[pcourtney]

Thank you. I'm trying my Samsung fast charging wall charger now. Just seems kinda lame that these $400 headphones require very specific charging conditions - especially when people tend to use these for travel. USB ports in planes, airports and hotels likely will not work.

I disagree, I had no problem in hundreds of hotels, airports, restaurants etc - even wall points that had USB built in worked, I also carry spare AAA batteries, so running out of power to run the NC was not an issue

 

[pcourtney]

over Xmas time I got the chance to compare the NAD HP70 with the 8's ( they are both idential circuitry inside )

https://nadelectronics.com/product/hp-70-wireless-headphone/

they sounded pretty much identical to me, so I am very happy with my 8's - I thought I might be missing out - doh !

NB however, the NAD HP70 do not have removeable AAA batteries - so that ruled them out for me ( even if they sounded a little
bit better SQ wise, I would have stayed with the 8's )

 

[pcourtney]

very good info in comparison to the Bose 35's - starts at 7:09

 

[threenorns]

I received a new pair of M4U 8'S and couldn't get them to charge. PSB sent me a replacement set - also brand new - and these, too, won't charge. I've tried the included USB cable as well as high quality after market cables, and various USB wall chargers, but no luck. Here's what happens:

I plug in the micro USB cable and the red light slowly blinks. Then, after about a minute, the red light begins to blink rapidly. With the first pair, I was able to get them to fully charge once after several attempts, but the next time I kept them plugged in for 30 hours and the red light continued to rapidly blink. With the new pair, I took them out of the box and I've had them plugged in for 25 hours and the red light is still rapidly blinking.

According to tech support, the light should turn solid red once they have finished charging. Not sure if that's accurate or not. Also, they could not tell me the difference between the initial, slow blinking red light and the rapid binking light, and there is no mention of these lights in the documentation. My hunch is that the slow blinking red light means that they are charging and the rapid one indicates an error of some kind, but I have no idea if that's true. Any help would be greatly appreciated!

This is so totally late, but i had the same problem with the red blinking light and the not charging.

Change the batteries. Problem solved.

Here's the thing: if you look at the instructions for changing the batteries, they're awful. they give the impression that you're supposed to rotate the ear cuff to access the battery cover tabs. you don't. pinch the bottom of the left ear cuff (the side without the buttons) and the bottom will pop through to the outside - you'll see the two tab clips and the headphone jack port. dig your nails right under the lip where the tabs are and pull - you'll need to use moderate force but be careful about it. the outer ring surrounding the PSB logo will peel/pop off allowing you to switch the batteries out. then just press around the ring to reinstall it making sure to get all the clips in.

about the batteries: if they're missing, you'll get the rapid red blinking. i ran into a few posts where ppl ordered headphones (not psb's - i was going farther afield at this point) and the batteries inside were worn out (it was a product return), put in the wrong way, or, in one case, completely missing (how that got past QC is beyond me).