Floor speaker 2015

The Floor speaker 2015 was a speaker-building project that Audiopoli organised in spring 2015, in which members built three-way floorstanding loudspeakers in the student workshops of Otaniemi. 61 people signed up for the project's listening night at Kinopoli, and 40 members ended up joining the build. About 80 speakers were produced.

The same floor speaker was built again in spring 2019, with 16 builders and a price of €250 per speaker (€500 per pair).

The speaker

• Three-way, bass reflex
• About 1.05 metres tall, body made of 19 mm MDF
• Tweeter: SEAS 19TAFD/G
• Midrange: SEAS CA18RNX
• Woofer: Peerless SLS 10"
• The tweeter waveguide was machined from black POM plastic
• Passive three-way crossover
• Price for builders: about €250 per speaker in 2015

The crossover has large air-core coils and capacitors. The components alone would have cost more than a ready-made crossover for one speaker, so the crossovers were bought ready-made in one large batch.

The prototype enclosure: drivers mounted, enclosure not yet finished

Building

The project was started in autumn 2014, and the prototypes were assembled in December. In spring 2015 the project went as follows:

• 11 Feb: listening night at Kinopoli, where the prototype speakers were played
• 18 Feb: registration closed
• 6–8 Mar and 20–22 Mar: workshop weekends, plus a workshop Sunday on 15 Mar
• 25 Mar: veneering demo, and the group order for veneers closed on 7 Apr
• Apr–May: collecting veneers and electronics, a workshop day for latecomers, and a veneering weekend after May Day

The holes were routed with a top router using plastic templates: the router's copy ring followed the template and guided a thin 6 mm bit. The hole routing went well. Assembly and sanding were done in a second workshop.

Assembling enclosures and routing holes using plastic templates

Lessons

Floorstanders are a lot of work, and much time was spent in the workshop during the spring. Storing the finished bodies also turned out to be a challenge: about 80 floor speakers were kept for several months in an empty clubroom next to the workshop.