Thursday, July 2, 2009

- Split top of speaker


2.2 Recycling options are identified for the materials to meet the requirements of the design brief.

My first recycled material is MDF. MDF is an engineeredwood product made by breaking down softwood into wood fibres, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure. I am reprocessing it to form a speaker by following my engineering drawing. I mark the wood and cut out the parts I need from it to create a speaker.

My other recycled material is carpet underlay. Carpet underlay is used in the speaker to absorb unwanted frequencies, to stop phase cancellation which makes the speakers sound tinny. I cut it into the shape of my front and back plates and it is stapled onto the inside.

Standing Waves notes

Standing waves are wave forms that 'stand' on the edge of the front plate, lingering around not dispersing properly. As they linger they interfere with other waveforms coming through, cancelling out waves that you want to reproduce. It produces a baseless speaker response.This is easily fixed by rounding the edges of the front plate. The standing waves will disperse outwards as they hit the edge, stopping any wave cancellation.

Carpet Underlay Notes.

Carpet underlay is an absorber of unwanted frequencies inside the box. Low frequencies inside the box bounce of the wall of the box, hitting other frequencies that need to be reproduced, cancelling out the bass. The speakers sound tinny. The carpet underlay absorbs any unwanted frequencies.

Bracing Notes

Bracing is an acoustic treatment of the box. It allows the box to stop the flexing waves forms that are reproduced inside it. The port is the 'interface' between the box and the outside. It counterbalances the moving of the voice coil by pushing out when the coil is moving in (through magnetism) and vice versa.

- Clamped second layer

- Clamped second layer

- Replacement top

The part that had to be bent over the top was too dry and snapped and so it had to be replaced with two small pieces.

- Second speaker, first layer

The second speaker with the first layer complete, not as nicely as the first speaker.

- First speaker, first layer

- First speaker, half first layer