This is a review and detailed measurements of the Revel F208 speaker. It was kindly purchased by a member and drop shipped to me for measurements. Revel F208 costs $2,500 each or US $5,000 for a pair.
Note: our company, Madrona Digital is a dealer for Revel speakers. Feel free to read as much bias as you like in this review.
The unit as tested is in piano black which gives a luxurious feel to the unit. Alas, the unit was too heavy for me to lug it up to my listening room so you have to settle for a plastic wrapped version of it in my test "lab:"
There was a sturdy sheet of plastic covering the front which I took off but left the rest of the plastic on it to protect it as you see in this shot:
I went through a bit of hell trying to figure out why the speaker would not plays the highs at first. After hours of trying to figure it out, and losing out a day, I realized it was a simple thing: the bar wires I was using would not always allow the shorting bar to do its job. I have to use a bare wire as to lower the interference around the speaker as the robotic arm moves the mic around. Anyway, I have to take the speaker to the owner in an hour so no time for listening tests either.
This speaker was the heaviest I have tested and despite having that wonderful lift you see in the first picture, it was a killer to unpack and move around.
I played with the bass compensation and it does what it says: if you set it to boundary, it lowers the bass level. I did not test the tweeter one but I suspect it does the same. An array of power resistors behind that panel makes these simple level changes.
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.
All measurements are referenced to the tweeter axis with frequency resolution of 2.7 Hz. I used a high number of scans (over 1000 measurements).
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:
Edit: these are updated measurements based on optimization of the numerical analysis in the bass response.
There is good correlation with Harman measurements:
I was puzzled that the on-axis response was not as smooth as I expect Revel speakers to have. That disappeared when I looked at the rest of the measurements starting with predicted in-room response:
Wow! With no DSP this speaker managed to get such balanced and smooth response. It appears that the off-axis response is tuned to counter the on-axis response as we see here:
This makes the speaker fairly room independent and sharply increases your chances of putting this in any room and enjoying accurate sound reproduction.
Distortion levels are very much controlled:
Ignore the rise in very low frequencies as that goes beyond the speaker's ability to reproduce. The rest shows no "acoustic events" other than a bit of wiggliness between 100 and 200 Hz:
In this calibrated graph where the range is 50 dB, I like to see nothing but blank space for distortion and the F208 gets there with the exception of the lower frequency range.
Impedance test shows dipping to 3.5 ohm so you better have a high current amplifier that doesn't mind such loads:
Horizontal directivity diagram shows very wide response which means you don't have to sit in a vice to get good sound:
And if you left the side wall reflections bare, you should get wider image. The inclusion of that mid-range gives good dispersion to whopping 100 degrees!
Vertically the situation is not as good as we typically see in non-coaxial designs:
I am in a hurry so could not optimize the CSD plot so here it is:
I wanted to see if I could diagnose the up and downs in high frequencies so ran this 3-d plot:
The problem could also be the mid-range still going as we see in the hot area below the tweeter.
Speaking of that, I had time to run the lower bit by itself:
But am out of time to calibrate the tweeter response and overlay it.
Conclusions
I expected textbook on-axis response but did not quite get that out of Revel F208. But the speaker came to its own with stellar predicted in-room response which is what ultimately matters as you hear both direct and indirect sounds. Off-axis summed response also looks superb. People ask me if they should buy Revel speakers. I always tell them they should for two reasons:
1. You can put them in just about any room and they sound great due to off-axis response being carefully designed.
2. They are the only speakers designed and released with double-blind listening tests.
I wish I had done my listening tests so I could make my own judgement with F208 but I don't have time as I have to pack and drive them to the owner in a few minutes. But based on measurements, I think they come very close to my Revel Salon 2. If so, they should sound wonderful.
