Killer Bass...
with a purpose.



Nothing drives me crazier than hearing a ridiculously loud car stereo that is nothing but bass and maybe a little treble thrown in here and there. In this section we will discuss using a subwoofer to support and round out your listening experience.

You can have very high levels of sound in your vehicle with copious amounts of bass and still have good sound over the ENTIRE audio spectrum (or least a major listenable portion of it).

Picking a subwoofer
The best advise I can give if you are not buying an "already matched" speaker system is to wait until you have installed your mids and tweeters and listen to a test CD with sweeps on it to see what is missing. This is not always possible as most folks will install everything at once so they only have to do surgery on there car once. But, trust me on this, your patience will pay off in lower costs and better overall sound too.

Let us say, for instance, you were going to buy 2 12" woofers that were on sale for $100 each and an amp to run them while you were picking up your tweeters, mids, wiring, etc. You get home install everything according to manufacturers recommendations and you use an online calculator and the specs on the box to build a box. Now, you turn it on and you can faintly hear voices but you mainly hear a thundering bass line and it is rattling the hell out of everything. WOW!!! That is so impressive! But what a waste of money! You listen for a few seconds, and turn down the level on the amp you bought to drive the subs to about 1/3 and everything sounds a lot better.

While it is a good idea to buy an amplifier that has some headroom, buying one that is way overpowered is just plain dumb. So now you have bought $200 worth of subs built a large box to hold them and a $300 amp to run them. When, all the while, you could have gotten a single ten and a $150 bridgeable amp and a built a much smaller box and done just what your $600 setup did for about $275 or so.

Don't feel so bad, it happens everyday.

Now that you have been listening and testing your mids and highs and are satisfied with the way they sound...except for the bass, it is time to start looking at subs and deciding what type of enclosure will fit in your car, what frequency range needs to be covered, and what drivers will work in this enclosure.

Enclosures
There are a myriad of enclosure types out there and most have their purpose and are fairly straight forward to build. I will cover the basic three here: sealed, ported and 4th bandpass. I have used 6th and 7th order BP configs and found them to be way too complicated for the benefit I received from using them.

I will not cover a how-to on fiberglass but will touch on it. Also, If you check my links page there are links to online calculators to help in the design so I will not cover much math here either. No sense in reinventing the wheel!

Some of the benefits of the various enclosures and there drawbacks are listed in the table below.

ADVANTAGESDISADVANTAGES
SEALEDEasy to build, more tolerant of design flaws,
High power handling, good transient response		Less efficient than BR or BP enclosures, usually will not have as low of F3 either
Bass Reflex/PortedMore efficient that sealed, usually will have a lower F3, easier to design to a specific F3May cause driver to "unload" at frequencies below Fs,
not as design tolerant, must allow room for air flow
from port so placement is more critical
4th order bandpassWay more gain than either above, covers a specificand more predictable frequency
range		Much more difficult to design and build, may damage driver with excessive gain if not designed properly,
usually takes up more room than either of above


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