About the Kicker 51HS8
Product highlights:
- Featured in our article: Best car powered subwoofers for 2025
- compact powered subwoofer
- 8" woofer
- built-in 150 watt RMS amplifier
- frequency response: 25-120 Hz
- variable low-pass crossover (50-120 Hz)
- high-pass crossover (25 Hz)
- variable phase control (0 or 180 degrees)
- bass boost control (0dB to +6dB)
- speaker-level inputs (will also accept preamp-level signal using optional adapter, item 20646KiSL, sold separately)
- auto turn-on switch
- wired remote bass control
- dimensions: 15.13"W x 3.13"H x 9.25"D
- warranty: 1 year
- MFR # 51HS8
- Item # 20651HS8
- California customers: Please click here for your Proposition 65 WARNING.
What's in the box:
If you need assistance accessing this owner's manual, please give us a call.
- 8" Amplified subwoofer
- Wiring harness (17' Power input/ 8' Speaker level input/ 2' Ground/ 2' Remote turn-on)
- 12" Power wire with in-line fuse holder and installed 15A ATO fuse
- Two 10A ATO fuses (1 installed in the chassis of the unit/1 spare)
- Remote bass level control
- 19.5' Remote cable (3.5mm TRS plugs on both ends)
- Two 29" nylon mounting straps
- 4 Mounting brackets
- Four 1-1/2" screws
- Four 3/4" pan head screws
- Eight 3/4" flat head screws
- Two 3/8" screws
- 4 Flat washers
- Two 10-12 gauge crimp-on ring terminals
- One 10-12 Gauge butt connector
- Mounting template
- Owner's manual (En/ Sp/ Ge/ Fr)
More details on the Kicker 51HS8
Researched by Crutchfield's Pat M.
Features & specs
| General | ||
|---|---|---|
| Enclosure Type | Sealed | |
| Finish Material | Aluminum | |
| Grille | Metal mesh | |
| Connector Type | Harness | |
| Quick-disconnect Plug | Yes | |
| Bi-amp Inputs | N/A | |
| Woofer Size (inches) | 8 | |
| Woofer Material | Not given | |
| Passive Radiator | --- | |
| Width | 15-3/16" | |
| Height | 3-3/16" | |
| Depth | 9-1/4" | |
| Parts Warranty | 1 Year | |
| Labor Warranty | 1 Year | |
| Specifications | ||
| Frequency Response | 25-120 Hz | |
| Amplifier Power (RMS) | 150 watts | |
| Maximum Wattage | N/A | |
| Sensitivity | N/A | |
| Impedance | N/A | |
| Second Voice Coil Impedance | N/A | |
| Crossover Point | 50-120 Hz | |
The Kicker 51HS8 replaces these items:
Product Research
Features
Overview: The Kicker Hideaway HS8 (51HS8) subwoofer features a built-in 150W RMS amplifier and an 8" sub housed in a compact enclosure designed to fit in tight spaces.
Remote Control: The wired remote puts output level control within easy reach. The remote comes features an integrated bracket to mount it under the dash. The included 19.5' cable, with 3.5mm TRS plugs on each end, connects the remote to the amplifier.
Note: The Remote Bass Control measures approximately 1.65" wide x 1.03" high x 1.27" deep (3.20" deep including the knob and cable).
Subsonic Filter: A built-in subsonic filter improves the performance of the subwoofer by eliminating frequencies that are too low for the subwoofer to play. The 24 dB/octave subsonic filter's crossover point is 25 Hz. The subsonic filter cannot be disengaged.
Mounting: The subwoofer, with its 3-1/8" height, can be mounted in applications with limited space, even under a seat in the passenger compartment of many vehicles.
Controls:
- Auto Turn-on: two position switch
- +12V: amp turns on when 12 volts is applied to the remote turn-on wire
- DC: amp turns on when a signal is present on the speaker-level input
- Input Level: two position switch
- Hi: accepts signal input from 250mV to 10 volts
- Lo: accepts signal input from 125mV to 5 volts
- Phase: two position switch; set the subwoofer phase to 0° or 180°
- Bass Boost: rotary dial to adjust the bass boost; continuously variable from 0 to 6 dB; boost centered at 40 Hz
- Crossover Frequency: rotary dial to control the low pass crossover frequency; 50 to 120 Hz; 12 dB/octave slope
- Gain: rotary dial to set the amplifier gain control; 250mV to 10 volts for speaker level inputs and 125mV to 5 volts for line level inputs
Connections:
- Harness: The Quick-Connect harness has wires for power (17 feet), ground (2 feet), remote turn-on (2 feet), and signal input (8 feet). If using a speaker level input, just splice into the wire in the harness. If using a line level input, a speaker wire to RCA adapter is needed (sold separately). The included in-line fuse holder should be added to the power wire at the battery location
- Remote Bass: 3.5mm mini-jack for use with the included wired remote
- Fuse: one 10-amp ATO fuse installed in the chassis.
The Kicker 51HS8 replaces these items:
- enclosure with one 8" woofer
- built-in amplifier (150 watts RMS)
- fits under most vehicle seats
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Customer Q&A
6 questions already asked
Q
Looking to install under the drivers seat on a 2025 CRV Hybrid, which speakers to tap for signal ? are speaker cables included ? any tips and recommendations
arda Jun 21, 2025
1 answer
A
Greetings Arda. If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can get you the best location and the color codes to tap into for your subwoofers signal. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website.
If you did not purchase the unit from Crutchfield, then you can try contacting the manufacture at 405-624-8583
thomas Jun 21, 2025 (Staff)
Q
Can you hook 2 up one under each seat?
cody alan Jun 16, 2025
1 answer
A
If the Kicker 51HS8 powered subwoofers are a physical fit in your vehicle Cody, you can install one under each seat.
bo Jun 16, 2025 (Staff)
Q
2023 Hyundai Elantra here with wireless car play. No Bose emblem on the door. Will an installer be able to install with no extra kits/wires needed?
johnny May 09, 2025
1 answer
A
Greetings Johnny. Thank you for your question. The Kicker 51HS8 comes with the power, ground remote volume knob, and speaker input level harness. An installer would need to use some speaker wire, and some wire taps to get the signal into the powered sub with a factory radio.
thomas May 10, 2025 (Staff)
Q
for signal do i tap into the front left/right wires, or the rear left/right wires? installing in a 22 wrx factory 11" display headunit.
adiel Mar 27, 2025
1 answer
A
In most installs Adiel, the front speaker wires will provide the strongest input signal for your Kicker 51HS8 subwoofer.
bo Mar 28, 2025 (Staff)
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No additional amp, paired with 6 Infinity Reference Speakers. Much needed upgrade without being overkill. 23' Subaru WRX premium. Great customer service. Crutchfield Charlottesville, VA.
Blake from Hendersonville, TN