BACKGROUND OF THE INVENTION
1. Field of the invention
[0001] This invention is about a kind of digital audio frequency optimizer. In especial
with refers to a kind of digital audio frequency optimizer can output flat frequency
response curve through operation mode.
2. Description of the prior art
[0002] Conventionally used, for solving disoperation causes by speaker essence frequency
response curve and additional defect of the second time frequency response curve disoperation
causes by voice box, usually adds complementary circuit among circuit to proceed adjustment
of speaker and voice box frequency response curve. And components of complementary
circuit of conventionally used are described as follow:
1, Conventionally used complementary circuit uses multiple passive device, e.g. :
low-pass filter, high-pass filter, band-pass filter etc. multiple types filter comprise
by inductance, capacitance, resistance. Arranging and combing by series or parallel
method, solve frequency response disoperation by decay or increase method. Nevertheless,
although method described above can improve defect of frequency response disoperation,
but because it perms inductance, capacitance, resistance. Once have more frequency
points on frequency curve need amend. Degree of difficulty it causes is relatively
high. And number of elements it needs is relatively increased. So, while volume increases,
cost will promote relatively. And this method usually only amends part can't amend
overall.
2, For improving defect makes integral circuit volume relatively increase cause by
using volume of element is bigger of conventionally used complementary circuit described
above, so replace filter by amplifier. It is designed to be initiative amplifier such
as high-pass amplifier, low-pass amplifier, band-pass amplifier etc. by feature of
amplifier in preamplifier. Applying feature of amplifier amplifying power make suitable
"+, -" method. And must perm by multiple sets of series mode or parallel mode to gain
needed frequency curve. Although, volume of element needed by using circuit of multiple
amplifier is smaller than applied element of filter. But the number of elements it
used is more. If when frequency points needed adjustment are more will lead to need
more series. So, not only cause increase of volume and cost but also making distortion
relatively increase. Making it promote difficulty on design.
[0003] Furthermore, using filter or amplifier to be complementary circuit, both possess
a common disadvantage, i.e. frequency response curve must be change after change speaker
essence. While design and manufacture of voice box has alteration, it's frequency
response curve will follow to alter too. So, while speaker and voice box have alteration,
it must redesign all of circuits. Once speaker or voice box can't do any alteration
will cause frequency response curve can't adjust. This is important bottleneck on
design.
[0004] Hereby showing, conventional used object described above still has many defects.
It is actually not a good design and need inflict improvement.
[0005] Inventor of this case examines every defects issued from complementary circuit mentioned
above. So think repeatedly to improve and innovate. Studying painstakingly lonely
meticulously for many years, finally researches completely this digital audio frequency
optimizer successfully.
SUMMARY OF THE INVENTION
[0006] The purpose of this invention is to provide a kind of frequency response curve of
speaker and voice box can obtain at anytime. Does suitable apery adjustment previously
on computer, then save data of this curve, to get digital audio frequency optimizer
of the best frequency response curve.
[0007] Another purpose of this invention is to supply a kind of read-only memory saves with
frequency response curve of speaker and voice box only must plug on board in manufacture
process. Will complete digital audio frequency optimizer of altering design purpose
at any time.
[0008] The other purpose of this invention is to provide a kind of DSP operated result transfer
to serial signal through CPU. And then transmit to digital / analog signal transducer
to transfer to analog signal to reduce needed load when DSP dose complicate operate.
Achieve digital audio frequency optimizer with maintaining sound quality purpose progressively.
[0009] The last purpose of this invention is to provide a kind of previously setting digital
/ analog signal transducer which outputs maxima level. Preventing power amplifier
generates cut distortion phenomenon cause by too large signal input. Making digital
audio frequency optimizer dose not like traditional method which using multiple elements
and complex circuit combine to be a compress circuit to improve cut distortion.
[0010] Achieving digital audio frequency optimizer of invention purposes mentioned above
includes analog / digital signal transducer, CPU, digital signal processor, digital
/ analog signal transducer, filter / buffer, power amplifier, speaker and voice box.
Therein, the read-only memory can save frequency response curve of speaker and voice
box. The analog / digital signal transducer receive audio frequency signal. And transfer
the audio frequency signal into digital signal then transmit to CPU. CPU will transfer
signal received into apposition signal then send signal to DSP to operate with frequency
curve save on read-only memory. And then send operated result back to CPU to transfer
to serial signal. Then transmit to digital / analog transducer to transduce to analog
signal. Then through filter and buffer proceeding filter and power amplify by power
amplifier. Then output to speaker and voice box. Making it can output flat frequency
response curve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings disclose an illustrative embodiment of the present invention which serves
to exemplify the various advantages and objects hereof, and are as follows:
Fig. 1 is block diagram of digital audio frequency optimizer of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Please refer to Fig.1, digital audio frequency optimizer supplied by this invention
principally includes:
[0013] An analog / digital signal transducer 1, it receives audio frequency analog signal
10 from acoustic. And transfer the audio frequency analog signal 10 to digital serial
signal 11 then transmit to CPU 2.
[0014] A CPU 2, the CPU 2 is a control center, it receives digital serial signal 11 from
analog / digital signal transducer 1. And after arranging the digital serial signal
11 to apposition signal 21, then transmit the signal 21 to digital signal processor
3 ( DSP ) to operate. After operating, then send back operated parameter signal to
CPU 2 to transfer to digital serial signal 22, and then transmit to digital / analog
signal transducer 4.
