The Peavey 18" Lo Max Subwoofer Driver features power handling capability of up to 2400W. A great design combines this power capacity with high efficiency, excellent frequency response, and low distortion for high performance. It even works well in compact enclosures.
The Lo Max utilizes a strong Kevlar composite cone and dust cap. The cone is strong and tough and uses an innovative, asymmetrical-M surround for superior excursion and motion control. High-quality gold on brass spring plunger terminals, accepting large gauge wire, are attached to large diameter, high-current tinsel leads with silver solder to withstand high currents, high temperatures, and long excursion. The tinsel termination is coated with an elastomer material to improve flex life.
The 4” diameter voice coil uses polyamide insulated copper ribbon wire, edge wound and bonded onto a durable and heat-resistant polyamide composite former. With a winding length of 1.15”, the long coil has much more surface area to dissipate heat, and its increased length drives the cone to a far higher excursion. The coil is over coated with a tough thermoset epoxy for added durability, abrasion resistance, and heat dissipation. The coil wires are solderless diffusion welded to high conductivity OFHC copper ribbon leads, which are embedded inside the former assembly and soldered to the tinsel leads with high-temperature silver solder. The solder joint is then coated with a special, thermally conductive silicone adhesive for encapsulation and heat dissipation.
The voice coil assembly is bonded to the Kevlar composite cone. The spider and surround are bonded to the frame with a high-strength, toughened adhesive. The 28 lb, chrome-plated Lo Max magnet structure is designed using extensive Finite Element computer modeling. The back plate/pole piece is cold forged from a single massive billet of carbon steel. The pole is extended well beyond the 12.5 mm thick front plate to improve coil cooling and make it more magnetically linear. The magnet structure is powered by 2 full size Black Widow magnets in stacked configuration. A specially designed vent plate greatly improves voice coil cooling. This heat conductive, ported, and finned aluminum ring delivers cool air pumped by the spider directly to the voice coil to keep operating temperatures under control. The improved cooling increases power handling and reliability, and reduces power compression.
The cast aluminum frame is tough and rigid and has the strength needed to hold the cone and huge magnet assembly in perfect alignment. The deep dish design and large spider clearance make high excursion and high output possible. This dynamic driver also utilizes the user friendly Black Widow replaceable basket assemblies with Rubatex gaskets (sold separately). The high power handling capability and more than 1.5” of available cone travel combine for low frequency output, while the possibility of small enclosures adds a new dimension to compact, high-output sound reinforcement systems. The Lo Max is specifically designed for subwoofer use, with high output capabilities and power handling. It is usable to frequencies as high as 500 Hz.