Synergy
LETSHUOER Cadenza 12 2024
The LETSHUOER Cadenza 12 2024 is a universal IEM with a 12-driver setup, using one dynamic driver and 11 balanced armatures from Sonion and Knowles, tied together through a 6-way crossover.
The stock cable is quite good here. The build is solid, and it does not leave a very obvious gap that instantly makes you want to swap it out. So, I went into this pairing a bit sceptical.
The biggest shift was in how it pushed the musical quotient of the Cadenza 12. On the stock setup, this IEM can come across a bit sharp in the treble. People who have heard the Cadenza 12 would probably know the sound signature already.
Its strengths are effortless to notice, but the treble energy can also hold it back a little, depending on the track or listening volume. Copper Fusion Hybrid works nicely around that.
In simple terms, it adds some warmth to the mix and brings down some of that excess energy up top. The result is a sound that feels more coherent and easier to enjoy. The handoff from the midrange into the treble comes across smoother.
That change also helps the overall note presentation. There is a touch more body in the low end and lower mids, which makes the sound carry a more natural weight.
I am not expecting Cadenza 12 to turn into a very lush and warm-sounding IEM here. The base character remains. But it fills things out enough to make the presentation feel less lean and less dry.
On the technical side, I would not say the stage changes in any dramatic way. It stays more or less similarly organized. There may be a slight increase in perceived depth, and that likely comes from the added body in the low end and lower midrange.
BGVP Solomon
BGVP Solomon uses a nine-driver setup with two dynamic drivers, three Sonion balanced armatures, two Sonion electrostatic drivers, and two Sonion bone conduction drivers.
Even the stock Temple Cable that comes with it is already a strong performer. Still, the Copper Fusion Hybrid did make its presence felt in a way that suited Solomon quite well.
Solomon can sometimes come across slightly chilly and dry because of its focused top end. That sharp and airy presentation has its appeal, but it can also become a bit tiring in long sessions.
With the Copper Fusion Hybrid in the chain, the upper treble sounds more controlled and easier to live with.
Down low, I noticed better texture in the bass. It is not about adding more quantity. The low end just comes across a bit better defined and more satisfying in how it presents detail.
The lower midrange is where the cable quietly helps even more. It adds a slight bit of warmth and body, and that gives the midrange more richness and a more natural flow. Vocals and instruments sound less dry. The whole presentation feels more connected.
On the technical side, imaging also feels cleaner and easier to read. Positions come across with better clarity, but without that ultra-crisp edge that feels overdone. That is what I liked most.
The cable adds some of the missing naturalness without undoing Solomon’s technical strengths.
That is really the story of this pairing. It does not go around rewriting the tuning. It makes careful corrections.
A bit more warmth where needed. A slightly more polished treble. Better flow. Better cohesion. And just enough technical lift to make the pairing feel upgraded without losing what made the Solomon appealing in the first place.
THIEAUDIO Monarch MKIV
The THIEAUDIO Monarch MKIV is already a very clean and technically capable IEM, so the Copper Fusion Hybrid works more through control and refinement. The overall sound stays clean. Nothing feels thickened up for the sake of it.
In the bass, I noticed a bit more texture. Not more warmth. Not extra heft either. It keeps the low end tidy and well-shaped.
That clean approach continues into the lower midrange. The cable does not push extra body there, and I think that works in its favor with the Monarch MKIV. The separation in that region stays intact, and the presentation does not get muddy or dense.
Vocals do not suddenly come more upfront with this pairing. The focus shifts a little more toward the instruments instead. They seem to deliver improved presence, and the notes carry a touch more weight.
Treble is where I appreciated this particular pairing more. The Monarch MKIV has a treble tuning that sits very close to my limit for brightness.
Usually, it is enjoyable. But some tracks can still run a bit hot. Copper Fusion Hybrid helps here without taking away the good stuff.
Just taking the sharpest edges off so you’re not wincing at badly mastered stuff. The extra sharpness and energy feel slightly trimmed, but the treble does not lose its openness or resolving nature.
It also does not try to force out a lot more detail. Instead, it organizes things better. The soundstage might open up a hair wider, but honestly, that’s not what grabbed my attention. What stood out was the cleaner imaging and the sharper separation between everything.
Selected Comparisons
Effect Audio Code 23 MKII
Technical
The Code 23 MKII is a copper-only cable from Effect Audio. It is built using 16.5 AWG UP-OCC Pure Copper Litz and features a 13-bundle, multi-size layout within EA UltraFlex™ insulation.
At the center, the cable uses the Quad-FlexPro Solid Core system, which consists of four individual cores of varying sizes, each catering to a specific frequency range. This allows the cable to maintain consistency and electrical stability across all signal paths.
The 25AWG Copper Fusion Hybrid has a three-layer structure, with the inner layer comprising a Copper+Gold alloy, the middle layer comprising a Copper+Silver alloy, and the outermost layer using a mix of both alloys.
The conductors have a similar diameter within each layer, giving the structure a more organized look.
Design
Both cables have a very pleasing premium finish. The Code 23 MKII has a flashier touch due to its shinier appearance and hardware.
The Copper Fusion Hybrid is a bit more toned down, but the wires themselves have a shiny appearance, while the hardware mixes black and silver finishes to create more contrast.
The Code 23 MKII is a thicker and heavier cable, and its handling is not as comfortable as PLUSSOUND’s cable. The termination adapter and Y-split on the Code 23 MKII have a more elongated cylindrical structure, giving it a more mature look in comparison.
The Copper Fusion Hybrid is a thin and supple cable that you would hardly notice once you put it on.
The best part is that it doesn’t poke you behind the ears during usage, unlike the Code 23 MKII. It puts a little pressure on the back of the ear, and the whole ear hook region feels a bit stiff on the Code 23 MKII.
