Consideration of amplifier design for loudspeaker system

 　　Many engineers working with speakers and amplifiers will tell you the same thing. If an over - operational amplifier, it will more or less damage to the speaker's drive. This process usually involves a gradual increase in the bass knob, or a sharp turn of the volume knob. What will be the result?

　　It may damage the speaker's high frequency drive. But why would this result? The majority of the high pitched drives are designed for 10W to 15W power range. Driving them at high frequencies requires very little energy. Midrange and woofer rated power is generally the average power of the whole loudspeaker (50W and 100W).

　　Think of what results can be produced in a limited system to increase the gain of a sine wave (using a fixed power rail). At this time, the signal began to limit. If you are driving a signal to a signal, the waveform is beginning to look more like a square wave. In the frequency domain point of view, we begin to obtain the input signal harmonics. Due to a large number of the emergence of a large number of harmonic amplitude. Now, if you use a passive divider, many high order harmonics can be easily found in the middle and low frequency drive to the high pitch. Because of the high - frequency drive power is very low, so the probability of damage is also much higher. In many systems, this is a real problem, especially those that use a simple analog processing (e.g., amp OP) or a EQ system. Two better solutions are: 　　

1.Double power amplifier system

 　　If in a closed system, such as: an active speaker, please consider allowing your system to use double power amplifier. Double power amplifier allows you to use a separate amplifier to drive a high pitched voice. Before the low frequency gain, the separation between the high and the low is accomplished, which can prevent the high frequency part of the high frequency part of the bass.

 　　Double power amplifier system allows you to run most of the simulation system with a highly flexible digital control function. The disadvantage is the high cost of the amplifier. However, we must make a tradeoff between the cost of a good passive divider and the additional amplifier. In digital analog converter (DAC) or multimedia digital signal codec (Codec), the use of digital frequency divider, to a certain extent, ease the problem.

 　　It is much easier to change the frequency divider in digital mode than to change a variety of passive components. This will also allow the same PCB to be designed for different sizes of speakers and speakers. Note that this system is valid only when you are able to access two drives alone. 　　

2.Intelligent postprocessing limited bass signal

　　Some developers will use the soft limit. This is a very simple method, but it is very rare in the home audio system. Generally speaking, we will increase the bass frequency to the highest. Some developers will remove 24 dB of low frequency, the purpose is to compensate for the low frequency response capability of the small 2 inch drive.

 　　If the frequency is generally low, try adding a low pass filter to the gain stage to reduce the high frequency limit. In the simulation system, to construct the low-pass filter usually requires a multi order filter with a sufficiently high cutoff rate, allowing the system bulky and expensive. However, in a digital processing system, it can be easily implemented, the condition is valid in the audio processor MIPS.