I do know of a loudspeaker manufacturer who hand tunes every single speaker that comes out of his factory.
It is very time consuming to do so using a traditional crossover, one method is to have multiple variable resistors connected in parallel to those in the circuit to lower resistance, with leads out of the port in order to tune the crossover.
Then when correct values for final tune are discovered, the crossover is removed and the correct value resistors are added, and crossover replaced.
This manufacturer now employs a tuning bay in the back of all of his current generation speakers. Brass screws are used to screw through the board the crossover is mounted on, which pass through to the outside of the back of the cabinet. Variable resistors are connected using alligator clips to the brass screws, after run in the variable resistors (pots) are dialed in with the use of Clio measurement system to match the speakers to an in house standard. A gasket is used between the crossover board and the external tuning port cut into the back wall of the speaker.
Not often, sometimes a capacitor is also added in parallel with the tuning resistor. By adding the resistors in parallel, resistance is actually lowered, this is in the shunting circuits of the crossover, so it allows more energy to return to ground.
This is just one manufacturer that I know of, I assume there are others who also have taken measures to final tune, or hand tune as you call it.
You'll just have to go find the others who take meticulous care of the products they produce.
If there is one, I dare say there are many!
It is very time consuming to do so using a traditional crossover, one method is to have multiple variable resistors connected in parallel to those in the circuit to lower resistance, with leads out of the port in order to tune the crossover.
Then when correct values for final tune are discovered, the crossover is removed and the correct value resistors are added, and crossover replaced.
This manufacturer now employs a tuning bay in the back of all of his current generation speakers. Brass screws are used to screw through the board the crossover is mounted on, which pass through to the outside of the back of the cabinet. Variable resistors are connected using alligator clips to the brass screws, after run in the variable resistors (pots) are dialed in with the use of Clio measurement system to match the speakers to an in house standard. A gasket is used between the crossover board and the external tuning port cut into the back wall of the speaker.
Not often, sometimes a capacitor is also added in parallel with the tuning resistor. By adding the resistors in parallel, resistance is actually lowered, this is in the shunting circuits of the crossover, so it allows more energy to return to ground.
This is just one manufacturer that I know of, I assume there are others who also have taken measures to final tune, or hand tune as you call it.
You'll just have to go find the others who take meticulous care of the products they produce.
If there is one, I dare say there are many!