It is very deep bass and the QC30 reproduced it well without driver rattle or break up. Writing this 70 days after purchase. If you wear them to work daily (I work outside at a retail plant nursery), they will last almost a year before they start to tear up/sole separating. And, this product is easy to assemble yourself. First time I wore these other than in the house and I have no blisters, painful areas, etc. I guess time will tell! Arrivo puntuale e perfetta come da descrizione. But Im disappointed about something Id read regularly about and can say that this is just not the case. The connection issue was my main disappointment though. It would be really great if it was just maybe an inch wider to squeeze in larger shoes since I do wear size 4D wide.