Crossover effect and the choice of basis Crossover
The role of crossover: In a speaker system, people to box, frequency circuit, the speaker unit speaker system is called Big Three, and frequency divider circuits, high-quality speaker system can play an acoustic signal to restore power extremely important role. Especially in the high-frequency part of the divider circuit is even more significant role to play. Its role as follows:
Rational division of work each unit frequency band;
Reasonable for the power distribution unit;
So that each unit has the proper phase relationship between in order to reduce the work of each unit appear in the interference of sound distortion;
Frequency characteristics of the circuit used to make up units in a band where the sound of defects;
The band will be rounded up and docked smoothly.
Clearly, frequency circuit effect has been recognized and accepted.
Crossover Frequency Selection:
A consideration of practical low-unit point of the boundary frequency f = 345 / d (d = effective diameter of the diaphragm unit). Usually 8 "unit boundary frequency of 2k, 6.5" unit boundary frequency of 2.7k, 5 "unit for the 3.4k, 4" unit is 4.3k. That is the use of such units, the crossover point can not be greater than the utility of each unit corresponding to the boundary frequency.
2, the resonant frequency from the tweeter to consider, crossover should be more than three times the resonant frequency. That is the perspective from the tweeter, crossover is usually greater than 2.5k.
3-end consideration woofer response Fh, usually Crossover should not exceed 1 / 2 Fh. In fact, the two frequency speaker very difficult to meet the above conditions. Then the three designers should have a good compromise choice. It must be stressed that the first condition that is practical and should be given priority to meet the boundary frequency.
4 one-third frequency of the case, usually two crossover point should be well separated survivors (should be more than three octaves), combination of the system response will become better. Otherwise, there will be the complex phenomenon of interference radiation.
5 bass and tenor of the crossover point should be considered as the positions of people repeatedly. People as possible should be the sound of Chinese and audio playback units to undertake in order to avoid the sound image localization vocal sound great changes have occurred. This is often easily overlooked by the designer. Usually the crossover should be 200-300Hz.
Here is the divider Maxim
3V, EconOscillator / divider
DS1073 is a fixed frequency oscillator, no external components. Use of internal calibration devices, and programmable pre-divider can provide approximately 27.3kHz to 100MHz operating frequency range of many.
DS1073 using the main oscillator, pre-calibration and programmable divider structure. Pre-calibration and programmable divider set by the user to the desired value, and the values can be stored in nonvolatile memory. This allows users to buy devices available in the market, and it became board-level products prior to their programming. Within the device by programming different values can be written to modify the design (or programming devices that have been re-programmed).
DS1073 is factory configured to the maximum operating frequency of the half, if you need special programming device, you can contact the factory. As a board oscillator, you can select an external clock or crystal as the reference signal. Reference source (internal or external) from the user to select the programming (or the chip does not work, if you choose the SEL model).
DS1073 with a double-effect I / O pins. If the device is in programming mode, start, the pin can enter the serial data to the register. Write command, the data is stored in nonvolatile memory. When the chip power in operating mode, these values are automatically stored to the internal register, then I / O pins as the oscillator output.
DS1073 can work in the commercial temperature range (TA = 0 ° C to 70 ° C) or industrial temperature range (TA = -40 ° C to + 85 ° C). Finally, the data information in the chip work in the temperature range of AC and DC electrical characteristics.
DS1073 in 8-pin DIP or SO package, the simple, to generate the clock signal, and take up minimal board space.