Crossover issue.

Mr. Shill
The resistor in that circuit checked out however a bank of 5 capacitors had only 3 connected... Perhaps broke during shipping.
Since there would be more bandwidth going through there that would probably make it louder too correct?
I soldered the broken wire, but will not have a way to check the SPL until I reassemble.
It does seem like that would do it though, agreed?

+1 stereo5

When you say the bank of capacitors had only three of the five connected, they are in parallel I presume?

That’s an unusual way to get a particular value, two maybe three, but five?
I don’t suppose they are marked with values on them? Voltage and Micro Farads?

It should do much more than simply change loudness of a driver, depending on the circuit, it may have two drivers trying to reproduce some of the same frequencies. Instead of there being a hand off of energies in merging frequencies between drivers, there may be an overlap?

Without a circuit diagram, it’s all a guess.
But I must say if a well made solder joint came apart during shipping, I am very surprised. Does it appear to have been all one piece at some stage?
Got good photos of this?

I used to work building crossovers and speakers cables, USB cables for a living. It was tough to solder solid silver wire to micro USB and even mini USB at times, as the plating on the metals made it harder to get a strong bind, even with good rosin.

With point to point soldering it’s a good method to crimp lead wires over or around each other with minimal contact point, using the solder to mechanically seal it, and also protect from oxidisation.

The @erik_squires post mentioned…

If it were me I would take out a DATS V2 from Dayton Audio and use it to compare the impedance curves of the drivers and the crossovers to diagnose. 

Assuming that they came out good (the same) then that would exonerate the speakers.
Without that I would more the cross over to the other box and visa versa. Then you can noodle out whether the speaker or the XO is bad, but soldering sounds like a clue to pursue.

Well my suggestion was just a start.  DATS is a great tool for diagnosing all sorts of problems.  By looking at the bad impedance curve you can tell if one or another section looks like it is missing, and the LCR measurements can discover bad drivers or components.

Yeah @erik_squires and a less elegant (kindergarten approach) is just to swap left parts between and right…

If one had a scope they could drive both LHS and RHS XOs and plot them against each other.
But you’ve also reminding me that I need to find my DATS.