Home Subwoofers

Home subwoofers are dedicated speaker to supplement bass reproduction of your main speakers in the lower frequency ranges below 80-120Hz.

Although our human hearing allows us to perceive lower frequencies, true bass performance (bass that can be felt rather than just heard) is underlying simple physical rules - namely woofer diameter, cabinet volume and thereby size of the loudspeaker.

Here's where home subwoofers come in.

They become desirable as an"add-on" when you're seeking a truly lifelike home theater experience with deep bass.

Also for stereo, your existing fullrange speakers might benefit from adding a good subwoofer, especially if you own rather smallish bookshelf speakers and miss serious "bottom end".

In a word -- if you love deep, powerful bass, why not build a subwoofer?

Before we get started, let's explore the "guts" of a subwoofer:

Essentially it's made of a large woofer with a diameter anywhere between 8 and 40 inches built into a dedicated cabinet (usually a cubic one). The enclosure itself can be either bass-reflex or closed. Because of the large woofer size, it's capable of moving lots of air making low frequencies truly tangible.

By the way -- low frequencies below 100Hz are non-directional. Once properly set up, you won't be able to detect the position of your subwoofer.

Modern subwoofers are normally powered or "active" devices, meaning they have their own built-in dedicated amplifier plus adjustable filter electronics (often fitted on the rear panel of the speaker box) No extra juice is drawn from your main power amplifier. Plus they allow you to fine-tune various aspects such as gain or phase from front or rear panels knobs. All of the above accounts for a smooth integration into your audio/video system.

To see how you hook up the subwoofer to your home entertainment system, check out my wiring diagram

Which Drivers or Woofers should you pick?

Pick a woofer by range of application and room size. For home theater, you want a woofer with the following attributes:

  • Transmitts frequencies as low as 20Hz
  • Suitable for high sound pressure levels

    For music, your criteria is likely different as you probably won't need high sound pressure levels. Rather choose a "fast" woofer. Reviews often state whether a particular driver is recommendable for music or home theather.

    Next, choose your favorite driver based on your room size. Use my home subwoofers selection table as a rough guidance:

    Room Size

    Woofer Diameter

    6-16 m2

    22 cm
    20-30 m2 30 cm
    30 m2 or more 38 cm

You might want to start by picking a complete kit for your very first home subwoofer project. Click here to compare complete home subwoofer kits
including cabinet for less than $300!

Making your Own Custom Speaker Enclosure

Home Subwoofers are more or less cubic boxes but here's where your creativity is demanded. If you start with a fully developed and engineered subwoofer design, which I personally recommend, then you can already begin to build your own woofer enclosure right now.

Start by calculating the cabinet dimensions. Don't worry, this isn't terribly hard to do. Manufacturers often quote the recommended enclosure volume in litres. Simply follow the instructions of the woofer or kit manufacturer for best results.

 

 

Example of a pre-built subwoofer cabinet

Sounds like plain sailing? Of course you can cut your own path by developing home subwoofers concepts from scratch but you'll need tools of the trade to get good results. For starters I recommend reviewing some professional enclosure design software packages. Be prepared for other investments, too and bring lots of patience.

How to Build Subwoofer Amplifier and Filter?

This is an easy one!

The DIY market already offers a broad array of nice integrated and ready-to-run modules combining the crossover filter and beefy amps capable of delivering 100 Watts or more.

Don't skimp on the power ratings and shop for an appropriately sized module with reasonable quality. Remember that you can never have enough power but way underpowered modules could potentially damage your precious home subwoofers!

Click here to browse a huge selection of inexpensive, ready-to-run subwoofer amplifiers

I would recommend something capable of delivering 100W into 4 Ohms but to be on the safe side, I'd double this rating for rooms larger than 20 square metres.

Amplifier modules based on newer Class-D technology are a good choice, too because of economical pricing and low heat dissipation. Entry-level models can already be had from approximately $150.

You could also buy a separate subwoofer filter and use a spare amplifier (or get a cheap PA amplifier if you're on a budget).

Separate Crossover Filters and Amplifier

Instead of using built rear-panel mounted subwoofer modules containing crossover filter and power amplifier, you can also buy these components separately. Dedicated filter electronics often utilize better, higher quality parts, offer more advanced features such as room correction or DSP-based digital equalizers. One prime example of a good DSP is the Behringer DEQ2496 Ultracurve Pro Digital which has been highly acclaimed among audiophiles featuring the famous 24-bit DA converter chips by AKM!

  Behringer Digital EQ Processor DEQ2496

  • AKM® 24-bit/96 kHz A/D and D/A converters and SHARC® DSP's

  • 113 dB dynamic range

  • AES/EBU and S/PDIF inputs and outputs (XLR and optical)

Buy the Behringer DEQ2496 Ultracurve Pro Digital for just $299.99 at Parts Express

For its asking price, the Behringer is a steal IMHO. If you plan to add room correction or equalizers to your system anyway, they are worth the extra expense. Integrated subwoofer modules are more economical because power-supply and enclosures can be shared by the amplifier and filter. If you own an AV-amplifier with built-in lowpass filter, you could get away by just buying an external amplifier to power your subwoofer directly.

What if you've got an A/V amplifier with "LFE" of "Sub Out"? Cool! You can probably forgo the extra expense of a crossover filter but you may still need a power amplifier as shown in my subwoofer wiring diagram. Connect your subwoofer to your preamplifier using Y-cable or to an AV-amplifier's "Sub Out".

Other Subwoofer Related Tips


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