You don't tell anything about your configuration.
Not even which ADI-2 you have.

The subwoofer should be feed with an unfiltered signal.
So the simple answer is "No", if the sub is connected to the same output it would not get the bass signal if you run through a highpass filter.

I've read through your other postings and found you've got the ADI-2 DAC.
ADI-2 DAC has ONE DAC or digital output path only.
You cannot apply a filter just for the Line-Out only.

So it stays with what I've written above.

Connect the sub in parallel to the satellites, rely on the satellites built-in highpass filters.

If you got an iPhone download AudioTools free version, the best little Real Time Spectrum Analyser around to get visual help setting sub's room position, x-over frequency, phase and level.

If you highpass no bass comes out of ADI-2 DAC FS (the one you have, yes?! )

There are 3 ADI-2s:

ADI-2 FS: no display, no DSP like EQ
ADI-2 DAC FS: display, DSP, no analog input / ADC
ADI-2 Pro FS: display, DSP, analog input

Your ADI-2 DAC FS is the source your music is comming from, right?
The speaker level output gets the sound from ADI-2 DAC too, yes?

Now, if you highpass in ADI-2 DAC FS you filter away the bass from your music.

As a test, set the High Pass Filter Frequency to 2kHz, bass is ALL gone, even the sub is silent, right?

If 50Hz highpass sounds better to you, your sub is not setup well.

This is what counts:
• position in the room (little moves of 20cm can make a difference)
• x-over frequency
• x-over phase (if available)
• sub level.
Each influences each other.

No chance to set this even close to good without analyzer if you're out for a natural sound.
If one wants just some "boom, boom ..." it doesn't matter, but you don't seem to be alike.

Get the mentioned App.
I'll explain how to use it.

just bought Audio Tools Pro version.I would appreciate your input on how to use all 3 apps: RevMeter Pro, dBMeter Pro and RTA Pro
Thanks again. :-)

How to setup ADI-2 DAC or ADI-2 Pro in a setup with
main speaker+subwoofer.

The following sounds a bit lengthy and complicated, but is in fact quite straigth forward and can be fun.

What we need:

• iPhone/iPad with "FFT“ by Andrew Smith, $12 in the Appstore:
https://apps.apple.com/de/app/fft/id298840058
Or, if you like a more coarse view, RTA:
https://apps.apple.com/de/app/rta/id298839433

• Something to place the iDevice in free air at the listener's position, e.g. a photo tripod, a selfiestick, or any stick+tape, or any mount.
Don't lay the iDevice on something big, this would disturb the soundfield around it’s mic.

• Pink noise from any source.
The AudioTools' FFT and RTA have a generator built in.
You can either connect this iDevice, or a 2nd one with the same app (that's what I usually do), or use PinkNoise from a CD or from Youtube:
https://m.youtube.com/watch?v=ZXtimhT-ff4

• In AudioTools FFT / RTA's Setup "Mic Compensation Filter", and "Measurement Mode" should be Enabled.
Set "Output Mode" to "Mono", not "Balanced"!

• Switch OFF the subwoofer.
• Set FFT to Equal Points/Octave, 1/3 Octave smoothing, Average — or RTA to 1/3 Okt., 30s Decay.
• Look at the room noise.
• Play the Pink Noise.
• Dial in a Pink Noise level 15-20dB above room noise.
The average from 100Hz to 1kHz should meet a scale line, as reference line.
• Switch OFF the main speakers, ON the sub.
• On the sub's controls, set the level at:
(case 1): One output - main/sub on the same ADI-2 DAC / PRO output: 10dB,
(case 2): Two outputs - main/sub on separate ADI-2 PRO outputs: 3dB,
- above the the FFT’s / RTA's reference line, with sub's x-over frequency try to find a range between 60-110Hz that looks the most linear. Make a pencil mark.
• (case 1):
On ADI-2 DAC, use the lowest EQ band: Shelving, Level -8dB, f=like sub, Q=0,7, as a startpoint.
• (case 2):
On ADI-2 Pro, use the lowest EQ band: HighPassFilter, f=like sub, Q=0,7, as a startpoint.

• Now, switch the main speakers ON too, linearize the response by playing with:
- the sub's phase switch,
- the EQ settings, but only the low band.
- the sub's frequency control around the pencil mark,
- and a bit with the sub's room placement if possible.

These are all interactive.

Goal is a slightly, 3dB, elevated bass and a relatively linear bass response.
With a good setting you can counteract room resonances too.
Don't care about higher frequencies at this point.

Take notes when you found a good setting before trying another.
Listen to music inbetween if you found a good setting.

This looks simply perfect, well done, gratulations!

How does it sound?

Thanks,still learning and reading :-)
I love this dac !