The Role of Digital Signal Processing in Preventing Speaker Failure
published onMarch 19, 2012

Did you have a few nail-biter moments prior to Superbowl Sunday, or were you confident your sports bar or nightclub’s audio systems would perform as expected? The only tension during big events should be whether or not the home team is going to win — not if your audiovisual systems are going to successfully broadcast the game on every screen, with sound going to every speaker in the house.

In this article, we’re going to talk about 5 ways you can prevent speaker failure, so your guests are sure to hear everything from the roar of the crowd during that final touchdown to the tense silence in the last minute of the game.

But first, a few words for non-technical users regarding how amplifiers work to keep you from blowing speakers.

How Speakers and Processing Work Together

Along with your speaker boxes and amplifiers, your audio integrator will also install system processors. It’s the sound systems’ processing limiters that protect speakers from signal levels that could cause failure or degeneration. A properly calibrated system will react to signal peaks before they can damage the loudspeaker.

In the past, when this occurred, users would hear and see a number of cues that the system was being driven too hard.

    Amplifier clipping would cause distortion

  • The speaker would sound distorted
  • Various displays on the amplifier would signal that something was not quite right

However, today’s digital signal processing is so effective at limiting peaks silently, you may not realize the speaker’s being driven too hard until the amplifier or loudspeaker blows. A speaker on overdrive for prolonged periods gradually increases its average power levels. If this goes on too long, the speaker’s transducers experience thermal damage and the speaker stops operating.

How can you prevent this with digital signal processing?

1. Turn down the drive level when you see peak limiters repeatedly activated. Play close attention to the high-frequency limiters, since these are more likely to activate.

2. Talk to your audiovisual contractor to make sure your software, firmware and presets are up to date. Using the latest firmware and its accompanying software not only ensures better performance for your speaker system, it ensures you have the latest technology for peak limiting to protect your speakers from thermal failure.

3. Use the right limiter thresholds for your amplifiers. – If you update or upgrade an amp, make sure the limiter thresholds are changed, too. Your audiovisual specialist can make sure the thresholds are set properly for your sound system.

4. Aim your speakers properly. – Improperly aimed speakers may cause your operator to drive the system to hard to reach the desired SPL. If you’ve recently moved seats in your venue or made renovations and speakers are no longer reaching the spots where you need sound, call your audiovisual installer to make the appropriate changes.

5. Make sure you have enough speakers and amplifiers. – If you don’t have enough speakers, it stands to reason that you’ll turn up the SPL to cover the space at the volume required. Rather than risk blowing your speakers or amplifiers, make sure you have a big enough system to cover the room.

Ideally, you don’t want to think about the speaker systems in your venue, but it’s important to be aware of situations where you could be over-driving your system and risking thermal failure. If you’re not sure if your speakers are performing properly, call an experienced audiovisual contractor and have the pros check it out.