PLUSSOUND includes a leather pouch and a cleaning cloth with the Copper Fusion Hybrid, whereas the Code 23 MKII arrives barebones with no accessories at all. For the price, I would definitely appreciate a pouch.
Performance
Code 23 MKII is a copper-only cable, and that comes through quite clearly in the way it sounds. It adds more lushness and warmth. The midrange gets a richer and more musical tilt.
Copper Fusion Hybrid, in comparison, keeps more of the original tuning’s energy and transparency intact. The copper, silver, and gold mix helps it sound cleaner and a bit more open up top.
In the low end, Code 23 MKII has slightly more heft and warmth. Bass feels a touch fuller and more grounded. That added weight also gives IEMs a slightly better sense of dynamics.
Copper Fusion Hybrid sounds leaner here. It does not push that same warmth into the mix, and because of that, it keeps things tighter and a bit cleaner.
The same pattern continues into the lower midrange. Code 23 MKII adds more substance and weight. Male vocals sound fuller. String instruments carry more body and presence. The whole midrange feels more musical and a little more emotive.
Copper Fusion Hybrid does not go that far. It sounds cleaner, a bit lighter, and lets more of the original character come through.
Up top, Copper Fusion Hybrid has more air and more energy. It keeps the sparkle alive and does a better job preserving that extra sense of openness.
Code 23 MKII is not lacking in detail, but it pulls down more of the sharper peaks and top-end bite. Along with its warmer tonality, it makes it the more obvious choice for brighter IEMs.
If the IEM is bright-leaning, I would pick the Code 23 MKII. If the IEM already has some warmth and you want to bring in more clarity, air, and a cleaner sense of transparency, Copper Fusion Hybrid makes more sense.
Astral Acoustics Mars
Technical
Mars is a premium release from the Hong Kong-based brand Astral Acoustics. It is a 2-braid coaxial cable priced at $650.
At its core, it is also a copper-only cable. Mars uses 5N Long Crystal OFC Copper Litz wire and features a three-size stranded coaxial design with a combined effective gauge of 21 AWG.
Design
By design, Mars is an effortless cable to handle, much like the Copper Fusion Hybrid. The hardware on Mars is quite slim and subtle, finished in matte black.
The wires are more pliable due to the thinner sleeve. They do carry a slight firmness, but storing and coiling are easy, and they do not spring back or fight you.
The same is true for the 4-wire Copper Fusion Hybrid, which is also a very easy-going cable.
The hardware on the PLUSSOUND cable feels more robust, giving it a slightly more premium touch, though some may prefer the cleaner and more minimal look of the Astral cable. Both cables are quite lightweight and hardly bother you, even during longer sessions.
One thing I really appreciate about PLUSSOUND as a brand is that they include a leather pouch and a cleaning cloth, along with better overall packaging. We do get a pouch with the costlier Mars, too, but Astral could do a bit better here.
Performance
In the low end, Mars feels more grounded. It offers better definition and texture, but it does not add obvious warmth. It gives the low end a steadier base and a bit more substance.
Copper Fusion Hybrid goes for a cleaner approach. It does not add much heft or weight. What it does instead is improve texture and keep things tidy. The bass feels lighter on its feet.
The midrange is where Mars starts sounding more natural and more musically involving. It has a smoother flow, a better note body, and a slightly richer presentation. Vocals especially sound denser and more nuanced on Mars.
Copper Fusion Hybrid leans more into transparency. It keeps the energy more intact. Instruments get a stronger sense of presence here, partly because of the better extension and the way the treble stays more open.
Up top, the difference is easy to hear. Mars does a better job of smoothing the treble. It trims that extra sharpness.
Copper Fusion Hybrid preserves more air and keeps the top end more alive. So, while Mars sounds calmer and more refined, Copper Fusion Hybrid sounds more open and a touch more vivid.
Technically, Mars presents a deeper and more holographic stage. Instruments sit in a more layered space, and the image feels more rounded.
Copper Fusion Hybrid can sound flatter next to it, or at least more width-focused than depth-focused. It still separates fine, but Mars just paints the whole picture in a way that pulls you inside it.
So, if your monitor’s running neutral or bright and you want to mellow it out, Mars is your move. Copper Fusion Hybrid plays it safer. Keeps everything coherent and clean, doesn’t mess with the energy too much. It’s the balanced choice.
My Verdict
The Copper Fusion Hybrid IEM cable feels like a well-judged experiment from PLUSSOUND, and honestly? It works.
It’s got this relaxed, laid-back character that just fits with everything you throw at it. And honestly, that’s what I expect from a cable at this price point.
PLUSSOUND is not trying to reinvent the wheel here, just fixing the little stuff. And somehow it plays nicely with pretty much any IEM I paired with this cable. That’s precisely why I’d tell people to grab one.
This comes through more clearly with IEMs like the BGVP Solomon and LETSHUOER Cadenza 12 2024. Both can sound a bit bright or energetic in the treble.
Copper Fusion Hybrid does a nice job of smoothing that edge. This cable just takes the edge off without compromising on details. With warmer IEMs, it gives a cleaner and airier presentation while dialling back some of the extra warmth.
At its asking price, I think it stays very competitive. The build is strong. The looks are premium. The handling is excellent. And the performance does not compromise.
If you are a cable enthusiast and seeking something that does not burn a hole in the wallet but still gives you enough to appreciate in both feel and sound, Copper Fusion Hybrid is absolutely worth a look.
PLUSSOUND Copper Fusion Hybrid Technical Specifications
- Material: Ultra-Pure OCC (Copper/Silver Alloy + Copper/Gold Alloy)
- Size: 25AWG
- Design: Tri-Size, Tri-Layer Coaxial Type Litz
- Insulation: Proprietary PS + Enamel Coated Strands
