What is the weak point in my system?

Tell me about your room. 

Snippet:

"By measuring our room’s acoustic behaviour, we empower ourselves to make informed decisions about improving its sound and lessening the impact of its transfer function. It’s a step many audiophiles skip for financial and aesthetic reasons but it’s a crucial one if we’re serious about achieving audio satisfaction.

The room is arguably the single most dominant factor in what we hear from our loudspeakers. It has more of an impact than any upstream hi-fi component. And by understanding the room’s transfer function and the challenges specific to different frequencies, including the important distinction between reverberation (as measured by RT60) and echo, we lift our listening experience whilst simultaneously disembarking the hi-fi hardware ‘hype train’ (gee, how I hate that phrase). It’s a bitter pill to swallow but while room correction software, loudspeaker placement and furniture placement can help, dedicated acoustic treatment is usually the only way to secure proper results. I know this from first-hand experience: since 2020, I’ve had three rooms treated with excellent results."

https://darko.audio/2025/02/why-your-room-is-your-most-important-hi-fi-component/

Posters here say there is not much difference in the sound of streamers

Misconception. The source matters the most because of GIGO. You want the purest and cleanest possible signal entering the chain so the rest of the components can preserve its quality.

Streamers reveal differences in sound quality due to variations in (in order of importance) clocking and timing, power supplies and noise control, digital output implementation and isolation, app and software design, and so on. Do not think naively, as some do, that streaming is “just 0s and 1s.” Yes, the data itself is binary, but the timing information that accompanies it matters far more.

The number of streamer trials I’ve gone through is almost on par with DACs. Every streamer sounds different to my ears. I would suggest upgrading your BS vault to like ICON if you want to stick with BS line.

I would suggest upgrading your BS vault to like ICON if you want to stick with BS line.

This could be good advice if his room is not the problem.

The streamer absolutely does matter...

For the first time in nearly 30 years, I have no dedicated room with sound treatments.  The system is in our condo living room with the TV in between the speakers.  So I recognize that as part of the problem.

But if that's the case, why did the midrange even out with the ARC?