February 28, 2014

Clearance - items for sale

S1 - point source horn prototype pair - 60 x 60 degrees, MDF pyramid - raw unfinished box.

Drivers and passive crossover not included.

This is a raw horn MDF shell that works very well with low cost Pyle 6" closed back drivers available from Parts Express and a 1" exit compression driver.

The mouth is 500mm square.
This can be finished in textured black by request.

S3 - point source horn prototype pair - 80 x 60 degree, MDF pyramid - raw unfinished box.

OEM dedicated mids available for the pair (not available without the horn).

The mouth is 900mm wide x 600mm high (approx).

This can be finished in textured black by request.

Bass trap with opening for either S1 or S3

This is a corner bass trap with an opening to suit one of the point source horns. It hides the horn and bass box and fits things neatly into a corner. Grille required (can be added by request).

The idea with this panel is to create a bass trap and also hide the speaker in the corner. The result is very neat and avoids the need to finish the horn nicely.

18" Bass module

60L sealed box ideally suited to either prototype, with an Eminence Magnum 18" woofer and a very well damped sealed box with bitumen lining. 55kg in total!

All these items would best suit someone located in Melbourne aspiring to have a very impressive horn on a budget.

12" Rythmik curved sub

Curve sealed sub (raw MDF) - can be finished in textured black by request.

370w Rythmik plate amp - driver and new servo board can be added but I don't have them currently.

Amp and sub available for separate purchase.

Enquiries >

Building a curved speaker with constrained layer damping - 4

After some sanding and filling:

There is still quite a bit more sanding and filling to come before veneering. There is also a base and a port to install and tune.

February 24, 2014

Building a curved speaker with constrained layer damping - 3

Attaching bracing and bottom:

The box lining is attached in place, along with the vibration damping (either bitumen or rubber sheets) prior to assembly. Access will be limited later. A staple gun comes in very handy here. 

Gluing first curved segment:

Many clamps are used, not only to apply pressure but also for adjustment. The use of CNC panels does not make a good result certain. If not correctly assembled, the box may not end up square. The diagonal clamp in this picture is used for adjustment.

Long clamps are required in a project like this. I'm using 1m clamps here:

 The glue ooze is expanding polyurethane glue. It's expensive and harder to work with, but necessary in certain places. Why is it harder to work with? Even getting it out of the bottle needs more effort, firm pressure is required. Gloves must be worn, since it's very difficult to clean off your hands. If you get it on your hands, washing immediately will usually not get it all off.

Dowells added as bracing and the top also goes on:

February 21, 2014

Building a curved speaker with constrained layer damping - 2

Test fit of curved segments together with a constrained layer damping sheet:

Not yet attached ...

 Clamping together:

CLD (Constrained Layer Damping) curved segment: 

Ribs are modified so they fit together better:

Priming the bitumen:

Front baffle stoppers - these hold the ribs into position firmly.

Vibration damping applied to the internal surface of the front baffle.

Absorption applied.

First layer of bitumen over primed MDF:

Top walls clamped whilst the glue sets, bitumen applied also. Masking tape is there to keep the bitumen off the middle, where a dowell will be used as bracing.

First layer of bitumen over the first assembled CLD composite segment:

All layers of bitumen applied:

February 19, 2014

Building a curved speaker with constrained layer damping

This is a challenging custom build for a client who wanted a curved box with constrained layer damping on the side panels. A difficult combination!

 Front baffle. Fixing the depth of holes for the neo magnets. Grille will be attached by concealed magnets.

Bottom panel which holds the down firing port.

 Applying bitumen to internals of some of the panels.

Gluing base panels together.

 Bottom panel accommodates a panel that screws in. This allows access to the port and crossover which will be installed in the base. 

The thin segments here nest better for machining, but in hindsight it wasn't worth the extra trouble just to save on MDF in a project that unavoidably wastes a great deal of material. 

 Ribs about to be glued together: 

 Assembling rib sections. Dowells lock them together and align the ribs.

 Outside ribs:

 Ribs temporarily placed over bottom of speaker:

 You can see burn marks at the centre of each rib, where the tool starts and ends each cut. A compromise must be chosen in setting up the CNC tool paths. In future it will be done differently (this is the first box with more to follow). 

The holes for the dowells weren't quite big enough, so a custom tool was made to bore them concentrically.

Rib segments (20 per speaker) are clamped after assembly.

 All segments glued together:

Sanding the internal surface to ensure a tight fit with the rubber sheet that will be used as the constrained layer:

 Segments after sanding:

These are simply for one box!