15 April 2013

DIY Nearfield Monitor Speakers with Fostex FE103En

Fostex FE103En DIY Bass Reflex Bookshelf Speakers

These small computer desktop speakers were built using the in-expensive Fostex FE103En fullrange speaker drivers following the bass reflex enclosure box plans that were provided with the FE103En datasheet.  The enclosure volume is noted as 6 L and tuned to 95 Hz but the the gross volume was calculated to be 6.9 L and the box tuning frequency to be about 97 Hz.  The Fostex FE103En drivers are 100 mm in diameter and have a rated sensitivity of about 89 dB / 1 W / 1 m.  There are a couple of easy modifications that can be made to improve the FE103En drivers which are described in detail on the modifications and tweaks for the small Fostex fullrange speaker drivers information page.  A photograph of the stock Fostex FE103En drivers is shown below.

Fostex FE103En Fullrange Speaker Driver
The speaker cabinets are built from 15 mm thick Baltic birch (11 ply multiplex) plywood.  Acousta-Stuf fiber fill is used inside the speaker enclosure to dampen the rear wave from the driver and to reduce standing waves and internal reflections.  The finished speakers are shown below with the computer.  Since this position the speakers are used in the nearfield, there is no need for a baffle step compensation filter.  The  Fostex FE103En DIY Bass Reflex Bookshelf Speakers project page has full details regarding baffle step compensation for farfield use and pairing the speakers with a subwoofer.

DIY Bass Reflex Monitor Speakers with Fostex FE103En  
These little speakers have bee in use with the desktop computer in the office for a few months now and I am quite pleased with the end results.  With no crossover or filters the speakers deliver wonderful playback full with rich details.  For full project details see the Fostex FE103En DIY Bass Reflex Bookshelf Speakers (Nearfield Monitor) project page.

1 comment:

  1. Those speakers are pretty small but nearly perfect for use with a computer. Maybe an active version would also be possible?