How to choose a subwoofer

What do subwoofers do?

Subwoofers are speakers that are dedicated to producing low frequency sounds. This can be anything from the booming symphony timpani to an explosion in Die Hard 2.

Subwoofers typically add sound from 20 Hz to 200 Hz depending on the crossover. The crossover filters out the higher sounds and only allows the low frequency sounds into the subwoofer.

Subwoofers augment a bookshelf system by adding the bass a small woofer can't reproduce and by allowing the 4, 5 or 6 inch mid-woofer do a better job of handing critical mid sounds like vocals and acoustic instruments.

Adding a subwoofer to floor standing speakers can add the extra oomph that fills out the soundstage.


How do subwoofers work?

Low frequency sounds take a lot of air to be created. So Subwoofers work by moving a lot of air! The bigger the speaker, usually 8 – 12 inches the more air it can potentially move. Many LFE (Low Frequency Effects) found in today’s action movies can produce some serious LFE.

How much power does a subwoofer need?

To more lots of air subwoofers require lots of power. As a rule of thumb for each octave you go down you need 4 times the amount of power to create significant volume for that frequency. This does not mean you need a 400 Watt amp for a subwoofer to be effective but this is why subwoofers are equipped with their own amplifiers. In most cases unless you want wall shaking volumes 100 -150 Watt amplifier in a subwoofer will suffice.

Where should I place my subwoofer?

Subwoofers only reproduce low frequency sounds which are omni-directional, which means you can’t tell where they are coming from. This allows you to place your subwoofer almost anywhere in the room you’d like. They also do not produce stereo sound so you only need one.

Types of subwoofers

Down firing vs. side firing. Most subwoofers have one speaker but some have two smaller ones. There will be almost no difference. Some subwoofers have down firing speakers and some have front firing speakers. Again there is little difference in performance. Which you choose depends on the sub's design and on your personal preferences.


Why add subwoofer to my stereo?
As mentioned earlier, if you have large floor standing speakers with a 8 or 10 inch woofer in them you might not need a subwoofer unless you want to hear floor shaking bass a subwoofer can deliver, especially for movies. In most cases if you have a bookshelf speaker system with 5 or 6 inch mid-woofers you will benefit by hearing more of the music or sound effects and free up your bookshelf speakers to do a better job of producing the mid-range music and vocals.
Things to consider when buying a subwoofer
  • How much space do I have to place one?How large is my room? Small rooms 12 X12 or less won’t need a lot of power, 100 Watts should do.
  • Does it have a variable crossover? Most do allowing you to decide what frequency range the subwoofer should handle.
  • Will it bother your neighbors or frighten your dog?
  • Did you check with your spouse? (really, trust me!)

No comments:

Popular Posts