If there’s one thing I learned this week, it’s that the road to high-fidelity audio perfection is paved with cables, mistakes, and more cables. This is the story of my journey to squeeze the maximum sample rate out of my KEF LSX II speakers—one that led me through a tangle of wires, miscalculations, realizations, and, ultimately, some satisfying conclusions. Sometimes, it’s also about finding humour in the madness—and convincing Tia that I haven't lost my mind completely.
"You’re going crazy with all these cables," Tia said, shaking her head as I told her about yet another one I just ordered. It was hard to argue with her—I was knee-deep in wires, trying to figure out what I really needed.
It Started With the Topping DAC and an Assumption
My journey began with a sense of optimism: I had just ordered the Topping DX3 Pro+ DAC and was ready to push my KEF LSX II speakers to their limits. When I first saw the output from the DAC read 384 kHz, I felt a rush of excitement and fulfilment.
I imagined a smooth ride ahead—plug in, sit back, and bask in high-fidelity sound. Little did I know, I was about to embark on a week-long saga filled with twists, turns, and a mountain of cables.
Initially, I thought the LSX speakers had an RCA input, so I eagerly ordered an RCA to RCA cable. But after a closer look, it turned out I had misjudged the input options—no RCA input to be found. I needed something different.
Tip #1: Always double-check the input options on your speakers before ordering cables—it’ll save you a lot of time and frustration!
From RCA to 3.5mm to USB-C: A Detour Through Analog and Digital
With my RCA cable destined to remain unused, I pivoted to an RCA to 3.5mm cable, figuring this would let me use the Topping DAC to drive the speakers through their analog input. But my research quickly led me to a hard truth: while 3.5mm AUX would indeed work, it wouldn’t deliver the 384 kHz sample rate I was chasing. The analog input doesn’t carry a "sample rate" in the same way as digital, and the path to high-res audio led elsewhere.
The solution seemed clear: use the USB-C input on the KEF LSX II, which could handle digital signals directly, allowing the internal DAC of the speakers to process the music at the highest sample rate. Think of sample rates like frames in a video—the higher the rate, the more detailed and lifelike the sound. So, I ordered an RCA to USB-C cable, hoping that would bridge the gap. But once again, the gap remained: the USB-C input on the KEF LSX II accepts digital signals only, and an RCA output, as analog, simply wouldn’t cut it.
The Hunt for a Digital Transport with USB-C Output
This led me down a rabbit hole of researching digital transports and audio streamers. As I mentioned in my earlier post, I had already been exploring DACs, trying to understand how they could help me achieve the 384 kHz sample rate I desired. The research was eye-opening—I learned about the importance of digital versus analog signals and the different ways DACs and streamers could be used to enhance audio quality.
With my growing collection of cables piling up, I turned my attention to finding a digital transport or music streamer with a USB-C output that could support 384 kHz. This seemed like the ultimate solution: send the high-resolution digital signal directly to the speakers. But as I delved into the options, I quickly found that anything meeting my needs was far beyond my intended budget. Devices like the iFi Zen Stream and Singxer SU-2 were perfect in terms of functionality, but their price tags were anything but budget-friendly.
The Limitation of the Inter-Speaker Cable
In the middle of this chaotic search, I stumbled across a limitation I hadn’t considered before: the inter-speaker connection between the primary and secondary KEF LSX II speakers. While the primary speaker could accept and process signals up to 384 kHz, the secondary speaker was capped at 96 kHz when using the supplied inter-speaker cable. This was an important realization that, although it didn't completely derail my goals, made me adjust my expectations about achieving a consistent high-resolution experience across both speakers.
Ethernet Wins Over Wi-Fi
"I think I’ve lost count of how many cables you’ve ordered," Tia joked as yet another box arrived at the door.
Finally, after all the orders, returns, and Tia’s amused comments, I stumbled on a method that actually worked. I realized I could send upsampled audio files from Roon to my speakers over my home network. Initially, I tried this over WiFi, but the results were disappointing—the network simply couldn’t handle the bandwidth, and the playback was choppy.
However, when I connected both my Roon Core server (a trusty old Dell XPS) and the KEF LSX II speakers to my home network via Ethernet, the magic happened. I was finally able to stream at 384 kHz to the primary speaker, albeit with the secondary speaker limited to 96 kHz.
Conclusion: Chasing HiFi Perfection is a Marathon, Not a Sprint
This week has been a series of small wins, multiple setbacks, and endless cables. The journey of trying to get the absolute most out of my speakers led me to understand that sometimes, limitations aren’t just about hardware—they're also about practicality, patience, and finding joy in the process, even when it's filled with unexpected challenges. I learned a lot about digital versus analog inputs, the reality of what different cables can and cannot do, and, most importantly, that not all high-resolution numbers translate to better sound in real-world setups.
In the end, I achieved my goal of 384 kHz streaming, but not without compromise. It turns out, the pursuit of HiFi audio perfection is less about arriving at a final destination and more about enjoying the road you take to get there—cable missteps and all.