JBL Club 1024 / Club 1224 Subwoofer Owner's Manual
Introduction
Thank you for choosing JBL Club subwoofers. These Reference subwoofers are designed for a wide range of automotive sound systems and can perform in various enclosure types, delivering enhanced, powerful bass in the limited space of a vehicle.
For optimal performance, professional installation is recommended. While this manual provides general guidelines for subwoofer installation, it lacks specific enclosure or mounting details for particular vehicles. If you do not feel qualified, do not attempt self-installation; consult an authorized JBL dealer for professional installation options.
Keep your proof of purchase and this manual in a safe place for future reference.
Safety Information
WARNING: Playing music at high volumes in a vehicle can mask surrounding sounds and cause permanent hearing damage. The maximum sound levels achievable with JBL speakers and high-power amplifiers may exceed safe levels for prolonged listening. Use low volume levels while driving. JBL, Inc. is not responsible for hearing loss, personal injury, or property damage resulting from the use or misuse of this product.
Vehicle Bass Reproduction
Depending on the listening space size within a vehicle, bass frequencies below 80 Hz can be reinforced by approximately 12 dB per octave as frequencies decrease. This phenomenon, known as the in-car response, significantly impacts the subwoofer's frequency response in a vehicle.
Subwoofer Enclosure Types
Subwoofers are designed for optimal performance in medium-sized sealed enclosures, vented enclosures, and prefabricated bandpass enclosures. Infinite baffle mounting is possible, but the subwoofer's mechanical power handling will be reduced due to the lack of air to stiffen the suspension and prevent over-excursion. For infinite baffle installations, halve the RMS and peak power handling ratings specified in this manual.
The enclosure type should be chosen based on the available space, the power driving the subwoofer(s), and listening habits.
Sealed Enclosures
Air in a sealed enclosure is compressed when the subwoofer cone moves backward and rarefied when it moves forward. In both cases, the air inside and outside the chamber will equalize, pushing and pulling the subwoofer cone. This results in a stiffer suspension compared to free-air designs. Consequently, the subwoofer cone will be more resistant at lower frequencies, protecting the unit from physical overload but requiring more power to achieve the desired sound.
Advantages of Sealed Enclosures:
- In-car performance will exhibit the flattest overall frequency response.
- In-car response will have the widest bandwidth (usable in-car low-frequency response will extend below 20 Hz).
- An optimal sealed enclosure will always be smaller than an optimal enclosure of any other type.
Disadvantages of Sealed Enclosures:
- An optimal sealed enclosure will have lower efficiency than an optimal enclosure of another type.
- A subwoofer in an optimal sealed enclosure requires more amplifier power to achieve the desired acoustic output than an optimal enclosure of another type.
Sealed Enclosure Construction:
A sealed enclosure features a simple design with high tolerance for calculation errors in volume, though air leaks must be avoided. Construct the enclosure using medium-density fiberboard (MDF), glue, and screws, then seal all joints with silicone.
Recommendation for Sealed Enclosures:
Subwoofers in sealed enclosures are best suited for enthusiasts seeking accurate sound reproduction and flat frequency response, those with limited space for a subwoofer enclosure, or those who have allocated significant amplifier power. The sealed enclosure design presented in this manual offers the best compromise for deep low-frequency extension and flat response.
Vented Enclosures
A vented enclosure behaves like a sealed enclosure above its tuning frequency (resonance). At resonance (determined by the vent), the vent is the primary sound source – the subwoofer cone is nearly stationary while the air within the vent vibrates. This provides greater mechanical power handling at and above resonance but reduced mechanical power handling below resonance. Since the subwoofer cone and voice coil move very little at resonance, airflow through the voice coil is limited, and thermal power handling is slightly reduced at resonance.
Vented enclosures offer better efficiency in the 40 Hz - 60 Hz range at the expense of output in the lowest octave (below 40 Hz). A subsonic filter is recommended for vented enclosures. An optimal vented enclosure for a subwoofer is larger than an optimal sealed enclosure.
Advantages of Vented Enclosures:
- An optimal vented enclosure offers greater efficiency and higher sound output in the 40 Hz - 60 Hz range than an optimal sealed enclosure.
- An optimal vented enclosure produces more palpable bass than an optimal sealed enclosure.
- A subwoofer in an optimal vented enclosure requires less amplifier power to achieve the desired acoustic output (including the enclosure's resonant frequency) than an optimal sealed enclosure.
Disadvantages of Vented Enclosures:
- Reduced sound output at the lowest octave (below 40 Hz).
- Reduced mechanical power handling below the enclosure's resonant frequency. Using an electronic subsonic filter is recommended to limit the risk of over-excursion below the enclosure's resonant frequency.
