This is a review and detailed measurements of the Canon S-50 wide directivity ("omni-directional") speaker. It was a venture from their UK division from what I have read (in early 1990s). Phil Ward tells the story well in this article: https://musicandmiscellany.com/2019/06/08/canon-audio-part-1/ . The S-50 was purchased by a member and kindly sent to me from UK.
As with most omni speakers, the S-50 has a very unusual shape:
Yes, you can call it Packman speaker. Or Darth Vader helmet. I tend to think the latter.
They made a poor choice of putting the speaker terminals underneath which made termination and measurements a bit of a pain:
I have seen a stand in some of the picture so that may have helped with this problem.
If you want to peak inside, this is what it looks like with a down-firing little driver:
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
I used a relative high number of scan points (> 800) but it still was not enough to characterize the response above 10 kHz. So there is some error there.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
We quickly see that the speaker lives up to its definition if you look at frequencies up to 3 kHz or so. Sound power (red) is nearly identical to on-axis response!
After 3 kHz, bad things start to happen and with it, screws up the directivity as well.
Early reflections shows what we already know:
Ditto for predicted in-room response:
Examining the horizontal directivity in detail we get a better view:
Even up to 3 kHz we get +- 180 degrees of dispersion indicating omni-directional dispersion.
Of course the details are quite flawed. We have a hole around 500 Hz and then wheels fall off the wagon above 3 kHz. Directivity narrows and response is very uneven.
Vertical directivity is also wide but much, much messier still:
So I don't think vertically you get even response if you move up and down from speaker axis.
While on pretty colorful pictures, I thought I plot the 3-D representation of the soundfield at 17 kHz:
Stunning to look at! But not to listen to as it indicates so many resonances and problems distributed in space. No wonder Klippel NFS can't characterize it unless we measure at thousands of points.
Impedance shoots way up high in low frequencies indicating a high pass filter of sorts:
Distortion is off the charts in low frequencies but also problematic at higher:
And this is just at 86 dB SPL, not the 96 I usually run. So don't expect to play it loud.
Speaker Subjective Listening Tests
I connected the S-50 to my system in the usual left corner position ( a few feet from walls). I was immediately greeted with significant distortion with every bass note. Turning down the volume helped a bit but the problem was still there.
I went to it and realized it was the "helmet" that was vibrating like crazy with every beat. I pushed down on it and it almost eliminated the problem.
I thought of sitting on it for the rest of the listening tests but got worried as to what might hatch under me.
So instead, I dialed in a high pass filter in Roon player:
This was enough to give me the ability to turn up the volume reasonably to listen. Needs even more filtering for any real use.
Anyway, I went to town, avoiding my bass heavy tracks. Since you all keep asking me for my tracks, here is one of my favorites (both for content and fidelity despite its age):
Ah, boy did this track sound good! The wide dispersion gave it more openness, provide more of a "live" feel to this track. Anyone who thinks "reflections are bad" needs to get this speaker and play this track! No, it didn't add any echos. It just ever so slightly adds ambiance.
The high distortion did not let me enjoy many other tracks but as far as I could tell, it would add the same but more subtle version of the above to instrumentation tracks I played. Overall tonality was actually good.
I then went down to the speaker level and shifted 90 degrees to the side of the speaker. It was uncanny how the tonality overall did not change. This would be a great feature for background listening even in mono.
Vertical response in high frequencies was noticeable though with best response pointing right at the speaker.
Conclusions
Testing the Canon S-50 was a wonderful exercise in measurements and listening to something different. It is a good concept for some music but with highly flawed execution. Perhaps the higher ups in the line would not have had the problems this little guy has. If you can pick one on the cheap (I read some people buying them for $150 and such), it is very worthwhile from educational point of view, if not listening.
And who doesn't like a cute little speaker like this?
-----------
As always, questions, comments, recommendations, etc. are welcome.
