The interface between the power amplifier and the loudspeaker is a critical link in the audio reproduction chain. We believe it to be as much a component in the audio system as is a power amplifier.

 

If the speaker cable were a perfect conductor, the amplifier a perfect current source, and the loudspeaker a perfect current sink, absolute fidelity would be achieved. Unfortunately, the impedance of the loudspeaker varies by frequency, and also by how loudly the loudspeaker is played. An impedance plot measured using a uniform tone-burst is only a poor proxy of the actual performance of the loudspeaker when played with dynamic musical content.

 

Amplifiers are also not perfect current sources. Tube amplifiers, in particular, usually have output impedance that is significantly above zero. The output impedance also changes with frequency. Solid-state amplifiers, on the other hand, have very low output impedance, but this is affected by the ability of the power supply to deliver current when faced with the dynamic load of music. Hence, the loudspeaker-amplifier interface is not as straightforward as many cable designers and manufacturers will have us believe.

 

Genesis loudspeakers are quite unique in two ways. First, they have a servo-controlled powered bass section. With the built-in amplifier providing the “heavy lifting”, very little current is carried in the loudspeaker cable at the frequencies handled by the powered bass section. This is totally unlike other loudspeakers where the lower the frequency, the greater the current needs.

 

Second, they have a ribbon tweeter that is almost completely resistive – again unlike the characteristics of typical dynamic tweeters that have rising impedance with frequency.

 

This means that the typical design of loudspeaker cables is not optimized for Genesis loudspeakers. Usually, you will find that the more expensive the cable, the larger it will be and the more current it can carry. When such a large cable is used, it can make music sound slow and ponderous on Genesis loudspeakers. Attack and transients may be good, but then decay will be truncated, with the micro-dynamic details swamped by the macro-dynamic bombast. Such a cable may also make the Genesis tweeter sound aggressive and bright. So, we ended up having to design our own loudspeaker cables with optimal characteristics for Genesis loudspeakers.

 

We started out with individual strands of high-purity copper, and put a thick, smooth plating of pure silver on it. These strands are then twisted very tightly together so that they don’t rattle, and are sheathed (again very tightly) with PTFE Teflon (dielectric constant=2.1).

 

Four of these wires are braided together into twin twisted pairs in a balanced structure to cancel out external EMI. Each pair is given a banana plug at the loudspeaker end, and a spade lug at the amplifier end. These are pressure cold-welded on for a perfect gas-tight connection. The four wires are then sheathed in a conductive metallized polypropylene sheath for static resistance, and then again sheathed in an insulating polyamide net. The result is a supremely fast and transparent cable that matches the impedance and sonic characteristics of Genesis loudspeakers.

When compared to general-purpose loudspeaker cables, the Absolute Fidelity Loudspeaker interface has much better micro-dynamic resolution. As a result, the decay of notes is more extended and the music has better tonal color. Bass is also tighter, more tuneful, and has better pace and rhythm. The coherence makes the various singers and players in an orchestra or band gel together better to bring about a much better musical performance.