Patent Grant
11205409
This application is an application under 35 U.S.C. 371 of International Application No. PCT/HU2018/000040 filed on 27 Sep. 2018, which claims priority from HU Application P1700403 filed 29 Sep. 2017, the entire contents of which are incorporated herein by reference.
The invention relates to a programmable signal processing and musical instrument setup system for stringed musical instruments, which comprises at least one analog signal processing circuit, a control circuit operably coupled to at least one analog signal processing circuit and a storage unit operably coupled to the control circuit, being arranged on the musical instrument. The musical instrument also comprises electro acoustic transducers, which are operably coupled to the signal processing circuit through controllable switches, and also mounted on the musical instrument there are continuously and discretely changeable setup means operably coupled to the control circuit, where the storage unit operably coupled to the control circuit stores at least one set of instrument setup parameters.
Stringed musical instruments in connection with the invention can be bowed er plucked stringed instruments, especially guitars, violins, zithers, lyres etc. Considering guitars the invention can be related to both acoustic, electric and bass guitars.
In recent time the sound of acoustic musical instruments is converted into an electric signal (except some classical pieces performed in concert halls), the electric signals are processed according to need, then amplified and reach the audience with the help of high performance speakers. Traditional acoustic musical instruments can be installed with electro acoustic transducers, e.g. electric pickups, therefore their sound can be easily converted into an electric signal. Genuine electric musical instruments don't have a resonant body, and without electric signal processing and amplification they are inaudible compared to traditional acoustic instruments. In the next section we will be focusing on electric stringed musical instruments, especially electric guitars, but the following statements in most of the cases apply to other stringed musical instruments as well.
Under the strings of the electric guitar there are pickups, most commonly electromagnetic pickups, which are generating an electric signal from string vibration. The number of pickups commonly varies from one to five. Pickups generally have either a single coil or a double coil (humbucker) design. In case of double coil humbucker pickups, it is possible to change the connection between individual coils. Beside electromagnetic pickups, there are piezoelectric and other types of pickups as well. Active pickups are pickups with a built-in preamplifier, whereas pickups without pre-amplification are called passive pickups. In contrary to that, this document uses the term active and passive in the context of signal processing, where a passive guitar has only passive (R, L, C) elements, and an active guitar has active amplifier means in the signal processing. Signal processing with active amplifiers can be either analog or digital. In case of digital signal processing, electric signals generated from pickups are digitalized, digitally processed, and then converted back to analog signal.
General expectations towards electric guitars are excellent sound quality, versatility and ease of use.
Main criteria for excellent sound quality at signal processing without delay and the processed signal should contain the whole acoustic spectrum (frequency range) of the sound generated by strings.
Guitars instilled with active and passive electronics have no perceived delay in their signal. Signal delay is a main quality factor in digital signal processing, as analog to digital (AD) conversion, digital signal processing and digital to analog (DA) conversion cannot happen in real time. Furthermore, sound quality is exceptionally dependent on the quality of AD and DA conversions (number of bits, sampling frequency). Better sound quality requires more bits and higher sampling frequency, resulting in more data to process, therefore higher data processing capability and higher energy consumption are needed. As energy consumption is limited by the capacity of the battery, higher sound quality can only be achieved with higher signal delay.
According to prior art, the use of digital signal processing resulted in highly compromised solutions. Compared to analog signal processing, digital sound quality is worse and the appearing signal delay rules out professional use. The main advantage of digital signal processing is the versatility of sounds that can be achieved, as there are endless possibilities for altering a digital signal. The only restricting factor is that additional digital processing operations demand more processing capability, which in practice immensely limits versatility.
The other factor of sound quality is signal spectrum.
