Post by ati7500 on Feb 16, 2013 14:22:05 GMT
Hello everyone!
Discovered this great forum while searching for informations regarding Superlux headphones. I ended up buying all 681 models and 668b
I would like to share with you my findings, sorry if it's something already known. Yesterday, I've measured impedance of all my Superlux at the jack:
HD681
Left Channel: 30.8 ohm
Right Channel: 30.8 ohm
HD681B
Left Channel: 32.5 ohm
Right Channel: 32.2 ohm
HD681F
Left Channel: 31.6 ohm
Right Channel: 32.7 ohm
HD668B
Left Channel: 56.8 ohm
Right Channel: 58.2 ohm
And just for completeness:
Audio Technica M50
Left Channel: 34.5 ohm
Right Channel: 36.3 ohm
We can see some interesting differences. Going by logic, it is natural that single cabled headphones exhibit different impedance between left and right channel because you have to account the impedance of the connection cables between the two drivers. Guess what, the only two that exhibit volume imbalance are the 681 and 681B.
Example: the HD668B has the left channel directly connected to the jack, and it registers 56.8 ohm. If the right channel measures 58.2 ohm it means that the interconnection has a resistance of 58.2-56.8=1.4ohm. Therefore the two drivers are electrically balanced (and it sounds so).
The 681B sounds clearly shifted to the right driver, therefore it means that the impedance of the right channel is actually lower compared to the left.
HD681 though, sounds SLIGHTLY shifted to the left. I can only assume that the left channel has less resistance than it's supposed to.
My assumption is that single cabled headphones must register different impedance when measured at the jack.
And now my question: in the Superlux 681 and 668B, both metal rods are used for connecting the two drivers, or only one?
Thank you all for reading!