A powered subwoofer is an active loudspeaker that includes a built-in power amplifier to drive the speaker, thus eliminating the need for a separate power amp. A passive subwoofer does not have a built-in amplifier and must be used with an external amplifier.
There is little between them in terms of sound quality, performance, and flexibility. However, using a powered subwoofer is usually more convenient because you do not need to match the sub’s impedance and your amplifier. Both active and passive subs can be designed for very high sound quality.
However, some people prefer to use a passive subwoofer because they believe it sounds better or has less distortion. In addition, there are some benefits to using a passive subwoofer, such as the ability to easily share one subwoofer among two or more systems or amplifiers. However, a passive subwoofer does rarely sound better than an active one – having said that, there are certainly cases where they will not sound as good either.
Are there any cases when it is better to use a passive subwoofer?
There is a long list of these cases when a passive subwoofer will be better than an active one. Let’s divide the cases into two groups: it is practically impossible to use an active subwoofer and another where such a construction of the number of channels may be less optimal than, for example, stereo, but still has its right to exist.
The first group includes cases when the required effect is achievable only using a passive subwoofer, or it comes from deep bass at frequencies below those reproduced by the active subwoofer. For example, it typically occurs in large rooms with a small listening area, where you can not place enough subwoofers on the floor. Or in the cases when the common listening is in a semi-open space, for example, from balconies or terraces, it would be too much effort to carry an active subwoofer.
In this case, it is better to choose a passive solution with long cables from the processor/preamplifier to the loudspeakers and a high-pass filter to exclude deep bass from the main loudspeakers.
The second group includes cases when the required effect is achievable using an active subwoofer. Still, you will have more limitations and probably less optimal sound quality than in the previous case in such a case. Such cases can be seen in smaller rooms where additional subwoofers are not enough.
In this case, it is better to choose an active subwoofer with a low-pass filter set at around 50Hz removing deep bass from the main loudspeakers.
How do you choose between a powered and passive subwoofer?
- It is essential to know that if you buy a passive subwoofer, it will require an amplifier to function.
- Second thing you need to understand is that the power rating of your passive subwoofer and amplifiers should be at least double or more than what would be required to power the drivers/speakers inside the subwoofer.
- The Last thing to understand is that the amplifier will not only power the passive subwoofer, it will also take care of powering all your indoor speakers (floor speakers/rear speakers) as well. So basically, if you are purchasing a large number of indoor floor speakers, consider an amplifier.
- The benefit of buying a passive subwoofer is that it will allow you to have more powerful drivers inside the box, meaning deeper bass. Also, consider that buying an amplifier might cost twice as much as what you would pay for a good quality passive subwoofer.
- The benefit of buying a powered subwoofer is less wiring and a simple connection. First and foremost, it will give you the capability to adjust the output level and crossover frequency settings from your head unit or factory radio.
- Powered subwoofers usually come with a high pass filter that allows only the high frequencies to go through your front and rear door speakers, leaving the low frequencies for the subwoofer driver(s).
- When considering the purchase of a subwoofer, it is essential to consider the size/dimensions of the subwoofer.
