The What, How and Why?

FAQ

There are a number of questions which crop up regularly with regard to our drive units and design philosophy. If you have such a query, please check the replies below to ensure that we have not already answered a similar point. Click on the question to take you directly to the answer.

Q1. Is there an advantage in adding a super-tweeter to the JX92S?
Q2. Why does the JX92S have a rise in its upper frequency response?
Q3. Are there any phase or 'combing problems' due to the separated drivers in the Linear Array?
Q4. Are there any advantages in using more than four JX53 drivers in a longer array?
Q5. Can the Linear Array be used with your active sub system alone or are bass drivers needed?
Q6. I have a JX53 Linear Array and JX150 bass units. How should I cross over between them?
Q7. Your own bass units are currently unavailable, what alternative units do you recommend?
Q8. Can I use a lower/different crossover frequency for the JX53?
Q9. Can I use the JX92S as a bass unit for the JXR6 HD?
Q10. Will the performance of your drive units be improved if I coat the cones with Audio Supergunk (tm)?
Q11. Your design philosophy is firmly critical of the phase anomalies due to crossover circuitry. How then do you justify the use of passive bass compensation?
Q12. What enclosure do you recommend for the JX92S?
Q13. Can I horn load the JX92S?
Q14. The enclosures on your website recommend MDF. Is plywood also suitable?
Q15. Can the JX92S be used in enclosures made of other materials?
Q16. In your VTL box design, why is the JX92S fitted in the wide face when it is common knowledge that the box should be as narrow as possible?
Q17. What are the recommended advantages of positioning loudspeakers as close to the wall as possible?
Q18. Will placing next to a wall ruin the stereo image?
Q19. Will the shallow VTL enclosure cause audible reflections behind the JX92S?
Q20. Why are your design solutions often different from the majority of commercially available speakers?
Q21. Are there any commercial designs using your drive units?
Q22. Can you design me an enclosure to my requirements or check my design if I email it to you?
Q23. Where can I find the Jim Griffin JX92 mini-monitor design?

Q: Is there an advantage in adding a super-tweeter to the JX92S?

A: No. It is often claimed that super-tweeters improve detail and definition. For a conventional system this might possibly be true. However, the exceptional detail and phase coherency provided by JORDAN Wide Band Single Cone drivers could only be impaired the intrusion of a spatially displaced high frequency radiator having characteristics totally incompatible with those of a wide band cone driver. This argument also holds true for the JXR6, which has a transient response and resolving capability beyond that of most commercially-available tweeters.

Q: Why does the JX92S have a rise in its upper frequency response?

A: Because it is intended to be listened to with the axes of the stereo pair toed well in, to cross well in front of the listening area. This optimises stereo imagery over a wide listening area.

Q: Are there any phase or 'combing problems' due to the separated drivers in the Linear Array?

A: The JXR6 drivers have chassis specifically designed to allow them to be mounted as closely together as possible. At distances greater than 1 metre there will be full sonic integration.

Q: Are there any advantages in using more than four JXR6 HD drivers in a longer array?

A: Apart from increased power handling there is no sonic advantage.

Q: Can the Linear Array be used with your active sub system alone or are bass drivers needed?

A: The low frequency response of the linear array is sufficiently extended for use with a subwoofer. An specifically optimised active sub bass system is available from E. J. JORDAN DESIGNS.

Q: I have a JX53 Linear Array and JX150 bass units. How should I cross over between them?

A: The Linear Array handles the full range and should be connected via the air load compensation circuit shown in Systems. This is not a crossover circuit, Its function is fully explained. Also shown is a 2mH inductor in series with the parallel pair to provide a first order roll-off at about 500Hz.

Q: Your own bass units are currently unavailable, what alternative units do you recommend?

A: We are currently researching commercially-available passive units to match our drivers. In the meantime, we recommend our powered bass system for use with the JX92S and the JXR6 Linear Array.

Q: Can I use a lower/different crossover frequency for the JX53?

A: Yes but we can't predict the results or offer design advice.

Q: Can I use the JX92S as a bass unit for the JXR6 HD?

A: Yes you can but the JX92S is perhaps overkill in this situation. A better solution would be a proprietary bass unit, capable of crossing over to the JXR6 HD at around 120Hz.

Q: Will the performance of your drive units be improved if I coat the cones with Audio Supergunk (tm)?

A: If it would, we would have done it. There is no Audio Supergunk in the world unknown to us.

Q: Your design philosophy is firmly critical of the phase anomalies due to crossover circuitry. How then do you justify the use of passive bass compensation?

A: Crossover circuits sub-divide the audio spectrum into sharply defined segments, which are then radiated from spatially separated drivers of diverse sonic and distribution characteristics. The seamless re-integration of musical fundamentals and their upper harmonics throughout the listening area is outside the laws of physics. Frequency compensation involves no such division and the entire sonic structure is radiated from the same source. It can further be shown that such compensation can actually enhance the intrinsic frequency and phase characteristics of the drivers.

Q: What enclosure do you recommend for the JX92S?

A: The ones on our website have been extensively tested and cover a range of options. There are a number of other designs on the web and we show some of these in SYSTEMS, however although these have good reports we haven't tested them and cannot vouch for their performance.

Q: Can I horn load the JX92S?

A: Yes. This has been done with excellent results. We have links to examples on the LINKS page.

Q: The enclosures on your website recommend MDF. Is plywood also suitable?

A: Birch plywood will be perfectly satisfactory if of the same thickness. High quality ply should be used as it is important to use a board with no voids or gaps in the material.

Q: Can the JX92S be used in enclosures made of other materials?

A: This driver will perform well in virtually any type of box. We have had excellent reports from customers who have mounted them in in everything from a flower pot to a full horn. There are examples on the web of enclosures made entirely of aluminium. We cannot supply designs for all the options as these are virtually unlimited. We have therefore chosen a range of designs which are well within the practical capabilities of most DIY individuals and give excellent results.

Q: In your VTL box design, why is the JX92S fitted in the wide face when it is common knowledge that the box should be as narrow as possible?

A: 'Common knowledge' and scientific fact are often very different. The narrow front face is a fashion concept supported by some very questionable marketing rational. 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 always sounds better.

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

A: 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.

Q: Will placing next to a wall ruin the stereo image?

A: 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.

Q: Will the shallow VTL enclosure cause audible reflections behind the JX92S?

A: On the contrary, it will raise their frequency and make them easier to absorb through use of acoustic damping material placed behind the JX92.

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

A: 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.

Q: Are there any commercial designs using your drive units?

A: These come and go, depending on fashion, but see the LINKS page for currently available designs and reviews of recent models. We will add to this as more designs become available.

Q: Can you design me an enclosure to my requirements or check my design if I email it to you?

We undertake design contracts for companies but do not have the time available to provide design work for individuals.

Q: Where can I find the Jim Griffin JX92 mini-monitor design?

This design has received a lot of attention online and is available both with and without a ribbon HF driver (the basic enclosure is the same for each design) For more detail, see our own Links page. The design is available as a downloadable PDF via this link.