The signal spectrum of a guitar means how well the output signal can contain the full frequency range generated by the strings. Electronic components in passive guitars form an RLC filter, where L is the inductance of the pickups, R is the resistance of the potentiometers and C is the capacitance of the capacitors. Signal spectrum is limited according to the specification of the RLC filter. If there are more than one pickup present in a passive guitar, the guitar's inductance (Le) is measured as a sum of the present individual pickup inductances (Lhn). Le=Lh1+Lh2+ . . . +Lhn. That means that changes in the RLC filter changes the signal spectrum, which means for example that signal generated from two pickups are not equal to the sum of the individual signals. Changes in potentiometer resistance have a similar effect, for example volume change modifies the tone of the guitar.
Active guitars usually have a high input impedance, which means that pickups work in voltage generation mode and signal spectrum isn't altered. In contrary to passive guitars, a signal generated from two pickups will be equal to the sum of the individual signals, so each pickup will represent its signal spectrum in the output signal. Furthermore, changes in volume won't have any effects on the tone of the guitar. Signal spectrum in digital signal processing is determined by the quality of AD/DA and the quality of signal processing.
In the context of the invention, versatility means the variety of tones (musical styles) that can be produced with a single guitar. Guitar tone can be altered with switching pickups, mixing the signals of the selected pickups, equalizing the signal and using effects.
Using more than one pickup is useful because the physical location and the type (single coil, humbucker, piezo) of the pickups fundamentally changes the signal spectrum, signal to noise ratio and phase. In theory a guitar with 3 single coil pickups can produce 26 distinctly different tones as every pickup can be used in 3 different modes (off, in phase, out of phase). The complexity of pickup switching means, that in practice out of the 26 tones only 5 can be used with a conventional 3 pickup guitar.
Mixing pickup signals means to what extent does a selected pickup represent itself in the ongoing signal.
With equalization, signal spectrum can be altered according to needs. In passive guitars equalization happens in a very limited way, by changing the R element in the RLC filter. In practice it is only capable of cutting higher frequencies. With active guitars there is a possibility of active equalization, which means that the signal spectrum (tone) can be altered by filters having multiple cutoff frequencies. In practice 2 or 3 band equalization is prevalent. In case of digital guitars, equalization is determined by the specification of the digital signal processor.
Guitar tone can be further altered with effects. Effects are signal operations that change signal spectrum according to a predefined algorithm, (delay, amplitude and frequency modulation, distortion etc . . . ). In case of passive guitars there are no effects. In case of active guitars usually 1 or 2 analog effects can be used. In ease of digital guitars, possibilities for effects are determined by the specification of the digital signal processor.
Usability is determined by built-in controls, switches or external devices that are necessary for a guitarist to have easy access to different sounds, a clean and simple way to program a guitar (if possible) and an easy to use power supply.
Programming a guitar means that new tones can be created, the parameters of the tones can be stored, reloaded and added to a collection. A collection is a list of tones assigned to certain switch positions. The benefit of a collection is that the guitarist has easy and quick access to very different tones with the help of a single switch. Programming a guitar has huge benefits in functionality, although more controls (switches, potentiometers) are necessary to be mounted on the guitar. However to increase usability, it is desirable to have the lowest number of controls possible in a guitar. This contradiction between functionality and usability can be resolved with the help of an external programming device, which either has a wired or a wireless connection to the guitar. Guitars requiring power supply has the problem of changing and charging batteries. The main factors of usability regarding power supply are operating time, difficulty of changing batteries and the way and time needed to charge rechargeable batteries.
In general it can be said that guitars having traditional passive electronics lack versatility, active guitars lack usability, while digital guitars lack excellent sound quality.
Summarizing the above, guitars have to compromise between these criteria. In theory the ideal guitar is both fulfilling the criteria of excellent sound quality, versatility and usability Attempts were made to reach that goal.
U.S. Pat. No. 5,866,834 patent document describes a digitally controlled analog sound processing system, were an active guitar's analog components (switches, potentiometers) are digitally controlled. Control parameters are stored and can be assigned to the switches and potentiometers. A guitar built according to the document has many built-in controls, limited programming capability compared to the number of controls, and can be programmed only with the use of above mentioned controls. Furthermore programming parameters cannot be backed up, nor transferred to and loaded into another guitar.
