[summary of the invention]
The object of the invention is to solve the slicing phenomenon that produces in the psychoacoustic principle using method, send the problem that " puff puff " sound shadow is rung performance when causing acoustical generator in working order, and propose a kind of apparatus and method of controlling the bass reproduction of audio signal.
In order to achieve the above object, technical scheme of the present invention is as follows:
A kind of device of controlling the bass reproduction of audio signal, comprise the first adder of stack low-frequency range left and right sound track signals, the low pass filter that is connected with adder, the nonlinear processor that is connected with low pass filter, reach the second adder that is connected with nonlinear processor, described second adder and also be connected with high pass filter by left and right sound track signals, what wherein setting was attached thereto before described low pass filter carries out the amplitude adjustment to signal, first amplitude limiter of control signal amplitude in 1; Behind second adder, arrange signal is carried out the amplitude adjustment, second amplitude limiter of control signal amplitude in 1.
Preferably, described the first amplitude limiter comprises that carrying out amplitude limit is adjusted at the sinusoidal processor of preset value in 1.
Described the second amplitude limiter comprises one judges whether the amplitude size of signal surpasses the electrical level judging device of preset value, reach the computing circuit unit that is connected with the electrical level judging device, and this computing circuit unit carries out amplitude limit to signal and adjusts the mathematical operation of computing in preset value.
Described computing circuit unit also connects the nonlinear processor of an increase harmonic signal composition.
A kind of method of controlling the bass reproduction of audio signal is characterized in that: may further comprise the steps:
The original audio signal of input left and right acoustic channels is passed through high pass filter;
The low-frequency range audio signal that to input simultaneously in the left and right acoustic channels superposes by first adder, synthetic first signal;
The nonlinear processor processing that described first signal is delivered to low pass filter and is connected with low pass filter obtains secondary signal;
Secondary signal and the original audio signal of passing through high pass filter are superposeed through second adder;
To be delivered to by the signal of second adder the second amplitude limiter and carry out the amplitude adjustment, the processing of control signal amplitude in preset value obtains composite signal, and composite signal is exported.
Preferably, be delivered to the first amplitude limiter after described first signal superposes by first adder and carry out the amplitude adjustment, the control signal amplitude is in 1, and described the first amplitude limiter is sinusoidal processor.
When signal is sent to the second amplitude limiter, the electrical level judging device and the computing circuit cell processing that comprise through the second amplitude limiter successively, after electrical level judging device detection signal amplitude surpasses preset value, pass the signal to the computing circuit unit and carry out the mathematical operation of amplitude limit adjustment amplitude in preset value.
To be delivered to through the signal of computing circuit unit and carry out the nonlinear processor that Nonlinear Processing produces the harmonic components of this signal.
Described amplitude limit is adjusted the mathematical operation of amplitude in preset value and is satisfied one of following two kinds of conditionals:
First condition formula: y=x/2+ preset value/2, y=x/2-preset value/2;
Second condition formula: y=x/3+2* preset value/3, y=x/3-2* preset value/3;
Wherein, x is the amplitude of input original signal, and y is the amplitude of corrected signal.
The present invention controls the apparatus and method of the bass reproduction of audio signal, and what setting was attached thereto before described low pass filter carries out the amplitude adjustment to signal, first amplitude limiter of control signal amplitude in 1; Behind second adder, arrange signal is carried out the amplitude adjustment, second amplitude limiter of control signal amplitude in 1, respectively the signal after each processing is carried out the amplitude adjustment, when preventing that the amplitude of input signal is excessive, thereby strengthen processing afterwards through bass and cause slicing so that the amplitude of signal surpasses 1, avoid sense of hearing " puff puff " sound to occur, to reach the effect of emulation fundamental frequency, optimize tonequality, so that bass enhancing technique effect is better.
[embodiment]
Below in conjunction with accompanying drawing, the present invention is elaborated.
As shown in Figure 1, control the device of the bass reproduction of audio signal for the utility model, the first adder that comprises stack low-frequency range left and right sound track signals, be connected with adder signal is carried out the amplitude adjustment, first amplitude limiter of control signal amplitude in 1, the low pass filter that is connected with the first amplitude limiter, the nonlinear processor that is connected with low pass filter, and the second adder that is connected with nonlinear processor, described second adder also is connected with high pass filter by left and right sound track signals, arrange behind the described second adder signal is carried out the amplitude adjustment, second amplitude limiter of control signal amplitude in 1 is delivered to the acoustical generator of connection after the second amplitude limiter is disposed signal.
The first amplitude limiter is sinusoidal processor in the present embodiment, it carries out sinusoidal calculation process with signal, suppose that input signal amplitude is x, then output signal is sin (x), purpose makes softization of signal exactly, and the amplitude of compressed signal, compare with original signal, nonlinear change after sinusoidal the processing is less, and odd harmonic is arranged, just because of its relatively original signal intensity is less, can be with softization of original audio signal, can also with original Signal Compression between-1 to 1 between-0.85 to 0.85, effectively avoid this signal through occurring the situation greater than 1 after the later processing.Process other Nonlinear Processing of cooperation with sine, evidence can obtain the high-quality hearing effect, and described sinusoidal processor can arrange according to actual needs.
