FAQ
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?
Q24. Why are my measurements so different from yours?
Q1:
Is there an advantage in adding a super-tweeter
to the JX92S? Top
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 JX6rHD, which has a transient response
and resolving capability beyond that of most commercially-available
tweeters.
Q2:
Why does the JX92S have a rise in its upper frequency response? Top
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.
Q3:
Are there any phase or 'combing problems' due to the separated
drivers in the Linear Array? Top
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.
Q4:
Are there any advantages in using more than four JXR6 HD drivers
in a longer array? Top
A: Apart
from increased power handling there is no sonic advantage.
Q5:
Can the Linear Array be used with your active sub system alone
or are bass drivers needed? Top
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.
Q6:
I have a JX53 Linear Array and JX150 bass units. How should I
cross over between them? Top
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.
Q7:
Your own bass units are currently unavailable, what alternative
units do you recommend? Top
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.
Q8:
Can I use a lower/different crossover frequency for the JX53? Top
A: Yes
but we can't predict the results or offer design advice.
Q9:
Can I use the JX92S as a bass unit for the JXR6 HD? Top
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.
Q10:
Will the performance of your drive units be improved if I coat
the cones with Audio Supergunk (tm)? Top
A: If
it would, we would have done it. There is no Audio Supergunk in
the world unknown to us.
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? Top
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.
Q12:
What enclosure do you recommend for the JX92S? Top
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.
Q13:
Can I horn load the JX92S? Top
A: Yes.
This has been done with excellent results. We have links to examples
on the LINKS page.
Q14:
The enclosures on your website recommend MDF. Is plywood also
suitable? Top
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.
Q15:
Can the JX92S be used in enclosures made of other materials? Top
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.
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? Top
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.
Q17:
What are the recommended advantages of positioning loudspeakers
as close to the wall as possible? Top
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.
Q18:
Will placing next to a wall ruin the stereo image? Top
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.
Q19:
Will the shallow VTL enclosure cause audible reflections behind
the JX92S? Top
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.
Q20:
Why are your design solutions often different from the majority
of commercially available speakers? Top
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.
Q21:
Are there any commercial designs using your drive units? Top
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.
Q22:
Can you design me an enclosure to my requirements or check my
design if I email it to you? Top
We undertake
design contracts for companies but do not have the time available
to provide design work for individuals.
Q23:
Where can I find the Jim Griffin JX92 mini-monitor design? Top
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.
Q24:
Why are my measurements so different from yours? Top
Ted Jordan wrote an article about this back in 1996. You can read it here. The parameter game
back
to top
|