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Micca RB42 Bookshelf Speaker Review

amirm

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This is a review and detailed measurements of the Micca RB42 bookshelf/desktop computer speaker. I purchased my sample from Amazon and it cost US $149 including Prime shipping. This speaker also seems to be the favorite of youtube bloggers, helped partly by generous seeding of such "reviewers."

The RB42 looks stunningly good for such a budget price if you stand a bit far:

Micca RB42 Bookshelf Budget Speaker Review.jpg

Curved cabinet with excellent fit and finish that would be at home (if it were a larger cabinet) in a high-end audio shop.

Zoom in though and you see that budget pricing doesn't get you perfection:

Micca RB42 Bookshelf Budget Speaker Woofer blemishes Review.jpg

I don't know what the two white dots are. They would not come off easily. The lousy gluing job of the dust cap encourages one to put them far from eyesight.

The back panel impresses again with nice binding posts:

Micca RB42 Bookshelf Budget Speaker Back Panel Connectors Review.jpg

If you didn't tell me in advance and I did not look closely, I would have thought these are $400 to $500 speakers.

Measurements of the Micca R42 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) to subtract room reflections. 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 anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

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:

Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Audio Measurements.png


There are lots of peaks and valleys in the on-axis (black) and listening window (dashed green) indicating everything you play with be EQed to that tune. The excessive energy from a few thousand hertz and up indicates this will be a "bright" sounding speaker which may impress people at first listening ("great resolution and imaging") but becomes tiring quickly.

The boost in 200 to 300 Hz is a common technique to give the impression of more bass than there really is.

Since the speaker was driven with 2.83 volts signal, we can directly read the sensitivity from the frequency response graph. Depending on what region you use and what averaging you perform, you get something in 80 to 85 dB which is within the manufacturer specs.

Zooming into the difference between our direct sound and what travels around the room gives us high level of non-uniformity:

Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Directivity Audio Measurements.png


This means two things:

1. You can't EQ these regions because EQ can't just fix the reflections that have different tonality than direct sound. It changes both so the net gain is zero.

2. Speaker will sound different in different rooms. So while you may swear it sounds great for you, it may very well not for an other person with different room/environment.

If you were to use these in far-field, i.e. normal stereo listening away from desk, this is the response you can expect to see:

Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Estimated In-room Response Audio Measur...png


Hard to know where to draw that line. Regardless, you will have a very uneven frequency response.

So overall, this is far from even and neutral response that you would like to have in a speaker. Listening impressions at the end.

Speaker Impedance Measurements
There is a pretty low dip in impedance making this speaker rather hard to drive when combined with its low efficiency:

Micca RB42 Bookshelf Budget Speakers Impedance Audio Measurements.png


Distortion Measurements
I have no way of verifying the correctness of these distortion measurements but here they are:

Micca RB42 Bookshelf Budget Speakers THD distortion Audio Measurements.png


Micca RB42 Bookshelf Budget Speakers THD percentage distortion Audio Measurements.png


These are all in-room measurements of my large garage. Since there is no real response below 50 Hz, I would ignore that region.

Advanced Speaker Measurements

Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Early Window Audio Measurements.png


Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Horizontal and Vertical Reflections Aud...png



Micca RB42 Bookshelf Budget Speakers CEA2034 spinorama Full Horizontal and Vertical Reflection...png


We can see how the woofer starts to "beam" (narrow its output cone) around 2 kHz before the tweeter takes over with its wider directivity (cone):

Micca RB42 Bookshelf Budget Speakers Horizontal Contour Audio Measurements.png


Micca RB42 Bookshelf Budget Speakers Vertical Contour Audio Measurements.png


Spin data is enclosed.

Speaker Listening Tests
I evaluated the Micca RB42 on a 5 inch stand on my desk since that is likely how it will get used. I powered it using the Purifi amplifier.

I was pleased that I had not shaved as the sharp highs nicely took care of any facial hair I had! This thing is bright. It also gets distorted quickly. If you see the woofer flapping around, it is distorted.

Toeing it out did not help much. What did help a bit was me plugging the port using my hand. I should test it that way and see what difference it makes.

I guess it is better than any plastic computer speaker. But if you are here to find something that produces proper sound, the RB42 is not it.

Conclusions
If something sounds bright to my aging ears, you better believe it is bright. I am surprised the online bloggers like this speaker as they are younger than me so they likely hear more of the high-pitched tones out of this. At times this was so bad I had sit farther back!

I suggest getting a powered studio monitor instead of these. You don't have to an amplifier for them and those that I have tested have far better objective and subjective response.

Net, net, the Mica RB42 is very well built as far as the cabinet and such, but when it comes to sound, it is not something I can recommend.

That said, the night is young and we don't have much data on other bookshelf speakers like it. We will get better calibrated as we test more (of which I have a good number waiting to be tested).

------------
As always, questions, comments, recommendations, etc. are welcome.

Someone has to pay to buy such speakers and I prefer it not be with my money so please donate what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

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MZKM

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Shame about the vertical directivity; for the price I’m assuming they know most owners will not use toe-in, hence being bright on-axis. Wonder how it’s more famous baby brother would perform.
Preference Rating
SCORE: 4.4
SCORE w/ subwoofer: 6.6

This is where we see limitations with the formula, it does not apply weights per frequency region; as such, the elevated treble where we are most sensitive does not hugely impact the score.
https://docs.google.com/spreadsheet...fuFxGmXKOcOzPFBueqj3q9DmG21kIcgln0VgR/pubhtml


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Screen Shot 2020-02-04 at 3.13.46 PM.png
Screen Shot 2020-02-04 at 3.14.00 PM.png
Screen Shot 2020-02-04 at 3.14.46 PM.png
Screen Shot 2020-02-04 at 3.14.54 PM.png
 
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ta240

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I'm just going to tell myself that they sounded great in the youtube reviewer's rooms because they wouldn't lie to me, right?

