The whole construction process of "Pit Vipers"

[Paul Carmody]

Some great ideas on crossover board layout. Very satisfying to watch.

[9sheng]

The installation position of the frequency divider is behind the woofer. There is enough space. It is very convenient for later disassembly, upgrading and maintenance.



The speaker terminal will also be installed next to the bass divider.


Starting from the frequency divider, I need about 40cm bass speaker line, 50cm mid-range speaker line and 60cm tweeter line

[9sheng]

Three parts of Crossover




Find a suitable position in the box,

Start fixing the base of the frequency divider

[9sheng]

I haven't found a capacitor of the appropriate specification for the mid-range C2, so I chose two capacitors in parallel. Of course, one capacitor of the appropriate specification can be directly welded in the PCB. I only reserved 2 capacitor welding positions.
It is very interesting that I designed the mezzo PCB into the shape of "USS Enterprise (NCC-1701-J)"!





For the C5 capacitor of the bass part, I also used two capacitors as parallel connection, and he also reserved the position for welding a single capacitor.

[9sheng]

This is my frequency divider PCB

[9sheng]

I started construction again today

[9sheng]

Continue to upload the latest photos

[9sheng]

Also 9sheng your thumbnail tells me you play guitar, am I right?

Thank you, you have extraordinary observation!

[9sheng]

First, I designed the PCB circuit board of the frequency divider (this is only the high pitch part). I plan to make three independent PCBs to separate high, medium and low frequencies






The back of the woofer was trimmed

[joshshetter]

This build is lovely and inspiring. Paul I assume your jaw is on the floor watching such craftsmanship be put towards one of your designs.

I will add I can't say I've had issues with veneer expanding and contracting, and I live in a house with effectively no climate control, so my speakers get the brunt of the temperature and humidity changes.

Also 9sheng your thumbnail tells me you play guitar, am I right?

[djg]

Probably too late, but I have used this method for three projects to bond two layers of mdf. Holding up very well.

[OldBeginner]

Those are going to be solid! Very nice build log and I appreciate your attention to the construction. My builds are never this careful, but I don't have the patience.

[9sheng]

After screwing, I separated the two boards and polished the holes between them.



I applied the strong woodworking glue, and afterwards I found that my glue was a little less.



They have already been stacked together. Lock the screws, which were originally said to be pressed with the F clamp. Later, a simple method was used.



Found a large stone (very heavy!) There is also a box of wine and a carton equipped with screw accessories. The overall weight is still not small.



Put it on the floor. It should be enough to press it. In fact, it doesn't need too much force.

I have finished the panel of one box, and I have to finish the other.

The progress was very slow, mainly because I was too lazy.

[9sheng]

I'm glad, I'm back here again


I put the woofer on and checked the back. I found that I should do some bevel trimming for the round hole on the back.

Maybe my mid-range box can't be operated after being pasted. So I first pasted the double-layer panels together, and then rounded and chamfered the back of the bass opening.



The two front baffles are stacked together. In order to avoid the problem of sideslip when pressing and drying after pasting glue, I am worried that the two layers of boards may slip and produce step joints when pasting directly. So I put a lot of screws on the back to make the two layers of boards locate, so there should be no movement.



The length of the screw is less than 36mm, so there is no need to worry about the problem of lock penetration.



This is the drill bit and the screw. Let's make a counterbore for the screw. Later, we will use some wood powder to fill it.

[DeZZar]

I like to glue down a layer of 3mm on the sides where end grain MDF is showing and try to make the construction so that all the end grain exposed is on as few sides as possible, either top bottom back (usually) or the sides.

I've found the thicker the MDF the more you will see the joint later through the veneer just from swelling movement, especially with anything above a matte finish.