This is a review and detailed measurements of the Revel M106 bookshelf speaker. It was kindly purchased and drop shipped to me. It is not a new sample but came to me with full packaging and protective wrapper. The M106 costs US $1,000 each or $2,000 for a pair. It is only sold through dealer channel so these are "list prices."
NOTE: our company, Madrona Digital is a dealer for Harman which includes Revel speakers. So please feel free to read as much bias as you like in this review.
The M106 is one of the heaviest and densest speakers I have lifted for its size:
The finish is first class and glass smooth. Back panel is highly curved which should reduce diffraction effects:
Sorry about leaving the protective plastic on. I try to keep as much as these things on so the finish is preserved when the owner gets the unit.
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 over 800 measurement point which was sufficient to compute the sound field of the speaker.
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:
There are some variations in the on-axis frequency response but some go away in the listening window (average of a few degrees around the direct axis). The large disparity in size between tweeter and woofer also creates some directivity error where the woofer starts to "beam" (its radiation narrows) yet the tweeter starts with a wider beam width causing a dip in off-axis response.
There are no signs of serious resonances though which is good.
Early window reflections are pretty smooth making this speaker easy to place in a room and have it sound good:
Putting on-axis and reflections together we get a predicted in-room frequency response in a hypothetical average room:
This is really good folks! Some of the variations in on-axis are filed away resulting in almost ideal frequency response. Since what you hear in your room is the sum of direct and indirect sounds, this type of response bodes well for actual performance in one's room.
I read some place that Kevin Voecks (most visible person behind Revel line) said that there was strong effort to reduce distortion and that they had managed to push it below audibility in mid to higher frequencies. So let's measure that:
Wow, seems true! At 86 dB the graphs essentially hugs the bottom of the graph. Even when pushed to 96 dB, there is hardly any rise in distortion. This is the type of performance we expect to see in high-end active studio monitors, not home bookshelf speakers.
Putting the distortion in context at 96 dB we get:
Usually I set the lower limit at -50 dB as shown. But received a good request to show it down to lower levels so here we are. We can see that distortion products linearly go down and hit some of their lowest where our hearing is most sensitive (2 to 5 kHz). Second harmonic dominates across the board. Third harmonic does peak up near 3 kHz but otherwise is not dominant.
Looking at how wide of a "beam" the speaker projects we get about 100 degrees:
The drop off is smooth:
Vertical is not bad for this type of speaker and gives you some wiggle room with respect to the height of your stance and your ear level:
You don't want to go so high or low below tweeter axis as to land in these "eyes" around 2 kHz.
Directivity is reasonably smooth as well again, given the type and design.
Impedance shows the typical minimum impedance:
So don't let the small size make you think you need a small little amplifier to drive it.
You all know I am not a big fan of waterfall graphs but this one sure looks clean and uneventful:
Subjective Speaker Listening Tests
For testing, I go through my reference track list, often playing 20 to 30 seconds before going to next one. This way, I can quickly get a sense of speaker's overall performance across wide range of content with different spectrum. Well, that didn't happen here. As soon as I played the first track, I froze in place. The sound was so incredibly smooth and beautiful that I could not hit "next" on my player! Incredible amount of detail. Resolution to die for. The note decay was tremendous. This was that first track, Youn Sun Nah - My Favorite Things:
The Youtube version sounds poor. I have the 88 kHz high-res download. Get a copy of this track and if it doesn't make you melt in your seat with audiophile bliss, you have the wrong speaker/system!
I go to the next track, Snowflake from Kristin Asbjørnsen
The starting strings seem to jet out of the speaker with startling realism. And then the beautiful vocals came through, with nice layering and separation.
Sit .... back... down. This is not some subjectivist speaker review. To wit, my wife was in the bedroom getting ready to go to sleep but she did not come out to tell me how great the speaker was!
Back to my testing, after listening to a dozen reference track and being most impressed with them all, I switched to bass heavy ones. There is no deep bass here but what is there is incredibly clean. And this speaker can play them loud. Really loud with no sign of strain. I had no trouble filling my huge space with just a single speaker playing. Tracks like the classic Samba by Jean Claude Kerinec & Staff Elmeddah could not be more dynamic coming out of this little speaker:
Words really fail me to describe the clarity, fidelity and yes, neutrality of this speaker.
Conclusions
The Revel M106 is not cheap in a sea of bookshelf speakers selling for 1/5 its price or even lower. But I am here to tell you that it achieves a level of fidelity many of us strive for. Its objective frequency response is very good. But I think part of the superb fluidity and clarity it brings to delicate notes is its extremely low distortion. I wish you could be here to listen to it and experience what I did. To say that I am impressed by it is an understatement.
The Revel M106 is one of the most perfect bookshelf speakers I have heard. As such, I am going to give it my strongest recommendation.
------------
As always, questions, comments, recommendations, etc. are welcome.
