CIEM STORY
Unbalanced - the only way to achieve ultimate sound in the portable field.
1. Introduction
Around a year ago, we disclosed some information about a project on a 4.4mm unbalanced system - MA-1S. It is natural to ask why on earth we spent time to enforce an “old-school” standard (unbalanced) onto the future star (4.4mm) of the audiophile market. Our answer does not come easy.
The market has been slowly yet steadily dominated by the balanced system, popularised by Astell & Kern, and later catalysed by Sony with its prominent 4.4mm termination. Almost every manufacturer, except Chord from the UK, joins the current, prioritising a balanced system over the conventional unbalanced system, from amplifiers to players.
Seeing such an inclination to the balanced system, we would like to make a stand against this current.
2. The Origin of a balanced system
In its simplest form, transmitting analog signals involves a LEFT + RIGHT + GOUND combination. However, it is found that this traditional (we called “unbalanced” for the sake of communication) signal would decay significantly in long-distance transmission. To overcome this, there came the balanced system.
In a balanced system, the LEFT(L+) and RIGHT(R+) signals are duplicated and inverted to (L- R-). At the end of transmission, the L- R- signals will be inverted back to L+R+, and finally combined with the original L+ R+ in the destination.
3. Advantage of a balanced system
There are THREE advantages of a balanced system.
1. Power doubled - signals are copied and added to itself, doubling the power to overcome the energy decay in long-distance transmission.
2. Noise cancelling - the noise will be offseted when the positive and negative signals are combined due to 180 degrees out of phase.
3. High channel separation - Balanced signals do not share the same path (ground) for LEFT and RIGHT channels. This would enhance the channel separation.
4. The drawbacks of a balanced system
Despite all the above advantages, we still think the drawbacks outweigh the advantages of using a balanced system in portable gears for four major reasons.
1. It is not neccessary to boost the power using a balanced system. The transmission in a portable system is fast and there is no energy decay as the situtaiton mentioned above. Therefore, boosting output power does not justify the use of a balanced system. Rather, adjusting the output level of the system is a much simpler and more effective way. Moreover we think that a higher power level does not necessarily mean better sound quality.
Is your favourite player/ amp the most powerful one?
2. Huge channel separation may not be an “advantage”. It has been a great controversy. We receive LEFT and RIGHT channels separately from earphones/headphones whereas we receive both channels from speakers. That’s why the channel separation of earphones is significantly higher than speakers (even without the balanced system). Some people applied crosstalk to deal with the over-extended sound stage so as to simulate the sound effect of speakers. Of course we do not mean that the channel separation should purposely be suppressed on portable systems as long as it’s well designed. (it’s another topic to discuss what is the “correct” soundstage which involves many factors such as headphones or speakers the producers were using etc.)
3. The size of a balanced system would complicate the circuit. A balanced system requires a double amount of components, and therefore highly increases the area of the PCB. Besides, imagine how much power an all-rounded flagship that has “DAC + I/V + LPF + AMP” will consume. A balanced version requires a DOUBLE of that energy consumption, which cannot be simply solved by increasing the size of the battery and device. The only option left is that the sound quality is compromised.. Although it is theoretically possible to solve this dilemma by making the device as big as a desktop one, is it still “portable” after all?
4. Last but not least, signals are twisted in a balanced system. As we explain above, signals are copied, inverted, transmitted. The inverted signals vary at every stage and become no longer a mirror of the original signal. Is it still “high fidelity” when two different signals are combined to one?
We have no doubt about the value of a balanced system in home/outdoor/hall audio, but not in portable, not at all.
Then why choose 4.4mm jack as our medium? It’s definitely not a marketing gimmick. Seeing the popularity of 4.4mm jack, no one would return to 3.5mm no matter how we boast about how good the unbalanced system can reach.
The main purpose of using 4.4mm jack in the unbalanced system is that consumers can simply switch between balanced and unbalanced systems with their present 4.4 earphone cable. Therefore, you can feel what we are trying hard to elaborate without any cost. It also avoids all the extra interconnect cables/plugs that could distort signals. “Less is more” is everywhere.
OK, does this mean HUM will stop making balanced products? No, but it'll only be used in the home audio and general consumer market. In the high-end portable market? Unbalanced system is the only way, at least before the major breakthrough in the battery industry.