Reviews for Bowers & Wilkins MM-1 Speakers

I'm a fan of Bowers and Wilkins; I have a full set of their speakers connected to my home theater system. So I was excited to purchase the MM-1 speakers for my Mac. I plugged them in, fired up iTunes, and started playing some music... And noticed white noise hissing in the background during quieter parts of songs. I discovered that if the speakers are on and connected to a live USB port, or if the auxiliary input cable is connected (with no USB connected, and even if the aux cable isn't connected into any device), the speakers let out an annoying "hiss" anytime they're on. If you unplug the cable, the hiss goes away. Unfortunately, the hiss is making its way through to the songs -- and is especially noticeable during quieter parts. The hiss doesn't increase in volume if you increase the volume, so if you play music loudly, you might not notice. But it's there.

This unacceptable for speakers at this price point. Previously, I had another brand of USB speakers, and there's no noticeable "hiss" when they're plugged in.

I'm trying to determine if there's a defect with mine, or if this is normal. If anyone has purchased these, can you post whether you can hear this whitenoise sound coming from the speakers when they're on, but nothing is playing? I would expect them to be completely silent. In a quiet room, I can hear this hiss across the room.

I've tried connecting them to different outlets and different computers, and in each case it exhibits this behavior.