Canon S-50 Wide Directivity Speaker Review

[Robbo99999]

Well it's an interesting speaker and I chuckled at your potential sitting-on-speaker optimisation strategies!

 

[mhardy6647]

Duuuuuude.
It's got a whizzer.

cool.





EDIT: Somewhat more seriously, the design is reminiscent of Zenith's "Circle of Sound".

I had one of these clock radios when I was an adolescent. Still have it, come to think of it. It is not a bad sounding little radio.

Here's a top-firing morph that perhaps better illustrates the implementation.

The great Stu Hegeman made a standalone loudspeaker that used a similar mode of dispersion starting in the late 1950s (come to think of it).

https://www.audioasylum.com/forums/hug/messages/18/183247.html

 

[Philberish]

Fascinating to see all these omni mirror speakers coming up, but of course the novelty of Hiro Negishi's Canon idea, and the fundamental claim of the patent, was that the apex of the conical mirror was not on the central axis of the driver.

Phil

 

[peanuts]

a linkwitz pluto clone for comparison
http://gainphile.blogspot.com/2008/05/linkwitz-pluto-sewer-pipe-omni-p.html

 

[SMc]

Here's how the Americans did it in the late 60s/early 70s.

I have a pair of these Empire Royal Grenadier 9000M mk2 i

I think they are around 125lbs each packed...

Much more impressive than my family's Harman-Kardon HK25 (also not my picture):

 

[Neuromorphism]

The diffuser cones are interesting, it would also be very interesting to see the SAW waveguide version measured. This is the same style waveguide that B&O still uses. Or perhaps a Beosound implementation would be a better choice to evaluate the concept just because it is more modern. Canon S-25:

 

[mhardy6647]

The JBL Century L-100s are (and were) a truly horrible speaker. I've owned them and sold them on as quickly as I could. I wish they were good, but they are ear burners. As for the AR-3s, I just don't get the love. They look and sound hideous to me.

View attachment 68332

Dad had a lot of speakers, the Empires stayed in the loungeroom and at one point had crystal decanters with whisky/sherry on top. Ah, the 1970s eh?

If you were selling the Empire's back in the day, you'd probably be aware the first 9000M used a 15lbs ceramic magnet on the woofer and a bespoke Empire manufactured compression tweeter, whereas the 9000M mk2 used a totally different AlNiCo magnet 15" bass driver and a modified (painted) Philips poly dome treble unit. They were quite different, more efficient and an increased power handling.

Sure, one day I'll pull them out and go crazy with active three way classD amps with DSP just for fun. Like a sleeper-car nobody would know.

That's an AR-3a
The AR-3 was even incrementally uglier.

AR3oneLF by Mark Hardy, on Flickr
In fairness, my original dump-find pair was extra-ugly. But the front baffle ugliness was petty much factory stock

I actually have a nice-looking pair of AR-3 loudspeakers still. They are pleasant to listen to but kind of distant.

I will defer comment about the Empahs' Empires' sonics -- but I will share this.

empahs by Mark Hardy, on Flickr

From a Lafayette Radio catalog (not that I remembered to document the year... probably early 1970s) . A good selection of LRE catalogs are now (finally!) available online at
https://worldradiohistory.com/Lafayette_Catalogs.htm

 

[Mauro]

Wow! This is particularly fascinating stuff 'cause as some of you will appreciate, I was part of the team responsible for the S-50 (and all the subsequent Canon Audio speakers). I won't go into any of that story here 'cause I've covered it in the blog posts (https://musicandmiscellany.com) that you've been kind enough to link to. What I will do though is comment on the measurements and some of the discussion they've raised.

First, although I always had my doubts about the use of the the parasitic cone (the S-50 design was mostly frozen when I joined Canon Audio in 1990), I really don't remember the top end response of the S-50 being quite as uneven as the sample measured here. It was never great of course, but I'm pretty sure it was better than this. Similarly, the distortion performance was better – that 1.5kHz - 5kHz mess wasn't present. I wonder what the history of the particular speaker is and whether they've been well looked after? The parasitic cone shown in the photograph has definitely gone a strange colour (it would originally been the same colour as the cone) so I wonder if its mechanical properties have degraded over the years? Sadly, considering my decades working with speakers, I don't really know anything about the ageing of paper diaphragms and how their characteristics change.

