SEAS CNO-4, built by Mark, Australia

Copyright 2021 © Troels Gravesen

Hi Troels. 

As you know, i have built a pair of your CNO4 speakers. I finished a few weeks ago and have been dialling in the treble level and the bass. I wanted to get them setup properly before commenting. 

I cannot stress enough to any builders out there that adjusting the treble can make such a difference and if you haven’t tried it then you must! If you don’t try then you will never know. This is one of the great things about building your own speakers, you can get it just right for your room and ears.

I have settled on a little extra resistance than what was supplied in the kit (probably due to having hard floors) 5 ohm for R1 at the moment. This may change as the speaker clocks up the hours and runs in. Time will tell.

The Hypex plate amp is using the high level input and is currently set to +10db. What a great feature! The ability to adjust the bass is very useful. It is great to have the option to just knock the level down a db or two instead of lugging the speakers in/out from the wall! This fact i am very grateful for, because boy they are heavy! I do not know how you lift all these big speakers around! I need a new back after just building these.

As for the sound… Wow. Incredibly dynamic, ultra Low distortion, extremely transparent, smooth mids, natural uncoloured sound, deep fast and punchy bass! The list goes on. And man can they play loud and hold it together. They seem to be comfortable playing any kind of music. I have found myself digging into music that I haven’t listened to for years and it sounds good. I get the impression that these speakers will improve with any upgrade in electronics that i wish to throw at them.

The construction was easier than expected and i absolutely love the shape and final finished design. I am very happy with this construction. Everything went to plan. The veneer is maple, and i used a water based polyurethane to prevent darkening (requested by wife).

Thank you greatly for allowing people such as myself to appreciate this level of hifi at a fraction of the cost. You are a very talented gentleman!

I have been listening to your speakers since i was 18 and probably still will be when I’m 70! (If i make it that far)





Hi Troels, thanks for the reply. I think I’ll give the fully passive version a miss. I am really satisfied with the performance of the CNO4  using the high level to the hypex amp. I have decided that I will upgrade to a Naim uniti Nova and stop worrying which setup might sound better. The setup as it is goes louder than I ever need anyway. Not sure if you have heard any, but Naim gear seems to have a very nice synergy with your speakers. These all in one units by Naim are really something, and so simple. Although I understand it’s not what most want.  
In the last few days I have adjusted our lounge room layout and moved the kitchen island bench (the things we do for our hifi) which has allowed a new location for the system. The speakers are now over 3 meters from sidewalls and this has made an amazing difference. Turns out I had mot really heard their capability yet! It is amazing how breathing room can make such a difference to the sound of these speakers. It is really like a source upgrade. I have attached a few pictures.
I think my next project might just be the Faital 10” to pair with my Atom once i get the new amp.  
Enjoy your CNO4!
Thanks again.