ER4XR twice the normal resistance, extremely quiet, no low end. Possible to fix?

staticV3

Member
2019-10-12 5:28 pm
A week ago I sniped a pair of broken ER4XRs on eBay for 80€. The seller said that one side didn't play and I was hoping that a simple cable swap would fix the issue. Sadly, it wasn't the cable's fault and instead the driver's. With my multimeter I measured 45 ohm for the working driver and 90 ohm for the broken one. If I really crank the volume, the broken side still plays but there is very little low end. I have already fixed/modded a fair amount of IEMs/headphones and so I was wondering if I could fix the issue by resoldering the connector or whether those are signs of a blown BA driver and therefore unfixable. I'm looking forward to your answers!
 

PRR

Member
Paid Member
2003-06-12 7:04 pm
Maine USA
Someone built them. Someone could repair them. Without supplies and tiny tools, and experience, it seems unlikely to succeed. I suspect the "receiver" is not VERY expensive, but you probably can not buy just one receiver to ER4 specification. (Knowles makes almost all such receivers, but the ER4 parts will be to Mead Killion's specs.)

Etymotic has a "special price" for out-of-warranty ER4s. It looks like $100 off their regular price. With the 80€ you already spent, you could have just bought ER4 new (with warranty). But it is a way to salvage your 80€. Shipping costs and stupid Customs collectors could spoil the deal.
Etymotic Research | Out-of-Warranty & Special Purchase Options
 

PRR

Member
Paid Member
2003-06-12 7:04 pm
Maine USA
There is an upgrade for the old version, and as I read it, a special price for out-of-warranty replacement of the new version. I agree the words are not as clear as the earbuds.

Mouser now lists *other* Knowles receivers. One at ~~$40 but it is down 20dB at 8KHz. The one which is near-flat into the top octave is ~~$80. Neither is likely THE part used in the ER4XR so won't be a stereo match. (Note that Knowles' published responses do not include significant effects in the ear-mold coupler and inside the ear, so you can't innocently judge the final response from the naked receiver response.)