5 out of 5
Bash 300S Digital Subwoofer Plate Amplifier 300W RMS
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Product Description
Manufacturer Part Number: 300S
BASH's patented 300 watt Subwoofer Amplifier technology was developed to offer extreme amounts of power with an efficient operation that escapes most traditional amplifier designs.
Key Features:
Bash 300S Digital Subwoofer Plate Amplifier 300W RMS
BASH patented amplifier technology was developed to offer extreme amounts of power without the wasted heat and energy of traditional amplifier designs. Add to this an intelligent circuit design, and you get benefits such as extremely low distortion and high signal to noise ratios. The combination of clean output and high power makes the BASH amplifiers some of the best sounding subwoofer amplifiers on the market. Features: 50 to 150 Hz low-pass crossover, 0° or 180° phase, line level inputs, speaker level inputs, LFE input, master on/off switch, auto on.
Specifications:
300 watts RMS @ 0.5% THD into 4 ohm load
Signal to noise ratio: 105 dB (A-weighted)
Line-in and high-level in crossovers: Adjustable 50 to 150 Hz, 12 dB/octave low-pass crossover
LFE-in crossover: Fixed 330 Hz, 12 dB/octave low-pass crossover
Power requirements: 120 VAC, 60 Hz
Dimensions: 11" W x 7" H x 3-1/2" D
Cabinet cutout: 10" x 6-1/4"
Connections and ControlsOn/Auto/Standby Switch Set to Auto to allow the amplifier to automatically turn on and off as a signal is sensed. Set to On for "always on" mode. Set to "Standby" for standby mode.
Phase Switch 0° or 180° selectable, 0° is normal phase, 180° will reverse the polarity of the subwoofer output
Volume Control Adjusts the output level of the amplifier
Freq Sets the low-pass crossover frequency, adjustable from 50 to 150 Hz
Line Level Inputs For connection to a full-range stereo line level signal, use the left and right line level inputs; the on-board low-pass crossover will be in effect. For connection to the subwoofer out on a home theatre receiver, use either the LFE input to bypass the internal crossover or the Left or Right input for additional crossover flexibility.
Hi Level Inputs Allows the connection of the amplifier to a speaker level output from a stereo amplifier or receiver
AC Mains Input Fused IEC input with 3 amp 250V GMA-style fast blow fuse; accepts standard male IEC cord
On/Off Switch Turns master power on and off
1. Locate R26 and R25 on the pre-amp board, the default values are R26=30K and R25=120K. R26 and R25 are located on the small vertical PC board adjacent to the phase reversal switch.
2. Remove the existing resistors by using a low wattage soldering iron and desoldering braid. Be careful not to apply too much heat to the PC board traces.
3. Using the charts below, determine the proper resistor values to achieve the desired boost. New resistors can be any wattage 1/4 or greater, but 1/4 will physically fit best. Note: values are in k Ohms.
4. Install the new resistors and solder in place making sure you put the correct resistor in the proper location.
BASH's patented 300 watt Subwoofer Amplifier technology was developed to offer extreme amounts of power with an efficient operation that escapes most traditional amplifier designs.
Key Features:
- High power output in a compact, lightweight design
- Speaker and line level inputs for connection to any stereo
- Limiting circuit prevents audible clipping and protects woofers
- Excellent choice use in new designs or even retrofitting existing subwoofers
- No wasted heat and energy for efficient operation
Bash 300S Digital Subwoofer Plate Amplifier 300W RMS
BASH patented amplifier technology was developed to offer extreme amounts of power without the wasted heat and energy of traditional amplifier designs. Add to this an intelligent circuit design, and you get benefits such as extremely low distortion and high signal to noise ratios. The combination of clean output and high power makes the BASH amplifiers some of the best sounding subwoofer amplifiers on the market. Features: 50 to 150 Hz low-pass crossover, 0° or 180° phase, line level inputs, speaker level inputs, LFE input, master on/off switch, auto on.
Specifications:
300 watts RMS @ 0.5% THD into 4 ohm load
Signal to noise ratio: 105 dB (A-weighted)
Line-in and high-level in crossovers: Adjustable 50 to 150 Hz, 12 dB/octave low-pass crossover
LFE-in crossover: Fixed 330 Hz, 12 dB/octave low-pass crossover
Power requirements: 120 VAC, 60 Hz
Dimensions: 11" W x 7" H x 3-1/2" D
Cabinet cutout: 10" x 6-1/4"
Connections and ControlsOn/Auto/Standby Switch Set to Auto to allow the amplifier to automatically turn on and off as a signal is sensed. Set to On for "always on" mode. Set to "Standby" for standby mode.
Phase Switch 0° or 180° selectable, 0° is normal phase, 180° will reverse the polarity of the subwoofer output
Volume Control Adjusts the output level of the amplifier
Freq Sets the low-pass crossover frequency, adjustable from 50 to 150 Hz
Line Level Inputs For connection to a full-range stereo line level signal, use the left and right line level inputs; the on-board low-pass crossover will be in effect. For connection to the subwoofer out on a home theatre receiver, use either the LFE input to bypass the internal crossover or the Left or Right input for additional crossover flexibility.
Hi Level Inputs Allows the connection of the amplifier to a speaker level output from a stereo amplifier or receiver
AC Mains Input Fused IEC input with 3 amp 250V GMA-style fast blow fuse; accepts standard male IEC cord
On/Off Switch Turns master power on and off
Modifying Bass Boost
1. Locate R26 and R25 on the pre-amp board, the default values are R26=30K and R25=120K. R26 and R25 are located on the small vertical PC board adjacent to the phase reversal switch.
2. Remove the existing resistors by using a low wattage soldering iron and desoldering braid. Be careful not to apply too much heat to the PC board traces.
3. Using the charts below, determine the proper resistor values to achieve the desired boost. New resistors can be any wattage 1/4 or greater, but 1/4 will physically fit best. Note: values are in k Ohms.
4. Install the new resistors and solder in place making sure you put the correct resistor in the proper location.
Product Details | |
|---|---|
| Brand | Bash |
| Model | 300S |
| Part Number | 300-750 |
| UPC | 844632001383 |
| Unit of Measure | Each |
| Weight | 3.75 |
Attention CA Residents: Prop 65 Warning
WARNING:
This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.
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Customer Reviews
By Charles Robbins
Date: October 09, 2025
Was the same brand as the original amplifier so some of the holes lined up with the existing ones in the cabinet, but being 1 narrower I had to make a plate to fill the void. I guess that's why an exact Polk replacement was $100 more for basically the same thing. Sounds just the original.
Rating: 
[5 of 5 Stars!]
[5 of 5 Stars!]
By BRB
Date: April 16, 2025
Bought two (built two 15 inch subwoofers with them). Great sound, no issues at all. Used for surround sound system.
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By Vinny Fanelli
Date: July 09, 2022
worked good for my klipch 1234;. Got that house shaking again!
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By Cole
Date: July 02, 2022
works great, exactly as described
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By john ewald
Date: June 02, 2022
Love it .....just get it. ...way better then a powered sub box you get at Walmart. Lol....wake your surround up with this
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]
By Cool Bc
Date: May 26, 2022
Great and it brought my klh sub back better than new sound I
Rating: [5 of 5 Stars!]
[5 of 5 Stars!]