Electro-Voice EVM-15L (1981)
Twenty pounds of diecast aluminum and a sixteen-pound magnet, rated at 200 watts the honest way - eight straight hours of shaped noise, with peaks hitting 800.
Overview
The EVM-15L, Series II is a fifteen-inch loudspeaker built for professional high-level musical instrument and sound reinforcement work. Electro-Voice's own manual says so plainly. Used full-range, its response is tailored for lead guitar, and per E-V's literature it also suits the bass player who likes a bright sound. That's a narrower brief than a general-purpose woofer carries, and it explains nearly everything about how the driver is put together.
Start with the motor. The EVM-15L uses Electro-Voice's largest 16 lb magnetic structure, driving a low-mass edgewound voice coil wound on a laminated polyimide form. Both the coil and the magnet assembly are vented to help dissipate heat where it collects. The cone is a heavy-duty curvilinear type on a fatigue-resistant suspension, and the whole assembly sits in a husky eight-spoke diecast aluminum frame. The Series II revision added beryllium copper flatwire leads and other voice coil refinements. The manual is explicit that reliability improved without changing the driver's other performance characteristics. So if you're buying one used, the Series II badge is a durability claim, not a different voicing.
The numbers behind the rating are worth reading closely. Power capacity is 200 watts per the revised EIA Standard RS-426A. That figure isn't marketing arithmetic. The test feeds shaped white noise through the driver for eight hours, with continuous power set at 200 watts into the 6-ohm EIA equivalent impedance, or 34.7 volts true RMS, and amplifier clipping setting instantaneous peaks at 6 dB above continuous, or 800 watts peak. E-V notes it was, to its knowledge, the first U.S. manufacturer to develop and publish a power test closely related to real-life conditions. The reasoning holds up. The long-term average stresses the speaker thermally, the peaks test mechanical reliability, and the shaped spectrum carries more energy at the frequency extremes than typical program material does.
Sensitivity is quoted as 93.5 dB at 10 feet with 1 watt input, and 124.5 dB at 4 feet with 200 watts. That makes the EVM-15L an efficient way to turn amplifier power into sound pressure. Nominal impedance is 8 ohms, with a minimum of 6.5 ohms, and the voice coil's DC resistance is 5.2 ohms ± 10%. The coil itself measures 6.35 cm (2.50 in.) in diameter.
Frequency response is specified as usable from 60 to 6,000 Hz in the TL606 vented 3.2 cubic foot enclosure, measured in a half-space anechoic environment at 10 feet on axis with 4 volts of swept third-octave random noise. The TL606's low-frequency 3 dB down point is 63 Hz. The manual notes that's ideal for lead guitar, whose lowest fundamental sits around 80 Hz, and for plenty of vocal reinforcement work. Box tuning of 55 Hz reduces cone excursion across a usefully wide band from 55 Hz to over 150 Hz. For bass guitar, the manual recommends partially covering the TL606 vent to drop tuning to 40 Hz in what E-V calls step-down mode. That discourages bottoming at the lowest bass notes and rolls off slowly below 150 Hz with an f3 of 78 Hz. With appropriate electronic boost, an f3 of 42 Hz is also obtainable.
The driver is 15.13 inches in overall diameter and 6.50 inches deep, with a 14.56-inch mounting bolt circle, eight evenly spaced mounting holes drilled to .281 inch (letter L drill), and a 13.88-inch baffle opening for front or rear mounting. Net weight is 20 lbs. Front or rear mounting both work without an adaptor. E-V's installation notes call for 1/4-20 screws, T-nuts recommended, with fillister heads that seat down into the recess of the frame.
Key Features
Sixteen-Pound Magnetic Structure, Vented Both Ends
The magnet is E-V's largest, at 16 pounds, and it's paired with a low-mass edgewound coil on a laminated polyimide former. The design logic is heat. Both the voice coil and the magnetic structure are vented to maximize dissipation in the coil area, which is where a driver under sustained high-level use actually fails. A 2.50-inch coil diameter gives the heat somewhere to spread, and the venting gives it somewhere to go.
Eight-Spoke Diecast Aluminum Frame
The basket is a husky eight-spoke diecast aluminum casting, not stamped steel. That suits a driver meant to be bolted into a working cabinet and left there. The frame holds the gap geometry under load, and the recessed screw seats E-V specifies are part of the same casting.