U.S. Pat. No. 9,640,162 patent document discloses a digitally controlled pickup switching matrix, which can be programmed by an external device. This solution can only store and control pickup switching parameters, and only one guitar and one programming device can be connected.
The purpose of this invention is to provide a programmable signal processing system for stringed musical instruments, especially for electric guitars, which is able to provide excellent sound quality, versatility, programmability and ease of use at once.
The invention also provides a musical instrument setup system, where an external programming device is used for instrument setup, adjustments to the sound takes place real time and at least one set of setup parameters can be stored and loaded to an optional instrument.
The invention also provides a system, where nearly abundant sets of setup parameters can be created, safely stored and can be shared between instruments and users.
The invention provides a system, which is able to adopt to the physical configuration of different instruments and create setup parameters according to the configuration data of an individual instrument.
The invention provides a musical instrument setup system. Where the musical instrument has built-in analog signal processing and digital control unit with low operational power consumption, and much lower idle power consumption.
The object of the invention in the most general way can be reached according to the musical instrument setup and signal processing system and method provided herein.
In one embodiment of the invention
In one embodiment of the invention the communication module is preferably a wireless communication module and the instrument configuration file contains the type of electroacoustic transducers of the musical instrument and other setting related data, and the type of controls and switches of the musical instrument and other setting related data.
In a further embodiment of the invention the external programming device can be switched to either programming or monitoring mode, and in monitoring mode the external device can display information to the user about the state of the controls and switches, the state of the control circuit and can load, store and display information from the musical instrument storage, including setup parameters.
In another preferred embodiment of the invention the external programming device connected to the instrument in programming mode can modify at least one setup parameter in the musical instrument in real time, store setup parameters in the external device storage, in a setup parameter file, mid send at least one part of the setup parameter file to the musical instrument storage.
In a further preferred embodiment of the invention controls and switches on the musical instrument are programmable controls and switches, where the function of the controls and switches can be determined by the external programming device and stored in a musical instrument configuration file and/or in a setup parameter file, and can be sent to the musical instrument storage.
In one embodiment of the invention the external programming device may be a personal computer, laptop, mobile device, that can be connected to a wireless local or remote network.
In alternative embodiment of the invention the external programming device can connect to a local or remote database server, where the setup parameters can be stored, searched and downloaded.
In another alternative embodiment of the invention, the database is a central database stored on a local or remote computer, and the user after a registration and identification process has access to the database through a server application.
Acorring to a further aspect of the invention, users can share setup parameters through the server application.
In one embodiment of the invention the electronic circuits in the musical instrument have a low consumption active operating mode and can be switched to an ultra low consumption idle mode.
In the method according to the invention
In the method according to the invention, as a communication module we are practically using a wireless communication module and in the instrument configuration file we are storing the type of electro-acoustic transducers of the instrument and other related data, and the type of controls and switches of the instrument and other related data.
In one favorable method related to the invention the external programming device can be switched to either programming or monitoring mode, where in monitoring mode with the external device we are downloading and storing the state of the controls and switches, the state of the control circuit and the data stored in the instrument storage, including guitar setup parameters, and we are displaying at least one part of the downloaded data on external device's screen in real time.
In another favorable method related to the invention using the external programming device connected to the instrument in programmable mode we are modifying at least one setup parameter in the instrument in real time, storing setup parameters in the external device storage, in a setup parameter file, and sending at least one part of the setup parameter file to the instrument storage.
In another favorable method related to the invention we are organizing sets of guitar setup parameters into collections, and we are transferring one of the collections into a connected instrument.
In another favorable method related to the invention controls and switches on the instrument are programmable controls and switches, where we are determining the function of the controls and switches with the external programming device and storing this information in an instrument configuration file or in a setup parameter, which we are sending to the instrument storage.
In a favorable method related to the invention we can practically connect the external programming device to a wireless local or remote server.
In another favorable method related to the invention we are connecting the external programming device to a local or remote database server where the setup parameters can be stored, searched and downloaded.
In another favorable method related to the invention, the central database is stored on a remote computer, and access is granted to the user after a registration and identification process to the database through a central (server) application.
