Hi all, I just bought a new pair of RS 170 yesterday from local BestBuy (Normally I would use amazon but they matched price so it was nice) for $192 to replace my broken Logitech G930 that I have been using for over 2 years. (Really disappointed with Logitech for using cheap material to hold ear cups)
So right after I switch them on, I can feel RS 170 delivers much better sound quality so I was happy. However, my happiness didn't last long. I noticed the RS 170 plays a noticeable background a low pitched hum noise when it was quiet. So I tried to determine what may have caused that:
First, I kept the headphone on my ears and use the power button to switch it off. The hum when away. It wasn't ambient noise.
Then, I increased computer output volume and used the buttons on the right ear cup to reduce volume on the headphone to just one level above mute, nothing changed, still humming. (note: I also tried to flip the switch between 0db and -8db on the transmitter, didn't help)
Next, I muted the headphone with both side button and volume control on my computer, nothing changed.
Finally, I unplugged the 3.5mm jack from the transmitter, nothing changed.
At this point, I'm confident to say that the hum is within transmitter and headphone. I'm very puzzled by this conclusion because I have been a big fan of Sennheiser and respected their product for producing one of the best sound quality in the market. Plus a $200 headphone shouldn't have issue like this no matter who made it. Heck even my $150 Logitech G930 don't produce such noise unless plugged in the charging cable.
I wish someone here may know if this issue is common on all RS 170 or I just got a defective unit. I have read a lot of reviews on amazon and newegg and most users are very positive about this headphone. So I hope this is just a defective unit.
Oh one more thing, I charged the battery full this morning and tried it again, still humming, it's not loud but definitely noticeable.