Bought a set of these on Ebay for $35, 'Buy It Now". ( I had ordereed CX300-II)
Yeah I know. I’ve bought and sold stuff on ebay for years and I know what to look for.
Got these in the mail and the packaging looked identical in all details to Sennheiser packaging. Barcode, fine print, everything looked perfect. Earbuds were a dead-on match to what Sennheiser shows on their web site.
Opened them up and plugged them in. Left earbud was dead and right earbud was almost dead. Huh!
So, I got on the Sennheiser web site and asked Support if this ebay seller (gave them the ebay id) was authentic. They responded back and said NO, and that the units were counterfeit.
I immediately emailed the ebay seller and told him this. Never heard from him. Nada. Got on the PayPal site and relayed the story to them with a refund request. Went over to ebay to look at the add again and it was GONE! It seems that Sennheiser must have relayed my story to ebay!
Ok - I said what the heck and plugged the earbuds in and let them go at full volume all night. The next morning they sounded almost perfect! Still a little tinney, but after 12 more hrs they sound almost perfect!
What I think I got was not counterfeit, but contraband. Probably stole from the factory in China or hijacked from a freighter in the south seas. Anyway, looks like I got a dandy set of earbuds for free but now I’ll feel guilty when I use them! Maybe I’ll give them to the girl down the street.
I did get a nice leather case with it that holds the earbuds AND my Fuze! Plus a dozen earpieces, cable winder, and clip.
If it looks to good to be true, it probably is!
Don’t feel that guilty. The seller will find another way to dispose of his stock, Paypal can easily afford the $35 (if they haven’t squeezed it back out of the seller) and Sennheiser should have told you it was an unauthorized dealer rather than a counterfeit headset–this authorized dealer business always seemed like price-fixing to me.
Happy listening.
Honestly, I’d still doubt they’re genuine until you test them against a legit set of Sennheiser’s. I could have sworn I warned you against buying Sennheiser on EBAY - on your earbud search thread.
Regardless, don’t feel bad about enjoying the earbuds, because chances are they’re still bogus - though they sound good. There have been similar good reviews online (including headfi.org) - which were subsequently proven counterfeit. The counterfeiters are getting better at their trade.
Yeah, you did warn me but I’m hard-headed! 
I went to Best Buy and looked at a Sennheiser pkg and they looked identical to me. I think they probably are contraband. They are really sounding good.
Mike
Well, if you ever had to send it in - you wouldn’t be the first guy shocked by perfect packaging leading to a warranty rejection due to counterfeit product. :-) Also - my CX500’s showed next to no improvement with burnin. They sounded great right off the bat. I have other headphones, however, that have shown drastic improvement after 50 hours of burnin.
I’m not trying to convince you that you got a counterfeit set, just pointing out that it’s a possibility. So if they sound great to you, there’s no need to feel guilt about getting them for “free”, just enjoy them. Heck, I thought about getting a 2nd pair of CX500’s which I was 95% certain were counterfeit - just to have the handy volume control for running with.
