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Custom MKII version: HDT Build Images (Read 34280 times)
RFZ_Quest
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Posts: 296
Custom MKII version: HDT Build Images
01/08/08 at 02:41:11
 
These images preview some of the stages for this assembly with more to be posted when the project is finished. The major aspect which makes this set unique from the standard MKII model is the upper deck assembly comprised of the ribbon housing which I designed myself, and the surrounding elements for which it interfaces.


This set is constructed from superior grade Russian Baltic Birch (13 layer composite) for the internal structural components plus the top and bottom plates. The outer shell is constructed from standard grade plywood with thick cherry-wood outer layers forming the internal and external finish surface. The cabinet edges are routered to accept inlaid strips of hardwood made from African Padouk which create the accents.



The general cabinets are built in accordance with the blueprints with everything internal being within specifications. The choice of plywood over MDF will create an alternate sound signature for this set. The top plates are adjustable with tensioning devises which allow for cabinet tuning. The port tubes for each chamber are custom flared types which have been adjusted in length to compensate for the characteristics of the straight PVC pipes.


Other than that, this build is very straight forward, conforming close to the original design for the MKII version. There is very little absorption material placed within the cabinets. Just enough to control the wave pressure behind the drivers and reflections from above the drivers. There is acoustical foam placed at the bottom of the averaging chambers and that is the extent of it.

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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #1 - 01/08/08 at 03:00:34
 


The center plate assembly housing the three tuned chamber ports.
These are custom flared tubes adjusted for proper length. The support
plate is constructed from Baltic Birch.




As seen, the interior finish is cherry wood as is the outer surface.

The internal perimeter edges around the side passive drivers have been
reduced with a 1/4 roundover bit.




These views show the averaging chamber which feeds the transmission line.
The bottom plate is constructed from Baltic Birch as shown.




As seen, the port tubes are flared at both ends for maximum flow
stability with decreased internal turbulence.

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RFZ_Quest
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Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #2 - 01/08/08 at 03:27:58
 


The difference in structural composition between Baltic Birch
and standard 5-ply material is seen here. The bottom flares
are seated within routered areas to allow for a tighter
fit within the plate. There are gaskets seated between the
port flares and the plate itself.




The port tubes have adjustable sleeves which are cut
to length as specified by speaker design and glued in
place for final assembly.




View of the bottom averaging chamber prior
to installing bottom cabinet plate. The floor will
be treated with acoustical foam. The open V
area represents the entry point to form
the transmission line.



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RFZ_Quest
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resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #3 - 01/08/08 at 03:42:11
 


These views show the internal layout from
the side passive port looking outward
through the front driver area.








This view shows the installation of critical cross members
which greatly strengthen the interior structure for
increased control of cabinet resonance.



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RFZ_Quest
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Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #4 - 01/08/08 at 04:00:19
 


View of stiffening brace mounted just below
the opening for the driver.




Direct view from the front driver port.



View looking up from driver chamber. Shown at top
is the threaded tensioning rod for adjusting
the top dispersion plates. A compression seal is
used to maintain cabinet integrity.




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RFZ_Quest
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Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #5 - 01/08/08 at 04:27:23
 


These views represent the center dispersion plate
assembly. The unit is shown being
temporarily test fitted.




The spheres are the actual compression points
between the plates and the speaker top. These are
very dense hardwood, all mounted directly
to the center plate. The top plate will compress
against these spheres and held tightly
by the threaded rod. The tension is controlled
by this rod which tunes the plates
resonance factor.




The opening from the transmission line can be
seen under the rear of this plate.




This center plate is constructed from MDF with
the hardwood spheres glued directly to it's top
and bottom surfaces. Jam nuts will secure the
height adjustment for each plate along the
threaded rod. The top plate (not shown) is
constructed from solid African Padouk
hardwood. This view is direct from the front
looking back. The black pad forward of
the center plate is where the ribbon element
housing is mounted.


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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #6 - 01/08/08 at 04:47:07
 
The following images are of my custom designed
ribbon element housing in kit form. I developed
this design package for the upper frequency
driver assembly. It mounts directly onto the
cabinet top where the pad is used as an
isolation buffer.






The large capacitors are high grade German M-Caps
which are silver in oil types. These are mounted directly
within the rear housings with full isolation from vibration
supporting them. Internal wiring is solid silver.





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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #7 - 01/08/08 at 05:03:06
 


These images show the other housing assembled
and ready for mounting. Note the silver leads exiting
from the bottom. These will be hardwired into the
main harness going directly to the main driver
terminals. The unit is shown lying on its face. Once
mounted, the unit will be calibrated for an angle
of attack set at 5 degrees aft. The unit is hinged for
adjustability. Provisions are allowed for alternate
adjustment.



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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #8 - 01/08/08 at 05:06:40
 
Stay tuned as more images will follow with an update to this build.
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Falconer
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Re: Custom MKII version: HDT Build Images
Reply #9 - 01/08/08 at 21:17:52
 
Nice work RFZ Smiley
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HDT Alt Tuning
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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #10 - 01/15/08 at 01:22:28
 
These views show the actual acoustic foam installation within
the chambers. What is seen is the total amount installed.



Shown is a thin gasket cut from cork sheet (adhesive backed)
and installed as an interface between the cabinet and the
driver frame. Rubber spacers are used between the mounting
screws and the front part of the driver frame for maximum isolation.



Foam is installed in upper driver chamber where the tensioning rod mounts.



Cabinet is ready for installation of driver assemblies.
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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #11 - 01/15/08 at 01:27:12
 


Another view of  the cabinet shown ready for installation
of the drivers and passive radiators. Note the cork
gasket installed prior to installing driver.
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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #12 - 01/15/08 at 01:33:50
 
These views show the top completed in preparation for installation
of the top plates and the ribbon element housing.






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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #13 - 01/15/08 at 01:51:25
 
This is the driver set ready for installation. Note
the acoustic foam surrounding the main driver
motor.

This will control  deflections behind the driver by
absorbing reflected waves aft of it. This is a trial basis,
as this application will need to be tested for confirmation
of it's effectiveness.

It may have to be trimmed around the sides,
as this fills in a good portion of the area behind the
driver. If this proves to be excessive, it will be easy
to remove the driver for trimming if found necessary.



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RFZ_Quest
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The key to a perfect
resonating chamber.

Posts: 296
Re: Custom MKII version: HDT Build Images
Reply #14 - 01/15/08 at 01:55:55
 



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