Why do you advocate using a single drive unit rather than separate woofers and tweeters?

Crossover circuits sub-divide the audio spectrum into sharply-defined segments within the frequency range, usually in the area where the ear is most critical, around 1 kHz to 3 kHz. These are then radiated from spatially-separated drivers of diverse sonic and distribution characteristics. To achieve the seamless re-integration of musical fundamentals and their upper harmonics throughout the listening area is outside the laws of physics. With a single, full-range drive unit the entire sonic structure can be radiated from the same source.

Why does the Eikona 2 have a metal cone rather than paper or plastic?

The performance of a loudspeaker from the midband upwards is largely governed by the flexural waves travelling from the voice coil to the surround.

Flexing involves alternate displacement and restoration of a material about its normal state and in order to preserve low level detail, this flexing needs to have a fast and linear response to the driving forces from the voice coil. This requires true elasticity as defined by Hooke’s Law. This is a characteristic of materials having crystalline structures where the elasticity is due to intermolecular forces.

The light metal alloys are the optimal practical choice for this. Paper and synthetic materials are elastomeric – they depend for their elasticity upon the folding and unfolding of long molecular chains, which is a non-linear and relatively slow process.

Sound quality is subjective and loudspeaker design is a compromise – factoring bandwidth, response consistency, transient performance, distortion and impedance parameters. Most of these characteristics are interrelated and you cannot change one without affecting many of the others. The Jordan approach has always been to use the most appropriate materials and work with the laws of physics.

This is not a matter of fashion. We pioneered the use of full-range metal cone drive units in 1963 with the release of the Jordan-Watts Module. Other manufacturers have attempted to copy the Jordan controlled flexure cone technology but we feel that our developments continue to lead the field.

Why do you use a 100 mm diameter cone?

It is the ideal compromise of a number of factors, including bass and treble extension, moving mass, transient response and frequency response. Balancing these gives us the 100mm cone size. The Eikona 2 has an exceptionally smooth response which extends to beyond audibility for the vast majority of listeners. It is enough to get the full atmosphere and texture of acoustic and orchestral music.

Why does the Eikona 2 have a phase plug instead of a cap?

Development work on the Eikona showed us that a cap can introduce very high frequency resonances. Even on the highly-regarded Jordan JX92S, these resonances were noticed by a number of very critical listeners, particularly on sibilant sounds. The cap has been replaced by the phase plug to avoid resonances within the voice coil/pole tip cavity. Together with a number of additional refinements, it greatly improves the performance.

Why do some wideband drive units show higher HF extension?

There is a great difference between achieving an extended HF extension on a graph and in reality. The Eikona is designed to extend the HF response in as natural a manner as possible, with no resonance or overhang. Whereas other, similar units may appear to hit a higher frequency by spikes or resonance, we refuse to do this. We aim for a smooth, natural response which is non-fatiguing for long term listening.

Are there any advantages in using more than one Eikona per enclosure?

Assuming the drivers are identical and have a nominally flat frequency response, then due to the characteristics of the radiation curve, the use of two or more such drivers will increase the efficiency of the bass and mid-band frequencies relative to the upper frequencies. The transition frequency and distribution pattern will depend upon the layout geometry of the drivers. We have looked at this in more detail in our Audio Building Blocks series on the blog.

Will the Eikona 2 work with low-power amplifiers, such as tube amps?

The Eikona 2 works remarkably well with tube amplifiers and lower-power class A amplifiers. The lack of crossover means that the impedance curve is substantially level. 

Although an Eikona-based loudspeaker system will work well with tube amps and solid state. It can be driven by good quality AV receivers and integrated amplifiers but is transparent enough to allow higher quality source and amplification to shine through.

Will the performance of your drive units be improved if I coat the cones with Audio Supergunk ™?

If it would, we would have done it. Coating the cone will alter the mass, affect damping and quite possibly glue up the works. It will certainly alter the carefully balanced design of the Eikona and we do not recommend it.

Are there any other Jordan drive units available?

The Eikona 2 is the only drive unit currently available which has been designed, tested and approved by Ted Jordan. 

What enclosure do you recommend for the Eikona?

For the ultimate performance, we recommend our Aurora Systems which are precisely matched to the characteristics of the Eikona.

For a conventional, small enclosure we recommend our Reflex 7 design. It gives good bass to below 50Hz which covers the majority of music. It can be further extended by the addition of a sub-woofer system.

For a full-range, free-standing system, we recommend the VTL or SL enclosures, which are compact and room-friendly.

Our ultimate DIY design to date is the Eikona Transmission Line Array. This can reach down to the lowest notes on piano or orchestra and the increased sensitivity means that it can handle orchestral climaxes with ease.

Full details of all these are on our Loudspeaker Plans page.

Can I horn-load the Eikona?

Yes. The Eikona will work well in a suitable, matching horn. Our other drive units have often been used in horns, including the JX92S and the 50mm cone JX53. 

In your VTL and DCR enclosure designs, why is the Eikona fitted in the wide face when it is common knowledge that the box should be as narrow as possible?

Common knowledge and scientific fact are often very different. The narrow front face is a fashion concept supported by some very questionable marketing rationale. The indisputable scientific fact is that the ideal mounting for a loudspeaker is an infinitely large, flat baffle and this is the concept used for all loudspeaker analyses. A wide baffle sounds better.

What are the recommended advantages of positioning loudspeakers as close to the wall as possible?

This positioning secures, to some extent, the advantages described in the previous question. In addition it minimises the time delayed reflections from the rear wall which contribute to confused imaging.

Will placing next to a wall ruin the stereo image?

We cannot see any reason why this would impair imaging. Possibly more than any other manufacturer, we have concerned ourselves with accurate and stable imaging and certainly would not promote a design that would impair this.

Will the shallow VTL and DCR enclosures cause audible reflections behind the Eikona?

On the contrary, it will raise their frequency and make them easier to absorb through use of acoustic damping material placed behind the Eikona.

Why are your design solutions often different from the majority of commercially available speakers?

We will freely admit that much of our work conflicts with current fashionable thinking but we are old enough to remember the Golden Days of Hi-Fi where the aim was to reproduce the natural sound of music as accurately as possible.

Can you check my design if I email it to you?

We are happy to view and offer comments and tips on your own designs. We are always happy to support customers who our building one of our own loudspeaker designs. Many examples of this can be seen on our blog.

Do you repair older Jordan products?

We don’t have repair facilities here at present but we are compiling a list of suitable repairs centres for vintage and older audio, including drive units. You can find them on our Resellers page.

The Jordan Preamp and Power Amplifier can be repaired in the UK by Amploft in Bristol. Mike Devine has experience with the design and has already repaired them for customers. Click on the link to go to his website.

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