JBL EONSUB-G2 manual Block Diagram, About Subwoofers

Block Diagram

LOOP

THRU OUTPUT

LINE

LEVEL

INPUT

SPEAKER LEVEL INPUT

	POLARITY
SIGNAL	NORMAL	PEAK
	REV	REV

EQ HPF LPF 250W

VOLUME

About Subwoofers

Here are a few bass basics. The ear is far less sensitive to very low frequencies than it is to mid- range frequencies. A 1,000 Hz sound at 95 dB SPL may seem obnoxious and painful to the ear while 50 Hz. at 95 dB SPL will seem pleasantly powerful. Musicians, composers, and producers know this instinctively and create music that contains a great deal of energy below 100 Hz. In order to properly produce or reproduce this music, an audio system needs to be capable of delivering much more acoustic output at low frequencies than in the mid band. Note that the capability of delivering more output should not be confused with the characteristic of low-frequency equalization boost. A system that is equalized to be perfectly flat may require as much as 20 dB more maximum SPL capability in the low bass. This is because the requirement for the extra energy is already built into the music. And contemporary dance music may rely even more on low frequencies for its power and energy.

To meet this need, speaker designers developed specialized speakers called subwoofers. Subwoofers are intended to work below 150 Hz. In fact, most subwoofers will sound downright bad if you try to use them to reproduce sound above 200 Hz. There are even sub-species of subwoofers. Some subwoofers are designed for extreme low–frequency extension and will go down as low as

20 Hz. This type of performance is usually more useful for cinema effects than for music. A sub that goes down this low will be very large and probably require a lot of amplifier power. Another variety of subwoofer that may be more appropriate and practical for portable music applications concen- trates on delivering “punch”. Punch is what you experience when the kick drum hits you in the chest. Much of what we think of as punch is in the 80 Hz. region.

Until recently, adding a subwoofer to a system was a complicated matter that required external crossover networks, extra power amplifiers, and of course the subwoofer itself. The EON Sub G2 simplifies this task by combining all this into a single, simple and light weight system.

8