Ok, so the product is "ADI-2 DAC FS".
You said you want to connect a subwoofer and your amp directly to the ADI-2 DAC FS.
So your setup will be this:
NAD CS1
Tidal Endpoint---SPDIF---ADI-2 DAC FS---cinch-----[unbalanced]----cinch---SET45 TubeAmp---Klipsch Heresy IV
\---XLR-------[unbalanced]---------------------------cinch---Subwoofer
I discovered on the Klipsch webpage that none of their subwoofers support connection of satellites also not balanced connections. This is not good.
In the above design you have several disadvantages. The biggest one is, that you will get a frequency overlap.
Without the ability to route the satellite speakers through the subwoofer, both the subwoofer and the satellites have to cover their respective frequency ranges independently. This can lead to overlap in the frequency range, often resulting in a "boomy" or imprecise sound. The overlap in low frequencies can muddy the bass and make the overall sound less clear.
Properly separating frequencies is crucial for balanced sound. If the subwoofer lacks an internal crossover for the satellites, the crossover frequency must be manually set, which is often difficult and imprecise. A well-integrated subwoofer with a built-in crossover ensures clean separation of frequency ranges and better sound quality.
Satellite speakers, when not supported by a crossover in the subwoofer, may struggle to accurately reproduce the full midrange and treble. This can be particularly problematic if the satellites are designed to work with a subwoofer and are incapable of handling lower frequencies on their own. This is maybe not the case for your Klipsch speakers, you say they only lack a little bass, but I wanted to mention it for completeness regarding this thematic.
Balancing the volume between the subwoofer and the satellites can be more challenging. Typically, the subwoofer's volume must be adjusted separately, requiring additional tweaking to achieve a harmonious sound. A subwoofer with satellite connections usually allows for synchronized and automatically better-matched volume control.
Furthermore, the unbalanced wiring is suboptimal. I would use a "more professional" subwoofer with balanced inputs and the possibility to connect the Satellites to it.
Overall, a subwoofer without satellite connection options complicates integration into a HiFi system and can negatively impact sound quality, especially if the synchronization between speakers is not optimal.
I think you have less of a cable / adapter problem, the whole design that you are after doesn't look good to me.
Get a better sub which allows connection of satellites. Then use balanced cables up to the sub.
The shorter cables from sub to the amp can be unbalanced using an adapter.
There are a lot of subwoofers available with different features up to 7.1 and DSP / alignment kit.
To put only two examples:
https://www.thomann.de/de/neumann_kh_750_dsp.htm
https://www.thomann.de/de/genelec_7350_apm.htm
My personal opinion is, that subwoofer designs are always more complex. I prefer to get active monitors / speakers that fit my demand and not having to handle the additional complexity of subwoofer designs.
An alternative could also be to sell your speakers and get bigger ones.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14