Right out of the box, connected to 20-watt Leppy amp, these are great sounding speakers. Not amazing, but very good indeed. Great bass, crystal clear highs. They have about 8 hours of break-in time as of this review. I understand they need about 40 before they truly become amazing. I connected my old 100-watt receiver and these really came alive! If you're on a budget, a $20 Leppy amp sounds great. If you have something more powerful, these will have your neighbors dancing. As surprising as the bass is for a 4-inch woofer, the tweeters are where these REALLY shine! The woven carbon fiber and tuned port give deep, punchy, room-filling bass, without being boomy or artificial. The sound is very natural. My old ears are terrible, so I shouldn't comment on the high-frequency response. But I can hearEVERYTHING like I haven't heard in years! I used to be a Bose fan, but more recently I've been listening to JBL. Klipsch is known for their horn tweeter. I'd be foolish to compare inexpensive Micca to Klipsch. So call me an old fool. These are hands down the best sounding speakers I've ever purchased... and they're not even broken in yet! I'm using these as a second little stereo in my office. They'd be great in a garage, workshop, bedroom, dorm, apartment, anywhere you want small speakers. They do sound good enough to be your primary living room speakers.***UPDATE*** Everyone here says these need about 40 hours to break in. I played them about 16 hours Saturday and Sunday. That's 32 hours. Add in a few hours each Thursday and Friday and I've hit that number. I can now retract the power statement. My vintage amp needs service. The pots are bad and it sounds like a summer thunderstorm. Until my contact cleaner and fader lube get here, I reconnected the Lepy Amp. The speakers are just as alive. Perhaps the receiver woke them up. A friend of mine does an Internet Radio Show every Saturday and Sunday at noon. Even with the little Lepy amp I could crank up the volume and hear these throughout the house! The bass is strong enough to resonate the walls. The highs are so bright and crisp, even muted in another room it was still very listenable. Sound that big from such a small speaker is nothing short of amazing. Add into the equation the fact that I'm driving these with a $20, 20 watt x2 amp and it's unbelievable. I'm not an audiophile, but I used to be. Don't let the Lepy amp fool you. The original TA2020 chip, while very low power by today's standards, was classified as an audiophile chip. The Lepy amp is using the same circuit as designed by Tripath and includes Texas Instrument's improved version of the TA2020 chip. The Lepy is very small, very low power, and very inexpensive. But it is an audiophile quality Class-T amp. It will drive these Micca speakers without breaking a sweat. I did replace the power supply with a 6 amp supply though. A worthy $11 upgrade. An audiophile-quality system that sips the tiniest bit of power and costs less than $100? Yes, it IS possible. These Micca speakers are at the heart of it! The last piece of the puzzle is the audio source. An old iPhone connected to wi-fi for streaming is a great start. The DAC in the iPhone is not audiophile quality, but it is very good. A $99 Dragonfly USB DAC makes a wonderful upgrade. I use an old laptop. I installed Linux Mint XFCE and use it only for streaming Spotify, Pandora, Slacker, other Internet Radio Stations, and my own CD collection ripped to high-quality AAC files. It sounds great with it's built-in DAC, but the Dragonfly is on my list.Update: Forget the Dragonfly - Overpriced. Instead, I found this: Signstek HIFI USB to Coaxial S/PDIF Converter Convert Digital to Analogue Signal Mini USB DAC PCM $22.99! The same DAC can be found under the names Muse, Q5, and others. These incorporate a renowned DAC chip, with decent supporting circuitry. It is a fairly simple process to upgrade the capacitors, but I have not found it necessary.There is an old computer term, GIGO, Garbage In Garbage Out. This applies to audio as well. With the DAC in place, even my old restored vintage receiver sounds good. You may not notice the subtle flaws in the sound, but once they're amplified, these speakers will faithfully reproduce them. With pristine audio feeding the system, you get pristine sound out. My restored receiver was ready for recycling. I'm glad I gave it one more shot with the DAC in place. If your Miccas do not sound amazing, you better check the source material. These speakers are so clean and clear you will notice the limitations in the source.Update: I've had these for 2 years now, and they play streaming music all day, every day. The slight bump in the upper bass range has turned into a full-blown resonate response around 125-150 Hz. They do, or will, require equalization. I use a software EQ and pull that nearly all the way down. That being said, many people say these require a sub. While a sub would do the same thing, and provide even more bass, these will surprise you. They are rated down to 60 Hz. I can bump up the 50 Hz band and these little guys kick! Going down to 35 Hz they'll begin to distort. That's just too low for a 4-inch driver. Still, a little bump at 50 and you can actually feel it, AMAZING! They like power too. If you using a decent receiver or amp, you should be good. Many, myself included, are powering them with a Lepy 2020A. 20 amps may not sound like much, but back in the day, most receivers were 15 amps. They had huge power supplies and plenty of reserves. They could power large speakers and shake the walls. The Tripath chip, at 20 watts, was a little monster. Using the Signstek DAC, they just didn't play as loud as my big receiver. I have a Fosi Audio DAC Q4 that I was using on another system as a headphone amp. This little couple came together and were married recently. The result is audiophile bliss. I have the power back to be heard throughout the whole house. The Lepy can really show what's it's capable of, and the Micca's reproduce it from deep bass to highs my ears can barely hear. In case you're wondering about the vintage receiver the Fader cleaned the pots and restored the audio to its original glory, but leaking capacitors could be allowing DC voltage on the output. This would burn out the voice coils in the speakers and headphones. Recapping it is not a job I'm ready to undertake at this time and the Lepy's portability gives me more options.To X or not to X? That is the question. I did 2 things to correct that 125-150 Hz resonance. I'm pleased to report it worked! One, I ordered the crossover kit direct from Micca. $29.99 which converts the MB42 into the MB42X. Does it make a difference? Yes. Is it a massive change? No. The change is subtle, but they actually DO increase the high frequency output and improve the clarity. Is that what flattened the upper bass bump? I'm not sure. To install the kit you must remove the drivers. Not that big a deal, 4 screws each. When reassembling, Micca's instructions say to make the screws snug but to not over-tighten. I'm not sure how much this will help in the long run, but I applied thread lock to each screw. I figured with the vibration of these little woofers and the lack out torqued down screws I might be asking for trouble. This I believe has helped the most. Ensuring the woofers are securely attached to the box with no room for vibration. Are the crossovers a recommended upgrade? At ~$30 for the pair, yes. Would you be sorry you saved that much on the 42 vs, 42X? No. I also prefer the wood grain of the 42 over the flat black 42X. You can always upgrade later. How difficult is the kit to install? Do you have to solder the connections? If you can plug in a lamp, you can install the kit. No soldering required, plug and play.