What Makes a Subwoofer Good?
According to King of subwoofers, SVS, choosing a full-range speaker is considered a subjective decision while choosing a subwoofer is considered an objective process. Whether that’s true or not, one fact about subwoofers is that they’re special types of speakers that are quite different from the rest. Most music, blockbuster movies, and live orchestral performances comprise of different frequency ranges.
One of these frequencies is the low frequency that can go to as low as 20Hz. Since these frequencies behave differently as compared to high-frequency waves, a subwoofer hence becomes a vital peripheral in your home theater setup as it’s the one responsible for handling these low frequencies to their specific requirements.
With that said, whether you’re looking for loud bass, tight bass, or just a way to improve the sonic potential of your full-range speakers, here are some factors that make a subwoofer a key requirement.
But First, What is a Subwoofer?
A home theater, home cinema, or a home studio speaker set up comprises of a variety of speaker setups that range from the front/center speakers, bookshelf/tower speakers to the mighty subwoofer. While most of the front speakers handle the mid and high frequencies, the subwoofer, also called the loudspeaker, is tasked to only handle the low-frequency waves which are the bass and the sub-bass frequencies.
Now, the human ear is designed to hear frequencies ranging from 20Hz-20 kHz. Thankfully, most of the high-quality home theaters are capable of reproducing audible frequencies within this range. But, there’s a problem. The low frequencies, which is the deep bass that shakes you up, is quite demanding hence require a special type of speaker to handle it.
Tasking the full-range speakers to handle this type of low-frequency waves will only damage them as they can’t endure the sound pressure level (SPL) of such low octaves especially when played in very high decibels.
Therefore, the subwoofer is quite paramount in your home theater setup as it handles the low frequencies to free-up the rest of the speakers so that they can take care of the full and high-frequencies with ultimate clarity.
Which Qualities Make a Good Subwoofer?
Having explained what a subwoofer really is, I will now move to the next section where I’ll discuss some key qualities that make a subwoofer worth it.
Accuracy in Frequency Response
One of the factors that make a subwoofer a worthy bargain is its high accuracy in reproducing low frequencies.
According to experts, the human ear can hear sounds ranging from as high as 20kHz to as low as 20Hz. With this in mind, most movie and music artists/directors feature special LFEs in their contents to make them more entertaining.
Supposing you’re using your floor standing woofers to handle the low-frequency waves, your woofers will generally reproduce sub-bass ranging from 40Hz to 2500Hz. This means that much of the LFEs falling in the narrower frequency range of below 35Hz will generally be lost and you won’t hear them the way the artists and the producers would have hoped.
But, with a subwoofer, these massive speakers can reproduce extremely low frequencies ranging from 20Hz to 200Hz. This way, they can easily handle those narrower frequency ranges that create the earth trembling effects.
Come in Passive and Powered Variants
Subwoofers come in two variants which are passive and powered subwoofers. To start with passive subs, these types of loudspeakers rely on an external amplifier to sound at their best. What happens here is that you need to first connect the amp to the preamp output of the receiver. This way, the preamp will send clean audio signals to the amplifier for amplification.
Since passive subwoofers require a lot of power to reproduce the low-frequency waves, this type of setup will be necessary. Otherwise, failure to add an external amp means that your subwoofer will not have enough power to reproduce the deep floor trembling bass.
On the other hand, there’s the powered subwoofer. This type of sub is very different from its passive counterpart as it doesn’t require an external amplifier to compensate for the power. Instead, this subwoofer relies on its own inbuilt amplifier which does a decent job of providing the required power to amp up the large driver.
Although its performance is one to be recognized, it doesn’t come without a cost. This type of subwoofer demands an independent power source which means you must plug it on the power outlet for it to work.
A powered subwoofer has its own independent gain and volume controls which are separate from the ones in the receiver. These allow you to tune the subwoofer to meet your required specifications.
The Crossover
Every high-quality subwoofer has a crossover frequency that stands at around 100Hz. In definition, a crossover is an electric circuit that limits the amount of audio frequency getting to your speaker. In most cases, subwoofer crossovers are designed with two filters which are the low pass and the high pass filters.
The high pass filter on its side is designed to direct high-frequency waves towards the full-range speakers while leaving the low pass filter to direct only the low-frequency waves to the subwoofer. By doing this, there will be reduced mix up as each speaker will handle the frequency it’s designed to handle easily without causing any distortion or lack of clarity in the sound reproduced.
When tuning your subwoofer, it’s always advisable that you set the crossover setting at least 10Hz above the lowest frequency your subwoofer can handle. However, if you’re not sure about your sub’s frequency range, you can just set it at 100Hz as that’s the universal frequency range.
It Produces Low Frequencies even at the Highest SPLs
Subwoofers are amazing types of speakers. They manage to reproduce deep heart thumbing bass at high volumes without causing any distortion. Most woofers in your tower speakers are only designed to handle full range frequencies. Tasking them to reproduce deep bass will only make them clip or bottom off.
The reason for this is because such speakers have less powerful drivers that can’t cope with the high sound pressure levels generated. Some lesser woofers even use amplifier limiting to cap the output whenever there are very low-frequency effects. This means that you’ll miss a lot of the LFEs when watching a movie or listening to music.
While this is done to prevent damaging the amp and the driver, subwoofers are designed to handle such situations with a lot of enthusiasm where they reproduce very low frequencies in some of the lowest octaves regardless of the volume level.
Blends Well With Full Range Speakers
I have read several posts where authors have asked potential readers whether a subwoofer is a necessity or a luxury when it comes to audio systems. Although the topic didn’t seem to create a debate at first, I was surprised to find that most customers believed that a subwoofer was just a luxury and it wasn’t an absolute must.
But, if you’re a movie or music enthusiast, then you know how fundamental a subwoofer is in your home theater system. Although it’s designed to only reproduce the low-frequency waves, a subwoofer doesn’t have to be too loud in such a way that it overpowers the full-range speakers.
Instead, it’s supposed to work as a team with the rest of the surround speakers by energizing and pressurizing the room with a moderate amount of bass without drawing any attention to itself. This way, your sub will blend perfectly with the rest of the full-range speakers to create a dynamic and 3-dimensional listening experience.
Conclusion
In conclusion, the idea of what makes a subwoofer good is not about the loud bass it generates but rather the bass representation in terms of how accurately it’s delivered. Since most woofers and full-range speakers can’t handle the low frequencies quite well, the subwoofer is usually the perfect remedy when it comes to generating these low frequencies. So, if you’re a music or a movie connoisseur, then spicing up your home cinematic experience with a quality subwoofer will automatically be an inevitable step.