The resonance of the dome is an odd one. There's a rubber o-ring at the join between the dome and the baffle, in place both to provide an air-seal and to damp the dome bell resonance, so I wonder if it has perished? It's also possible that the screws holding the dome in place (one on the underside of the baffle, two on the top under the central plug) have come loose - that might well be the case if the o-ring has disintegrated. Replacing the o-ring is, by the way, a pretty simple job.

Along with the HF unevenness, the measurements reveal what was of course the fundamental problems with the Canon "off-centre acoustic mirror" (and the many examples of axially aligned conical mirrors): Firstly, the mirror loads the driver over a narrow mid-band (I forget exactly where it was but I think it was in the high hundred Hertz) where the ear is really sensitive, so even if you can EQ it flat(ish), which was done on the S-50, it still tends to result in a characteristic colouration. Secondly, even though the mirror is actually a surprisingly effective dispersion control device, wherever you listen/measure you're always going to have a degree of direct sound arriving first, and that results in all sorts of audible comb-filtering effects. Despite the fundamental problems though, as described in the subjective assessment, the S-50 had some really interesting qualities. It wasn't really "hi-fi" in the sense that it produced an accurate reproduction of the source material, and that was never really the intention, but it could be a genuinely engaging and entertaining listen. I kind of wish I had a pair.

Lastly, having expressed doubts about the parasitic tweeter in my blog posts, I was contacted not long afterwards by an S-50 owner, who like me, had been wondering about the possibility of fitting a contemporary dual-concentric driver. Since the original KEF dual-concentric patents lapsed a few years ago there's been quite a few similar drivers launched, so the dual-concentric S-50 idea is now rather more feasible than it was in 1990. So, once lockdown is over and things picks up again the plan is to give it a go. I'll report back.

Thanks again for the S-50 measurements and chat! You've made my day.

Phil

PS. So sad that Allen Boothroyd, who did the S-50 industrial design, isn't around to see folks still chatting about it - he left us a couple of months ago. It was a project he was very committed to and very proud of.

Very interesting post Phil! As always..on the blog and on Sound on Sound. My favorite speaker reviewer..sorry Amir to give Phil the edge ..I learn a lot from the work of both! Thanks

 

[Philberish]

Very interesting post Phil! As always..on the blog and on Sound on Sound. My favorite speaker reviewer..sorry Amir to give Phil the edge ..I learn a lot from the work of both! Thanks

Thanks Mauro. You're too kind.

I've just remembered a bit of trivia about the Canon Audio years that's mildly relevant here. Negishi-san, who's project the whole thing was, loaned a desk in our R&D office for a while to a PhD student he'd met at an AES event who was working on new speaker analysis and modelling tehniques. The guy's name was Wolfgang Klippel.....

 

[infinitesymphony]

Canon S-35 adds a tweeter and conventional crossover, with a cast zinc structure atop a plastic base.

Measurements here:

https://www.stereophile.com/content/canon-s-35-loudspeaker-measurements

Now I want a cup of coffee.

 

[Jukebox]

MBL speakers sound great even though they have the same diffraction errors at the high frequencies. The problem is that they are outrageously expensive and inefficient.

Expensive yes they are; but not that inefficient as one might think; in my tests with MBL 126 and 116F I found them in the ball park with a normal front radiating speaker, maybe slightly lower.

 

[Jimster480]

When I was a kid I remember a family friend had speakers just like this. I am not certain if this was the exact model but it looked just like this. Back then I couldn't ever tell if it "sounded bad" as they played music or radio in the house and it was "fine" from my perspective at the time.

 

[rødsvart]

Yes, you can call it Packman speaker. Or Darth Vader helmet.

Looks like slimmed Banzai Bill to me.

 

[tuga]

These guys know how to design beautiful speakers:

https://www.davoneaudio.com/mojo.html

 

[stevenswall]

With the backlog I suppose you have what's the point in measuring this 30-years old weird stuff?

