Schu

the Klipsch RB61ii is already relatively bright for a speaker... I think your issue might be a physical one and one of age. Most voices are not up in that 10khz range anyway... sibilance is usually in that 7k-8k range. ask your friend if you can try them before you buy them... if hes a friend. are you by any chance running your sound thru an AVR that is not set up correctly?

get better headphones...

Flatten It...

I REALLY do not hope that they are offering an upgrade path...

I've used those 'tracks' before with great success...

for those interested, are the subs included?

Here

I think OP just want's connectivity as opposed to other possible solutions.

Class D is accurate and PRECISE, which many people consider Sterile... It is merely a personal preference. It is not a mistake to own class D, but it is a choice to make with care. To me the most revering thing about class D is 'Blackness', which is important... Secondly is the transient and damping factor, which is ENORMOUS. Blackness is always good, but I think to much transient response can be a bit sharp and fatiguing at times... Specially when combined with high efficiency. Ive used a Pioneer SC35 ICE based unit and a more modern SC85 for 5.1 and home theater, and they are really nice... super clean, fast and big dynamic range. Ive used a pair of Bel Canto REF500m monoblocks for 2-channel in addition to my current ATI 526 which is 6 mono channels that is pushing two 3-way speakers. Both are VERY highly regarded class D topologies and build qualities and they do the job. none of the Class D (for 2-channel work) is what I would consider 'be all end all' because with the wrong or weak source material, they can be brutal to listen to... painful and beyond fatiguing. With really good source material they are pretty decent. My personal fondness leans towards class A topology... either tubes or solid state, probably mainly because of the beauty of the Harmonics. Klipsch are extremely revealing and efficient so they tend to magnify any short comings in a system. I remember after I had run class D for years I bought a tiny little chifi tube preamp and I knew... immediately, that was the sound I was looking for. No one can decide for you... it's part of the journey.

DELETE!

where are you located?

EEK...

I have used class D with Heritage FOR DECADES... and I currently use class D. I dont think that Class D is the 'best' match for Heritage... but they are clean, Silent, efficient, and BLACK. The Class D transients are supreme and super fast/strong... but this can lead to fatigue and harshness.

What about a dedicated streamer connected to your dac that you control via wifi?

something with wifi6/wifi7 would be cool...