Installed the Burger King app on my phone to take advantage of the discounts they offer. Just got a notification that the Whopper is being sold for just $2!!! I am going to run out there and get one instead of quality/healthy food which would cost more. That is where I am money-wise. If you want this to change, please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
As with most omni speakers, the S-50 has a very unusual shape:
Yes, you can call it Packman speaker. Or Darth Vader helmet. I tend to think the latter.
They made a poor choice of putting the speaker terminals underneath which made termination and measurements a bit of a pain:
I have seen a stand in some of the picture so that may have helped with this problem.
If you want to peak inside, this is what it looks like with a down-firing little driver:
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
I used a relative high number of scan points (> 800) but it still was not enough to characterize the response above 10 kHz. So there is some error there.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
We quickly see that the speaker lives up to its definition if you look at frequencies up to 3 kHz or so. Sound power (red) is nearly identical to on-axis response!
After 3 kHz, bad things start to happen and with it, screws up the directivity as well.
Early reflections shows what we already know:
Ditto for predicted in-room response:
Examining the horizontal directivity in detail we get a better view:
Even up to 3 kHz we get +- 180 degrees of dispersion indicating omni-directional dispersion.
Of course the details are quite flawed. We have a hole around 500 Hz and then wheels fall off the wagon above 3 kHz. Directivity narrows and response is very uneven.
Vertical directivity is also wide but much, much messier still:
So I don't think vertically you get even response if you move up and down from speaker axis.
While on pretty colorful pictures, I thought I plot the 3-D representation of the soundfield at 17 kHz:
Stunning to look at! But not to listen to as it indicates so many resonances and problems distributed in space. No wonder Klippel NFS can't characterize it unless we measure at thousands of points.
Impedance shoots way up high in low frequencies indicating a high pass filter of sorts:
Distortion is off the charts in low frequencies but also problematic at higher:
And this is just at 86 dB SPL, not the 96 I usually run. So don't expect to play it loud.
Speaker Subjective Listening Tests
I connected the S-50 to my system in the usual left corner position ( a few feet from walls). I was immediately greeted with significant distortion with every bass note. Turning down the volume helped a bit but the problem was still there.
I went to it and realized it was the "helmet" that was vibrating like crazy with every beat. I pushed down on it and it almost eliminated the problem.
I thought of sitting on it for the rest of the listening tests but got worried as to what might hatch under me.
So instead, I dialed in a high pass filter in Roon player:
This was enough to give me the ability to turn up the volume reasonably to listen. Needs even more filtering for any real use.
Anyway, I went to town, avoiding my bass heavy tracks. Since you all keep asking me for my tracks, here is one of my favorites (both for content and fidelity despite its age):
Ah, boy did this track sound good! The wide dispersion gave it more openness, provide more of a "live" feel to this track. Anyone who thinks "reflections are bad" needs to get this speaker and play this track! No, it didn't add any echos. It just ever so slightly adds ambiance.
The high distortion did not let me enjoy many other tracks but as far as I could tell, it would add the same but more subtle version of the above to instrumentation tracks I played. Overall tonality was actually good.
I then went down to the speaker level and shifted 90 degrees to the side of the speaker. It was uncanny how the tonality overall did not change. This would be a great feature for background listening even in mono.
Vertical response in high frequencies was noticeable though with best response pointing right at the speaker.
Conclusions
Testing the Canon S-50 was a wonderful exercise in measurements and listening to something different. It is a good concept for some music but with highly flawed execution. Perhaps the higher ups in the line would not have had the problems this little guy has. If you can pick one on the cheap (I read some people buying them for $150 and such), it is very worthwhile from educational point of view, if not listening.
And who doesn't like a cute little speaker like this?
-----------
As always, questions, comments, recommendations, etc. are welcome.
Installed the Burger King app on my phone to take advantage of the discounts they offer. Just got a notification that the Whopper is being sold for just $2!!! I am going to run out there and get one instead of quality/healthy food which would cost more. That is where I am money-wise. If you want this to change, please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
