F.A.S.T.-Monitors Revived
The Story
About 10 years ago I built my first actively crossed over speaker project. The concept is of the "F.A.S.T." type - Fullrange And Subwoofer Technology. Back then they were used as near-field monitor speakers for our small basement recording studio and they were built in a fast-and-rough style. Enclosures were made of 19mm MDF with a 2L cabinet for the Tangband W3-315 aluminium-magnesium cone 3 inch fullrange and a approx. 20L ported cabinet for the Tangband W69-1214 Woofer. The were actively crossed over at 150Hz with LR-12 filters using OPA2132 Opamps and were bi-amped by a pair of LM1876 chip amps.
Despite their very simple and boxy enclosure and the very simple crossover circuit they still sounded great!
Since then I learned a lot about speaker design. And since I got them back a while
ago I decided to revive them with a better enclosure and a more suitable crossover
using Pulseaudio Crossover Rack.
The side and top baffles were doubled up with 19mm MDF and 18mm birch plywood
for the front baffle to make a large radius at the edges possible. The
port was closed up and the bass response will be equalized flat down to ~35Hz.
The active crossover electronics were ripped out and an additional input was added
to make the amp a true 4 channel amplifier to be fed directly by the outputs of a
(>=) 4 channel soundcard. The PaXoverRack file can be found below. Measurements will
hopefully follow soon...
Listening Impressions
TBD...
Photos and Files
| Name | Size | Type | |
| Old schematic of crossover and amplifiers.T3001 | 229.2 KB | application/octet-stream | |
| Old schematic of crossover and amplifiers.PDF | 70.5 KB | application/octet-stream |