Overview
This was my first attempt at a single driver full range speaker. The aim was to make a cost effective well performing set of desktop speakers. Using a single BMR driver in each speaker, capable of wide a flat frequency response due to the dual modes of resonance, the goal of the box was to extend the bass as far as possible. This proved challenging in the small space I gave myself, but some extension was possible.
The resulting speaker was good for small room listening and satisfied the aims.
Design
The design is a traditional 4th order reflex enclosure, with the port down firing in this case. The speaker therefore stands on a open sided base, providing a clearance around the port greater than its diameter to avoid significant interference. In the tuning process, while extending the low frequency output I kept looking to reduce the box size too. Ensuring a desktop size and foot print was essential, with a bit more vertical height allowed to bring the speaker to ear level. To too however and the box would begin to behave as a single tube. Due to the compact size and use of a full range driver, I was aware resonances could be a problem. To reduce this I made a the side walls non parallel to oppose standing waves and used extensive padding inside.
