Subwoofer Testing for the Ultimate Sound
One thing most people love about subwoofers is the fact that you can feel the musical emotion directly with your body as the powerful bass streams through the sub with a full, rich sound.
If you’ve decided to get a sub for your audio setup, then you’ll need to learn about subwoofer testing to get the perfect sound, one that’s not too boomy, but enhances your music instead by seriously beefing up your bass.
Fine-Tuning Like a Pro
Tuning and testing your new sub will take some time and effort, in order to get the right bass sound, however, the rewards of a well-tuned sub can be very satisfying.
Before we get started discussing how to tune and test your new sub, if you’re looking for information about upgrading your audio system, you can click here to read our buyer’s guide.
Additionally, if you just brought your new sub home, you’ll also need to purchase an enclosure. Most major brands produce their own lines of enclosures, such as the top selling model the P3-2X12 1200 Watts Dual Rms Subwoofer Enclosure by Rockford Fosgate.
How to Avoid Distortion at All Costs
The first step is setting the speaker level. Obviously, distortion is the enemy. Distortion can destroy eardrums, subs, and speakers. If you’re not familiar with distortion, it sounds like hissing, popping, crunching, and crackling, and it interferes with the distinct sound of a musical instrument. If you use an amp to power your full-range speakers, then it’s crucial that the amp’s gain is set properly in order to prevent distortion.
After setting the amp gain to low, play some music, turning up the receiver until you hear distortion. Now, back off the volume until the music sounds clear. Mark or note where the volume is set at. This is the max volume setting that your receiver can go to and play cleanly.
Next, turn up the gain until you hear distortion once again, backing off slightly until it goes away. the gain is now set, so you can turn down the receiver’s volume until it’s at a more comfortable level. You’ll still need to find your receiver’s max volume point, even if you don’t have an amp.
Adding that Bass
Let’s focus now on testing the sub. Turn the sub’s amp gain to the lowest setting, switching the low pass filter on and setting it as high as it can go. If the sub has a bass boost be sure to switch it off. If it comes with a remote level control, place it in the middle position. This way, you’ll have a choice of cutting or boosting the bass for each individual song.
The receiver’s bass tone control should be adjusted to its flat, zero, or middle setting, whichever it’s called on the stereo. If you have a sub level control, set it to the no gain or middle setting. Some models will have bass boost, low pass filter, or crossover on their sub output. Be sure you switch all of those off as well.
Keep in mind that you should never use bass boosts, crossovers, or low pass filters on the amp and the receiver at the same time. If you do, this can result in something known as phase distortion, which generates around each boost or filter’s crossover frequency, instantly muddying up the sound.
Adjusting the Sub’s Low Pass Filter and Gain
Turn down the volume on your receiver to about one-quarter of the way and switch on a track you’re familiar with. On the sub, turn up the gain until the sound from the sub totally overpowers all of the other speakers without any distortion.
The gain should then be turned up until it distorts, then ease off it until the sound is clean. Still listening to music coming out of the sub, adjust the sub’s low pass filter downward, slowly, until all of the mid and high-frequency notes disappear.
The low pass filter will eliminate notes you don’t want the sub to play. It will also capture the edges of the kick drum’s sound acting like a tone control. Next, filter out the guitars, vocals, strings, and cymbals, leaving the low and bass drums.
Subsonic Filter and Bass Boost
If the sub has bass boost, carefully try tuning it to hear what the drums sound like when you do so. You should apply just a little bass boost gradually. You need to be very careful with the bass boost since this is where distortion is typically introduced into a system. If you note any distortion, lower the gain until it disappears.
In order to tame any overly loud low notes you’ll need to use a subsonic filter for ported subwoofers. This helps to minimize the levels of the notes that the enclosure resonates. You’ll need to fine-tune the filters to make the bass drum sound reverberant and loose or dry and tight. This will be based on personal preference.
It’s time now to bring all of the music into focus now that everything has been set correctly. The next step is matching the sub’s level to the receiver’s volume.
Crank up the volume on the receiver, into the max distortion-free position. Now you can turn up the sub’s amp gain, slowly, until the bass sounds balanced.
Run the level control or bass boost up and down in order to hear what it does. Sometimes, the subs don’t combine their sounds constructively with the rest of the system’s sound waves because of the size of the acoustic space in a car. If your bass seems to lack punch but has plenty of volume reversing the sub’s speaker leads can help. This will reverse the sub’s backward and forward movements, which can pull the sound waves together.