I am going to put Revel F208 speaker on my recommended list. I know, shocker.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Killed my back moving this speaker around so had to hire someone to get rid of all the weeds as @Thomas savage is not available. He is charging me $100/day so on top of the expenses for this site, I need money for that. So please donate as much as you can 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 Revel speakers. Feel free to read as much bias as you like in this review.
The unit as tested is in piano black which gives a luxurious feel to the unit. Alas, the unit was too heavy for me to lug it up to my listening room so you have to settle for a plastic wrapped version of it in my test "lab:"
There was a sturdy sheet of plastic covering the front which I took off but left the rest of the plastic on it to protect it as you see in this shot:
I went through a bit of hell trying to figure out why the speaker would not plays the highs at first. After hours of trying to figure it out, and losing out a day, I realized it was a simple thing: the bar wires I was using would not always allow the shorting bar to do its job. I have to use a bare wire as to lower the interference around the speaker as the robotic arm moves the mic around. Anyway, I have to take the speaker to the owner in an hour so no time for listening tests either.
This speaker was the heaviest I have tested and despite having that wonderful lift you see in the first picture, it was a killer to unpack and move around.
I played with the bass compensation and it does what it says: if you set it to boundary, it lowers the bass level. I did not test the tweeter one but I suspect it does the same. An array of power resistors behind that panel makes these simple level changes.
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.
All measurements are referenced to the tweeter axis with frequency resolution of 2.7 Hz. I used a high number of scans (over 1000 measurements).
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:
Edit: these are updated measurements based on optimization of the numerical analysis in the bass response.
There is good correlation with Harman measurements:
I was puzzled that the on-axis response was not as smooth as I expect Revel speakers to have. That disappeared when I looked at the rest of the measurements starting with predicted in-room response:
Wow! With no DSP this speaker managed to get such balanced and smooth response. It appears that the off-axis response is tuned to counter the on-axis response as we see here:
This makes the speaker fairly room independent and sharply increases your chances of putting this in any room and enjoying accurate sound reproduction.
Distortion levels are very much controlled:
Ignore the rise in very low frequencies as that goes beyond the speaker's ability to reproduce. The rest shows no "acoustic events" other than a bit of wiggliness between 100 and 200 Hz:
In this calibrated graph where the range is 50 dB, I like to see nothing but blank space for distortion and the F208 gets there with the exception of the lower frequency range.
Impedance test shows dipping to 3.5 ohm so you better have a high current amplifier that doesn't mind such loads:
Horizontal directivity diagram shows very wide response which means you don't have to sit in a vice to get good sound:
And if you left the side wall reflections bare, you should get wider image. The inclusion of that mid-range gives good dispersion to whopping 100 degrees!
Vertically the situation is not as good as we typically see in non-coaxial designs:
I am in a hurry so could not optimize the CSD plot so here it is:
I wanted to see if I could diagnose the up and downs in high frequencies so ran this 3-d plot:
The problem could also be the mid-range still going as we see in the hot area below the tweeter.
Speaking of that, I had time to run the lower bit by itself:
But am out of time to calibrate the tweeter response and overlay it.
Conclusions
I expected textbook on-axis response but did not quite get that out of Revel F208. But the speaker came to its own with stellar predicted in-room response which is what ultimately matters as you hear both direct and indirect sounds. Off-axis summed response also looks superb. People ask me if they should buy Revel speakers. I always tell them they should for two reasons:
1. You can put them in just about any room and they sound great due to off-axis response being carefully designed.
2. They are the only speakers designed and released with double-blind listening tests.
I wish I had done my listening tests so I could make my own judgement with F208 but I don't have time as I have to pack and drive them to the owner in a few minutes. But based on measurements, I think they come very close to my Revel Salon 2. If so, they should sound wonderful.
I am going to put Revel F208 speaker on my recommended list. I know, shocker.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Killed my back moving this speaker around so had to hire someone to get rid of all the weeds as @Thomas savage is not available. He is charging me $100/day so on top of the expenses for this site, I need money for that. So please donate as much as you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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