Audio Database

LS5/12A Grade1 Miniature Monitor Loudspeaker developed by the BBC as a new reference for small speakers. Grade1 means the highest grade monitor speaker used for sound check before sending from the studio to the transmitter. LS5/8, LS5/9, LS5/12A etc. were used.
By the way, LS3/5A is a grade 2 for checking speech program.

A 11.5 cm cone type woofer of 15W7508BBC (made by Dynaudio) is used for the low band.
A 7.5 cm large diameter aluminum voice coil is used to obtain stable reproducibility.

A 2.8 cm diameter dome type tweeter D-260BBC (manufactured by Dynaudio) is used for the high-frequency band.
Ferrofluid cooling is used in this unit, and magnetic oil is applied to the voice coil to enhance its durability by promoting thermal diffusion when the voice coil becomes hot.
In addition, excellent transients and low distortion are obtained by carefully molding and damping the rear chamber.

The unit uses a sealed magnet to prevent magnetic flux leakage, and can be used as a TV monitor.

The network section can be simplified by smoothing the characteristics of the unit, eliminating the complex characteristic correction network, using top-grade components such as air-core inductors, and using 5-ounce copper instead of the usual 1-ounce substrate.

The enclosure has been designed based on CAD, with particular attention paid to the rear bass reflex port, which has an unusually large diameter relative to the enclosure size, and has optimized shape and structure to improve the bass response in order to obtain rich bass from a small volume.
The front baffle has been rounded to prevent acoustic wave diffraction.
It has a rosewood finish.

The speaker terminal is bi-wired and has banana plug specifications.

Each unit has smooth characteristics and allowable input, and meets the standard of tolerance of 0.25 dB or less.

The final balance of the system is optimized by intensive listening with experts from various fields gathered in the BBC studio and comparing the speaker output with the sound of live performance. The system is polished with an emphasis on reproducibility under actual operating conditions as well as theoretical measurements in an anechoic room.

Model Rating
Method 2-Way, 2-Speaker, Basref System, Bookshelf Type, Simple Magnetic Shielding Type
Units Used For Low Band : 11.5 cm Cone Type (15W7508BBC)
For High Range : 2.8 cm Dome Type (D-260BBC)
Frequency characteristic 80 Hz ~ 20 kHz ± 3 dB (2m, Grill Attached)
70Hz -6dB
Pair matching Within 0.75 dB
Output sound pressure level 81.5dB/W/m
Impedance 8 Ω
Max Input 50W ~ 150W
Crossover frequency 2.5kHz
External dimensions Width 184x Height 295x Depth 227 mm
Weight 7kg