Pensil Series - Creative Sound Solutions

Pensil Series
updated
16-June-2011
Damped Air Coupler
Added: New Versions for Latest Generation Models
The Pencils are a small range of easy-to-build floorstanding cabinet
designs for Mark Fenlon Audio drivers. They use a combination of
traditional quarter-wave design, a custom T/S volume alignment,
and Transmission Line damping to provide a balanced response with
a flavour of both vented and TL enclosures.
The Pencils are designed not to require any form of correction
circuits for step-loss. This is achieved through a combination of the
compensation already built into the driver responses, and the
damped air alignment, which together bring the system response
~flat in-room. The impedance load is easy, being largely unreactive,
and driver displacement is well controlled.
Many have been built, and with many happy end users. See
diyAudio.com for discussion, comments, variations, reviews, and
help.
Default recommended damping quantities (assuming dacron
hollow-fibre material) are suggested in the plans; tailor these if
required to suit your own amplifier[s] / room / taste. It is suggested
that a removable back is employed on all boxes to allow easy
tweaking of the damping
superPensil 12
Pensil 12
Pensil 10.2
Pensil 10
Pensil 7.3
Pensil 7
Pensil 6P
Pensil 6R
Pensil 6
Pensil RP70.3
Pensil R70
Pensil P70
markaudio
New Audio Fidelity
current
Alpair 12
Alpair 12
Alpair 10.2
Alpair 10
Alpair 7.3
Alpair 7
Alpair 6.2P
Alpair 6.2M
Alpair 6
CHR-70.3 / CHP-70.2
CHR-70
CHP-70
designed by S Lindgren drawn by dld
16-june-2011
©2010, 2011 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
Pensil Series
Example Builds
Notes:
0/ drawing uses 3/4" (19.1mm) material. Quality multi-ply recommended
1/ stuff with 1/2 to 3/4 pound per ft^3 (1.15 to 1.8 pounds = 0.52 - 0.8 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the stuffing
3/ boptional racing shown on next sheet
12
[304.8]
8 1/4
[209.6]
41 1/2
[1054.1]
40
[1016]
10mm radius
internal cleats for fixing
removable back
Alpair 12 superPensil 12
10 1/2
[266.7]
2
[50.8]
14 7/8
[377.8]
markaudio
16 3/8
[415.9]
New Audio Fidelity
designed by S Lindgren drawn by dld
05-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
Alpair 12 superPensil 12
Optional bracing scheme
markaudio
New Audio Fidelity
Notes:
0/ drawing uses 3/4" (19.1mm) material. Quality
multi-ply recommended
1/ large panel spans may be subject to unwanted
resonance and colour the sound. Shown is an optional
bracing scheme we have found to be effective in
combatting this.
2/ Any braces you add should not impede the 1/4-wave
action of the design (ie they should be vertical), or
impede the terminus slot
3/ this scheme divides panels such that the aspect ratio
of the subpanels is greater than the panel being braced.
4/ braces are not dead centre as that does not
affectively kill the 1st mode. (see figure below) They
are placed with an edge on centre. Side to side braces
have more placement latitude
5/ braces should be 30-50% holes. They do not have to
be circles. This proportion of holes also acts to make
side-to-side standing waves more complex (making
them less audible) and to hold the fibrous damping
material in place
6/ the brace behind the driver is intended to shunt
vibration energy to the back panel, and not just leave it
all in the baffle. This spreads the energy across more
panels, reducing the likelihood of exciting a resonance.
And if a resonance is excited, one on the back panel
will be much less audible. The brace should be tight up
against the magnet, but not so tight as to stress the
basket, If you leave it a bit deep, fill the space with
something relatively stiff (paper, wood, compressed
neoprene closed cel foam).
Adding this bracing can be as much work as the whole
rest of the cabinet, but really helps to get the last bit of
performance out of the design
The same or similar scheme can be used on all the
other pensils. On the smaller ones the side to side
braces will be unnecessary and the driver brace can be
abbreviated.
panel modes with centred brace
designed by S Lindgren & D Dlugos
18-july-2010 |drawn by dld
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
10 3/8
[264.1]
14 1/2
[368.2]
8 7/8
[226]
13
[330]
Notes:
0/ drawing uses 3/4" (19.1mm) material. Quality multi-ply recommended
1/ stuff with 1/2 to 3/4 pound per ft^3 (1.15 to 1.8 pounds = 0.52 - 0.8 kg) of
polyfill
2/cleats on back to allow for removable back, useful for adjusting the stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7 1/8
[180]
internal cleats for
fixing removable back
37
[939.8]
35 1/2
[901.7]
Simulated Response
(MJK Worksheets)
2 1/2
[64]
10mm radius
Alpair 12 Pensil 12
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
Pensil Series
©2011 Woden Design & Markaudio
designed by Scott Lindgren
drawn by dld / 17-june-2011
free for non-commercial use only
Notes:
0/ drawing uses 3/4" (19.1mm) material. Quality multi-ply
recommended
1/ common internal dimensions all 35.5in height, 7.125in Zd.
