Subwoofer Power Consumption (Explained)

Subwoofers produce bass by handling the lowest frequencies of the sound waves which requires more power.

Hence, they can draw more power from the amplifiers, especially at higher sound levels or loud volumes.

However, the power consumption also depends on their size, type, sound levels, playtime duration, and how frequently they are used.

In this article, we will discuss the factors responsible for high power consumption and some tips to minimize it to some extent.

So that you can still enjoy your bassy notes with a lesser impact on your power bills.

How much power does a subwoofer consume?

Average subwoofers consume around 50 to 100 watts of power and the numbers will vary depending on their type and how powerful they are (wattage rating).

The more wattage the subwoofer is rated with, the more power it consumes, especially at higher sound levels.

In general smaller subwoofers consume less power compared to larger units.

You can refer to the below table for the general guidelines indicating average power consumption by subwoofers of different sizes.

Subwoofer SizePower consumption (in watts)Comments
8 to 12 inches
Around 50 watts to 100 watts
These units are categorized as smaller subwoofer units with a low power rating.
12-15 inchesAround 100-200 wattsThis specific range are medium sized subwoofers with moderate power ratings.

15 inches and above
Around 200-400 wattsThese are larger subwoofer units that can consume more power in their categories.

More powerful subwoofers can draw more power that can go up to 1000 watts and more.

That being said, the power consumption of subwoofers depends on their size, power rating, and according to your music-listening habit.

What does thermal and mechanical energy mean in subwoofers?

When it comes to Speakers and Subwoofers, there is another crucial factor to consider for their maximum power handling abilities such as thermal and mechanical energies.

Thermal

Some of the energy transferred to the subwoofers and speakers can fail to emit sound and get converted to heat.

Over time, the constant flow of high-level signals can lead to thermal damage further impacting the efficiency of the subwoofer in the long run.

Mechanical

Subwoofer and speaker components have mechanical limitations that should be prevented from exceeding the level.

However, there’s always a possibility that they may exceed by even a very brief power peak.

For instance, a subwoofer or speaker driver will not move in a back-and-forth motion over the excursion limit without mechanical damage.

However, most speaker systems have very different power-handling capacities at different frequencies.

For example; Tweeters can handle high-frequency signals and are physically small and prone to damage more easily.

On the other hand, subwoofers that handle low-frequency signals are larger and more potent.

How do you calculate the power consumption of a subwoofer?

Let us discuss the ways to calculate or figure out the amount of power your subwoofers consume.

Power consumption measurement devices

There are several energy monitoring devices available that can be used to monitor the real-time power consumption of your subwoofer.

One of the most popular devices is the Kill-A-Watt Meter used to monitor the power consumption of most electronic devices.

Let us see how you can go about using this device.

  • Plug the Kill-A-Watt Meter device into the power outlet.
  • Next, plug in the subwoofer to the meter.
  • Play songs and audio on your subwoofer at different sound levels (volumes).

By doing this you will be able to determine the amount of power your subwoofer uses.

Additionally, you can also understand the major factors involved in more power consumption by a subwoofer.

Such as power consumption at different sound levels, frequency ranges, and playtime duration.

Wattage Measurement Formula

Another way to calculate energy consumption is by using the formula Watts (Power) = Volts x Amperes (current).

  • Usually, the voltage can be 120v to 240v supplied by electrical outlets in a home or needed by a subwoofer.
  • To know the amperage rating of your subwoofer you can refer to its owner manual or contact the manufacturer with the model number.
  • Multiply the two to measure the wattage which is the power consumption of your subwoofer.

You will be able to obtain a rough figure on the power consumption and it may vary depending on the usage pattern and the unit efficiency.

Online wattage calculators

There are online websites that can help you figure out the approximate value of the wattage used by a subwoofer.

These websites will allow you to enter a few details such as;

  • The type of appliance such as subwoofer.
  • The wattage rating of your subwoofer.
  • Number of hours you use the subwoofer per day.
  • The amperage rating of the appliances, etc.

The information demanded may vary so does the calculated value.

Why do subwoofers draw more power? AND How do you prevent subwoofers from drawing more power?

Let us discuss the various factors involved in consuming excess power by subwoofers along with some tips to prevent them from doing so.

Prefer using energy-efficient subwoofers

Although energy-efficient subwoofers may initially cost high (purchase cost), they can compensate by consuming less power and saving on the power bills in the long run.

The efficiency of subwoofers is determined by how well they convert electrical energy into sound energy (producing sound).

Tip: You can replace your old subwoofer if it’s no longer efficient and buy a subwoofer considering its efficiency. 

Use moderate volume

A subwoofer can draw more power when you play them at increased volumes.

The longer you play a subwoofer at increased volume will keep on drawing more power from the amp.

Tip: You can avoid playing subwoofers on higher volumes when it is not necessary. Instead, you can keep the volume to moderate levels and still enjoy the bassy notes. 