I'm looking forward to more speakers, including name brands available in big box stores, in this price range getting tested to see if this performance is the norm for the price or if people were really being guided towards junk by the 'influencers'. Is this an example of us being in the audio version of the Fyre Festival with so many poor performing products getting gushed all over?
 
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amirm

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direstraitsfan98

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It is. I think they have already arrived.
Looking forward to that, thanks for the insider info. I do hope you measure both and compare the two. They offer two models, one is substantially larger and twice as expensive.
 

ta240

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napilopez

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Measurements don't look too bad to me for the price - I've seen worse at much more expensive. Biggest issues seem to be that 600Hz scoop and the broad 5Khz hill off axis (which is present at every angle other than the on-axis one), so you can probably EQ that a bit. I imagine that's the biggest source of the brightness. There's that 3Kish listening window peak too. But not bad. Preference score is pretty solid too.
 
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joentell

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JoeNTell sold the speakers at one show. I'm not sure how that affects ones impartiality but I guess we can assume he sold them because he liked them so much and not the other way around.

I had to make an account just to respond to this. I asked Micca for some to give away at T.H.E Show and they sent a pallet to my apartment! I wasn't expecting that. I hauled all of those to the show because I did not want to go home with any. That was my primary motivation. I wouldn't ever want to do that ever again.

I was showing a budget room paid for by a few companies, Micca, Vanatoo, SVS, Schiit, Kanto, and some moderators at Budget Audiophile on Reddit. It was to show budget audio at what was mostly a high-end show. We weren't compensated for the 3 days of work we did and any "profit" from selling those speakers went towards flying in someone from NY to help out and another guy to show the speakers we had in the second room. We do have to go to the bathroom and eat once in a while, so a 3rd person allowed us to do that. Anyone who has done a trade show knows how much time, effort, energy it takes to setup and tear down.

Regarding these measurements, they actually look very similar to my in-room measurements. It's just that I don't agree with the conclusions made that the speaker sounds bright. In the listening window, which is how I measure, you can see the top end peaks at maybe +1dB or so. If you smoothed out that response, you would see it isn't rising. Now, I understand that the DI and sound power graphs show otherwise, but I would think that is room dependent.

I'm not here to argue with Amir on his website, just wanted to clarify where I stood. I deal with a lot of brands and have good relationships with many of them. They understand that I will be honest about my opinions in my reviews. LG invited me to CES despite me never having given any of their products a raving review. My last review of their sound bar was title "Painfully Honest Review." So I am a bit defensive if it's insinuated that a someone who got the speakers early and for free might be swayed by that. I have a whole storage unit full of speakers. The last thing I need are speakers. They were $129 at the time. It wouldn't matter if they were $12,900, I would still say what I thought. But to think that other reviewers were swayed at $129 is even less likely in my opinion. What's that, like $25 worth of parts?

Amir, I do appreciate the direction you're taking with the measurements. Thank you for investing your time and effort on that.
 
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spacevector

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Shame about the directivity; for the price I’m assuming they know most owners will not use toe-in, hence being bright on-axis. Wonder how it’s more famous baby brother would perform.
Preference Rating
SCORE: 4.4
SCORE ignore LFX: 6.6

So this beats out the KEF LS50? Clearly the formula needs some work?
 

MZKM

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You can't EQ these regions because EQ can't just fix the reflections that have different tonality than direct sound. It changes both so the net gain is zero.
The main reasons for the poor directivity as seen in the reflection graphs are because of the rear and ceiling, both will have limited impact on the perceived sound. As seen in my directivity graphs, the 2000Hz-3000Hz is very controlled, so EQ should actually yield good benefits.
 
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amirm

amirm

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napilopez

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So this beats out the KEF LS50? Clearly the formula needs some work?

The formula has an 86 percent accuracy, so there will always be outliers. But also, it doesn't surprise me all that much from the measurements. Amir found it bright. That's fine. I bet it would still do okay in a large blind test based on the measurements.
 

MZKM

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So this beats out the KEF LS50? Clearly the formula needs some work?
Compare their graphs, they actually aren't far off, the KEF is much better vertically as one would expect. These graphs don't tell you how easy it can be powered, max SPL, distortion, etc.
As I also pointed out, the formula does have limitations (doesn't weight frequencies), so it for sure isn't perfect.

And, if you never compared them side-by-side (ideally in an elaborate DBS like Harman does, but thats unrealistic for people to do at home), don't discount "cheap" stuff. Not saying it's the case here, but tell a person with a $5000 boutique DAC that a $200 Chinese one is better and they'll claim the measurements are wrong or don't tell the whole story.
 

napilopez

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Compare their graphs, they actually aren't far off, the KEF is much better vertically as one would expect. These graphs don't tell you how easy it can be powered, max SPL, distortion, etc.
As pointed out, the formula does have limitations (doesn't weight frequencies).

Also the currently contended issue of slope. But yeah, as always, one should take the formula in consideration of the larger data. I see it as a summary that helps put some sound aspects in perspective, but it's of course not the full story.
 
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