When you add a powered sub you'll not only find how much bass you were missing out on, but you'll also get major improvements in the sound quality from your main speakers. Using a powered sub will add to the dramatics your home theater can produce. Making movies more energizing and exciting than before.

Powered or Unpowered
Most subwoofers sold are powered, meaning they have their own onboard amplifier, but there are few subs that come without amplification. Unpowered subwoofers offer little or no advantage in sound quality compared to normal speakers with woofers.

Don't waste your time with any unpowered sub. Budget powered subs can be had for as low as $250. While they won't offer near the bass quantity or quality of more expensive subs, they'll blow away any unpowered sub.

How Big
With subwoofers the rule of "larger equals better" usually applies. In the last couple of years technological breakthroughs have been overcome that allow subs only one square foot in size to play the same level of bass that coffee table sized subs provide. Manufacturers simply add more wattage to get a smaller woofer with more incursion (the distance a speaker cone moves back and forth) to produce the same bass as larger subwoofers.

Sunfire Labs created this design trend, and since then other subwoofer manufactures have followed suit. These subs come in around $1000-$2200 and easily compare with subs in that price range. They offer the same bass from a box that can be easily tucked away out of site.

If you don't want a sub that expensive (or you simply want a monster sub to brag about) there's plenty of subs out there for you. With these subs the general rule of "more" applies. More woofer, more enclosure, and more wattage equals more bass. It's simply a matter of price ranges.

For around $600 you'll find a 10 inch woofer in a modest sized box with 100-150 watts of power. Around $800-$1000 you'll find a 12 inch woofer, possibly with an assisting driver such as a passive radiator, large enclosure and 200-300 watts of power. $1500 and up and were talking about some cranking subs with super large enclosures, 15 inch woofers, and possibly up to 500 watts of power.

The higher priced units don't just equal more bass; they equal better sounding bass. These subs offer more detail while shaking the room. The best "bang for your buck" subs are in the $800-$1200 price range.

The Woofer
This driver should be made of a very durable material with some type of rubber surround to withstand the test of time. Woofer cones will come with many different styles, looks, and designs with each manufacturer claiming superiority due some exotic blend.

Keep an open mind when auditioning subwoofers and judge the looks after you've listened. Many people will let the look of the unit alter their perception of the sound. Subs don't look like anything fantastic and you will probably never look at the driver, except for when you clean the grill. Start with solid listening tests, then base your opinion from there.

Enclosure
The enclosure should be solid and sound with a nice finish to it. Enclosures which feel flimsy and cheap should not be given a chance. There should be plenty of internal bracing to add to the solidity of the unit so the sub won't fall apart from the stresses of playing deep bass. The more solid the unit feels, the better.

Connections
The back of the sub should have many different options for connections and calibration:

1. Left and right RCA Composite ins an outs for connecting from a 'subwoofer out" jack
2. Speaker jacks for connecting the sub between the receiver and the main speakers through speaker cable
3. Volume knob
4. Crossover knob or switch
5. Phase knob or switch

Most subwoofer connections only require a single connection from the "subwoofer out" jack on your receiver and plugging the power cord in. For those who don't have a subwoofer jack you will need to run the main speaker cable to the sub, then from the sub to your main speakers.

The "subwoofer out" connection is the best way to connect a sub to your system. The crossover that's in the sub (when using speaker cable as the connection) can degrade the sound before it arrives to the main speakers. To utilize a digital surround format, using the "subwoofer out" connection is the only way to get the proper bass from digital surround sources. All receivers that have digital surround capabilities offer a subwoofer output jack.

What To Look For
When auditioning different subs you will need to strike a balance. You'll want a sub that sounds detailed and tight while still being able to produce thunderous bass.

Manufactures are forced to balance out what the subwoofer can do. They can either make tight bass or thunderous bass. Really tight subs produce less thunderous sound while overly thunderous designs greatly can take away from musical details and nuances.

Most manufacturers build their subs somewhere in the middle. They try to retain a satisfactory amount of detail combined with decent visceral impact. It's a hard balance and almost every sub will accomplish this differently. Tighter bass will usually sound best for music while thunderous bass is best for movies. You'll have decide which sound you prefer, and hopefully be able to find a happy middle.

What Will Your Money Buy?
Below $600:
You'll find modestly sized woofers, amps, and enclosures that can shake your room decently. You really won't find very articulate sounding subs in this price range. Look for a sub that doesn't have a "muddy" sound quality. The biggest box with the biggest woofer won't always produce best sound in this price range.

$900 to $1500:
Within this range you really get into something nice. You should be able to find a sub that's very articulate while being able to shake the hell out of your room. In this price range bigger usually equals better.

$1800 and Higher:
You'll get bass that'll make it feel like the room is falling apart. It will literally shake stuff off the wall. Don't worry, subs have never been known to cause structural damage... yet.

Suggested brands: (in alphabetical order)

• B&W (www.bwspeakers.com)
• Klipsh (www.klipsh.com)
• M&K (www.mksound.com)
• Paradigm (www.paradigm.com)
• Sunfire (www.sunfire.com)
• Velodyne (www.velodyne.com)

Anyone should be able to find a sub that's to their liking among these companies. It comes down to personal taste as to which type of sub is right for you. Audition them all and have some fun. Happy hunting!