200 Watts by the Eight-Hour EIA Test
The RS-426A rating is the feature, in a sense. Eight hours of shaped white noise at 34.7 volts true RMS, with clipping peaks at 800 watts, is a punishing qualification that most period fifteens were never asked to survive. Not every "200 watts" on a 1980s datasheet meant the same thing.
TL606 Enclosure Tuning and Step-Down Mode
The TL606 is a 3.2 cubic foot vented box, tuned to 55 Hz, and E-V published the numbers to build one: mechanical Q at resonance of 4.96, equivalent suspension compliance volume of .245 m³ (8.65 ft³), effective diaphragm area of 855.3 cm² (132.6 in²), peak linear diaphragm displacement of 3.3 mm (.13 in), and peak displacement volume of 282.2 cm³ (17.2 in³). The company developed an in-house computer program to predict speaker-box behavior in the piston range and pointed technically advanced users at the Thiele and Small literature directly. Builders' plans for the TL606 were available from the factory on request as Form 1545-523, and a dual TL606 doubles internal volume with vent area doubled and vent length unchanged. For bass players, the step-down trick of partially blocking the vent to retune to 40 Hz is documented in the manual itself.
Recone Path and Mounting Flexibility
The genuine E-V recone kit is a Series II 8-ohm part, and it's shared across more than one driver. The same kit is used for the EVG15 and can be used for EV15TRXB coaxial low-frequency reconing. Drivers can be wired in parallel or series. The 13.88-inch baffle opening accommodates front or rear mounting without an adaptor.
Historical Context
The period press treated the EVM-15L as a component that turned up inside other people's systems rather than as a headline product. DB-Magazine (October 1983, p.53) covered the FR15-2, a two-way sound reinforcement system built around a rugged 15-inch EVM-15L Series II woofer in a 4.3 cubic foot optimally vented enclosure, crossed to a compression driver on a 90-by-40-degree constant-directivity horn. Recording-Engineer (October 1983, p.204) described the Pro-Line assemblies as driven by E-V's largest 16-pound magnetic structure, with both voice coil and magnetic structure vented to maximize heat dissipation, and noted the EVM-15L was intended for general-purpose low-frequency reproduction. By early 1984 the driver had become a selling point in other manufacturers' advertising. Carvin's factory-direct listings in Mix-Magazine (February 1984, p.133) and Modern-Recording (February 1984, p.29) both name the EVM-15L explicitly in the copy for a horn-loaded bass cabinet at $279. The same ad line reappears in Modern-Recording (September 1984, p.4) with the cabinet at $299.
Warranty was five years from original purchase against defects in workmanship and materials. The usual carve-outs applied for finish, appearance items, burned coils, and abuse, and repair by anyone other than E-V or its authorized service agencies voided coverage. Service addresses in the manual place the company in Buchanan, Michigan and Visalia, California, with manufacturing plants also listed in Newport and Sevierville, Tennessee and Ganjaque, Ontario.
Collectibility & Value
The EVM-15L is a driver built to take punishment. The 16-pound magnet, the vented coil and structure, the diecast frame, and that eight-hour EIA test describe a part built for the working musician and the installed sound system, not the listening room. Anyone maintaining a period bass cabinet, a horn-loaded bottom, or a lead guitar rig from the early eighties will likely find one already in the box.
Market pricing reflects that working-driver status rather than collector fever. A tested vintage EVM-15L 15-inch 8-ohm example has listed on eBay at $300, while a used Series II in very good condition has sold for $175 and an original, unreconed example has surfaced around €99. Recone kits remain available. A DIY kit for the 15-inch EVM-15L 8-ohm is catalogued as F.01U.110.882, and the genuine E-V kit reportedly serves both the 200-watt and 400-watt versions of the speaker. Buyers should confirm which version they're looking at, since sources disagree on the wattage attribution and the recone kit note is the only documentation that both exist. Watch for burned coils, which E-V's own warranty language singled out as an excluded failure. A driver that's been fed a clipped amplifier is the one to inspect closely. No original retail price for the driver itself appears in the surviving record, and the only period prices tied to it are Carvin's cabinet figures.
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