Altec 418-8H

A 15-inch instrument speaker with a three-inch edge-wound copper ribbon coil and a die-cast aluminum frame. It is overbuilt, and that is why it ends up in bass cabs.

Overview

The 418-8H is Altec's 15-inch musical instrument loudspeaker, made in the USA and sold both as a bare driver and loaded into Altec's own cabinets. Altec's literature calls it a "rugged 15" loudspeaker for moderate size systems needing high fidelity and high power output." That tells you most of it. This is a working speaker meant to take abuse and stay clean, not a delicate hi-fi woofer. The factory sheet puts its response at 45 to 8,000 Hz, with 8-ohm impedance. One Reverb seller calls it "this legendary speaker from the 80's." The decade is the seller's phrasing, not a documented production run, but it shows how the driver is remembered: as a guitar and PA speaker with a reputation.

Owners treat it as a guitar speaker first and a general-purpose woofer second. A TalkBass user notes that their Acoustic 201 cabinet is loaded with 418-8H 15-inch speakers and admits "I know that these are guitar speakers and cabinet but want to use them," so the driver shows up even in bass rigs. Another player on TDPRI runs a pair alongside JBL E120s in a '69 Dual Showman Reverb. An Amp Garage poster used four of them for PA duty and called them "great speakers." Across the owner accounts, people load them into whatever needs a loud, efficient 15 and then leave them there.

The most repeated figure in owner accounts is power handling, 150 watts, per a Gear Page seller who calls it "an incredible guitar speaker with a high (150 watt) power rating." The same seller lists sensitivity at 103 dB SPL and weight at 20 lbs. A TDPRI poster describes the 418-8H as "the 150 watt version" of the 412B and says they've owned a pair "since 1973-74." That is an owner's purchase date, not a documented production year.

Key Features

Three-Inch Edge-Wound Copper Ribbon Voice Coil

The factory sheet calls out a 3-inch-diameter edge-wound voice coil wound from copper ribbon. Edge-winding puts the flat of the ribbon against the coil former rather than the narrow edge, which packs more copper into the gap and helps the coil shed heat — the reason a driver like this can be pushed hard without the coil cooking. It's the kind of detail that separates a working instrument speaker from a consumer woofer, and it's the single most consequential piece of engineering in the 418-8H.

Reinforced Die-Cast Aluminum Frame

Altec's documentation describes "a structurally reinforced die-cast aluminum frame." A cast basket holds the magnet assembly and cone alignment far more rigidly than stamped steel, which helps when the driver is bolted into a cabinet that gets loaded in and out of a van. It is also the reason these drivers survive decades of gigging when cheaper speakers warp or rattle loose.

Sealed, High-Compliance Cone Suspension

The factory sheet notes "a cone suspension having exceptional compliance. It is sealed against dust and dirt." High compliance means the surround and spider let the cone move freely at low frequencies. The sealing keeps grit out of the gap, a real concern for a driver that lives in a club or a rehearsal room. A Gear Page owner identifies the cone in their unit by its stamp, "21353-7, which is an original Altec factory cone." Buyers use that kind of marking to tell original-cone examples from recones.

Heavy Permanent Magnet

Altec's literature refers to a "heavy permanent magnet," and an Amp Garage poster identifies the magnet type as Alnico V. A Shopozz listing title, though, references a "Series II 15 Speaker Ceramic Magnet" variant, so magnet material appears to differ between versions. Confirm which magnet a given example carries rather than assuming alnico across the board.

Mounting Dimensions

For anyone cutting a baffle, the driver needs a 13-5/8" hole, bolts on a 14-9/16" diameter circle, and sits 7 inches (17.78 cm) deep. Those figures come from an Altec document. Check them against the cabinet before committing to a cut.

Historical Context

Documented history for the 418-8H is thin. One owner on TDPRI reports buying a pair in 1973-74 and describes the model as the 150-watt version of the 412B. A recone-kit listing groups the 418-8H with the 418-8H II, 418B, 420A-8, 421A-8, 421-8H, and 421-8H II, but it does not state how those models relate to one another, so don't assume a family hierarchy. A Reverb seller dates their example to the 1980s, and the ceramic-magnet Series II variant suggests the line was revised at some point. The research does not establish when, or what else changed. Production years remain unconfirmed.

Collectibility & Value

The 418-8H trades on its reputation as a guitar and PA driver, and condition drives the price. Listings describe examples as "in immaculate condition… All original" and as "Recently Re-coned," with the latter noting "Good Physical Condition (shows signs of wear and use on back side of unit, Front side is New. Fully functional." A 2013 diyAudio for-sale post advertised "a pair of Altec Lansing 418-8H alnico woofers, immaculate condition, white frames, original cones." Buyers clearly care about originality, and a factory-stamped cone (21353-7) is the marker to look for. The Music Room listed a pair as "fully tested and no issues found."

The practical guidance from the listings is to verify originality — original cone, correct magnet type for the variant — and to expect that a reconed example, while functional, sits in a different category for collectors than an all-original one. No common failure modes or spare-parts information were documented in the research.