Are you using the sub from the Z-2200 with the BX5a monitors? Or are you using the Z-2200 2.1 sub and satellites on their own and the BX5a monitors on their own?
Turntables are tricky because some include the RIAA phono preamp internally and output a regular line level signal. Lower end consumer turntables do that and some DJ turntables. Most turntables though will need a separate RIAA phono preamp to equalize the signal and get the signal up to regular line level level.
The current DJ turntable craze means there's a good selection of phono preamps available running for relatively cheap (under $30) to crazy expensive (lots of $$$).
It is possible to run the turntable through the FW410. Doing so would be inconvenient for regular playback use, but it can be done. It would mean using the FW410 as a recording device even though you're not going to record. You'd need to get familiar with the various settings and plugs and dials and input and outputs on the FW410. Playing the turntable would mean opening the FW410 control panel, making sure the right bus and input is selected, make sure the levels are right so you don't clip, make sure the output is right. Then you can play the turntable. The audio will go through FW410 and right to the monitoring outputs. The good news about doing a setup that way is you would be all setup and ready to record your vinyl if that's what you want to do. But for regular playback of records it would not be the most convenient. You also wouldn't be able to play your records unless the computer is on (the computer needs to be on for the FW410 to work).
A better, but more expensive, option would be to get something like a
Mackie Big Knob. The Big Knob is a monitor controller that also happens to include an RIAA phono preamp on one input. I have a Mackie Big Knob. A big reason why I chose it was because it would give me a phono input for my turntable. Convenience.
As a studio monitor controller it will give you a very convenient volume knob for your BX5a monitors. It can control up to three sets of monitor speakers. So you could have one of the monitor outputs going to your BX5a and another monitor output going to your Logitech. Both monitor outputs can be active at the same time (so you could have both the BX5a and Logitech speakers playing at the same time).
The Big Knob can also control four inputs (one is dedicated to the phono). I have one input as my onboard sound. One input as my FW410. And one as my turntable. All the inputs can sum just like a mixer. So all inputs can be active and playing at the same time. If two inputs are active and playing you'll get the sound from both mixed together (summed). That's different than your typical home preamp where only one input can be active at a time.
There are other monitor controllers as well. The Big Knob works for me. Inputs and outputs are very flexible. It even has a special output intended to go to a headphone amp (and guess what I've got connected there?). It's a handy unit for controlling desktop audio that includes headphones and speakers.
The headphone outs on the Big Knob aren't that good. It has two headphone outs. They're quite powerful. But their output impedance is 150 ohms. That's a bad match for many headphones and consequently the headphone outs sound bad with many headphones. I consider the headphone outs on the Big Knob to be unusable and useless.