- An optimal vented enclosure will always be larger than an optimal sealed enclosure.
Vented Enclosure Construction:
Vented enclosure construction is more complex than sealed enclosures. Enclosure and port dimensions have a specific relationship to the subwoofer's physical and electromechanical parameters, requiring strict adherence to recommended enclosure and port specifications. As with sealed enclosures, use MDF, glue, and screws, and seal all joints with silicone.
Recommendation for Vented Enclosures:
Subwoofers in vented enclosures are recommended for enthusiasts seeking pronounced bass response, those with ample space for the unit, or those using less powerful amplifiers. For optimal performance, strictly adhere to port dimensions and volume levels.
Subwoofer Mounting
Subwoofers should be mounted externally to the enclosure. Use the included foam gasket to seal the connection between the subwoofer frame and the enclosure.
Subwoofer Connection
Impedance Setting
Club subwoofers feature a Selectable Smart Impedance™ (SSI) switch. This unique feature allows you to set the impedance to 2 ohms or 4 ohms using a switch (refer to illustrations below). This enables users to fully utilize their subwoofer amplifier's potential in any situation.
The 2-ohm SSI setting increases the subwoofer's sound output level by up to 3 dB compared to the 4-ohm setting, depending on the amplifier. All other performance parameters remain unchanged. If your amplifier is designed for 2-ohm operation and its power ratings at 2 ohms are within the subwoofer's handling capabilities, setting the SSI switch to 2 ohms will achieve the highest possible sound output level.
Illustration Description: Two diagrams show the SSI switch. One labeled "2-ohm setting" shows the switch in the "2Ω" position. The other labeled "4-ohm setting" shows the switch in the "4Ω" position.
Amplifier Connection
Subwoofer terminals are compatible with quick-disconnect (not included) and soldered connections. The recommended cable gauge is 14 AWG to 8 AWG, depending on the cable length between the amplifier and the subwoofer. For lengths over 2 meters, a larger gauge is recommended.
The wider terminal is positive (+), and the narrower terminal is negative (−), as marked on the terminal cover.
CAUTION: With unplated, bare-wire connections, ensure positive and negative terminals do not touch. Contact between these terminals can cause a short circuit and damage the amplifier.
Illustration Description: A diagram shows how to insert wires into the connector terminals.
Technical Specifications
The document includes detailed Thiele/Small parameters for both the Club 1024 and Club 1224 models, listed for both 2-ohm and 4-ohm configurations. These parameters include DC resistance (REVC), inductance (LEVC), radiating area (SD), force factor (BL), equivalent volume (VAS), compliance (Cms), moving mass (Mms), free-air resonance (Fs), mechanical Q (Qms), electrical Q (Qes), total Q (Qts), magnetic gap height (Hag), voice coil height (Hvc), and excursion limits (Xmax).
Enclosure volume recommendations are provided for both sealed and vented configurations for each model. For example:
- Club 1024:
- Sealed Enclosure Volume: 0.50 ft³ (14.20 L)
- Vented Enclosure Volume: 0.75 ft³ (21.20 L)
- Vented Enclosure Port: 3" diameter, 11.3" length, tuning frequency (fB) 30.0 Hz
- Club 1224:
- Sealed Enclosure Volume: 0.75 ft³ (21.20 L)
- Vented Enclosure Volume: 2.5 ft³ (70.8 L)
- Vented Enclosure Port: 4" diameter, 11.7" length, tuning frequency (fB) 30.0 Hz
General technical specifications are also provided:
- Club 1024:
- Diameter: 10" (254 mm)
- Sensitivity: 92 dB (at 2.83V/1M)
- Power Handling: 250 W RMS (1000 W Peak)
- Frequency Response: 30 Hz–175 Hz
- Nominal Impedance: 2 or 4 Ohms
- Voice Coil Diameter: 2" (50 mm)
- Mounting Dimensions: Depth 5-5/8" (142 mm), Height 11/16" (17 mm), Mounting Diameter 9" (228 mm), Outer Diameter 10-3/4" (272 mm)
- Club 1224:
- Diameter: 12" (305 mm)
- Sensitivity: 93 dB (at 2.83V/1M)
- Power Handling: 275 W RMS (1100 W Peak)
- Frequency Response: 25 Hz–175 Hz
- Nominal Impedance: 2 or 4 Ohms
- Voice Coil Diameter: 2" (50 mm)
- Mounting Dimensions: Depth 6-1/2" (165 mm), Height 11/16" (17 mm), Mounting Diameter 11-1/4" (285 mm), Outer Diameter 12-15/16" (328 mm)
The document also includes diagrams illustrating the mounting dimensions and enclosure volume calculations.
