My experience with Uncle Wilson was great, but the experience with the VB was not so good. I was looking for the best bassy IEM I could buy under $100, and the VBs sure seemed to fit the bill. I bought them and was surprised how quickly they arrived. I listened to them for a good 3 weeks and really liked the sound signature, but something wasn't right. After quite a bit of listening, testing, and switching ears, I determined that one driver was not reaching the same output as the other which lead to an odd, unbalanced feeling in my head.
I contacted UW and they were more than happy to send a replacement. That was the good news. The bad news was that the replacement was even more polar than the first set. One ear piece was just plain muffled compared to the other. I didn't need to do much listening at all with that set and requested another replacement. The third set finally came and it was much more like the first, but something was still off. Was it my ears? Maybe they were fine and it was just me....that thought went through my head so many times, but switching them back and forth between ears proved that it was indeed the earbuds.
I really wanted to find out what the problem was. The exact problem was that one channel was slightly quieter overall and had dramatically less bass compared to the good side. So, I got my flashlight and removed the screw plate from each IEM to try and get a better look. Nothing inside gave a clue. I thought about it some more, and it akin to one earbud not having a good seal. I knew the seal wasn't an issue because I was using Comply foamies. Then I thought, what if the driver is not sealed properly? I know from my experience in car audio and my acoustics class that a speaker in a lossy enclosure, that is one that does not isolate the front and rear waves from the speaker cone, will have lossy performance. Turns out I was right. By using my mouth, I created an ever so slight amount of suction on the good earbud. As expected, no air moved and there was a slight crackle from the driver being pressurized. When I did this on the bad side, there was quite a bit of airflow across the driver. For the skeptics, air was not entering through the wire entry because placing a finger on the backside of the enclosure to cover up the screw plate port immediately halted the airflow.
I wish I had thought of trying that on the first two pairs as I am fairly confident it was the same problem. I know that a few Headfiers described a similar issue with their VBs. For these reasons, I have to advise against purchasing them. However, I will say that Uncle Wilson has EXCELLENT customer service, and they turned a really crappy experience into something positive.