This is one of my most popular posts, so I want to make sure to point out that this is the first of two posts comparing the CNO and Spendor SP2/3, the second post is: https://onetwothreeaudio.wordpress.com/2012/11/14/sopwamtos-and-cno-review-continued//
Originally I titled this “Zen and the Sound of One Speaker Pulsing” as a takeoff on the famous Zen question, “What is the sound of one hand clapping?” as I only have a single CNO speaker. I built the CNO-T25 loudspeaker, designed by Troels Gravesen and using Seas Excel drivers (see http://www.troelsgravesen.dk/CNO.htm and CNO-T25.htm), as a center channel for music and matched up with a pair of Spendor SP2/3 loudspeakers. The Spendor SP2/3 speakers are semi-famous, they are a simpler version in a lineage (the BC1, then the Spendor SP1, etc.) based on BBC designed loudspeakers for broadcast monitoring. One online review of the Spendor SP2/3 is http://www.enjoythemusic.com/magazine/equipment/0601/spendorsp23e.htm; a few quotes, “It’s that damn good. Get the picture?” and “one of the most musical sounding speakers that I’ve ever had the chance to hear. They surprised me by their levels of transparency and detail…”
My Spendors are 18 years old, are they past their prime? Hard for me to know, but they sound good to me, perhaps the bass is less than when they were newer, perhaps some of the clarity has declined over time. The new Spendor SP2/3s look the same but are completely different speakers (new woofer, new crossover, new tweeter, new cabinet, etc.), and I haven’t heard them to compare.
At any rate, here are some thoughts about the sound of the CNO-T25. The CNO-T25 compares favorably to the Spendors, and I consider that high praise. While the CNO-T25 does not sound exactly like the Spendors, the combination works well together for music, especially since for many recordings the position of voices/instruments is fixed for a recording (I suppose a live recording of say a musical or opera might be an exception), so slight differences between the center and left/right speaker are less critical. In my opinion, the CNO, with a 24 litre cabinet, has better bass, more clarity, and seems more dynamic. Spendor loudspeakers are famous for their magical, seductive midrange quality. I would say that for pure tonality, the Spendor SP2/3s are hard to beat. But the clarity of the CNO was quite noticeable to me, the aural equivalent of suddenly looking out a freshly cleaned window and realizing how dirty the window actually had been.
Since I only built one CNO speaker, I don’t really know what a stereo pair would sound like, but if it’s not a complete oxymoron to state, it seems that the CNO has a spatious sound, even in mono. The sound doesn’t change much as I stand up or sit down, or as I move around the room, an important quality for me. To contrast, I briefly auditioned some Dynaudio speakers and they sounded great when I was in the sweet spot sitting down, but if I got up and walked around the room, the sound changed a lot. So not all speakers have the property of an “even power response” – sounding about the same in different listening positions.
While the CNO-T25 isn’t meant for killer volumes, it easily fills my large listening room at what I would call reasonable listening levels. Perhaps because of the clarity, it is tempting to play it louder than the Spendors, and while the CNO sounds fine at low volume levels, it comes alive with a bit more volume than the Spendors. And, something very important to me, both the CNO-T25 and the Spendors are enjoyable with less than ideal recordings. I remember when I was auditioning the Spendors, the dealer also had a pair of Spendor SP7/1 speakers, and it made most of my recordings sound bad, so I said no thank you.