BillFitzmaurice.info

I first decided I wanted build a BFM system about a year ago. I knew it wouldn't make any sense to have speakers without amps and processing so I've been working on that and finally have a DBX Driverack PA, a Crown CL-2, and Crown CE 1000. My eventual plan is to have a pair of OT 12s and 4 Tuba 30s for mostly throwing smaller outdoor dance music events.

Just before this weekend, I received my kit from Leland for building a pair of OT 12s with the melded arrays and Delta Pro 12s. Since I have to wait till Monday to get to the lumber store to buy some Baltic Birch, I figured I'd get started on the crossovers this weekend.

Per the recommendation in the plans, I'm doing the high and low pass on separate boards. I got the boards cut out tonight and finished the soldering for one of the HP crossovers. I drove screws through from the bottom to act as terminal posts on each end (and made sure the screws conduct before doing so). With most of the components, I just soldered the lead from one component to the other(s) rather than soldering leads to connecting wires.

The 4 way connection between the 2 resistors, the cap, and the coil is ugly and looks odd but does jive with the diagram in the plans. If my memory serves me correctly, rosin core solder is a conductor so my liberal application of it to that juncture should keep things flowing. I didn't hot glue the components in place yet. I figured I'd post some pics and see if I need to redo this in a better way. It's a lot easier to undo solder than undo hot glue!

First two pics are close-ups of the questionable juncture from different angles and last one is a top view of the whole crossover board. I feel I consistently get good advice on this forum so

Function is more important than looks!
That looks fine. Glue them down.

Just be careful about how much heat you're putting into the components when you have large blobs of solder...

As long as the connections are strong, no worries.

Use hot melt glue, then zip ties. the hot melt keeps them from rattling and the zip ties hold them down.

Sure hope that's a misprint on the cap . . Don't think a 5.6 pico is gonna cut it!

It's 5.6uf. You're right, I never noticed that. I only have about 50 or 60 of them in the bin.

Hackomatic wrote:Sure hope that's a misprint on the cap . . Don't think a 5.6 pico is gonna cut it!

Now I feel like this

But before I did some googling and review of caps and farads, I felt like this

This is going to be a fun adventure!

And we're off! Use plenty of hot melt glue on everything and zip ties too for the coils.

Looks good. Make sure that the inductor is perpendicular to the speaker magnet/voice coil.

Crossovers are finished. The solder doesn't really 'stick' on the connection between the leads and the screws. The friction hold is very solid and I have current coming through but would sure hate to have a speaker cut-out because of one little bad connection. Would nails or something else work better? I'd really feel better if the leads and wires wouldn't budge on whatever I use.

MisterB wrote:Crossovers are finished. The solder doesn't really 'stick' on the connection between the leads and the screws. The friction hold is very solid and I have current coming through but would sure hate to have a speaker cut-out because of one little bad connection. Would nails or something else work better? I'd really feel better if the leads and wires wouldn't budge on whatever I use.

Solder the speaker leads and the jack leads directly to the crossover wiring.....no need for the screws.

Bruce Weldy wrote:
Solder the speaker leads and the jack leads directly to the crossover wiring.....no need for the screws.

That is a beautifully simple and logical solution. I think the screws can just serve as 'placeholders' for the wires until I get further in the build. I could foresee myself losing sleep over that damn wire spinning on the screw!

Is 16 gauge thick enough for the internal wiring on the cab or is a thicker gauge recommended? I know I can use a thin gauge for the connections between piezos in the array.

If you take the screw(s) out now, you have a place to hook your wiring in, then solder.

Also, can I suggest you cut out the zip ties you have there for now and drill a hole in the centre of the inductor(s) so you can put 2 zip ties on each? ie one zip tie goes around each inductor on the "left" and another on the "right", both zip ties passing through the centre hole.
Then the inductors are captured.

14 to 16 G wire is fine in the cab...

Grant Bunter wrote:If you take the screw(s) out now, you have a place to hook your wiring in, then solder.

Also, can I suggest you cut out the zip ties you have there for now and drill a hole in the centre of the inductor(s) so you can put 2 zip ties on each? ie one zip tie goes around each inductor on the "left" and another on the "right", both zip ties passing through the centre hole.
Then the inductors are captured.

14 to 16 G wire is fine in the cab...

More good advice regarding the securing of the inductors... and yet something simple that might not have occurred to me. I have to take care of some of my 'domestic obligations' (cleaning the kitchen, doing some laundry, etc...) and then I can make the corrections. If only cleaning the kitchen was as simple as cutting a zip tie and drilling a hole through some plastic!

Nice-looking crossovers! Once you implement Bruce/Grants' suggestions you'll be good to go. Good on you for getting this PITA step out of the way early on. These little cabs are really 8,000lb elephants; you have to eat them a few bites at a time, and that's exactly what you are doing.