Building an affordable home theater: 4.0 Choosing a Subwoofer

Choosing the right subwoofer is imperative to the quality of your home theater experience. For this reason, most home theater in a box setups don`t cut it. This is because not only are the speakers usually substandard or inferior, but the Subwoofer is even more so. The subwoofer can compensate for your main speakers inability to create low frequency sounds (usually from 20-20,000hz) that movie sountracks produce. These sounds can be anywhere within audio from voices, music, weather or crashes and booms from explosions, etc. The accuracy of that sound is what makes all the difference. Garbage just sounds boomy and muddy.

I have mentioned previously the concept of timber matching. This is when you buy all the same series of speaker so the construction, enclosure(box) and materials are all the same. This way the speakers were all built to work together and there is less need for tweaking to make the sound reproduction accurate to your ear. If you have good speakers then I would recommend buying the sub that is made by the same manufacturer and if possible the same series of speakers. However, if you have less then high quality speakers then a good sub can make the difference or improve the experience you may or may not be experiencing as of yet.
Personal preference can make a huge difference and sometimes you just cant put a sub into your system due to loudness constraints that make it not feasible. Sometimes if you have high quality speakers the need for a
sub can be diminished. For example I have a 7.1 JBL Northridge series of speakers that have 6 inch woofers in each speakers that are capable of creating quite a range of bass. As a result, you technically could get away without it but I can`t just because I require the full range for my listening pleasure.

Now with all that being said, consider this fact when you buy speakers. If you want the full movie or music experience, you need a sub. If you just can`t or won`t do it, make sure you buy speakers at least for fronts (bigger woofers) that can create some range of bass so you`re completely wasting your money on your home theater.

I think the most important thing to consider about sub-woofers is how does it work with your current system. The easiest way to choose one as I`ve explained previously is to buy the matching sub with your current speakers.

There are other things to consider. Firstly, you can chose different Subs with different porting. Again, these different types are entirely a matter of how it sounds to you and I honestly cannot tell you, one is better than the other (nor can anyone). You can get front firing, rear firing or down firing. Personally there are a couple things you may want to consider. If you cheap out and your sub isn`t high powered or maybe a passive sub(no internal amplifier) you may want a down or rear firing sub so you can corner load it. This is essentially using a corner in your theater room to reflect the sound making it louder or sound bigger than it normally would. That being said, I think a down firing is the most versitile as you could do this or put it next to your couch if need be :)

Subs can have several configurations.  They can come in different sizes, 8,10,12,15 inch woofers.  They can have one, two or even three ports..etc.  The port is where the air is released when the sub is active. The size of the woofer is usually an indicator of the range of sound the sub can usually handle.  Bigger woofers can handle lower frequencies.  The amplifiers within them can also range in power quite drastically. These considerations are all a matter of preference. To the right, is an example of a Velodyne down firing sub. Sound created is different by every sub and as I`ll recommend with any product listen to it first, extensively before committing to a purchase.

Testing of your entire home theater should be done by playing favorite movies, music and I always like playing sample discs or media from Dolby digital, DTS, THX, trueHD etc. Such media will give you a solid expectation as these are the sorts of thing you hear at the beginning of movies in the theater (and they should sound awesome). Of course you may need to alter some settings like frequency levels or gain on the subwoofer but this is expected. When your entire system is setup, if it doesn`t give you the theater experience you were looking for. Return it and buy the one that does.

I know its a lot of information, but really it is quite simple. Buy what you like. Ill be reviewing subs in the next portion of this series.