JBL Control 2 (JBL On Air Control 2.4G)

Name: JBL Control 2
Brand: JBL

JBL's answer to getting surround speakers across the room without tearing up the drywall. It's a 2.4 GHz wireless speaker system with a 15-watt amplifier in one of the cabinets.

Overview

The Control 2 is one of the odder entries in JBL's long-running Control Series. It's a self-powered wireless loudspeaker system sold under the full name JBL On Air Control 2.4G. You get a pair of compact two-way speakers, one active and one passive, fed by a small transmitter module that accepts analog audio and sends it across the room on the 2.4 GHz band. JBL's own manual describes the intended uses plainly: adding surround speakers to a home theater without running wire to the back of the room, or putting speakers in remote locations around the house.

The rated frequency range is 80 Hz - 20 kHz (±3 dB). That tells you what kind of speaker this is. There's no attempt at deep bass. The manual says a powered subwoofer fed from the active speaker's subwoofer output will deliver "deeper bass response than is possible with speakers alone." That subout is full-range and unfiltered, so JBL specifically warns against using the LFE input on a sub, since it would get a lot of higher-frequency information it was never meant to reproduce. Use a sub with its own low-pass crossover and select it.

Amplification is 15 watts per channel, driving a 100mm (4") magnetically shielded woofer and a 12mm (1/2") titanium-laminate tweeter, also magnetically shielded. The shielding is there because this product was aimed at sitting next to a CRT television, and unshielded drivers in that spot would have been a non-starter. The crossover between the two drivers is set at 1.7 kHz, a 6th-order acoustic Linkwitz-Riley alignment. That is a steeper slope than you'd typically find in a speaker of this class, and it suggests JBL was serious about keeping the handoff clean in the range where the ear is most sensitive.

Wireless operation runs on the 2.4 GHz band, the same spectrum as Wi-Fi home networks and cordless phones, which JBL's own documentation acknowledges. Operating range is rated up to 21 meters (70 feet) depending on conditions. The manual says building construction, materials, atmospheric conditions, and other interference sources will all affect real-world range. A four-position ID Code selector on both the transmitter and the active speaker lets owners change channels if they hit interference, or run two pairs of speakers from a single transmitter. In that configuration JBL notes the two active speakers need to be at least 10 meters (33 feet) apart, or reception may degrade in one or both units.

These are small speakers. They measure 229mm x 156mm x 140mm (9" x 6-1/8" x 5-1/2"), with the active speaker weighing 2.1 kg (4.6 lb) and the passive 2.0 kg (4.3 lb). The transmitter is a tiny 29mm x 124mm x 98mm box weighing 0.2 kg (0.5 lb), 95mm tall with the antenna extended. Each speaker has a 1/4"-20 threaded insert on the back for third-party wall brackets and another on the bottom for floor stands. The manual is explicit that the bottom insert is not for wall-bracket attachment, and that the customer is responsible for selecting and installing appropriate brackets. It also carries the standard warning that the product should be mounted to a wall or ceiling only as the manufacturer recommends.

Connectivity is more flexible than the wireless-only pitch might suggest. The transmitter accepts balanced or unbalanced signal via a Neutrik "Combi" XLR-1/4" combo jack. Positive voltage on XLR pin 2 or the tip produces outward woofer motion. The active speaker adds a local input on the rear for a portable audio player, switchable from the remote, so you can run the system off a receiver and still plug in a phone or player at the speaker itself. Power comes from universal 120V - 230V, 50/60 Hz supplies for both the transmitter and the active speaker, so it works worldwide depending on local regulations. Two AC cords are included, covering the most common outlet types.

JBL's manual is candid about one operational quirk: whether the source's volume control affects the Control 2's output depends on the source. If it doesn't, you can set the source volume wherever you like. If it does, the manual prescribes keeping the source at about half-way for audio and A/V receivers, about three-quarters for a computer, and at maximum for a portable audio device. After that, volume is controlled from the included remote.

In the professional world, the Control name carried weight. Recording-Engineer (June 1973, p.28) ran a JBL advertisement claiming that more music was recorded, played back, mixed down, and mastered on JBL monitors than on any other brand, citing the 4310 Control Monitor and 4320 Studio Monitor as the tools of the trade. The Control 2.4G is a very different animal from those studio workhorses. It's a consumer convenience product wearing a professional badge.

Later, the Control name appeared again on the Control 2P, a compact powered monitor that Mix-Magazine (September 2008, p.81) described as using the same transducers and crossover as the Control Pro, sold as a two-speaker system with onboard amplification in one cabinet. That's a different product from the On Air Control 2.4G covered here. Owners should keep the naming overlap in mind when hunting for documentation or parts.

The 80 Hz - 20 kHz rating and 15 watts per channel mean it will not fill a large room on its own, and the 2.4 GHz band is far more crowded now than when this system was current. What you get is a self-contained wireless speaker system from a major brand, with a combo jack input, a subwoofer output, and enough documentation to set it up correctly. It was meant for rear channels or a second listening zone without fishing cable through walls.