JBL 2145 Crossover (1975–1978)

The JBL 2145 is a 2-way passive crossover network — a bare printed circuit board meant to be mounted inside a speaker cabinet, not a complete loudspeaker. Produced from 1975 to 1978, it was designed for 8-ohm systems and wired between the woofer and tweeter in JBL two-way enclosures. It's commonly associated with the JBL 123A woofer and LE25 tweeter, and owner accounts place it in the L56 and similar JBL bookshelf speakers of the era.

The board itself is straightforward: two inductors, multiple electrolytic capacitors, and screw-type terminals for connections. The crossover slope is 12 dB/octave. One point of disagreement in the record: the crossover frequency is listed as 3,000 Hz in one source and 2,500 Hz in another, and without a manufacturer spec sheet to settle it, I'd rather flag the discrepancy than pick one. The screw terminals work fine for bare wire but are a known annoyance for anyone wanting to use modern banana plugs.

What little owner feedback exists is consistent: it's a decent value crossover, not a premium one. The electrolytic caps dry out over time — a common complaint — and recapping with film capacitors is the standard fix. Replacement caps are widely available from Mouser, Digi-Key, and Parts Express, and refurbished units command a premium on the used market. Expect to pay roughly $30–$60 for a working original, or $75–$100 for a NOS or recapped example. The original JBL-branded electrolytics are long discontinued.

Surviving documentation is thin — no official JBL spec sheet, no original price, no dimensions or weight recorded. What we know comes from period listings, forum posts, and the boards themselves. Sound and Communication (September 1991, p.36) ran a piece on coaxial driver history that included the 2145 alongside the Altec Lansing 604E and Electro-Voice SP15, which at least confirms its place in the broader JBL component ecosystem of the era. The rest is collector knowledge.

• Type: 2-way passive crossover network
• Crossover frequency: 3,000 Hz or 2,500 Hz (sources conflict)
• Slope: 12 dB/octave
• Impedance: designed for 8-ohm systems
• Connections: screw-type terminals
• Components: 2 inductors, multiple electrolytic capacitors on PCB
• Common pairing: JBL 123A woofer, LE25 tweeter

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JBL D8R2145HF Recone Kit (New Old Stock)

$99.00

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