In another favorable method related to the invention we are operating the central application in a way, that users are able to share their instrument setup parameters with each other.
The system and method related to the invention enables electric stringed musical instrument players, especially guitar players with
The invention is further described in detail according to the attached drawings of example embodiments, where
With reference to
The electric guitar 100 includes electro acoustic transducers, in this illustrative embodiment electromagnetic pickups 101, 102, 103, continuously and discretely changeable setup switches, in this illustrative embodiment two potentiometers 111, 112, a main selector switch 121, and a secondary selector switch 122, an output jack socket 130, a LED indicator light 140 and an electronic module 200. The electronic module 200 is described in more detail in connection with
In this illustrative embodiment
The control circuit 220 is preferably a low consumption microcontroller, which has a storage, at least one AD input, a reference voltage output, more than one control outputs (GPIO) and able to communicate with the analog signal processing circuit 400 and the communication module 250 via standard bus and standard protocol.
In an embodiment, two potentiometers 111, 112 are connected to the control circuit 220 through AD inputs. The two potentiometers are preferably linear potentiometers with three terminals, which may be reference voltage Vref, ground Gnd and voltage output Vout. The reference voltage Vref is connected to the reference voltage output of the control circuit 220. The voltage output Vout is connected to an AD input of the control circuit 220. Voltage measured on the voltage output Vont determines the state of the potentiometer.
The electronic module 200, which can be mounted in an instrument, includes the communication module 250, which has a unique identifier, and is preferably a Bluetooth module. The communications module 250 can establish a connection with the external programming device 500, which is preferably a smartphone or a tablet that is capable of running an Android, IOS or similar operating system. Communication module using the Bluetooth protocol can provide connection at distances typical in a recording studio, rehearsal room, stage or in a smaller concert hall. WiFi protocol can be used for greater distances, which can also provide connection to a local area network (LAN) or to a wide area network (WAN), like the Internet. The electronic module 200, which can be mounted in an instrument preferably has a communication module 250 with at least one of the above communication protocols, while the external programming device 500 preferably has a communication module with both communication protocols available.
According to its main functions, the control circuit 220 (microcontroller):
The 220 control circuit can charge the battery in each operation mode.
The control circuit 220 turns into programmable mode, when the main selecting switch 121 is in EDIT state. In programmable mode the control circuit 220 turns on the power supply of the communication module 250 and establishes a connection with it using the UART protocol. In this mode the external programming device 500 is able to establish a Bluetooth connection with the communication module 250, and thus with the control circuit 220. The LED indicator light 140 flashes at least once, preferably twice in a second to indicate that the communication module 250 is ready and waiting for the external programming device 500 to establish a connection with it. When the external programming device 500 has connected to the communication module 250, and the control circuit 220 is in programmable mode, the LED indicator light 140 flashes at a lower rate, preferably once in every 2 seconds.
In programmable mode the external programming device 500 is capable of changing parameters of the analog signal processing circuit 400, either one by one or in a set of parameters (PRESET). Tone can be refined by changing the parameters one by one, than the final set of parameters can be stored in a uniquely named PRESET in the external programming device 500. Using the external programming device 500, each uniquely named PRESET can be selected to determine the sound quality (tone) of the analog signal processing circuit 400.
Each 101, 102 potentiometer can be assigned to certain PRESET parameters (e.g. volume, pickup mixing rate), and this assignments can be stored in an individual PRESET.
When the communication module 250 and the external programming device 500 are not in connection, and the main selecting switch 121 is in a state A, B, C, D, E, F, G, H, I or J, the control circuit 220 is operating in standalone mode. In standalone mode according to the combination of the state of the main selecting switch 121 and the secondary selecting switch 122, PRESETS are loaded from a collection stored in the storage of the control circuit 220. In this mode the communication module 250 is in power off state. The loaded/selected PRESET is being sent to the analog signal processing circuit 400 through the I2C interface of the control circuit 220. As a result, the tone of the instrument changes. If one of the potentiometers 111 and 112 are assigned to a certain PRESET parameter, turning the potentiometer will change that parameter in real time, in standalone mode the LED indicator light 140 is turned off.
