Active Instrument Subwoofer System for Low Frequency Enhancement

Abstract

An instrument amplification system provides improved low frequency enhancement. A powered subwoofer system enhances the low frequency components of a standard instrument amplifier by incorporating a speaker level high-pass filter crossover network 5 prior to connection to a standard instrument speaker. The speaker level instrument amplifier output is also attenuated, low-pass filtered and re-amplified to drive a dedicated low frequency subwoofer speaker. In one embodiment, a single speaker cabinet connects via a single speaker cable and includes both typical instrument speakers and an active powered subwoofer system. In another embodiment, a stand alone active powered 10 subwoofer connects to a standard instrument amplifier and includes a speaker level high-pass crossover output for connection to a standard instrument speaker cabinet. The instrument amplifier speaker output is attenuated, low-pass filtered, re-amplified and connected to a low frequency subwoofer speaker. A differential attenuator is incorporated allowing connection to instrument amplifiers with differential bridge 15 outputs.

1 . A method of enhancing the low frequency audio components of an instrument amplifier output signal comprising the steps of:
 applying the instrument amplifier output signal to an instrument speaker;   attenuating the instrument amplifier output signal to produce a line level signal;   low-pass filtering the line level signal to provide a filtered signal;   amplifying the filtered signal to provide an amplified filtered signal; and   applying the amplified filtered signal to a low frequency speaker.   
     
     
         2 . A system for enhancing the low frequency audio components of an instrument amplifier output signal comprising:
 an instrument speaker receiving said instrument amplifier output signal;   means for attenuating the instrument amplifier output signal to produce a line level signal;   means for low-pass filtering said line level signal to provide a filtered signal;   means for amplifying said filtered signal to provide an amplified filtered signal; and   a low frequency speaker receiving said amplified filtered signal.   
     
     
         3 . (canceled) 
     
     
         4 . A system according to  claim 2 , said attenuating means comprising a differential attenuator. 
     
     
         5 . A system according to  claim 2  further comprising means for adjusting said amplified filtered signal.