Why Subwoofer Break-In Matters

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HDX418 Surround. The surround will loosen up a little bit during break-in, which results in better subwoofer performance. become more plaint
The surround will loosen up a little bit during break-in, which results in better subwoofer performance. become more pliant

Subwoofer Break-In means better bass and longer life for your car audio system.

Some claim that subwoofer break in is a myth. 

SoundQubed subwoofers are built to last for years to come, not just built to be sold. To get a full life out of these subs, you’ll need to break them in. 

Your new subwoofer is a low compliance driver, with extra stiff suspension that needs to be loosened a little bit to perform its best. Our subs are designed to provide high levels of control in ported enclosures.

Compliance is the ‘springiness’ of the driver and describes how easily your suspension can be compressed. 

Break-in softens the resins in the spider and causes them to break up a little bit. 

HDX418 Spider and Cone, Medium Close-up. For best performance form your subwoofer, proper break-in is essential.
HDX418 Spider and Cone.

The spider serves a dual purpose: It centers your voice coil in the gap and using force, keeps it in place. 

During break in, woven fibers that comprise the spider begin to stretch out while the surround becomes more pliant. 

After they’re broken in, you’ll be able to play lower, with a greater dynamic range, and with better efficiency than before break-in. 

This will translate to a better excursion and a lower Fs. 

Fs, or free air resonance, is a representation of the resonant frequency of the driver or the frequency at which the driver has the highest output at the lowest power input. 

After break-in, the dynamic range will extend and you’ll get better output at lower frequencies at the same power as before the break-in. 

The volume of air inside the box serves to “stiffen” or reduce the compliance of the driver. 

Stiffening of the overall compliance causes the driver resonance frequency (Fs) to decrease.

You don’t need to possess an audio engineer’s understanding of the Thiele-Small Parameters to appreciate the change that break-in will have on your subwoofer.

You’ll notice the subtle difference as it slowly plays lower and louder on the same power as pre-break-in. That is because of the spider and surround softening. 

Ready to break your new subwoofer in?

Close up image of the HDX418 Spider. The resins in the spider will break up and soften a little bit during subwoofer break-in.
Close up image of the HDX418 Spider. The resins in the spider will break up and soften a little bit during subwoofer break-in.

Subwoofer break-in involves playing them on music at a low volume or by playing sine sweeps.

There are two ways to break your new subwoofers in. 

You can break them in without an enclosure (free air) or in an enclosure. 

Enclosure Subwoofer Break-In

If you’re breaking them in inside the enclosure, simply play music with a clean signal at a moderate volume while you’re in the car.  

Be mindful not to play outside the bandwidth of your enclosure. For instance, if your enclosure is tuned to 34 Hz, playing 20 Hz bass during break-in will result in undesirable performance from your subwoofer.

Depending on how much drive time you get in, you’ll want to keep the volume low for several weeks, or for 24-48 hours in total play time. 

After this low volume period, adjust your gain from low to medium. 

Apply the same power to it as before break-in and note how much further the surround is moving. You should be able to hear how much deeper the subwoofer is playing now.

Free Air Subwoofer Break-In

Subwoofer Break In Table. If you are breaking in your subwoofer using the free air method, this will make life easy!
Free Air Break-In Table

If you’re using the free air break in method, you’ll need the folowing:

  • Tone generator or tone generating app
  • Amplifier
  • Spare head unit
  • Batteries
  • Power supply
  • 3.5mm to RCA connection
  • Solid, BREATHABLE surface

Connect your amplifier to your source unit, like your phone or computer, as well as to your new subwoofer.

Now play the tone you’ve chosen to break the subwoofer in.  We typically use 25 Hz for breaking woofers in. 

Since there is no air spring pulling the suspension back into place, it will be capable of further and further excursion as the surround and spider soften.

Table for free air subwoofer break-in.
Subwoofer Break In Table. If you are breaking in your subwoofer using the free air method, this will make life easy!

After about 24 hours of break-in time, install it in your enclosure and enjoy the bass!

Failure to break your new Soundqubed subwoofer in may result in a blown sub and an RMA.

Next time, we’ll cover Voice Coils and why Dual Voice Coils matter.

If you need help installing your first amplifier, are curious about upgrading your door speakers, or want to know more about what makes a Monoblock Amplifier different from a Multiple Channel Amplifier, check out the Knowledge Base!