Update: I also bought the v2.1 to test. This is the version with no passive radiator and has the high gain switch and a small bass module that sits under your desk. This model has significantly more head room in the bass section than the v1 and even the v3. These sounded best when utilizing a graphic EQ to push the frequencies below 60hz. The overall timbre of the speaker was very similar to the V1 (read my review below for that). This is hands down the best pebble speaker set. The bass module is not powered but it does provide more headroom and less distortion than “passive radiators” ever could. Best of all it doesn’t color the beautiful midrange and high end of the V1. I ended up keeping these. The V1 is still great for the money. But it’s night and day between the V1 and V2.1 - I think it’s worth the extra for the bass moduleI bought all three pebble speakers: V1, V2, V3. I could not find any good reviews of all three together so here is my attempt - Hope it helps! My back ground I love music, perform live regularly and own speakers from Definitive Tech, Mirage, Hsu Research, etc.V1 - Very transparent sounding top end. Airy, open, detailed are immediate words that come to mind. These speakers nail this sense of "air" on tracks like Eric Claptions Signe (Unplugged). It does so in a way that is honestly shocking for the $18 I paid. These qualities evoke the appropriate emotional reaction to certain music like Norah Jones as the piano notes "float" in the sound stage the way they should and the brushes on the snare have the right shimmer. try these tracks your self to see for your self. Now the con's against these speakers lean more on the bass side - they severely lack bass response. That being said they also dont pretend to have any - there is no over bloated mid range. In certain pop tracks I found that I preferred using Apple's "sound enhancer" to accentuate the bass response.V2 - These physically are the same size as the V1 but they have a modified power amp section for a claimed double in wattage at 16 watt peak. They also include a high gain/low gain switch on the bottom of the right speaker. They sound good in both high gain/low gain - the high gain mode has a clear bump in the mid range. You can hear how the high power amp pushes those mid frequencies. There is a noticable increase in mid bass clarity compared to V1. When pushed on tracks like Ingrid Michelson's The Way I Am - The added mid range bass is a clear advantage. I would not call this "Punchy" Bass however as these speakers are still the same as V1. But the biggest con agains the V2 is the trade off for this slight mid bass is a lack of clarity in the top end. The magic of the V1's air is lost to the attempt to push the passive radiators to create a sense of low end. Not to mention it costs more.V3 - These speakers were very disappointing to me. They have an even more pronounced muddy top end due to an over accentuated mid range bump. I can see how some could hear this as "more bass" but take my review for what it is - these will not satisfy in the bass section. The worst part is the trade off's due to physics of having such a small speaker. All of these design choices trade ALL of the top end clarity that existed in the V1. They definitely sound more "boxy" and in your face. None of the subtlety of the V1 exists. These speakers sound like tiny speakers trying to be something they are not. Furthermore they cost double what the V1 are currently priced at. They do have a Bluetooth feature if that matters to you.Note: I also did a blind test with my wife who has a good ear - She also noticed the special clarity of the V1. Also, I did use a high powered USB source for max potential for each of the speakers (I also found little difference between this and using the laptops USB port). For those reviews that talk about more volume - ALL three speakers sound like trash at max volume so I don't think that should be a deciding factor - all three produce acceptable volume.In conclusion, all three speakers do have very similar frequency responses. They share more similarities than differences. They ALL sound good for what they are: hence the positive reviews for all of them. But after comparing head to head: the V2 and V3 are a compromise in the wrong direction. They are trying to push the wattage of these tiny speakers which can't handle it in the first place. Do yourself a favor... buy the V1 for $18. If all three were the same price I would still choose the V1 for its clarity and detail. When I closed my eyes this speaker evoked an emotional response from me... when the other two only reminded me of its limitations.