This is a review and detailed measurements of the Revel M55XC "extreme outdoor" speaker. It was kindly purchased new and sent to me by a member. I believe he is using it for surround on-wall application (indoor) due to small dimensions of this speaker. The retail cost for M55XC is $600 but there is a special (end of life?) going on bring the price for a pair down to US $420.
Note: our company, Madrona Digital, is a dealer for Harman and hence Revel speakers. I don't know for a fact but we install a lot of outdoor Harman speakers in commercial and residential installations. So feel free to read as much bias as you like into this review.
This is a very compact speaker as outdoor ones usually are:
There is sturdy metal grill that protects the drivers (which I did NOT use for measurements). The back panel shows screw terminals which is more of a standard for outdoor speakers (a boot covers and waterproofs it):
There is a plastic plug that you pull out where that dial is on the bottom to adjust the impedance for higher voltage drive to accommodate long speaker wire runs. I tested it in the default mode which is for normal amplifier wiring.
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. Measurement axis is the tweeter center.
Temperature was 78 degrees. Measurement location is at sea level so you compute the pressure.
Since this is an on-wall speaker, it is likely designed to get bass enhancement from the wall behind it. I could try to build some kind of wall to measure it that way but seemed too much work
. So what you see is the free-air measurement without such which will likely show lack of bass output.
Spinorama Audio 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 we could have guessed, bass output is too low relative to tweeter when measured assuming no walls behind it. Hard to then draw the trend line. I took a shot at it which would naturally show the speaker to be "bright" lacking bass without wall enforcement of bass.
Note how smooth the directivity is (dashed blue) line. And freedom from resonances. I have private measurements of a number of "architectural" speakers and they are generally horror shows.
Early reflections then show similar response to on-axis:
The rising directivity naturally reduces some of the highs making the response more flat.
Putting the two together we get a predicted in-room response which says what we already know:
Here is the impedance graph:
Here is the response of the individual drivers:
Speaker Dispersion Measurements
Looking how wide of a beam the speaker projects without much loss of energy we get:
We get a good 110 degrees with very smooth response.
Same in 3-D:
There are a lot of hi-fi speakers that fail to produce such an even response.
And here is the vertical:
Since you are wall mounting this speaker, this is an important measurement. Point the speaker down and keep it withing -30 degree window.
Speaker Distortion Measurements
Let's look at our Klippel system measurements first:
Looking at the left graph, we see that the not asking the little woofer to produce too much bass results in much lower distortion numbers. Once you turn it up though, distortion climbs in the rest of the range (right).
I should have captured the response at 86 dB but for consistency here is the distortion level at 96 dB:
Switching to Audio Precision analyzer we start with loudness compression:
This is very nice. There is essentially no loudness compression even at 114 dBSPL @1 meter! This speaker should play loud.
Taking a deep dive into distortion relative to frequency, let's look at 86 dB SPL:
And at multiple levels:
Displacement which mostly happens in bass frequencies is our enemy when it comes to distortion and we see this once again in above chart.
Finally here is our 32-tone test resembling "music:"
We actually beat our reference in above test. Here is the comparison at two levels:
Speaker Subjective Listening Tests
I started testing with the M55XC in my usual location which is at least 4 feet from back wall and 3 foot from side wall. Lack of bass was quite obvious so I moved the speaker back so that it has my system and Reel-to-Reel and TV behind it. That nicely boosted the bass although the speaker was still a tad bright. Proper placement on the wall would likely take that last bit away.
I then went through my usual playlist and was shocked how closely the sound of this little "outdoor" speaker resembled my much larger home Revel speakers. Clarity was superb. Distortion was nowhere to be found even when I turned the volume up. Indeed this speaker could handle incredible amount of power pumped into it without strain. Not letting it produce too much bass helped a lot here.
Tracks like this from Greek artist, Eleni Karaindrou's Medea album were to die for:
Sadly I can't find an online stream to share with you.
Another great performance (among many) was Patty' Griffin's Living With Ghosts Track, Cold As It Gets:
Track after track impressed.
Conclusions
I don't know what to tell you all. I keep wishing there is a Revel speaker that doesn't perform so I can put it down and in the process look unbiased. But I can't. These things are designed so well, even in this utilitarian outdoor packaging. Clearly similar design process is used for them as their home hi-fi gear (something Kevin Voecks of Harman confirmed with me years ago).
Using these of unobtrusive surround application indoor would be quite good as well as outdoor. And there, the much higher cost can be justified easier. Alternatively if you can place them against the wall, they will make very good "bookshelf" speakers.
Alas, if they are being discontinued, then we are late to the party. So better rush to get them. I might do the same myself....
