This is a review and detailed measurements of my NHT Pro M-00 powered studio monitor (speaker). I purchased it probably 15 years ago upon a hugely positive review from stereophile(?). It said some famous recording engineer used to mix a ton of popular albums. I bought the package with the S-00 subwoofer. Each speaker cost $249 and the sub was $500 for a total of $1,000.Years later, NHT hit hard times and closed shop for a while. Then went online direct. I have not kept track of what they do now. These speakers are no longer available but as part of our effort to build up some "speaker measuring muscle," I thought it would make for a good second review. Be sure to read my first review of JBL 305P Mark ii to understand this data better.The M-00 is a small but weighs like it is filled with rocks:The case is made of some aluminum alloy which also acts as the heatsink for the internal amplifiers which are discrete, class AB. Here is the back side:It has a very rough textured finish which can't be cleaned as you can see from all the scuff marks on mine.There is nice connectivity in the form of both RCA and XLR/TRS inputs. There is also a switch for "near-field" vs "far-field." I tested it in the former mode because I have them on my desk and assumed that was the correct setting. It is supposed to lower the high frequencies some.If you have read my previous review you know that the heart of our measurements are anechoic measurements of the speaker all around it. These measurements are grouped in different ways to give us insight into how the speaker can sound in our rooms:Glancing at all four curves up above we instantly see a major issue with this speaker: a sudden rise in response or put inversely, a suck out in upper bass frequencies. We want our on-axis response in black to be as flat as possible. Here it shows that wide drop which audibly is bad because more musical notes fall in it and hence are lowered in amplitude.There is also some peaking in high frequencies but if early reflections are allowed to get to you, they balance that out (since there is usually a drop off in high frequencies as you go off-axis from front of the speaker):If on the other hand you think every studio needs to resemble an anechoic chamber with side walls fully absorptive, then the speaker may sound somewhat bright.Guess what? We are done! We don't need 500 different graphs. The above tell the story and tell it well. But I know some of you want more data so let's provide a bit of that. As usual much more is available. For those of you who just want the top level message, I suggest jumping to listening tests.Folks like pretty and colorful graphs so here we are with contour plots in both horizontal and vertical axis:The more uniformity and gradual change, the better in these graphs. Vertical axis performance tends to be worse in many speakers and such is the case here. So absorbing those if your room is not already too dead may be advised.I took feedback to trim down these measurements some. Let me know if they are easier to read:They tell us what the contour graphs do but without the fancy colors.I setup the JBL 305P Mark ii as my left channel on my desk and the NHT Pro M-00 for the right. I matched the levels and then played one of the tracks I use for room optimization. The quality different was incredible. The 305P had a super balanced tone with lots of rich and warm detail in upper frequencies. The NTH M-00 in contrast sounded dead and bright.Thinking I may be biased by my measurements I invited my wife to listen. As I was showing her the controls with her standing on my side she immediately pointed to the JBL 305P and said, "I like that one better!" Still, I forced her to sit down and do the test properly (in Adobe Audition by selecting one or the other channel to play the mono track). She again quickly concluded that the JBL 305 was much better.Before leaving though, she said that if she was listening to guitar, she may like the NHT Pro better. She plays some guitar and brought it up to show me in person. Instantly I was reminded that neither speaker sounded as "real" has her guitar.That aside, she was tuning in to sharper tones in NHT thinking that it would allow her to distinguish the individual strings in an acoustic guitar better. I asked her if she just wanted to sit back and enjoy music, which one should would like and she said with confidence the JBL 305P Mark ii.Research shows that quality of bass is worth almost 30% in overall preference for a speaker. Best not get that wrong as is the case with the NHT. Fortunately there is a matching sub for it that helps mitigate some of this.Like a mechanic that listens to an engine and can quickly determine what may be the issue, I hope you are starting to get a feel for the power of these measurements. Even though the measurements are from "anechoic" origin (computed in this case), they are still powerful predictors of listener preference. You better not violate the edict of flat on-axis and smooth early reflection directivity easily.Knowing what I know know, I would not remotely use the NHT M-00 relative to JBL 305P Mark ii. The difference in overall fidelity and pleasantness is immense. So don't go looking for used NHT M-00. I would have given it a cut-off-head panther award but I want us to get more experience with other speakers to know whether it ranks at the bottom or not.------------As always, questions, comments, recommendations, etc. are welcome.I feel so poor I had to winterize our RV (camper) myself instead of having someone else crawl under the darn thing. I hope you feel sorry enough for me tousing