In monitoring mode the main selecting switch 121 is still in one of the above mentioned states A to J, but the external programming device 500 is in connection with the control circuit 220, through the communication module 250. In this mode the external programming device 500 is displaying the actually selected PRESET with ever parameter it has. (see
The main selecting switch 121 is preferably a twelve-state main switch, which can be for example built in a guitar to replace one of the potentiometers. The main switch 121 preferably has four terminals, which may be reference voltage Vref, ground Gnd, voltage output Vout and “wake-up” contact point. The reference voltage Vref is connected to the reference voltage output of the control circuit 220 and the voltage output Vout is connected to an AD input of the control circuit 220. Voltage measured on the voltage output Vout determines the state of the switch. The “wake-up” contact point is necessary to switch the control circuit 220 to normal operation mode.
The secondary selecting switch 122 is preferably a five-state secondary switch, which can be built in a guitar to replace the pickup selector switch. The secondary selecting switch 122 preferably has three terminals, which may be reference voltage Vref, ground Gnd and voltage output Vout. The reference voltage Vref is connected to the reference voltage output of the control circuit 220. The voltage output Vout is connected to an AD input of the control circuit 220. Voltage measured on the voltage output Vout determines the state of the switch.
The pickup 310 is of a single-coil type, which has one coil and in the coil there are six magnetic or ferromagnetic elements according to the number of the strings. The coil has two wires 312 and 311; of which the wire 312 is connected to ground and the wire 311 is the actual pickup signal wire. The pickup 320 is a double coil pickup, which has two coils. The coils have one magnetic or ferromagnetic element under each string. The two coils have opposite winding directions, which greatly reduces environmental electromagnetic noise. The two coils of the pickup 320 have two wires for each. The wire 323 is connected to ground (humbucker ground), the wire 322 is the common wire of the two coils (split humbucker signal) and the wire 321 is the double coil signal wire (humbucker signal). This type of pickup can be operated in double coil (humbucker) mode, if the signal of the wire 321 is used, or it can be operated in single coil mode, if signal of the wire 322 is used.
The analog signal processing circuit 400 is capable of selecting from the pickups 101, 102, 103, switching between single coil or humbucker mode when the instrument has humbucknig pickups, mixing the selected pickup signals, changing the tone of the musical instrument by increasing and decreasing the amplitude of certain frequencies (equalization), filtering out low frequencies and transferring spectrum analyzer data. It is practical to choose a analog signal processing circuit 400 with a multi-band, preferably seven-band equalizer where increasing and decreasing frequency levels are selectable in soft step mode. It is also advantageous to have a separate mute function in each amplifying stage. The parameters of the analog signal processing circuit 400 may be digitally controlled by the control circuit 220, practically according to the stored setup parameters of the control circuit 220. I2C protocol is preferably used for connecting the control circuit 220 to the analog signal processing circuit 400. Programmable parameters of the analog signal processing circuit 400 include pickup switching parameters, pickup mixing parameters, preamp gain parameter, equalizer parameters, high pass filter parameters, output level parameter and spectrum an parameters.
As the communication module 540 of the external programming device 500 is able to establish a connection with a remote, or a local network (WAN, LAN), remote users can share instrument setup parameters with each other. Instrument setup parameters created by users can be stored in a database which may be located in a distant (server, cloud) computer. Users can access the database through a server application after a registration and authentication process.
An application running on the external programming device 500 can provide functions to the system, such as creating instrument configuration files, assigning unique instrument identifiers/names to instruments, creating and storing at least one set of setup parameters (PRESET) per instrument, connection to a selected instrument, data transfer from or to a selected instrument once or periodically, storing data transferred from an instrument and monitoring an instrument with displaying periodically transferred data. An illustrative control algorithm (application) is presented, and described in detail according to the screenshots of the external programming device 500.
