I have tested two OpenHeart cables with a Crenova 890Z multimeter. Both are for Sennheiser HD600 series headphones (580, 600, 650, 660S/S2) and are each 2 meters long. One has a 6.35 mm TRS plug and the other has a 4.4 mm TRRRS plug also known as Pentaconn. I bought them on aliexpress to replace the stock HD650 cable that is too long for me currently, leading me to have to coil it on the desk. However, when pulled on enough it uncoils and getting it back into a nice coil is quite finicky. Alas, by the time the cables arrived from China, I had found a solution by using a velcro tie on the coil. Further, at 2 meters in length, they hang barely of the floor with the headphones on the desk, risking to be stepped on or rolled over by the chair. I knew before ordering that 1.4 meters would be too short but only found out 2 meters would be too long when the cables where already underway. I bought the 4.4 mm in particular to try the connector on my SMSL DL200.
I measured the impedances between connections on the cable to check for proper wiring of all 16 cores. Impedance from one segment of the plugs to another is beyond the meters ability of 9999 MOhm and thus displayed as OL. This indicates that all cores are correctly wired or at least that there are none wired incorrectly as some may not be connected at all. Impedances between plug and connector are displayed as 0.0 Ohm - the lowest the meter can show. The impedance between the negative connectors on the TRS cable is 0.2 Ohm. The impedance between all other connectors on either cable is displayed as OL. The TRS is wired correctly with the tip being the left positive, the ring being the right positive and the sleeve being ground. The TRRRS is wired correctly as well with the tip being left positive, the first ring being left negative, the second ring being right positive, the third ring being right negative and the sleeve not being connected.
The 4.4 mm connector is covered in heatshrink which moves when the pulling or pushing the plug into the tight jack of my SMSL DL200. The distance from the top of the splitter to the tip of the connectors is 44 cm. This is long enough to get stuck on the underside of the table. However, I have had no issues with that sofar unless forcing it by holding it in place. Still, it was not enoiugh to dislodge the headphones. Even though the connectors are long, they only barely touch my shoulders when turning my head all the way right or left without tilting it down. The stock HD650 cable connectors also do this. However, while the connector bodies extends the same length from the headphone when inserted, the Openheart cable has some fairly stiff heatshrink below it which may restrict range of motion somewhat. Either way, however I moved my head, I could not dislodge the headphones.
The weave separates when the cable is bent at an acute angle or pushed together. This is unnerving to me, but may not be an issue.
In terms of sound, in a simple sighted test, listening to the new to me 4.4 mm OpenHeart cable and then the stock HD650 cable I used before, the sound is very similar and I don't think I could identify them blinded. Then again, I was not expecting any differences.
Overall, since they don't do anything better for me than the stock HD650 cable does now, I will probably return them, but they are well constructed as far as I can tell.
I measured the impedances between connections on the cable to check for proper wiring of all 16 cores. Impedance from one segment of the plugs to another is beyond the meters ability of 9999 MOhm and thus displayed as OL. This indicates that all cores are correctly wired or at least that there are none wired incorrectly as some may not be connected at all. Impedances between plug and connector are displayed as 0.0 Ohm - the lowest the meter can show. The impedance between the negative connectors on the TRS cable is 0.2 Ohm. The impedance between all other connectors on either cable is displayed as OL. The TRS is wired correctly with the tip being the left positive, the ring being the right positive and the sleeve being ground. The TRRRS is wired correctly as well with the tip being left positive, the first ring being left negative, the second ring being right positive, the third ring being right negative and the sleeve not being connected.
The 4.4 mm connector is covered in heatshrink which moves when the pulling or pushing the plug into the tight jack of my SMSL DL200. The distance from the top of the splitter to the tip of the connectors is 44 cm. This is long enough to get stuck on the underside of the table. However, I have had no issues with that sofar unless forcing it by holding it in place. Still, it was not enoiugh to dislodge the headphones. Even though the connectors are long, they only barely touch my shoulders when turning my head all the way right or left without tilting it down. The stock HD650 cable connectors also do this. However, while the connector bodies extends the same length from the headphone when inserted, the Openheart cable has some fairly stiff heatshrink below it which may restrict range of motion somewhat. Either way, however I moved my head, I could not dislodge the headphones.
The weave separates when the cable is bent at an acute angle or pushed together. This is unnerving to me, but may not be an issue.
In terms of sound, in a simple sighted test, listening to the new to me 4.4 mm OpenHeart cable and then the stock HD650 cable I used before, the sound is very similar and I don't think I could identify them blinded. Then again, I was not expecting any differences.
Overall, since they don't do anything better for me than the stock HD650 cable does now, I will probably return them, but they are well constructed as far as I can tell.
