This is a review and detailed measurements of the Revel C10. It was kindly purchased used by a member and sent in for testing. It is discontinued (released in 2008):
As you see, the C10 is quite small. It is a 2.5-way design with four mid-woofers, tweeter in the center and dual ports one at each end. I could not easily take the grill off so I did not attempt to do so. Even using a flashlight all I could identify was the tweeter. The grill is solid rather than being soft fabric you push in to find the drivers by feel.
It comes with brackets for wall mounting. Here is the back side:
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.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Reference axis was the center of the tweeter (aligned by eye). It is getting colder with the measurement room temp at 14 degrees C. Accuracy is better than 1% for almost entire audio spectrum indicating a well designed speaker.
NOTE: our company, Madrona Digital is a dealer for Harman products which includes Revel. So feel free to read whatever bias you like in my subjective remarks.
Revel C10 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
As you will see later, there is a built-in high pass filter so there is not much bass to speak of. The rest of the response is well behaved though with a slight slope down. There is some disturbance between 1 and 2 khz which is likely interference from the ports. As noted before, I could not identify the location of said ports or midrange drivers so I have no near field measurements to confirm that. Impact on frequency response is very modest though so should not mess up tonality.
The good directivity gives almost textbook early window and predicted in-room responses:
2-way versions of these speakers has had horribly narrow horizontal beam width. The 2.5-way approach helps some here but doesn't solve the problem:
You see the choke point around 1 to 2 kHz but it is twice as wide as competing speakers we have tested.
Vertical directivity naturally is much better than most 2-way speakers:
Impedance measurements show the high-pass filter with the way impedance shoots up as we get down to DC:
That high pass filter pays dividends in keeping bass notes from causing a lot of distortion:
It does make the relative amount look worse though but that is because there is essentially no response at lower range:
I could feel the cabinet resonating strongly so we see that indicated in the waterfall display:
Remember that I noted cabinet/port resonances between 1 and 2 kHz. That is where we are seeing the bulk of resonances above.
Finally, here is the impulse response for fans of this graph:
Revel C10 Listening Tests
As soon as I started to play the C10, it sounded horrible. Quick confirmation showed that I had the EQ on from last speaker test.
Turned that off and man, does this little speaker sound natural with great tonality. Yes, there is no lower bass and the upper bass is a bit tubby as a result. But the rest of the spectrum is beautiful with warm and correct tonality, very much similar to other well designed speakers I have tested (especially Revels). I felt little need to create or mess with equalization.
On dynamics ability, this was excellent due to not having any deep bass to bottom out the drivers. I could get it loud enough to create some physical sensation in my belly and sudden notes were surprisingly impactful. There is a lesson here is designing a speaker that is allowed to play only what it can do well.
On directivity, changing one seat over caused a slight tonal shift in vocals but it was not at severe.
Conclusions
The Revel C10 gets us closer to what a tiny center speaker with multiple drivers should be. Despite its budget class, clearly a lot of engineering has gone into making it deliver excellently smooth off-axis response (which summed). High pass filter is smart although it makes it less than a full (spectrum) speaker. If it had more bass, it would be a knock out. But it doesn't.
As a bonus, it is also quite small. I put it in front of our flat panel and it disappeared below its standard stand.
I am going to recommend the Revel C10. If you can find it on the used market, it can be a great option compared to a lot of junk designs out there.
----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
As you see, the C10 is quite small. It is a 2.5-way design with four mid-woofers, tweeter in the center and dual ports one at each end. I could not easily take the grill off so I did not attempt to do so. Even using a flashlight all I could identify was the tweeter. The grill is solid rather than being soft fabric you push in to find the drivers by feel.
It comes with brackets for wall mounting. Here is the back side:
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.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Reference axis was the center of the tweeter (aligned by eye). It is getting colder with the measurement room temp at 14 degrees C. Accuracy is better than 1% for almost entire audio spectrum indicating a well designed speaker.
NOTE: our company, Madrona Digital is a dealer for Harman products which includes Revel. So feel free to read whatever bias you like in my subjective remarks.
Revel C10 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
As you will see later, there is a built-in high pass filter so there is not much bass to speak of. The rest of the response is well behaved though with a slight slope down. There is some disturbance between 1 and 2 khz which is likely interference from the ports. As noted before, I could not identify the location of said ports or midrange drivers so I have no near field measurements to confirm that. Impact on frequency response is very modest though so should not mess up tonality.
The good directivity gives almost textbook early window and predicted in-room responses:
2-way versions of these speakers has had horribly narrow horizontal beam width. The 2.5-way approach helps some here but doesn't solve the problem:
You see the choke point around 1 to 2 kHz but it is twice as wide as competing speakers we have tested.
Vertical directivity naturally is much better than most 2-way speakers:
Impedance measurements show the high-pass filter with the way impedance shoots up as we get down to DC:
That high pass filter pays dividends in keeping bass notes from causing a lot of distortion:
It does make the relative amount look worse though but that is because there is essentially no response at lower range:
I could feel the cabinet resonating strongly so we see that indicated in the waterfall display:
Remember that I noted cabinet/port resonances between 1 and 2 kHz. That is where we are seeing the bulk of resonances above.
Finally, here is the impulse response for fans of this graph:
Revel C10 Listening Tests
As soon as I started to play the C10, it sounded horrible. Quick confirmation showed that I had the EQ on from last speaker test.
Turned that off and man, does this little speaker sound natural with great tonality. Yes, there is no lower bass and the upper bass is a bit tubby as a result. But the rest of the spectrum is beautiful with warm and correct tonality, very much similar to other well designed speakers I have tested (especially Revels). I felt little need to create or mess with equalization.On dynamics ability, this was excellent due to not having any deep bass to bottom out the drivers. I could get it loud enough to create some physical sensation in my belly and sudden notes were surprisingly impactful. There is a lesson here is designing a speaker that is allowed to play only what it can do well.
On directivity, changing one seat over caused a slight tonal shift in vocals but it was not at severe.
Conclusions
The Revel C10 gets us closer to what a tiny center speaker with multiple drivers should be. Despite its budget class, clearly a lot of engineering has gone into making it deliver excellently smooth off-axis response (which summed). High pass filter is smart although it makes it less than a full (spectrum) speaker. If it had more bass, it would be a knock out. But it doesn't.
As a bonus, it is also quite small. I put it in front of our flat panel and it disappeared below its standard stand.
I am going to recommend the Revel C10. If you can find it on the used market, it can be a great option compared to a lot of junk designs out there.
----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