In
The “NEW GUITAR” button (
Before pressing the “CREATE” button, providing a unique guitar name, a guitar specific Bluetooth address and configuration of the pickups, switch(es) and potentiometer(s) are needed. After creating a new guitar it is possible to connect to it and change the guitar setup parameters.
On this screen the number of selected pickups can be set to one, two or three. Type of the pickups, such as single coil, humbucker or “splittable” humbucker can also be configured for each pickup.
On the other “SETTINGS” screen, shown in
In the “PICKUP SELECTOR” screen, depicted in
Pickup switching parameters determine how electromagnetic pickups are taking part in the creation of the electric signal. Electromagnetic pickups can work in the following states, depending on their type: single coil mode, humbucker mode, and split humbucker mode (only one coil of a dual-coil pickup is used). In each state the pickups can be on or off.
If a guitar configuration has split humbucker pickups, then pressing a pickup icon switches the selected pickup to single coil, or humbucker mode. The three faders next to the pickup icons are pickup mixing faders. With the help of these faders, each pickup's level can be adjusted in the range of +15 dB to −79 dB with 1 db resolution in a so called “soft-step” mode. The input gain fader controls preamplifier level, the volume fader controls main volume level which can be adjusted in the range of +32 dB to −80 dB with 0.5 dB solution. The output fader controls the output level of the instrument. Pressing the name of a fader which is bordered, brings up the “ASSIGN POTENTIOMETER” screen (
The seven-band equalizer has a −15 to +15 dB range with 1 dB resolution, and four selectable quality factors for each band (Q=1; Q=1,4; Q=1,8; Q=2,2). The lowest and the two highest cutoff frequencies are selectable (62 or 100 Hz, 4 KHz or 6.3 Khz, 15 KHz or 16 KHz). On the right hand side of the screen there is the same volume fader known from the pickup selector screen. On the upper menu bar “TU” button brings up the “TUNER” screen (
On the editing screen (
On the MANAGE PRESETS (
Pressing the Collections button in the main menu (
The maximum size of the collection list is determined by the number of positions the selecting switches can have. According to the presented exemplary embodiment of the invention, the main selecting switch has ten positions and the secondary selecting switch has five positions capable of preset assignment which means that a collection list can contain up to fifty items. Indicating the positions of the main selecting switch with A, B, C, D, E, F, G, H, I, J and the positions of the secondary selecting switch with 1, 2, 3, 4, 5, the switch combinations are A1, A2 . . . J4 and J5. Indicating presets with P1, P2 . . . Pn, the elements of a C1 collection can be described by a set C1={P1, P2 . . . Pna}. Presets can be assigned to a collection list according to the following example A1=P1; A2=P2; A3=P3; . . . J5=P50.
A collection can be edited, deleted and sent to an instrument on the PRESET COLLECTION EDIT screen depicted in
On the SPECTRUM ANALYZER screen (
9V—Voltage of the audio signal processing circuit (this illustrative embodiment runs on 9V), which is generated from the 4V of the Li-ion battery.
mAh—Battery capacity in mAh.
%—Battery capacity in percentage.
Vbatt—Battery voltage.
Ibatt—Battery charging current.
PWM—Duty cycle of the boost converter used for producing 9 Volts.
K1—Position of the main selecting switch (OFF, EDIT, A, B, C, D, E, F, G, H, I, J)
K2—Position of the secondary selecting switch (1, 2, 3, 4, 5)
I2C—Number of the I2C communications.
Temp—Temperature of the instrument's control circuit.
Pressing the IMPORT button under the MANAGE PRESETS screen (
| Number | Date | Country | Kind |
|---|---|---|---|
| P1700403 | Sep 2017 | HU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/HU2018/000040 | 9/27/2018 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/064035 | 4/4/2019 | WO | A |
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| Number | Date | Country |
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| 2787501 | Oct 2014 | EP |
| Entry |
|---|
| Machine English translation of EP2787501A1. |
| Number | Date | Country | |
|---|---|---|---|
| 20200320968 A1 | Oct 2020 | US |
