My neighbor has the same model. Got to try it out :)
I have an RV-B70 (budget model with only a radio and CD, no AUX), and I can clearly say that mine is much better in the audio path. Boomblasters's designed to pump out as much bass as possible. RV-NB51 has a punchig base that lacks that depth as the older models.
The sound is somewhat brighter and slightly better midrange. But bass sounds cheap and tinny at times. That lovely depth that one gets in older boomblasters is not quite there. A bit hard and explain in detail, one mpste really compare a new model with an old one.
Now's not the RV-B70 any AUX input, but that the new models do not have AUX is disastrous.
The new model is slightly smaller and slightly lighter. I do not like the design as it looks plastigare and cheaper than older models. It looks very fragile out. My RV-B70 looks definitely much stronger.
Can not recommend it: (I actually had high expectations for this, but it's not a worthy replacement for the older models ...
Unfortunately, so is the size, weight and features first even in a sound system like this nowadays. Everything else comes after, even audio performance.
Very disappointed: (
Works very well!
+ Plays really loud
+ Plays usb really well and ipod control is ok
+ Good quality overall
- Base DiStar bit so pull on full bass is not to recommend
- Looks a bit plasticky out
- Could have focused a little more on design
Think it works great. Awesome sound! The only downside is that there is no connection to the car battery to buy. (I have not found one anyways)
Unfortunately, I can not recomend this because they removed the AUX input, ie you can only play music from iPod, USB stick or disk. FM transmitter is your only option if you have a different mp3 player than the ipod.
Another thing that lowers the score is that the ipod control is a bit tricky, it only works with the iPod music player, you have to get it going first and then get manually terminate it on the ipod and launch spotify to play from there.
Moreover, not charging ipod if you do not run on AC power, which sucks. Buy the old if you get hold of it.