December 31, 2011

S2 + bass module

December 29, 2011

Bass module - part 4

Currently working on getting the boxes ready for painting. You can see an expressed join around the front baffle, but all other butt joins have had a groove cut, then filled with two part filler. 

Right side. The vertical on the right is the expressed join. All edges have a 3mm roundover.

Joins have all been filled at least twice, then a smooth filler is applied.

Front view: 

Rear view

Sanding tools - Bosch belt sander, Ryobi random orbital sander, Ozito palm sander

When you are planning to spray a high gloss paint finish over MDF, it pays to have some good sanding tools to make the job quicker and easier. I'm using a two part builders filler. I believe it is similar to automotive body filler, but intended to adhere to timber. I'm also trying out a filler over the top to get things smooth. It is premixed.

Belt sanders are extremely handy. I like to use the belt sander over butt jointed edges and it can help get things flat and it does a quick job. You can start with coarse grit paper but you can't expect it to get smooth and there is always a join. They also make a lot of mess so it's a good idea to get a good one. Bosch have a good filtration system. When you pay a bit more for a Bosch when compared to say a Ryobi or some of the cheapies, that's what you get. It's worth the extra.

After the belt sander, these two units come next. On the left is a Ryobi random orbital sander. You have to buy the special sanding discs that will stick on and they also have the holes - see the first photo. The beauty of this one is that it has suction built in so that most of the sawdust goes in to the bag. It costs little more than the cheapies and has variable speed and a better filtering system. If you use the belt sander in your workshop, it will cover everything in sawdust, but this unit doesn't have that problem. The paper only goes up to 240 grit so that does limit its use.

The palm sander on the right is a cheapie. I bought this one primarily to use with fine grit paper prior to polishing a painted surface. It needs not special paper, so you can buy big sheets and cut to size, meaning it's more economical. It has a 3 year warranty. The filtration system only works with a vacuum cleaner attached. This is why this unit is so cheap! 

December 16, 2011

bass module - part 3

Part 1 >
Part 2 >
Part 4 >

Box is now assembled and the driver cut outs are done.

I've used a router bit to cut a grove along butt joins. Normally when painting over MDF butt joins a hairline crack appears over time. One strategy to combat this is with a groove, another is to then fill the groove with two part bog filler. I plan to trial both on this box.

You can see the cut out for the speakon terminal at the back.

Part 1 >
Part 2 >
Part 4 >

December 11, 2011

Dastrix bass traps before and after - part 2

Bass module - continued

Bracing and top and bottom panels

Inside layer of the front panel added:



You may notice that I don't use a lot of clamps compared to many other builds posted online. I prefer to glue and screw because it allows me to keep working, as the screws hold things in place without the need to wait until the glue achieves adequate strength.

The vertical members below serve as bracing for the angled back walls. They also enabled the bracing to be connected together without adding any but the top and bottom panels.

Side walls were attached after the frame, followed by the back, with the angled sections added last.

Box now assembled:

The box is double layer on the front, single layer elsewhere. It will have a composite material applied on the internal walls later.

10mm strips were added so that I could do angle cuts on the table saw.

No, my fingers didn't get that close! Held in place for the photo to show how they were cut. 

December 4, 2011

Bass modules

This is the beginning of bass for my point source horns. The driver is an Eminence Magnum 18LF, an 18" pro woofer. It could work well in a 110L vented box but in my particular room a 60L sealed box is a good choice because the bottom end will be handled by subs. In this situation a vented alignment gains little except a bigger box.

The design is a simple sealed box with bracing and a shape which fits closer to the corners.
MDF has been cut and I've started to put together the bracing.