1. Ability to drive cables over long distances, like 50 feet or more. - ลากสายได้ยาวขึ้น
2. Additional power from bridging an amp. - ได้กำลังจากแอมป์มากขึ้น
3. Noise cancellation. - ความสงัด ปราศจาก Noise
4. Channel separation. - การแยกแชนแนลซ้าย-ขวา
Bold lines indicate common return of both left and right channels
The most important thing to note here is that as the left and right channels of the headphone amplifier drive the left and right driver coils, the return current from the drivers gets joined together and travels some distance before returning to the amp?s audio ground. This common pathway has some- possibly significant- electrical resistance from the wire, solder joints, contact resistance at the plug/jack, and so on, which causes a common signal to appear at the negative terminal of both driver coils. This common signal (a low-level summation of the left and right channel) will generate low level cross-talk and distortion in the sound heard on headphones. Just how low depends on the quality of the whole headphone/amplifier system (and, of course, we do a lot to minimize the problem with our amplifiers and re-cabling services), but it will always be there. There is, however, a way to completely get around the problem: balanced headphones.
Balance
Balanced headphones are just regular headphones that have been re-cabled in a special way. The normal three-conductor cable with the common ground connection is replaced with a cable that has four conductors: right positive and right negative conductors to the positive and negative connections of the right driver coil; and left positive and left negative conductors to the left driver coil. The cable is terminated in two XLR male connectors, one each for the left and right channel. A special headphone amplifier is used that has ?balanced? outputs where each channel has a normal audio drive signal and a mirror image inverted drive signal. The trick here is that there is no ?ground? to the headphones anymore, so there is no opportunity for the crosstalk distortion described above.
I started a thread about 8 months ago about balanced vs unbalanced and because I come from a pro film/video background, I couldn't understand why so many of these 1000+ headphone were being made unbalanced.
Many opinions in that thread said there is not much of a difference.
Well today my...
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