How to set a subsonic filter on a car amp?
A subsonic filter is used to remove very low-frequency noise from the audio signal going down your car’s speaker wiring. This can be a problem with some aftermarket head units because they often have high output voltage at very low frequencies.
The subsonic filter will block these from getting passed to the speakers and cause damage. It also ensures that clean sound from your music is brought to them without being distorted by deep bass, which the subsonic filter has stopped.
If you turn up an amp with no subsonic filter on it too loudly, you risk blowing your speakers. Even if you have a separate subwoofer powering them!
So how do I set my amp with a subsonic filter on it?
To set an amp that has a built-in subsonic filter, all you have to do is turn the Bass Control gain down. For example, turn the volume up while playing a song and turn the Bass Control Gain down until you can hear the bass cut out intermittently. Then adjust your gain to get a good clean sound from your music without blasting your speakers off your trunk.
If you don’t have an amp with a built-in Subsonic Filter, then what to do?
To make use of an external Subsonic Filter for use on our amps:
1: Disconnect either speaker wire from one of your amplifier’s channels and run it directly into the input of the Subsonic filter, then connect the output of that filter back into the same channel on your amplifier.
2: Connect ground to ground and positive to positive at all times.
3: Set the subsonic filter’s cutoff frequency control knob to the unit’s frequency that says “cut off.” For example, if it says “40Hz cutoff”, you should set it so that 40Hz is where bass cuts out in your tunes. If you don’t understand what we meant by this, look up an installation guide for Subsonic filters or test them yourself with a CD player.
4: Make sure you’re using proper gauge wire (18-22g) between your amp and sonic filter. A thicker wire can take more power without blowing.
5: Make sure the subsonic filter is grounded to a piece of metal that conducts electricity very well, like your car’s frame or an amplifier mounting bar.
6: Plug all equipment into proper electrical outlets (amps and subsonic filters into a wall outlet). If you didn’t grasp how to do this, find someone before doing it yourself. You might kill yourself.
7: Turn up your amp‘s gain until you get a good clean sound from your music. Cut off any excess bass which distorts by turning down the subsonic filter cutoff frequency knob until bass cuts out in your tunes. Now turn the gain even higher until you can hear no more bass.
It’s that simple. Now you should be able to not only hear your car audio well but feel it in the passenger and trunk area as well.
How does a subsonic filter work?
A subsonic filter is a type of electronic device which helps to control the amplitude or volume of notes played on the LFE channel at low frequencies. This reduces crowd noise and allows the lower frequencies sound to come through clearly.
Why would I want a subsonic filter?
A subsonic filter is beneficial for someone with an app that doesn’t have a built-in low pass filter or wants to protect their car’s speakers.
If you run an aftermarket head unit with high output voltage levels at very low frequencies (20-30Hz), the added voltage can cause damage to your stock speakers. The extra voltage causes increased excursion in speaker cones, leading to smoke and dielectric failure.
This will not only remove your warranty but prevent any chance of getting help from the manufacturer when repairs are needed. A subsonic filter will keep excess voltages at very low frequencies from getting through to your speakers.
Can any amplifier have a subsonic filter added to it?
No, only amps made for car audio usually have subsonic filters built into them. If you turn up an amp without subsonic filtering capability, you risk causing damage to the speakers, even if you have a separate amplifier powering them. It is because serious head units today can create high voltage at very low frequencies (20-30Hz).
The extra voltage causes increased excursion in speaker cones, leading to smoking or dielectric failure. This will not only cancel your warranty but prevent any chance of getting help from the manufacturer when repairs are needed.
How do I know if my car audio system has a subsonic filter in it?
You can usually see an adjustment knob marked ‘subsonic’ on most amps. It is the circuit that filters out deep bass frequencies. However, some amps don’t have this control. They come with subsonic filtering. Ensure that the amp doesn’t run at full power unless you know that there is no risk of blowing your speakers.
Look for a switch labeled “Subsonic” or something similar on factory head units. If it has one, switch it on! Some cars will come with an adjustable EQ (equalizer). Which also includes this function. So make sure to take a look through your manual to see if it’s there.
What does the subsonic filter do?
The subsonic filter is found on almost all car amps and can filter out very low frequencies, typically below 20Hz. This keeps their amplifiers from pushing extra power into speakers, which can cause damage.
The same effect happens even when a factory head unit moves high voltage at these frequencies. Although this doesn’t usually affect stock speakers as much as if an aftermarket amplifier was driving them. The added voltage causes increased excursion in speaker cones, leading to smoke and dielectric failure. A subsonic filter will keep excess voltages at very low frequencies from getting through to your speakers.
Conclusion
By removing frequencies below 20Hz, the subsonic filter on your car audio system keeps extra power away from your speakers. The added voltage causes increased excursion in speaker cones, leading to smoking or dielectric failure. It will void the warranty and prevent any chance of getting help from the manufacturer when repairs are needed.
Thank you for reading our article How to set a subsonic filter on a car amp. We hope that the information we passed along was helpful and will help you in some way, shape, or form. Please feel free to revisit us for more informative articles, reviews, and guides.
