The sound analysis of Code 51 was done using 64 Audio U18t with Lotoo’s LPGT, playing a selection of the test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Counting Crows “Big yellow taxi”, Galantis “Hunter”, Alan Walker “Darkside”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.
In my opinion, cable doesn’t have a “sound” which you can describe by itself like IEMs in terms of lows, mids, treble. Cable is a medium that could shape up and fine-tune the sound signature or expand the soundstage perception, something you can describe relative to IEM under the test or relative to another cable you compare it to. What you hear is a synergy between 3 elements in the sound chain: the source, the cable, and IEMs. Thus, it’s easier to describe the sound when you replace one of these elements and note the change associated with it.
Based on a number of different pair ups and comparisons to other cables, I found Code 51 to be able to finetune the sound with enhancement of sub-bass rumble, giving more weight to the bass and at the same time making the decay of mid-bass a little shorter/faster which gives the bass more control, tightness, and better articulation. Also, I hear the improvement in mids, especially upper mids/vocals, making them more revealing and helping to extract more micro-details without too much brightness while still keeping them relatively natural. With treble, Code 51 adds a little more sparkle and airiness without any harshness, a very delicate and well controlled enhancement.
As I was spending more time with Code 51, I couldn’t help but notice how Code 51 reminded me of bass improvements I found with Leo II and upper mids/treble improvement I found with Horus. And I also found the improvements in a perception of the soundstage expansion, in every direction, similar to both of these cables. To my ears, Code 51 sound improvements were not focused on just the lower or the upper parts of the spectrum, but rather providing a more balanced overall finetuning. Of course, nothing is night and day, and you shouldn’t expect EQ-like drastic changes. If you are not happy with a sound of your current IEMs, better look into a different sound sig instead of applying a cable band-aid.
Consistent with my cable testing philosophy, I used the same IEM (64 Audio U18t) and the same source, and only changed one variable at a time to note the sound difference I hear while keeping volume matched. Keep in mind, I’m describing how these cables sound with 64 Audio U18t IEM.
Code 51 vs EA Leonidas II Octa – the same soundstage expansion. Code 51 has a little more sub-bass rumble, with the bass going deeper, while the decay of the bass is faster/shorter, giving bass a little more control and tightness with Code 51. The bass with Leo2 goes low, but the rumble of sub-bass doesn’t exactly reach the same level, while the decay of the bass is a little longer which gives the bass a more rounded fuller body in comparison to faster, snappier bass response of U18t with Code 51. Mids also sound a little different where Leo2 gives mids more body, making vocals sound more organic and smoother and slightly more relaxed, while Code 51 makes mids a little leaner, giving vocals more transparency and more micro-details and also a slightly more forward presentation. And similarly, with treble, while both have a good extension and crisp definition, Code 51 adds more sparkle and airiness. These differences should be kept under consideration depending on the baseline signature of your IEM. If you have one with a brighter upper mids and crisper treble, Leo2 could be a better pair up choice, while a smoother more neutral tuned IEM could benefit more from Code 51, bringing more energy and better retrieval of details without harshness.
Code 51 vs EA Horus 4wire – another very interesting comparison with micro-tuning differences. The soundstage is the same, except with imaging I felt like mids/vocals were positioned a little more forward with Horus. With bass, the quality and the extension are very similar, but the quantity has more impact with Code 51, both having a stronger mid-bass punch and a bit more elevated sub-bass rumble. With U18t, Horus pair up makes bass sound a little more neutral in comparison to Code 51. With mids, both cables give vocals more transparency and improved retrieval of micro-details, but the imaging and presentation is more forward with Horus, which makes U18t sound a little more mid-forward (w/Horus) in comparison to a more balanced signature when paired up with Code 51. Treble quality and quantity are nearly identical, perhaps with Horus having just a little more sparkle. And again, the choice between these cables will depend on the original sound sig of IEM you pairing it with. If you are dealing with a smoother more neutral tuned IEM, either Code 51 or Horus would pair up well, and Code 51 can improve bass response. With brighter tuned IEMs, Code 51 would be a better choice if you don’t want to push mids more forward and want to keep the sound more balanced. But, for example, v-shaped tuned IEMs can benefit more from Horus if you want to make the sound more balanced in that pair up.
Code 51 vs PWA 1960 4wire – in this particular comparison using U18t and LPGT, the difference I found was not exactly in tonality but the sound sig. The soundstage is similar, though PWA wires of 1960 push the soundstage expansion just a little bit wider. With tonality, the quality of U18t sound, from lows, to mids and highs is nearly identical between these wires, but the quantity is different where 1960 lifts the bass more (from sub-bass to mid-bass) and elevates treble a little higher as well, shifting the sound of U18t more toward a slightly v-shaped sig. In contrast, Code 51 makes U18t sound more balanced. This should be taken into consideration depending on which IEM you are pairing with either of these cables, and which way do you want to micro-tune the sound.