CNO-mkIII, built by RM
Copyright 2021 © Troels Gravesen
Dear Troels,
First and foremost thank you for your efforts and well documented
projects. The level of dedication and craftmanship on your webpage has
been a great source of inspiration trough the years.
Since your ProAc clone paper I wished to undertake one of your projects.
(By the way, now that Scanspeak has a new nice little tweeter in the
D2104 it might be time to revisit the 2.5?)
The CNO-mk3 are my first take on one of your many speakers and are a
knock out hit.
Both construction process, and sound quality have lived up to my
expectations, and I wish to share my build.
Construction:
The stepped baffle had me a bit worried, but after you talked me out of
pursuing the MK2 version, I ordered the plywood and got planning.
Huge shout out to Jantzen Audio. The kit arrived very fast, and the
packaging was exceptional. They did everything possible to ensure a safe
trip, and if something got broken in transit (it didn’t) then it was not
their fault.
The speakers themselves are pretty straight forward and most of the
build came together fast. Originally I planned to build the slim tower
for 1 driver only, but after getting hold of the wood I kept going back
and forth between all tree versions. In the end I decided to go for the
regular tower, reasoning that if I want to upgrade down the road, the
CNO 25mk3 should be easy.
A couple of other takeaways from the build:
1. The correct number of Clamps needed for job can be found with this
simple formula: Clamps currently owened + 1
2. Routing circles is stressful. For years I used a big plunge router,
but decided to invest in a more compact palm router. The bigger machine
feels to powerful and is clunky as hell, while the palmrouter not only
is more easy to guide but it has more than enough power. (It is still
the most feared tool my wirkshop)
3. It takes 75% of the time to build Speaker A and speaker B not only is
faster, but more precise. One should plan to build 3 speakers where the
first is just to figure out any issues.
All in all, I really enjoyed the building process.
Sound:
At the moment my source is Spotify (..I know, can’t wait for them to
launch Hi-Res) > Bluesound Node > MhdtLabs Istanbul > Quad VaOne
integrated.
Every change I have done to my system has improved the sound quality,
and when I swap a component out I am aware the weak link is still the
source.
The little Quad is a 14 watt El84 push pull amp, and it felt to me to
have more than enough power to shake the house. The CNOs can Play really
to loud with the less the a quarter of the volume dial.
Overall the sound is clearer and smoother than my previous Diy Fostex
fe127, Klipsch Heresy, and Altec speakers.
I value a strong sense of 3D imaging and air between instruments, and
the CNO impressed me even after just a couple of hours.
Currently still breaking in, the drivers are settling in, and for the
past weak the entire spectrum has grown and become more precise.
Especially the bass feels deeper than day one.
I find the speakers very enjoyable and love how music is reproduced even
in their current placement. The current TV table is to wide to
accomodate the towers, so as soon as a new console is finished the
speakers will reside slightly closer to the back wall. Still a good
40/50 cm away, but am curious how bass will be affected.
There are hidden magnets inside the front baffle for easy snap on for a
grill cloth. Need to finish it before I loose the remaining magnets!
Of to hear some Jazz! Thanks again Troels.
RM
