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: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: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: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.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 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: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: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.There is a pretty low dip in impedance making this speaker rather hard to drive when combined with its low efficiency:I have no way of verifying the correctness of these distortion measurements but here they are:These are all in-room measurements of my large garage. Since there is no real response below 50 Hz, I would ignore that region.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):Spin data is enclosed.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.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 pleaseusing