Here is my routine every night: eat dinner, go to the garden and dig, de-weed, put compost on plants, fertilize and water them. The come inside at 9:30 pm (it doesn't get dark till after that!) and wash all the dirt from under my nails. Then go in the garage measure speakers, process them and stumble into bed at 1:00 am. If this didn't make you cry and want to write me a big donation check, I don't know what will: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
NOTE: our company, Madrona Digital is a dealer for Harman which includes Revel speakers. So please feel free to read as much bias as you like in this review.
The M106 is one of the heaviest and densest speakers I have lifted for its size:
The finish is first class and glass smooth. Back panel is highly curved which should reduce diffraction effects:
Sorry about leaving the protective plastic on. I try to keep as much as these things on so the finish is preserved when the owner gets the unit.
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 over 800 measurement point which was sufficient to compute the sound field of the speaker.
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:
There are some variations in the on-axis frequency response but some go away in the listening window (average of a few degrees around the direct axis). The large disparity in size between tweeter and woofer also creates some directivity error where the woofer starts to "beam" (its radiation narrows) yet the tweeter starts with a wider beam width causing a dip in off-axis response.
There are no signs of serious resonances though which is good.
Early window reflections are pretty smooth making this speaker easy to place in a room and have it sound good:
Putting on-axis and reflections together we get a predicted in-room frequency response in a hypothetical average room:
This is really good folks! Some of the variations in on-axis are filed away resulting in almost ideal frequency response. Since what you hear in your room is the sum of direct and indirect sounds, this type of response bodes well for actual performance in one's room.
I read some place that Kevin Voecks (most visible person behind Revel line) said that there was strong effort to reduce distortion and that they had managed to push it below audibility in mid to higher frequencies. So let's measure that:
Wow, seems true! At 86 dB the graphs essentially hugs the bottom of the graph. Even when pushed to 96 dB, there is hardly any rise in distortion. This is the type of performance we expect to see in high-end active studio monitors, not home bookshelf speakers.
Putting the distortion in context at 96 dB we get:
Usually I set the lower limit at -50 dB as shown. But received a good request to show it down to lower levels so here we are. We can see that distortion products linearly go down and hit some of their lowest where our hearing is most sensitive (2 to 5 kHz). Second harmonic dominates across the board. Third harmonic does peak up near 3 kHz but otherwise is not dominant.
Looking at how wide of a "beam" the speaker projects we get about 100 degrees:
The drop off is smooth:
Vertical is not bad for this type of speaker and gives you some wiggle room with respect to the height of your stance and your ear level:
You don't want to go so high or low below tweeter axis as to land in these "eyes" around 2 kHz.
Directivity is reasonably smooth as well again, given the type and design.
Impedance shows the typical minimum impedance:
So don't let the small size make you think you need a small little amplifier to drive it.
You all know I am not a big fan of waterfall graphs but this one sure looks clean and uneventful:
Subjective Speaker Listening Tests
For testing, I go through my reference track list, often playing 20 to 30 seconds before going to next one. This way, I can quickly get a sense of speaker's overall performance across wide range of content with different spectrum. Well, that didn't happen here. As soon as I played the first track, I froze in place. The sound was so incredibly smooth and beautiful that I could not hit "next" on my player! Incredible amount of detail. Resolution to die for. The note decay was tremendous. This was that first track, Youn Sun Nah - My Favorite Things:
The Youtube version sounds poor. I have the 88 kHz high-res download. Get a copy of this track and if it doesn't make you melt in your seat with audiophile bliss, you have the wrong speaker/system!
I go to the next track, Snowflake from Kristin Asbjørnsen
The starting strings seem to jet out of the speaker with startling realism. And then the beautiful vocals came through, with nice layering and separation.
Sit .... back... down. This is not some subjectivist speaker review. To wit, my wife was in the bedroom getting ready to go to sleep but she did not come out to tell me how great the speaker was!
Back to my testing, after listening to a dozen reference track and being most impressed with them all, I switched to bass heavy ones. There is no deep bass here but what is there is incredibly clean. And this speaker can play them loud. Really loud with no sign of strain. I had no trouble filling my huge space with just a single speaker playing. Tracks like the classic Samba by Jean Claude Kerinec & Staff Elmeddah could not be more dynamic coming out of this little speaker:
Words really fail me to describe the clarity, fidelity and yes, neutrality of this speaker.
Conclusions
The Revel M106 is not cheap in a sea of bookshelf speakers selling for 1/5 its price or even lower. But I am here to tell you that it achieves a level of fidelity many of us strive for. Its objective frequency response is very good. But I think part of the superb fluidity and clarity it brings to delicate notes is its extremely low distortion. I wish you could be here to listen to it and experience what I did. To say that I am impressed by it is an understatement.
The Revel M106 is one of the most perfect bookshelf speakers I have heard. As such, I am going to give it my strongest recommendation.
------------
As always, questions, comments, recommendations, etc. are welcome.
Here is my routine every night: eat dinner, go to the garden and dig, de-weed, put compost on plants, fertilize and water them. The come inside at 9:30 pm (it doesn't get dark till after that!) and wash all the dirt from under my nails. Then go in the garage measure speakers, process them and stumble into bed at 1:00 am. If this didn't make you cry and want to write me a big donation check, I don't know what will: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
High praise. Thanks for the review, 
