Wattage (power) and driver size are most important when we’re talking about subwoofers. We’ll get to driver size in the next article. For now, let’s talk watts.
Once you have acquired some knowledge of the subject, you know that this figure does not mean much, at least not if it applies to an ordinary subwoofer, and especially if it is supposed to reflect the volume of the music you can listen to in your living room.
Subwoofer wattage is like horsepower in a car. What really matters is how you package and receive it. It has turned into such a gimmicky marketing term, it’s like knowing one small part of the equation, and without knowing the full equation, it’s not really useful at all.
Does wattage impact the loudness and clearness of a subwoofer? When buying, do we just look for the highest-rated sub in terms of wattage in our budget? How many watts make a good woofer?
How many watts is a good subwoofer?
In the field of subwoofers, few values are as associated with nonsense, half-truths, and other scams as performance expressed solely in a number of watts. Indeed, the volume and quality of your favorite music have nothing to do with the flashy figures of the brochures or boring technical sheets. A small foray through the mazes of watts and sound volumes.
The best wattage for a small-room subwoofer is between 100 and 300 watts. Most homeowners find 100 watts sufficient enough. A subwoofer for larger rooms can be 400 watts or 600 watts. For high-end subwoofers, the standard is over 1000 watts.
I looked for the best woofers from the most prominent subwoofer brands on the market to get a picture of average wattage. Here’s the average wattage by size:
| Subwoofer Size |
Average subwoofer wattage |
Recommended sub |
|---|---|---|
| 8″ | 100w | Yamaha 8″ 100W Powered Subwoofer |
| 10″ | 300w | Klipsch Reference R-10SW 10″ |
| 12″ | 450w | Polk Audio PSW505 12″ Powered Subwoofer |
| 15-16″ | 1500w | SVS PB16-Ultra 1500 Watt 16″ Ported Cabinet Subwoofer |
The sub amplifier wattage is only one spec of the whole system. Two subwoofers rated for the same wattage could be very different because of how sensitive the drivers are, how large they are, how large the enclosure is, what it’s tuned for, etc. The measurement of the full system is what’s more important in comparison, especially in extension and output.
Different organizations establish the norms for subwoofer power handling ratings. These organizations include Electronics Industries Alliance, the Audio Engineering Society, and the International Electrotechnical Commission. The different rating criteria confuse people, so most folks don’t understand watts in subs.
- The performance of a subwoofer is measured in watts.
- The amplifier provides the subwoofer with the necessary power.
- In audio systems, Watt-RMS is sometimes specified in addition to output power.
- The watt specification for subwoofers always refers to their load capacity.
- The load capacity of the subwoofers and the performance of the amplifier should always be matched.
Watts and loudness in subwoofers
Wattage hasn’t got much in common with loudness – particularly in the last 5-10 years when it’s just a number listed by the subwoofer manufacturers who are essentially straight-up lying to persuade uneducated customers that the higher the listed wattage, the louder the sub.
Sensitivity, layout, build, and straight-up truthful numbers are more important to loudness than wattage.
When I was selling subwoofers, people were afraid of buying subs with a big number of watts. Today I get the same questions from my friends and acquaintances that show the same thought process. They all think that subs with more watts are louder. And that’s WRONG!
What’s crucial is that a 500-watt sub isn’t necessarily louder than a 200-watt sub.
If you just want an idea of how loud a subwoofer is by its wattage, assume that almost anything under 100 watts is best used for bedroom listening and small spaces. 100 to 300 watts should be good for small to medium-sized rooms. 300 on up should be good for larger rooms or open-concept spaces.
Regarding the listed specs, it would be best to concentrate on Max SPL – which is measured in decibels.
The decibel system is based on units of 10 which means that one decibel is the amount of noise the human ear can detect, and every ten decibels is twice as loud.
I recently got a master’s degree in acoustical design, and one of the main questions I got from my friends who are into listening to music and/or having a home theater is, “what’s better, 1 large or 2 small subwoofers?”. In the linked article I explained all you need to know.
90db is twice as loud as 80db, and 80db is four times louder than 40db.
The relation between wattage in a subwoofer amp and decibels is not linear. We need ten times the wattage to reach a 10 dB gain, which is twice as loud. Doubling the watts is approximately a 3 dB gain. A 1000-watt sub is only twice as loud as a 100w sub if everything else is the same.
Wattage is basically a measurement of heat. The output wattage is frequently used to explain how loud a sub is because it measures the power that it is putting out.
You also need to look at RMS (continuous) power – the true power that a subwoofer can handle or a power amp can deliver. Then there’s practically insignificant Peak power.
Unfortunately, stores like to lie about the RMS performance and promise much higher wattage than the power amplifier can really handle or the subwoofer can really handle.
For example, I tested and compared SVS SB-3000 vs. SB-4000 to give you the most accurate comparison of these two series. These are the rare subs where manufacturers don’t lie about RMS.
Even those listed by the manufacturers are twisted and not real-world numbers – they are frequently calculated “theoretical” numbers.
Partying in your home and cranking the subwoofer as loud as it will go with a dB meter will give you a more reasonable idea about the loudness of the subwoofer than the listed wattage.