Musical instrument crossover circuits and method of using same

• US 5,814,752 A
• Filed: 01/15/1997
• Issued: 09/29/1998
• Est. Priority Date: 01/15/1997
• Status: Expired due to Term

• Current Assignee: Rivera Amplification Inc.
• Original Assignee: Paul E. Rivera
• Inventors: Rivera, Paul E.
• Primary Examiner(s): Witkowski, Stanley J.
• Application Number:
  US08/782,304
• Time in Patent Office: 622 Days
• Field of Search: 84/622-633, 84/661, 84/665, 84/699, 84/700, 84/711, 84/723-736, 84/741, 84/DIG. 1, 84/DIG. 9, 330/124 R-142, 381/28, 381/118, 381/120, 381/121
• US Class Current: 84/711
• CPC Class Codes: G10H 1/12 by filtering complex waveforms G10H1/14, G10H1/16 take precedence
• CPC Class Codes: H03G 5/12 incorporating negative feedback
• CPC Class Codes: H04R 3/14 Cross-over networks
• CPC Class Codes: Y10S 84/01 Plural speakers
• CPC Class Codes: Y10S 84/09 Filtering

Abstract

A musical instrument amplifier system (FIGS. 1 and 2) with a frequency selective crossover circuit (10) using passive band pass filters (36, 44) to separate the amplified signals from the power amplifier (14) of an amplifier system (12) into low frequency signals on an output connector (42) for a specially adapted bass audio speaker (38) while the higher frequency signals are applied to another speaker (46). The crossover circuit (10) is selectively connected with the normal speaker output (24) in lieu of the speaker (38) to add frequency crossover capability to any amplifier system. In another musical instrument amplifying system (88), the crossover circuit (FIG. 4, 122, 124, 130, 132) is internal to an amplifier system (90) and produces preamplified low frequency signals on a special output terminal (102) for power amplification by an external power amplifier (94) while the preselected low frequency signals are blocked from the internal power amplifier (118) so it produces only the relatively middle and high frequencies at the normal speaker output connector (98). The preselected low frequency signals bypass a special effects section (112) so that special effects is selectively only produced by the internal power amplifier (118) in the relatively middle and high frequency range, while the power of the external bass power amplifier (94) is separately adjustable from the adjustment to the power level of the internal power amplifier (118). When the external power amplifier is disconnected, the internal high pass filter (124) blocking low frequency signals to the internal power amplifier (118) is automatically removed to allow full frequency amplification by the internal power amplifier (118).

Claims

1. A method of selectively amplifying musical instrument signals comprising the steps of:

producing power amplified signals of signals of all frequencies on a speaker output connector of a base unit amplifier;

when normal operation is desired, selectively connecting the speaker output connector to a regular speaker to reproduce the amplified musical instrument signals of all frequencies; and

when large bass frequency amplification is desired,

selectively connecting the output connector to a crossover circuit to separate the power amplified musical instrument signals into relatively low and relatively high frequency signals components,

connecting the relatively low frequency component signal to a bass speaker especially adapted to reproduce relatively low frequency signals, and

connecting the relatively high frequency component signal to another speaker.

2. The method of claim 1 in which the other speaker is the regular speaker.

3. The method of claim 1 in which said crossover circuit performs the step of separating the power amplified signals into relatively low and relatively high frequency components by means of passive filter circuits.

4. In a musical instrument amplifying system having an internal power amplifier circuit with an input and an output, an input connector for releasable connection with an output cable of the musical instrument carrying musical instrument signals having different frequencies, and an output terminal for connection of the output of the internal power amplifier with an audio speaker, the improvement being a frequency selective crossover circuit, comprising:

a special output terminal;

means selectively blocking from the input of the internal power amplifier circuit musical instrument signals of only a preselected frequency range, the musical instrument signals of frequency outside said preselected frequency range being provided to the internal power amplifier for amplification; and

means for passing to the special output terminal, musical instrument signals of another frequency range within the preselected range blocked from the input of the internal amplifier by said selective blocking means.

5. The musical instrument amplifying system of claim 4 in which the other frequency range of the signals applied to the special output terminal is substantially the same frequency range as the one preselected frequency range blocked by said blocking means.

6. The musical instrument amplifying system of claim 4 in which the other frequency range of the musical instrument signals applied to the special output terminal include relatively low bass frequencies.

7. The musical instrument amplifying system of claim 6 in which the preselected frequency range of the musical instrument signals which are blocked are relatively low frequencies.

8. The musical instrument amplifying system of claim 4 in which the preselected frequency range of the musical instrument signals which are blocked are the relatively low bass frequencies.

9. The musical instrument amplifying system of claim 4 including

a special effects circuit for imposing special effects signal processing on the musical instruments signals from the input connector;

and

means for interposing the selective blocking means between the special effects circuit and the input of the internal power amplifier to block from the internal power amplifier special effects processed signals in the frequency range that is blocked while allowing special effects processed signals outside of the blocked frequency ranges to be amplified by the internal power amplifier.

10. The musical instrument amplifying system of claim 9 including means for bypassing the special effect circuit with the musical instrument signals passed to the special output terminal to enable power amplification of special effect processed signals only if they are passed to the input of the internal power amplifier.

11. The musical instrument amplifying system of claim 4 in which said selective blocking means includes

means for filtering out musical instrument signals while outside of the other frequency range which is passed to the input of the internal amplifier, and

means for selectively switching the filtering means into circuit with the internal amplifier.

12. The musical instrument amplifying system of claim 11 in which said selective switching means includes means responsive to the making a cable connection with the special output terminal for automatically switching the filtering means into circuit to block the musical instrument signals in the preselected frequency range from being applied to the internal power amplifier.

13. The musical instrument amplifying system of claim 12 in which the special output terminal is a jack receptacle with a tip connector which moves when engaged by a male jack connector and said selective switching means includes means responsive to movement of said tip connector.

14. The musical instrument amplifying system of claim 4 in which the means for passing includes

a low pass filter for passing signals in a relatively low frequency range to the special output terminal, and

means for connecting the low pass filter between the input terminal and the special output terminal.

15. The musical instrument amplifying system of claim 14 in combination with

an acoustic speaker, and

an external power amplifier with an input connected to the special output terminal and an output connected to the acoustic speaker.

16. The musical instrument amplifying system of claim 15 in which the acoustic speaker is especially adapted for a good linear response to relative low frequency signals.

17. The musical instrument amplifying system of claim 15 in which said external power amplifier has means for adjusting its output power to the acoustic speaker.

18. A method of selectively amplifying musical instrument signals comprising the steps of:

employing a base amplifier unit with an internal power amplifier for amplifying musical instrument signals of the full frequency range at a regular speaker output connector and for producing preamplified musical instrument signals of only a preselected frequency range at a special output connector;

connecting an external power amplifier to the special output connector for power amplifying the preamplified musical instrument signals of the only preselected frequency range; and

selectively blocking musical instrument signals within the preselected frequency range from being amplified by the internal power amplifier.

19. The method of claim 18 in which said step of selective blocking includes the step of selectively blocking automatically in response to connection of the external power amplifier to the special output terminal.

20. The method of claim 18 in which said step of blocking is only selectively performed when the external power amplifier is connected to the special output connector.

21. The method of claim 18 in which said preselected frequency range includes the relatively low frequencies and including the steps of

using the external power amplifier to drive a bass speaker especially adapted for producing signals in the preselected low frequencies, and

using regular broad band speakers to reproduce relatively higher frequency musical instrument signals from the internal power amplifier.