Subwoofer

[dobyblue]

This is a good article to read:

http://www.audiopulse.com/know-how/s...ut-subwoofers/

Here are some key points:

# 5 Subwoofers care what they play

Your subwoofer driver does not have a conscience, and it does not perform better with one type of music over another. It’s just a driver. Good subwoofer systems will play all types of music or movie material very well. A bad subwoofer system may have a null or peak in the frequency response that may benefit some material over others but essentially this non-linear behavior is not ideal. It is true that movies have lower frequency content and perhaps more dynamic bass than music, especially with the recent compressed CD’s of the last 10 or so years, but a good system can be used for movies and music alike if it is indeed a “good” system.

It is also true that it tends to be more important to emphasize subsonic frequencies in the home theater environment versus the music environment where there is simply less emphasis on subsonic inaudible material. As a tradeoff, you can align a system to be more efficient above 30Hz or so. This trade off reduces the bandwidth but increases the SPL. Careful consideration should be taken to insure linear response is still maintained. It is very easy to have peaky bass with low Q drivers in high tuned ported systems. This is approaching the concept of basic SPL vehicles which use low Q, highly sensitive drivers tuned very high for very narrow but ferociously peaky response. Such systems are not very ideal for listing to music material of any kind. If you want your system louder, then it is better to add a second driver, more volume and more amplification, rather than tuning higher. It is important to understand that getting more SPL without compromise is never very cheap!

# 8 Smaller drivers sound better than bigger drivers

One of the biggest myths about woofers is that 8’s and 10’s are “tighter” and “cleaner” than 15’s or 18’s. Nothing is further from the truth. What tends to happen is that the smaller drivers have lower Q’s because manufactures tend to put large cones on smaller motors to increase SPL and sensitivity but not BL product. Well unless the motor can compensate for the extra mass it has to push, then the Qts will not be the same as the smaller drivers and ultimately the driver may not be suited for the same kinds of alignments and could ring too much and compromise the perceived sound quality. Having said that, high Qts drivers are not any less “tight” or “musical” than well dampened drivers, it’s just they require larger boxes and less internal pressure to prevent ringing. Ultimately there becomes a point where a driver really should be used in an infinite baffle where its actual Qts and Fs becomes the system Qtc and Fc. As enclosure volume decreases, Qtc increases and it will take a driver with a low Qts to make for an average Q system. So in conclusion, the only reason to use a smaller bass driver is for space, weight and potentially power considerations, but likewise, it is inappropriate to try and fit a larger driver into a space smaller than it is ideal for.