Worth it because many 'modern' designs aren't as daring and don't try to take care of dispersion and diffraction like this. It didn't work well in this case, but I'd rather measure things pushing the limits and come across a gem, instead of yet another "drivers slapped on a boxy box" method so many employ.

 

[GXAlan]

The speakers made their way back to me. They're bigger than they look in pictures.

Based upon private conversation with @Philberish, I opened up the Canon's.

1) The O-ring wasn't quite seated well on the speaker that Amir tested. That accounts for the buzzing and why he couldn't get it up to volume. It's a flawed design with only two screws in the center of mushroom cap holding everything together.

2) First thing that greeted me was the WOOL filling instead of traditional "polyfill" (polyester)! The entire helmet is filled. You can see a small glimpse of the port which fires just behind the apex of the acoustic lens.

3. Close up of the speaker driver

Subjectively. Here are my thoughts.
1) I see what Amir is saying about these sounding actually pretty good. I listened to them in stereo and backed by a single wall to reinforce the bass.

2) I suspect this is how the speakers were voiced since the bass is pretty impressive for a tiny 5" full range driver

3) Vertical directivity is good if you imagine the speakers flanking a TV. That upward 10-20 degrees actually works in your favor.

4) IMD is surprisingly good in the vocal range.

IMD is one of the core weaknesses of most single driver systems. My favorite test for this is "Another Day of Sun" from the La La Land Soundtrack. In the opening, you can compare the band to the voices to make sure that the two are balanced and then when everyone is singing simultaneously at about 1 minute in, you see how loud you can turn up the speaker until it actually gets hard to discern the words.

The Canon does really well here even though it shouldn't. Single driver. Mismatch between direct and reverberant sound. But it sounds really good. The Canon in stereo even beats the IMD performance of a single Devialet Phantom. This might be the effect of the Alnico magnet under high volumes.

5) The super wide dispersion really adds a lot to the music experience. The speakers disappear. Center image still requires you to be in the middle (it's not the same effect as asymmetrical horns) but because so much of the sound also comes from the wall reverberation, it is impossible to localize the speakers. The lens isn't a simple cone -- there is a bit of a curve to it and I wouldn't be surprised if it's a complex mathematical formula for the lens.

6) It's humbling because I've got a lot of fancier and better measuring gear, but it is incredibly enjoyable to listen to these speakers. It's a different experience. It's veiled, the resolution isn't there -- but somehow it still works. I echo @amirm in saying that it is very worthwhile from an educational point of view because it shows you the power of a clean reverberant field in overall subjective joy.

 

[bigx5murf]

If there's any interest, I'll see about sending in a S-25. I haven't recapped them yet, which I thought should be done. Thoughts?

 

[GXAlan]

If there's any interest, I'll see about sending in a S-25. I haven't recapped them yet, which I thought should be done. Thoughts?

I don't think recapping is as necessary. it may change the crossover point somewhat, but looking at the quality of the internals of the S-50, I suspect that it'll be fine in the S-25. It would be interesting to see how the tweeter lens performs.

 

[GXAlan]

@Philberish
@amirm

I measured the same speaker after tightening the screws to reduce the resonances. With psychoacoustic smoothing, you can see that the measurements are a little bit flatter. (Orange = my in-room; Green = Amir's data; both smoothened)

That also translates into lower distortion, which isn't seen at the higher frequencies. I have masked out the distortion that was below the noise level in my room at the time of measurement. Everything from 325Hz to 8kHz is basically under 1%. The peaks at 1.73kHz is 1.1% and 8.7kHz is 2%.

Brown = measured, not smoothened
Red = THD, with THD below noise floor masked.

Still pretty impressive for a single-driver in my book.

 

[infinitesymphony]

My most inspirational holistic listening tends to be well off-axis of my speakers, letting the music breathe through the room, otherwise my brain is picking apart the mixing rather than letting it wash over me. Sometimes it's nice to forget about microscopically-perfect imaging and just let a cloud of music transport you. Seems like these speakers and other omni-ish models like Ohm Walsh would allow you to achieve that goal even if you're centered between them.