Bass Speakers and Subwoofers

The bass speakers and subwoofers in this category are individual bass drivers without an enclosure or amplifier. You buy them as a replacement part for a PA speaker, subwoofer or bass guitar cabinet, or for building your own speaker. The range includes Celestion and Turbosound drivers, for example the Celestion FTR12-4080DL or the Turbosound TS-15W300/8A. A driver on its own is not a complete speaker system: it needs a suitable enclosure and an amplifier, and, depending on the configuration, a crossover or processor.

How do you choose a replacement bass driver?

The safest option is to replace it with the same part that was originally fitted in the speaker. You'll find its designation on the driver's basket or magnet, in the service documentation or from the speaker manufacturer. A driver with the same diameter but different parameters may sound different in the original enclosure and load the amplifier with a different impedance.

1. Find the exact model or service designation of the original driver.
2. Compare the impedance, for example 8 Ω, with that of the original part and check that the amplifier supports the resulting load impedance.
3. Compare power handling using the same type of rating: continuous (RMS, AES) or peak.
4. Measure the mounting cutout, bolt spacing and depth of the driver.
5. With an active speaker, first check whether the fault lies in the amplifier module or the protection circuit.

A driver for PA, for a subwoofer or for a bass cabinet?

Bass drivers for PA speakers reproduce the lower part of the finished mix and integrate with the mid- and high-frequency drivers via the crossover. A subwoofer driver is designed for the lowest frequencies and for a cabinet built around its parameters. A bass guitar speaker, for example the Celestion Pulse 12, shapes the sound of the instrument, so don't confuse it with a driver for a PA subwoofer. Choose according to the type of cabinet the driver belongs in.

What do you need to build your own speaker?

When building your own, start from the manufacturer's driver parameters (Thiele-Small) and use them to design the volume and type of enclosure, for example sealed or bass reflex. Depending on the speaker design, a bass driver may need a crossover or processor to limit its frequency range; the amplifier must provide suitable power and support the resulting load impedance. The catalogue frequency response applies under the manufacturer's conditions, so verify the result in your enclosure by measuring it.

You'll find high-frequency drivers in the tweeters category, mid-range drivers among mid-range speakers and other service parts in the loudspeaker components category. For a finished subwoofer with an amplifier, look at active subwoofers; without an amplifier, at passive subwoofers.