Onyx NX12FD - Car speaker BOSS - Free user manual and instructions

Product type	Car speaker (subwoofer)
Brand	Boss
Model	Onyx NX12FD
Diameter	12 inches (305 mm)
Impedance	Dual 4 Ω voice coils (selectable 2 Ω, 8 Ω)
RMS Power	900 W
Peak Power	1800 W
Frequency Response	28 Hz – 2 kHz
Resonant Frequency (Fs)	39.5 Hz
Sensitivity	95 dB (1 W/1 m)
Xmax (linear excursion)	0.32 inches (8.1 mm)
Equivalent Volume (Vas)	1.43 – 1.56 ft³
Total Q Factor (Qts)	0.53 – 0.55
Cone Material	Polypropylene
Suspension Material	Butyl Rubber
Voice Coil	Dual 2 inches (51 mm) high-temperature black aluminum
Mounting Depth	3 inches (76 mm)
Mounting Diameter	12.874 inches (327 mm)
Recommended Enclosure Type	Sealed or ported
Recommended Sealed Enclosure Volume	0.63 ft³ (17.8 L)
Recommended Ported Enclosure Volume	0.92 ft³ (26 L) with 3 x 9 inch vent
Vent Tuning Frequency	39 Hz
Power Supply	12 V DC (car audio system)

Frequently Asked Questions - Onyx NX12FD BOSS

How to wire a dual voice coil subwoofer?

The Boss Onyx NX12FD has two 4 Ω voice coils. You can wire them in series (8 Ω), in parallel (2 Ω), or use a single coil (4 Ω). Choose the wiring based on the impedance supported by your amplifier.

What enclosure volume is recommended for this subwoofer?

For a sealed enclosure, the recommended internal volume is 0.63 ft³ (17.8 L). For a ported enclosure, the volume is 0.92 ft³ (26 L) with a 3 inch diameter by 9 inch long vent tuned to 39 Hz.

Can I use this subwoofer in a free air configuration?

No, this subwoofer is designed to be installed in a sealed or ported enclosure. Using it in free air could damage the speaker.

What amplifier power should I use?

The RMS power of the subwoofer is 900 W. It is recommended to use an amplifier delivering between 600 and 900 W RMS at the chosen load impedance for optimal performance.

How to set the low-pass filter?

Set your amplifier's low-pass filter between 80 and 100 Hz to avoid mid and high frequencies. The subwoofer reproduces frequencies from 28 Hz to 2 kHz, but it is preferable to cut around 80-100 Hz.

Is a break-in period required for the subwoofer?

Yes, it is recommended to run the subwoofer at low volume for the first hours (10-20 hours) to soften the suspension and stabilize parameters.

What is the mounting depth of this speaker?

The mounting depth is 3 inches (76 mm). Ensure your enclosure has enough space to install the subwoofer without obstruction.

Is this subwoofer suitable for marine use?

Yes, the Boss Onyx NX12FD is a marine subwoofer with a polypropylene cone and moisture-resistant butyl rubber suspension. It can be installed in humid environments.

How to convert enclosure volumes to liters?

1 ft³ = 28.3 liters. So 0.63 ft³ ≈ 17.8 L and 0.92 ft³ ≈ 26 L. Use these conversions to build your enclosure.

What material should I use to build the enclosure?

It is recommended to use 3/4 inch (19 mm) thick MDF (medium-density fiberboard). Ensure the enclosure is perfectly airtight.

USER MANUAL Onyx NX12FD BOSS

Recommended Enclosures

Please note : Our recommended box volumes are given for internal air requirements.

NX12FD Amplitude Response(dB/Hz)

Frequency

Box Volume: 0.63 Cu Ft

These woofers are recommended to be used with sealed enclosures Box is given as internal air volume including driver displacement

NX12FD Amplitude Response(dB/Hz)
Frequency

Ported Enclosure

Box Volume: 0.92 Cu Ft

Box is given as internal air volume including driver displacement

Port Frequency : 39 Hz
Port Diameter : 3 Inches
Port Length : 9 Inches

Product Specifications

Speaker Impedance

Free Air Resonance	(Fs)	39.5Hz	39.5Hz	39.5Hz
Total Q Driver @ FS including all resistance's	(Qts)	0.534	1.087	0.548
Q of the Driver @ FS including non electrical resistance only	(Qms)	7.213	7.242	7.254
Q of the Driver @ FS including electrical resistance only	(Qes)	0.642	1.279	0.635
The Driver's compliance expressed as an equivalent	(Vas)	1.426	1.507	1.562
Volume of all (cubic Ft.)
The Driver's linear displacement (inches)	(Xmax)	0.32	0.32	0.32
The DC resistance of the driver's twin voice coils(ohms)	(Re)	1.8Ω	3.6Ω	7.2Ω
Thermal Power rating of Driver (R.M.S./Peak)	(Pe)	900w/1800w	900w/1800w	900w/1800w
The Driver's sensitivity (dB)	(Sens)	95dB	95dB	95dB

Calculating Enclosures

It is difficult to give exact box dimensions that are universal for all cars and trucks. It is for this reason that you must be able to calculate the space in which you have available in order to achieve the proper air volume required.

It is recommended to build your enclosure from 3/4" thick MDF (medium density fiberboard).
Make sure the enclosure is sealed air tight.

Calculating External Volume

1) To calculate box volume, measure the outside Width x Height x Depth of the enclosure. Example 12'' × 14'' × 9'' = 1512''
2) Next you must convert cubic inches into cubic feet. To do this, You must divide the cubic inch total by 1728". Example 1512 ÷ 1728 = .875 Cubic feet

Calculating Internal Volume

1) To calculate the internal (net) volume of the above box you must first multiply the thickness of the wood you are using by Two (2) Example; 3/4'' × 2'' = 1.5''
2) Next Subtract 1.5 from each of the outside measurements of the box. Width 12 - 1.5 = 10.5 Height 14 - 1.5 = 12.5 Depth 9 - 1.5 = 7.5
3) Multiply the new totals (H x W x D) Example : 10.5 x 12.5 x 7.5=984.375
4) Next you must convert cubic inches into cubic feet. To do this, you must divide the cubic inch total by 1728" Example 984.375 ÷ 1728 = .5696 Cubic feet

Wiring

for the correct impedance

12”(305mm) Marine Woofer

(900 Watts RMS Sealed Enclosure)

12"(305mm) CUSTOM TOOLED HIGH EFFICIENCY
Polypropylene Cone
BUTYL RUBBER SURROUND
■ DUAL 2"(51mm) High Temperature Black Aluminum Voice Coil
1800 watts peak/900 watts RMS
FREQUENCY RESPONSE:28Hz-2KHz
■ SENSITIVITY:95dB(1WATT/1METER)
■ IMPEDANCE:DUAL 4 OHMS
■ MOUNTING DEPTH:3"(76mm)
MOUNTING DIAMETER:12.874"(327mm)