[0015] A read-only memory 5 ( EEPROM ), the read-only memory 5 connects with digital signal
processor 4. It save principally original frequency response curve parameters of speaker
8 and voice box 9.
[0016] A digital signal processor 3 ( DSP ), the digital signal processor 3 receives signals
from CPU 2 and read-only memory 5. And proceed operation according signal received.
Frequency response curve of speaker is operation parameter. E.g.: parameter value
of A + parameter value of B = parameter value of C. Signal A represents frequency
response curve of speaker 8 and voice box 9. Signal B equals to negative of signal
A. Signal C is flat frequency response curve. So, for making speaker 8 and voice box
9 can output signal C of flat curve. Operating the digital signal processor 3, must
distill signal A saves in read-only memory 5 to get negative signal B parameter of
signal A. And after transmitting the negative signal B parameter back to CPU 2 to
transfer back to digital serial signal 22 then transmit to digital / analog signal
transducer 4. Transmitting in such way can reduce load when digital signal processor
3 do complex operation. Avoiding reducing transmitted speed, lead to relative decrease
of sound quality at last.
[0017] A digital / analog signal transducer 4 receives negative signal B from CPU 2. After
transferring received signal to analog signal 41, then transmit to filter /buffer
to proceed filter and buffer, and then transmit to power amplifier 7 to do power amplify.
At last, transmit amplified negative signal B to speaker 8 and voice box 9. Making
signal A parameter plus negative signal B parameter can get signal C on frequency
response curve of speaker 8 and voice box 9. The signal C will equal to " 0". Making
speaker 8 and voice box 9 can output flat frequency response curve. Besides, CPU 2
will accord with operated result of digital signal processor 3 to set maximum output
level of digital / analog signal transducer 4. Prevent cut distortion cause by too
large signal input on power amplifier 7.
[0018] In addition, digital / analog signal transducer 4 obtains stereo audio frequency
signal data from CPU 2. Can add left , right two sound tracks of low pass filter and
high pass filter then divide by two through digital signal processor 3. Simultaneously
add low pass filter. After operating this signal with another speaker parameter, then
through another digital / analog signal transducer 4, such can obtain good curve output
of another sound track ( heavy bass ).
[0019] Again, save original frequency response curve parameter of speaker 8 and voice box
9 on read-only memory 5 or relative similar element. Once frequency response curve
of speaker 8 and voice box 9 alter, the altered frequency response curve parameter
can save on read-only memory 5 or relative similar element at any time to improve
defects of conventionally used complementary circuit.
[0020] Digital audio frequency optimizer supplied by this invention compares mutually with
other conventionally used technique possesses follow advantages:
1. Frequency response curve of speaker and voice box obtained by this invention can
do suitable apery adjustment previously on computer. Then save this curve data to
get best frequency response curve.
2. In manufacture process, this invention only need plug read-only memory which save
frequency response curve of speaker and voice box on board. Can complete purpose of
alter design at any time.
3. This invention takes DSP operation result to transfer into serial signal through
CPU. Then transmit to digital / analog signal transducer to transfer to analog signal.
To reduce needed load when DSP do complex operation. Achieving progressively maintain
purpose of sound quality.
4. This invention set previously output biggest level of digital / analog signal transducer.
Preventing phenomenon of cut distortion when power amplifier cause by too large signal
input. Making it need not like traditional method which uses multiple elements and
complex circuit to combine a compress circuit to improve cut distortion.
[0021] Many changes and modifications in the above described embodiment of the invention
can, of course, be carried out without departing from the scope thereof. Accordingly,
to promote the progress in science and the useful arts, the invention is disclosed
and is intended to be limited only by the scope of the appended claims.
1. A kind of digital audio frequency optimizer comprises :
an analog / digital signal transducer 1, it transferring audio frequency signal to
serial signal, then transmitting to CPU 2;
a CPU 2, it being a control center, after arranging digital serial signal 22 which
it received to apposition signal 21, then transmitting signal to digital signal processor
3 to do operation;
a read-only memory 5, it connecting with said digital signal processor 3, saving principally
original frequency response curve parameter of speaker 8 and voice box 9;
a digital signal processor 3, said digital signal processor 3 receiving signals from
said CPU 2 and said read-only memory 5, and proceeding operation according signals
received, and transmitting operated results back to said CPU 2 to transfer to digital
serial signal 22, then transmitting said digital serial signal 22 to digital / analog
signal transducer 4;
a digital / analog signal transducer 4, it receiving operated completely signal from
said CPU 2, and after transferring signal received to analog signal 41 then transmitting
to filter / buffer 6 to proceed filter and buffer, then transmitting to power amplifier
7 to amplify power, at last, transmitting amplified signal to said speaker 8 and said
voice box 9, making said speaker 8 and said voice box 9 outputting flat frequency
response curve.
2. Digital audio frequency optimizer as recited in claim 1, therein signal parameter
which is operated completely by said digital signal processor 3 being negative number
of original frequency response curve parameter of said speaker 8 and said voice box
9, after said speaker 8 and said voice box 9 receiving signal can output flat frequency
response curve.
3. Digital audio frequency optimizer as recited in claim 1, therein said CPU 2 setting
output maximum level of said digital / analog signal transducer 4 according operated
results of said digital signal processor 3, preventing cut distortion cause by too
large signal input in power amplifier 7.