Avoid overusing the subwoofer

The urge to listen to bassy notes from your long playlist or to feet that boom bass sound effects in movies are typically responsible for playing Subwoofers for longer.

It should be fine if it is infrequent and may not be applicable for many, however, the habit of overusing the subwoofers can lead to overheating problems.

The constant movement of drivers inside the subwoofer can put immense pressure on the overall moving components.

Over time it can cause damage to the drivers, moving parts, or to the entire unit.

Additionally, the time taken for cooling and heating the subwoofer can also lead to additional power consumption.

Tip: A subwoofer can run for longer and keep you entertained by reproducing bassy notes. It should be fine to play them for longer but make sure to avoid doing this frequently.

Let the subwoofer cool down completely at regular intervals or after long sessions if you need it to perform at specific occasions.

Crossover and gains setting on subwoofer amps

Improper gains and crosser settings on sub amps can lead to increased power consumption by the subwoofer.

By applying the right settings you can keep control of the power consumption by a subwoofer.

Additionally, it will prevent audio distortion and keep your power output within your subwoofer’s recommended range.

After setting the sub amp gains you will be able to control the sound system to produce the optimal clarity and improve the overall sound quality.

Tip: You should set the gains and the crossover frequency to a slightly higher range on the amp .

Unplug the subwoofer when idle

Most electronic appliances including subwoofers and audio systems can consume some amount of power in idle mode.

For instance, if you leave the subwoofer powered on or plugged into an electrical outlet without using it, it will still use some amount of power.

Simply put, subwoofers can continue to draw electricity, even if they are not actively used or if they are on standby mode.

Tip: You should make a habit of turning the subwoofers and sound systems off or unplugging them from the power when they are not in use. Especially, if they are not going to be used for longer duration.

This will help you save some amount of energy from being used unnecessarily by your sound system.

Do subwoofers consume power in standby mode?

If you keep the subwoofer plugged into a power outlet without playing songs or in a standby mode, it will still consume some amount of power which can range from around 7 watts to 20 watts.

The amount of power consumed on idle modes will vary depending on the size, type, and specifications of the subwoofers.

To sustain their internal circuitry and features subwoofers can draw power on standby modes.

Hence, you should keep the sound systems unplugged when idle to conserve some amount of energy.

What happens if you leave the subwoofer on?

Leaving the subwoofer on without playing audio can not only consume power but can also risk components of wear and tear due to electrical faults.

Keeping the sound system plugged in can cause potential damage to the electrical components due to power surges or other electrical faults.

It can also adversely impact the environment by contributing higher carbon footprint with increased electricity usage.

It is always advised to keep your electronic appliances including the subwoofers to be turned off when not in use. 

Additionally, you can use the power-saving modes available on most electronic equipment.

Doing this will help you minimize electricity costs, contribute to a more sustainable environment, and extend your device’s lifespan.

Final Thoughts

The power drawing capacity of a subwoofer depends on the wattage ratings and your style and habit of listening to music.

Electronic appliances including the subwoofers in your sound system will draw more power if you do not use them wisely.

Overusing a subwoofer and longer playtime with higher volumes can have a major impact on your power bills.

To prevent unnecessary power consumption by your sound system make sure to use them wisely and disconnect them from power when idle.

Frequently Asked Questions

Do subwoofers consume a lot of power?

The answer depends on your listening habits such as the usage frequency, volume levels (especially higher volumes), and the duration they are used for. Additionally, it also depends on the wattage ratings (the maximum amount of power they can draw during function), their size, sensitivity, and efficiency.

How do you prevent subwoofers from drawing more power?

Prefer installing energy-efficient subwoofers to your sound system and avoid playing the subs frequently at higher volumes. Also, avoid overusing them and keep them unplugged when the unit is idle or simply not in use. Finally, servicing the subwoofers regularly is equally important to maintain its efficiency.

How much power do I need for a subwoofer?

To power a subwoofer, you may need an outlet that can supply more voltage and handle the extra wattage than a regular power outlet. It depends on the power rating and the size of the subwoofer which typically requires 120v to 240v power outlets.

What consumes more power subwoofers or speakers?

Subwoofers with similar power specs such as voltage and wattage typically consume more electrical power compared to speakers. This is because subwoofers handle the lowest frequencies in a sound system that requires more power from the amplifier. Additionally, setting up the subwoofer crossover settings (LPF) to the lowest possible frequency with increased sound level (SPL) or volume will ultimately draw more power.

Armed with a Diploma in electrical engineering and a remarkable 12 years of expertise, he excels in rejuvenating music systems, washing machines, dryers, and laundry-related appliances. Manish's profound insights and practical know-how establish him as a credible authority in appliance and music system repairs. Contact: manish.singh (at) subwooferblog.com. He's always ready to lend a helping hand!