Shown in Fig. 2,3, the second amplitude limiter comprises two kinds of structures: the first comprises electrical level judging device and the computing circuit unit that is connected with the electrical level judging device, described electrical level judging device is just judged the amplitude size of signal, if amplitude surpasses preset value, then input to computing circuit and do calculation process, if amplitude does not surpass preset value, then do not process.Preset value is not unalterable, and it is an empirical value, can adjust according to the size of harmonic components.
Described computing circuit unit performs mathematical calculations to signal, is x if establish the amplitude of original signal, if x>0.8, then y=x/0.2+0.4; If x<0.8, then y=x/0.2-0.4; That is to say that the amplitude of establishing original signal is x, x can be for just or for negative, preset value gets 0.8, and when-0.8<x<0.8, then signal does not process; Otherwise, when input signal amplitude greater than 0.8 or negative value less than-0.8 the time, do following calculating:
When x>0.8, y=x/2+0.4;
When x<-0.8, y=x/2-0.4;
When x=0.8, y=x/2+0.4=0.8;
When x=-0.8, y=x/2-0.4=-0.8.At this moment, to process with not processing be identical to signal.Can allow like this amplitude of output signal less than input signal, thereby can avoid signal situation greater than 1 to occur with the signal plus of other parts after excessive, thereby guarantee the continuity of signal.
For the amplitude to signal is controlled, the computing circuit unit satisfies one of following two kinds of conditionals to the processing of signal and gets final product, that is:
Conditional 1:y=x/2+ preset value/2, y=x/2-preset value/2;
Conditional 2:y=x/3+2* preset value/3, y=x/3-2* preset value/3;
Wherein, x is the amplitude of input original signal, and y is the amplitude of corrected signal.As shown in Figure 4, original signal and the oscillogram that calculates through two kinds of conditionals, its amplitude all satisfies the needs of amplitude limit, the slicing phenomenon do not occur, and the signal after processing like this is all low than original signal amplitude.When the amplitude of input signal is smaller, identical with the original signal possibility; When amplitude is larger, then do amplitude limiting processing.Guarantee that output signal is controlled in certain scope.
The second amplitude limiter comprises electrical level judging device, computing circuit unit and nonlinear processor, the signal that nonlinear processor will transmit from the computing circuit unit increases the composition of harmonic signal, to export acoustical generator to through the signal of nonlinear processor, so that bass enhancing technique effect is better.
A kind of method of controlling the bass reproduction of audio signal may further comprise the steps:
The original audio signal of input left and right acoustic channels is passed through high pass filter;
The low-frequency range audio signal that to input simultaneously in the left and right acoustic channels superposes by first adder, synthetic first signal;
Be delivered to the first amplitude limiter after described first signal superposes by first adder and carry out the amplitude adjustment, the control signal amplitude is in 1, and described the first amplitude limiter is sinusoidal processor.Certain sinusoidal processor can arrange according to the size of the harmonic components of first signal.
The nonlinear processor processing that described first signal is delivered to low pass filter and is connected with low pass filter obtains secondary signal;
Secondary signal and the original audio signal of passing through high pass filter are superposeed through second adder;
To be delivered to by the signal of second adder the second amplitude limiter and carry out the amplitude adjustment, the processing of control signal amplitude in preset value, when signal is sent to the second amplitude limiter, the electrical level judging device and the computing circuit cell processing that comprise through the second amplitude limiter successively, after electrical level judging device detection signal amplitude surpasses preset value, pass the signal to the computing circuit unit and carry out the mathematical operation of amplitude limit adjustment amplitude in preset value, described amplitude limit is adjusted the mathematical operation of amplitude in preset value and is satisfied one of following two kinds of conditionals:
First condition formula: y=x/2+ preset value/2, y=x/2-preset value/2;
Second condition formula: y=x/3+2* preset value/3, y=x/3-2* preset value/3;
Wherein, x is the amplitude of input original signal, and y is the amplitude of corrected signal.
To be delivered to through the signal of computing circuit unit and carry out the nonlinear processor that Nonlinear Processing produces the harmonic components of this signal, obtain composite signal, after composite signal is adjusted through at least one times amplitude limit so that the amplitude of signal in preset value, thereby elimination clipping phenomenon, avoid sense of hearing " puff puff " sound to occur, to reach the effect of emulation fundamental frequency, optimize tonequality, so that bass enhancing technique effect is better.
The above only is preferred embodiments of the present invention; protection scope of the present invention is not limited with above-mentioned execution mode; as long as the equivalence that those of ordinary skills do according to disclosed content is modified or changed, all should include in the protection range of putting down in writing in claims.