The three sets of wires (one from each crossover board) are wired in parallel to the terminal cup. I'm sure you already know, but just in case, make sure you keep the "polarity" as indicated in the crossover schematic.
To wire my crossovers, I used speaker wire where one lead was tinned and the other was copper colored and made the copper colored wire the "+" polarity.
Therefore, I connected all three "+" wires (copper colored) from the crossovers to the red binding post on the terminal cup, and all the "-" wires (silver colored) to the black binding post.
Oh yes, the wider terminal on the Audax drivers is the "+" terminal and the narrower terminal the "-". This was not clearly indicated on my tweeter and I had to go the the Audax web-site to get their spec sheet to figure it out. ( I notice their web-site is still not on-line, so figured you would have a tough time getting to their specs )
I used .187 inch (4.8mm) female quick disconnect terminals to make the connections to my drivers. I used the same size for both + and - connections. Although they are available at Radio Shack in a terminal assortment they carry, I found the local Autozone parts store carried boxes of 22 for less than it would cost for the two or three assortment packs you would need to buy from RadioShack.
The terminals are a very tight fit, therefore I "loosened" them up just a tiny bit using the tip of a jewelers screwdriver before attaching them to the terminals on the Audax drivers. I did not want to damage the drivers by applying too much force.
Sounds like you are making lots of progress. I liked the picture of your old center channel speaker perched atop the new center cabinet. What type of display do you have in your theater to support the center channel? CRT
? Widescreen Direct view
? 12 inch B/W TV
Have you given any thoughts yet about stands for your speakers? I will have to decide myself. Currently, the Left and Right are sitting atop small subwoofer cabinets on each side of my stage. Those subwoofers will be replaced with a sonosub like the one you are building in the next few months. My wife and I are trying to find a style of stand we both like (and one that is easily built) for the L/R speakers. I want their tweeters to be at ear level when we are seated. The center channel is another issue.
I was lucky enough to attend a talk given by Dennis Erskine on the 2002 Home Theater cruise discussing theater design and audio. He described that we are much better off placing the center speaker above
the screen than below. This is because we are better at localizing sounds near the ground (below ear level) than near the ceiling (above ear level) Since in this case we want the sound to seem to come from the screen rather than below it, he said it will sound more integrated with the images on the screen if mounted above it.
I will be making a suspended shelf for my center speaker. It will be finished "flat black" to reflect as little light as possible and be above my screen, angled downward to point the speaker toward my front row of seats. When I do that, it will get rid if the distracting reflection of light from the screen I currently have from the top rounded edge of the cabinet.
So little time... so much sawdust... I have to get more MDF from Home Depot.
PS. Ok, now that you finished the sub at 1 AM, did you have the nerve to test it or will you wait till the morning when the rest of your family is awake? Let us know how it sounds.