to impedance. The speaker IS 4 ohms.

    A speaker's impedance is relevant in matching it with the appropriate amp.

    • N2Audio
      Lv 7
      6 months agoReport

      Nice, 3 dumb-dumb voters. Good work folks! ;)

  • don r
    Lv 7
    6 months ago

    It would be easier for you to see this by going to a stereo shop and auditioning equipment on display. Your vehicle won't necessarily duplicate this though since these are different environments, but expect it to be close. The lower the impedance (OHMS) the more CURRENT the amp will draw and produce more power- to the limit of available power the vehicle has. Also amplifiers often have a "stability limit" or ability to draw so much current before overheating or otherwise suffering risk of damage. Another thing useful for you to learn is how much volume of sound at which frequencies you can physically stand without discomfort or hearing damage. Lots of people like to call big numbers- bigger numbers than the next guy and fail the practical understanding of how to use it. If you have a 1000 watt stereo but can only use half of that comfortably did you get your money's worth?

    • Gold Diggers6 months agoReport

      They are LAZY or don't have money to go to shops so they just ask for help on the internet.

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  • On an amplifier, the ohm is the impedance. The lower the impedance drops from the amplifier, more power will be produced. A car amplifier operates on 12 to 18 volts and it operates on 14.4 volts with the engine running. It will operate on 12 volts with the engine off. It's not a good idea to be running it with the engine off. The battery will get very hot, stress out and die within an hour on a 1,000 watt system. Then you're gonna need to jump start it with another car.

    Here's an example to help you understand. The wattage increases as the impedance drop.

    9,000 watts at 1 ohm (18 volts)

    7,500 watts at 1 ohm (14.4 volts)

    4,500 watts at 2 ohm (14.4 volts)

    2,000 watts at 4 ohm (14.4 volts)

    But it doesn't mean the amplifier will give you that much power, your car's alternator needs to be able to produce it. The alternator is also powering other things in your car when the engine is running. When the engine is off, the car's battery becomes the power source. The battery keeps the car's computer alive monitoring the gas level, the oil level, the car's health, and to start up the car's engine. This is why the battery becomes dead when the car hasn't been driven for a long time.

    On a subwoofer, there's a DVC (dual voice coil) and a SVC (single voice coil). The DVC will give you a more wiring option to change the impedance level. Most people commonly go with a DVC. Now, the next thing is the RMS power (root mean square). This is the recommended RMS power that the woofer can be powered with without the voice coil burning out. Ignore the peak power because you don't need to know that.

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