Revel M16 Spinorama measurements (CTA-2034)

[Ageve]

Revel M16 is a 2-way bookshelf speaker made by Revel.

Just kidding. This is a test to see how close quasi-anechoic spins are to Klippel NFS, and Harman's own spinoramas.

These measurements were done in-room (in my garage, 3m ceiling). The weather was too cold and windy for outdoor measurements. I'll post pictures of the measurement setup tomorrow.

Equipment used:
miniDSP UMIK-2 (calibrated)
SPDIF out from PC to Denon AVR-4306 + Rotel RB-1590 (playback)
Macbook M1 Pro (REW V5.31.3, measurement)
Homemade speaker turntable
Mic mounted in a metal pipe, 140 cm from the mic stand (to avoid reflections)

There's no directivity info below 400 Hz, since the measurements are quasi-anechoic.

Here's the spin:

Klippel NFS measurement by Amir, for comparison:

Revel M16 Speaker Review

This is a review and detailed measurements of the Revel M16 stand-mount/bookshelf speaker. I purchased this through my company and it arrived a few days ago. Can't tell you my cost :), but retail price is US $900 (sold $450 each). As you can expect, when you pay more, you do get more as far...

www.audiosciencereview.com

Harman comparison:

The small dip at 2.5 kHz (ER and sound power) and minor directivity "peak" at 5.5 kHz are very similar. My measurement is closer to Amir's > 15 kHz.

Estimated in-room response:

Overall very similar, but some difference at 250-400 Hz, and the treble is not as rolled off > 10 kHz. Perhaps there are different revisions of the tweeter? My speaker is quite new (3 years old) and it seems to be somewhere in between the Harman sample and Amir's M16.

Amir's measurement:

Early reflections:

Amir's measurement:

Polar maps are hard to match between different software, and I only measured at 10 degree increments, so it looks a bit low res (because it is ; ) ).

I tried using the Klippel palette in VituixCAD:

I disabled the normalized view to match Amir's measurements:

0-90 deg, for comparison with Stereophile measurements:

Vertical directivity:

Using the standard color scheme in VituixCAD:

Directivity Index:

And finally, the horizontal reflections, compared to Amir's measurements:

I hope it was interesting.

The main drawbacks with these kind of measurements are the lack of directivity info below the merging point (400 Hz), and low resolution at 400-1000Hz because of the gating, but I still think it's kind of amazing what can be done with free software these days.

Please consider donating (I haven't yet, but I will ):

Please consider supporting REW by donating

I just had a short email conversation with John who creates the REW software. When you think about it, it is pretty amazing that he provides this software free of charge. Think about the immense value REW has provided and continues to provide to the larger audio community! I would therefore...

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VituixCAD Loudspeaker simulator

 

[eddantes]

Nicely done!

I hope to do the same exercise soon. Looking forward to seeing your setup. Expecially - vertical rotation - as I'm having a hard time visualising on how to do that beyond +-20 degrees or so.

 

[staticV3]

Nicely done!

I hope to do the same exercise soon. Looking forward to seeing your setup. Expecially - vertical rotation - as I'm having a hard time visualising on how to do that beyond +-20 degrees or so.

Simply lay the speaker on its side, no?

 

[Ageve]

Nicely done!

I hope to do the same exercise soon. Looking forward to seeing your setup. Expecially - vertical rotation - as I'm having a hard time visualising on how to do that beyond +-20 degrees or so.

It's quite easy with rectangular cabinets, but it was a bit harder with M16 (I used damping feet of different height because of the curved cabinet). You basically lay the speaker down and spin it (full rotation).

edit: Use a ratchet strap or similar, to secure the speaker to the test stand.

 

[eddantes]

It's quite easy with rectangular cabinets, but it was a bit harder with M16 (I used damping feet of different height because of the curved cabinet). You basically lay the speaker down and spin it (full rotation).

Ahhh - of course! Makes sense! TY

 

[Ageve]

Here are a few pictures of my simple setup.

I'm not exactly proud of the turntable. It does the job, but it's flimsy (and ugly). I'll post pictures when the new one is done.

I have a few base plates for speakers of different sizes, and with different heights (the stand itself is not adjustable). As for the damping material on the legs, it cleaned up the response a tiny bit (less "wiggly"), probably because of the legs being square.

I'm using a 25 mm steel pipe for the mic (inside diameter: 22 mm), to avoid reflections. Distance from the front of the mic to the mic stand is 140 cm.

Reflections from the stand (or from surfaces close to the mic) will cause a "wiggly" response.

I usually do nearfield and distortion measurements in my living room:

A few more measurements:

Measurements from Australian Hi-fi as a comparison:

https://www.excelia-hifi.cz/revel/test/revel-concerta-m16-australian_hifi_11_18.pdf

Quasi-anechoic response (1m), compared to measurement by Amir:

Early reflections front, compared to measurement by Amir:

Early reflections Floor (< 400 Hz) doesn't line up with Amir's measurement (It's probably why the estimated in-room response is different at 250-400 Hz), most likely due to the quasi-anechoic merging. Any directivity information below 400 Hz is interpolated, and not always accurate. It's not far off, but still:

 

[dominikz]

Great work @Ageve, thanks!

I find it especially interesting that @Ageve's measurements seem to track @amirm's in the region above ~14kHz, while my own (link to thread) seem to better track the vendor (Revel) spin - i.e. Revel and my own measurements show a rise in that region, while @amirm's and @Ageve's don't:

@amirm vs @Ageve (source):

Revel vs @dominikz (source):

This makes me wonder if there might be two iterations/versions of the M16 in the wild? Or could it just be a question of microphone calibration?

In any case this is not a big deal, just thought it was interesting.

Thanks again for sharing your work!

 

[Ageve]

Great work @Ageve, thanks!

I find it especially interesting that @Ageve's measurements seem to track @amirm's in the region above ~14kHz, while my own (link to thread) seem to better track the vendor (Revel) spin
…
This makes me wonder if there might be two iterations/versions of the M16 in the wild? Or could it just be a question of microphone calibration?

In any case this is not a big deal, just thought it was interesting.

Thanks again for sharing your work!

Thanks! Yep, it looks like there might be two versions of the tweeter.

There’s a small difference between my speakers (left and right). I used the one that’s closest to Amir’s measurement for the spin.

I don’t remember which one I measured here, but it was quite similar to the one from Australian Hi-fi:

https://www.excelia-hifi.cz/revel/test/revel-concerta-m16-australian_hifi_11_18.pdf

 

[dominikz]

Thanks! Yep, it looks like there might be two versions of the tweeter.

There’s a small difference between my speakers (left and right). I used the one that’s closest to Amir’s measurement for the spin.

I don’t remember which one I measured here, but it was quite similar to the one from Australian Hi-fi:

View attachment 406809

https://www.excelia-hifi.cz/revel/test/revel-concerta-m16-australian_hifi_11_18.pdf

My two units matched pretty well to each other (red and blue plots):

And this is how one of mine compared to measurements from ASR, Audioholics and Revel:

All in all it seems to me all of these different loudspeaker units measured with different equipment by different people match each other extraordinarily well!