Closer Examination

The cable that ships with the 7Hz Eternal depends on the termination you picked at the time of order. There is no modular plug connectivity system, so you pick 3.5 mm single-ended TRS, 2.5 mm balanced TRRS, or 4.4 mm balanced TRRS. I have the 3.5 mm version here, as evidenced by the gold-plated connector seen above. I do like the coppery aesthetic used throughout, including on the connector housings with the 7Hz logo here and on the splitter itself. The cable differs slightly from what we got with the 7Hz Timeless since the conductor is a mix of high-purity OCC (Ohno Continuous Cast) copper and silver as opposed to copper and silver-plated copper with the Timeless, and it's still a two-strand co-axially shielded unit. The splitter works as expected, but the cable cinch is not very handy since it easily slides up and down the cable rather than doing its job and remaining in place at the set distance to separate the two individual strands headed to the IEMs. The transparent plastic section on this end of the strands adds to the pre-bent cable hooks going over and behind the ears, which the MMCX connector lead from a slightly angled housing makes easier. The channels are marked "L" and "R" on the housing, although it's not immediately obvious unless looking for it. It could do better when it comes to microphonics, however, so I can definitely see an upgrade cable coming in handy, especially if you go with something that has modular connectors, such as the Kinera Leyding we saw recently that also fits the color scheme.


I thought of the Starship Enterprise when I first saw the 7Hz Timeless in photos online, and the 7Hz Eternal has gone with a very similar design scheme. But compared to the far more subtle Timeless, these are an attention-grabbing set and a half! As typical for IEMs, we see a two-piece shell design, and both are CNC-machined aluminium treated for the durable copper finish seen above. The face plate, if you will, is more involved with a sapphire-coated optical glass cover over a decorative piece that is shaped to look like a dynamic driver. What you see underneath the glass is not the actual driver; it's not that large in practice and would sound terrible if just under glass. There is no visible branding in use thus, but I'd obviously refrain from calling this a minimalist set.


Seen above is what I meant by the sapphire-coated glass looking quite different from just about anything else on the market, and the coating also reflects light differently based on the incident angle because of the slightly convex shape. This means it can be clear optically straight on for a good look at the decorative insert below, but looks quite purple and nearly opaque from a steeper angle. It will also to a degree reflect back light, and using it outdoors will inevitable reflect sunlight onto someone else's eyes. This will also make them look like huge, flashy earrings. The form factor is otherwise similar to that of the 7Hz Timeless with the circular fascia of the face plate cover extending past the body of the shells, which is sculpted more with ergonomics and the ear concha shape in mind. This extension also acts as a roof of sorts over the MMCX connector, and the 7Hz branding has been put here instead. It's still not ideal for anything smaller than medium-sized ears, though. This is clearly a case of 7Hz going with form and brand identity over function.

The inner side has quite a lot of ventilation for IEMs—a total of four vents for airflow and pressure equalization. Three holes are grouped further down, with the fourth placed separately above, which puts it more inside the ear to be the outlet itself. The left and right channels are also marked for those who need it, and the pre-installed ear tips are again different from the other three sets we saw before. Removing them, we notice a relatively narrow and stubby nozzle, which may affect fit further, although it has a notch to keep the ear tips in place once installed. There is also a metal grill with a finer mesh screen underneath to prevent contaminants from entering the acoustic chamber.


Fitting the different ear tips is trivial with that notch on the spout further holding them in place, and seen above are the various silicone tips that come with the 7Hz Eternal, all in size M, installed on these IEMs. Just make sure you go around the tips to ensure they are not in at an angle. Note that the widest point is ~6.3 mm at the notch, so you may well have to stretch the ear-tip bore for it to go around the notch. Regardless of the tips you go with, the next step is to re-connect the cable by carefully pushing the MMCX connectors back in place. I would have liked a 2-pin connector, or at least the inclusion of an MMCX extraction tool since it can be a bother to remove the cable for any storage or cable rolling. Be sure to match the channels correctly before connecting the connector of your choice to the source. I know there are many who prefer using IEMs throughout, but I like to use over-ear headphones when sitting down and IEMs/TWS earbuds on the go. I've paired the 7Hz Eternal with all the tested portable DAC/amps thus and personally liked the cleaner profile and handy EQ options of the Qudelix-5K as the source, paired to my phone or laptop.


Given everything is clearly based on the design of the 7Hz Timeless, I also provided some visual comparisons of the two. We see the Eternal is a significantly flashier looking set, but otherwise borrows elements to be more consistent, such as the shells and face-plate design. The base color is of course different too, and the main item of note functionally is the thicker face plate section than on the Timeless owing to the optical glass cover over the decorative insert. This means the 7Hz Eternal will be even harder than the Timeless to fit inside the ears.