Stuff from the top to the top of the vent with polyfill at density
specified
2/cleats on back to allow for removable back, useful for adjusting
the stuffing
3/ for bracing and other details check the Pensil12 drawing
Pensil R70.3
CHR70.3
6
[152.4]
Pensil P70.3
CHP70.2
6
[152.4]
Pensil 7.3
Pensil 10.2
Alpair 7.3 | CHBW70
6
[152.4]
Alpair 10.2
8
[203.2]
7 1/8
[181]
Stuff
1.0lbs ft^3
Stuff
0.75lbs ft^3
Stuff
0.75lbs
ft^3
Stuff
0.75lbs ft^3
35 1/2
[901.7]
10 oz
290 g
10 5/8
[269.9]
1 1/4
[31.8]
10 1/2
[266.7]
1 1/4
[31.8]
9 1/8
[231.8]
1 1/4
[31.8]
14 5/8
[369.9]
1 3/8
[34.9]
7 1/2
[190.5]
6
[152.4]
Pensil R70.3 | CHR-70.3
12 1/8
[308]
10 5/8
[269.9]
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
20-june-2011
© 2011 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats for
fixing removable
back
29 1/8
[739.8]
1 1/4
[31.8]
Notes:
0/ drawing uses 3/4” (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.7 lbs / 5^3 (14.7 ounces = 410 g) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7 1/2
[190.5]
12
[304.8]
6
[152.4]
10 1/2
[266.7]
Pensil P70.3 | CHP-70.2
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
16-june-2011
© 2011 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats for
fixing removable
back
29 1/8
[739.8]
1 1/4
[31.8]
Notes:
0/ drawing uses 3/4” (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.7 lbs / 5^3 (14.5 ounces = 406 g) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7 1/2
[190.5]
10 5/8
[269.9]
6
[152.4]
9 1/8
[231.8]
Pensil 7.3 | Alpair 7.3 / CHBW70
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
16-june-2011
©2011 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats
for fixing
removable back
29 1/8
[739.8]
1 1/4
[31.8]
Notes:
0/ drawing uses 3/4” (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.7 lbs / 4^3 (13 ounces = 355 g) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
9 1/2
[241.3]
8
[203.2]
Alpair 10 Pensil 10.2
16 1/8
[408]
for Alpair 10 Generation 2
14 5/8
[369.9]
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
21-october-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats
for fixing
removable back
29 1/8
[739.8]
1 3/8
[34.9]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality
multi-ply recommended
1/ stuff with 0.75 lbs / ft^3 (1.59 pounds = 0.72 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting
the stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in
the superPensil12 plans
Pensil Series
©2009 – 2011 Woden Design & Markaudio
designed by Scott Lindgren
drawn by dld / 16-june-2011
free for non-commercial use only
Notes:
0/ drawing uses 3/4” (19.1mm) material. Quality multi-ply
recommended
1/ common internal dimensions all 35.5in height, 7.125in Zd.
Stuff from the top to the top of the vent with polyfill at density
specified
2/cleats on back to allow for removable back, useful for adjusting
the stuffing
3/ for bracing and other details check the Pensil12 drawing
Pensil R70
Pensil P70
CHR70.2
5 3/4
[146.1]
CHP70
Pensil 6
Alpair 6
Pensil 7
Pensil 10
Alpair 7
5 3/4
[146.1]
Alpair 10
8
[203.2]
6
[152.4]
Stuff
0.75lbs 0^3
Stuff
1.0lbs 0^3
7 1/8
[181]
Stuff
0.75lbs
0^3
Stuff
0.75lbs
0^3
Stuff
0.75lbs 0^3
10 oz
290 g
35 1/2
[901.7]
6
[152.4]
9
[228.6]
1 1/4
[31.8]
11 1/2
[292.1]
1
[25.4]
5 1/2
[139.7]
1 3/4
[44.5]
7
[177.8]
1 3/8
[34.9]
12 7/8
[327]
1 3/8
[34.9]
9 1/2
[241.3]
8
[203.2]
Alpair 10 Pensil 10
14 3/8
[365.1]
12 7/8
[327]
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
internal cleats
for fixing
removable back
1 3/8
[34.9]
37
[939.8]
29 1/8
[739.8]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality
multi-ply recommended
1/ stuff with 0.75 lbs / ft^3 (1.59 pounds = 0.72 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting
the stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in
the superPensil12 plans
7 1/2
[190.5]
8 1/2
[215.9]
6
[152.4]
7
[177.8]
Alpair 7 Pensil 7
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats
for fixing
removable
back
29 1/8
[739.8]
1 3/8
[34.9]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.75 lbs / ft^3 (0.65 pounds = 0.29 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7
[177.8]
5 1/2
[139.7]
Alpair 6 Pensil 6
7 1/4
[184.2]
5 3/4
[146.1]
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal
cleats for
fixing
removabl
e back
29 1/8
[739.8]
1 3/4
[44.5]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.75 lbs / ft^3 (0.49 pounds = 0.22 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7 1/4
[184.2]
10 1/2
[266.7]
5 3/4
[146.1]
9
[228.6]
CHR-70 Pensil R70
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats
for fixing
removable back
29 1/8
[739.8]
1 1/4
[31.8]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 0.75lbs / ft^3 (0.55 pounds = 0.25 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans
7 1/4
[184.2]
5 3/4
[146.1]
CHP-70 Pensil P70
13
[330.2]
11 1/2
[292.1]
markaudio
New Audio Fidelity
designed by S Lindgren drawn by dld
13-july-2010
©2010 Markaudio All rights reserved
NOT for commercial use without prior
written approval from Markimage Limited
35 1/2
[901.7]
7 1/8
[181]
37
[939.8]
internal cleats
for fixing
removable back
29 1/8
[739.8]
1
[25.4]
Notes:
0/ drawing uses 3/4" (19.1mm) material. 18-20mm OK. Quality multi-ply
recommended
1/ stuff with 1.0 lbs / ft^3 (1.36 pounds = 0.62 kg) of polyfill
2/cleats on back to allow for removable back, useful for adjusting the
stuffing
3/ bracing is optional. For bracing ideas plase see the bracing sheet in the
superPensil12 plans