Needless to say, I am very happy to recommend the Revel M55XC.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Audio products that perform well always cheer me up so I don't need your money for that. But if you insist, you can donate using: 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 and hence Revel speakers. I don't know for a fact but we install a lot of outdoor Harman speakers in commercial and residential installations. So feel free to read as much bias as you like into this review.
This is a very compact speaker as outdoor ones usually are:
There is sturdy metal grill that protects the drivers (which I did NOT use for measurements). The back panel shows screw terminals which is more of a standard for outdoor speakers (a boot covers and waterproofs it):
There is a plastic plug that you pull out where that dial is on the bottom to adjust the impedance for higher voltage drive to accommodate long speaker wire runs. I tested it in the default mode which is for normal amplifier wiring.
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. Measurement axis is the tweeter center.
Temperature was 78 degrees. Measurement location is at sea level so you compute the pressure.
Since this is an on-wall speaker, it is likely designed to get bass enhancement from the wall behind it. I could try to build some kind of wall to measure it that way but seemed too much work
. So what you see is the free-air measurement without such which will likely show lack of bass output.Spinorama Audio 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 we could have guessed, bass output is too low relative to tweeter when measured assuming no walls behind it. Hard to then draw the trend line. I took a shot at it which would naturally show the speaker to be "bright" lacking bass without wall enforcement of bass.
Note how smooth the directivity is (dashed blue) line. And freedom from resonances. I have private measurements of a number of "architectural" speakers and they are generally horror shows.
Early reflections then show similar response to on-axis:
The rising directivity naturally reduces some of the highs making the response more flat.
Putting the two together we get a predicted in-room response which says what we already know:
Here is the impedance graph:
Here is the response of the individual drivers:
Speaker Dispersion Measurements
Looking how wide of a beam the speaker projects without much loss of energy we get:
We get a good 110 degrees with very smooth response.
Same in 3-D:
There are a lot of hi-fi speakers that fail to produce such an even response.
And here is the vertical:
Since you are wall mounting this speaker, this is an important measurement. Point the speaker down and keep it withing -30 degree window.
Speaker Distortion Measurements
Let's look at our Klippel system measurements first:
Looking at the left graph, we see that the not asking the little woofer to produce too much bass results in much lower distortion numbers. Once you turn it up though, distortion climbs in the rest of the range (right).
I should have captured the response at 86 dB but for consistency here is the distortion level at 96 dB:
Switching to Audio Precision analyzer we start with loudness compression:
This is very nice. There is essentially no loudness compression even at 114 dBSPL @1 meter! This speaker should play loud.
Taking a deep dive into distortion relative to frequency, let's look at 86 dB SPL:
And at multiple levels:
Displacement which mostly happens in bass frequencies is our enemy when it comes to distortion and we see this once again in above chart.
Finally here is our 32-tone test resembling "music:"
We actually beat our reference in above test. Here is the comparison at two levels:
Speaker Subjective Listening Tests
I started testing with the M55XC in my usual location which is at least 4 feet from back wall and 3 foot from side wall. Lack of bass was quite obvious so I moved the speaker back so that it has my system and Reel-to-Reel and TV behind it. That nicely boosted the bass although the speaker was still a tad bright. Proper placement on the wall would likely take that last bit away.
I then went through my usual playlist and was shocked how closely the sound of this little "outdoor" speaker resembled my much larger home Revel speakers. Clarity was superb. Distortion was nowhere to be found even when I turned the volume up. Indeed this speaker could handle incredible amount of power pumped into it without strain. Not letting it produce too much bass helped a lot here.
Tracks like this from Greek artist, Eleni Karaindrou's Medea album were to die for:
Sadly I can't find an online stream to share with you.
Another great performance (among many) was Patty' Griffin's Living With Ghosts Track, Cold As It Gets:
Track after track impressed.
Conclusions
I don't know what to tell you all. I keep wishing there is a Revel speaker that doesn't perform so I can put it down and in the process look unbiased. But I can't. These things are designed so well, even in this utilitarian outdoor packaging. Clearly similar design process is used for them as their home hi-fi gear (something Kevin Voecks of Harman confirmed with me years ago).
Using these of unobtrusive surround application indoor would be quite good as well as outdoor. And there, the much higher cost can be justified easier. Alternatively if you can place them against the wall, they will make very good "bookshelf" speakers.
Alas, if they are being discontinued, then we are late to the party. So better rush to get them. I might do the same myself....
Needless to say, I am very happy to recommend the Revel M55XC.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Audio products that perform well always cheer me up so I don't need your money for that. But if you insist, you can donate using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
