Post by Boomzilla on Oct 4, 2015 12:28:35 GMT -5
A comment in another thread from the esteemed @bmoney indicated that subwoofers are poorly understood in this forum. To clarify what makes a good subwoofer, I thought a discussion might be informative. In my humble opinion, a good subwoofer would have all the following characteristics:
1. A fast rise time. When the signal says "jump," the cone should jump - not laze along...
2. A fast stop time. When the signal stops, the subwoofer should also stop (abruptly and without overhang)
3. A broad frequency response - To mate well at the crossover point, the sub must have flat response for at least an octave above.
4. A flat frequency response - If the sub's response is highly peaked, then it will be a "one note wonder," so common in the inexpensive home theater world.
5. A response that remains dynamic throughout the volume range. At high volumes, many subs provide only a homogenized roar. This is NOT how music sounds.
6. A phase control (preferably marked in feet from the listening position - not in degrees). To do this, some assumptions would need to be made about the main speakers' distances from the listening position vs. the sub's distance to the listening position. The phase knob could be simplified by asking the user to enter only the difference (in feet) between the main speakers' distances (to the listening position) and the sub's. To date, I know of no manufacturer that provides such a user-friendly control.
7. An inert enclosure - Inexpensive boxes "sing along with the driver." This makes for peaks in the frequency response that have nothing to do with the input signal (and are, thus, "noise"). This is one of the most expensive things to engineer out of a subwoofer, and thus many boxes (even from "high-end" makers) lack the integrity to avoid spurious vibrations.
8. Low distortion - Anything not in the input signal should not be coming out of the subwoofer. Doubling of notes or "wolf tones" are not acceptable.
Note that this thread is NOT about subwoofer placement in the room (an entirely different discipline), but only about the specific characteristics that a good sub should have.
What have I missed?
1. A fast rise time. When the signal says "jump," the cone should jump - not laze along...
2. A fast stop time. When the signal stops, the subwoofer should also stop (abruptly and without overhang)
3. A broad frequency response - To mate well at the crossover point, the sub must have flat response for at least an octave above.
4. A flat frequency response - If the sub's response is highly peaked, then it will be a "one note wonder," so common in the inexpensive home theater world.
5. A response that remains dynamic throughout the volume range. At high volumes, many subs provide only a homogenized roar. This is NOT how music sounds.
6. A phase control (preferably marked in feet from the listening position - not in degrees). To do this, some assumptions would need to be made about the main speakers' distances from the listening position vs. the sub's distance to the listening position. The phase knob could be simplified by asking the user to enter only the difference (in feet) between the main speakers' distances (to the listening position) and the sub's. To date, I know of no manufacturer that provides such a user-friendly control.
7. An inert enclosure - Inexpensive boxes "sing along with the driver." This makes for peaks in the frequency response that have nothing to do with the input signal (and are, thus, "noise"). This is one of the most expensive things to engineer out of a subwoofer, and thus many boxes (even from "high-end" makers) lack the integrity to avoid spurious vibrations.
8. Low distortion - Anything not in the input signal should not be coming out of the subwoofer. Doubling of notes or "wolf tones" are not acceptable.
Note that this thread is NOT about subwoofer placement in the room (an entirely different discipline), but only about the specific characteristics that a good sub should have.
What have I missed?
