Spendor LS3/6

The Spendor LS3/6 is one of the more confusing entries in the BBC-derived monitor family. The name appears to cover at least two, possibly three, genuinely different speakers, and the historical record is thin enough that even the basic facts don't fully agree. Audio-Collection (p.141, p.142, p.144) notes that the LS3/6 began as an LS3/5, that the BC1 was an unofficial development of the LS3/6 programme, and that the LS3/6 was offered to commercial companies and eventually taken by Rogers.

Here is what's reasonably clear. The LS3/6 began as a BBC design, developed from a specification change to the earlier LS3/5. The active version came first, with the passive version following later. Audio-Collection (p.142) notes that Spendor's BC1 was itself an unofficial development of the LS3/6 programme, with Spencer Hughes leaving the BBC and applying that research to a commercial speaker. The LS3/6 proper was never really commercially available. It was built to BBC/IEC specification rather than sold through normal retail channels.

Beyond that, the sources split. One archive describes a 3-way bass-reflex design with a 30 cm woofer, an 18 cm midrange, and a 3/4-inch dome tweeter, rated at 4 ohms nominal, 22 kg, with a frequency response of ±3 dB from 48 Hz to 15 kHz. Another database lists a different 3-way bass-reflex configuration entirely: two 210 mm woofers, a 210 mm midrange, and a 26 mm tweeter, at 8 ohms and 86 dB/W/m. A third source appears to describe a modern floorstanding revival with entirely different drivers again. These cannot all be the same speaker, and no official Spendor documentation has surfaced to reconcile them. Treat any specific specification for the LS3/6 with caution.

A few things do show up consistently. The cabinet was built from 18 mm chipboard with a 28 mm front baffle, finished in real wood veneer. There were no tone controls. One archive mentions heat dissipation fins on the rear and unusually oversized binding posts. The passive version used a choke-based crossover with two Plexiglas capacitors. The active version used a "Cadenza" tweeter and, by at least one account, was the more coherent design. One commenter went so far as to suggest the passive LS3/6 "was a compromise" and "perhaps not a real LS3/6."

The LS3/6's relationship to the BC1 is its most solid historical anchor. The BC1 was Spencer Hughes' commercial interpretation of the BBC's LS3/6 research. It went on to sell over two thousand units to the professional market, while the LS3/6 itself remained largely an internal BBC project. Audio-Collection (p.144) notes that the LS3/6 was offered to a number of commercial companies and eventually taken by Rogers, who added the Celestion HF2000 with BBC approval.

Known Specifications (as documented)

• Type: 3-way, bass-reflex (per two sources)
• Cabinet: 18 mm chipboard walls, 28 mm front baffle, real wood veneer
• Weight: 22 kg (per one archive; conflicting figures exist)
• Impedance: 4 ohms nominal (per one archive; 8 ohms per another — unresolved)
• Controls: none
• Active version existed first; passive version later

Similar items on eBay

No exact Spendor LS3/6 listings are live right now — these searches show current Spendor and similar vintage audio gear on eBay:

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Related Models

• Spendor 1/2
• Spendor 2/3
• Spendor 3/5
• Spendor 4/5
• Spendor A1.2
• Braun AUDIO-1 (1965)
• Braun AUDIO-250 (1965)
• Magnavox Component Systems (1972)
• Acoustic Research AR (1967-1976)
• Acoustic Research 11