You made me go look up the drawings and pull a sample from the archives (couldn't find on in my desk).   The thread size was the same.  The exposed length is .125 on the current tool, and about .320 on the old plastic or aluminum ones.   There are still a few left of the old ones under a...

  The Knowles tool is made for removing filters from hearing aids, and earmolds (you can try a hearing aid shop, although I doubt they will give it to you to try).  They don't work to well with the ER-4.  We have a few here but they are pretty old.  I can't believe they are $286 now.  The screw...

You normally want an amplifier with an output impedance at least 10 times lower impedance than the load.  So with the 27 ohm ER-4P you would want an output impedance of 2.7 ohms or less.  Normally the ouput impedance is quoted at one frequency and can vary especially with inductive loads like...

On an ER-4P you should only see a drop off in sensitivity after 75 -80 ohms. 

I think we still will replace the cable to make it a 4P.  I think it is $50.

Yes,   The colors follow the values established by Knowles  

Actually none of the three flange eartips are silicone.  They are all supposed to be the same material specification, except for color.  There is always the possibility the colorant will have an effect, and the durometer will have some range due to molding.  In some peoples body chemistry the...

We switched the default tips attached to the ER-4's to the smaller "frost" eartip.  In the box you will find 2 pair of the gray "large" eartips which are the same as they have been for years.  IF you go back far enough they are the same as the white tips

The different filters will not have an effect on the low frequencies.  If I could only find the folder I put those curves with the different filters I ran in 1991!   The metal filters can cause cracking in the housing.  That one reason why we stopped using them.   If you insist on...

It's been long enough that I forgot my password, and I ended up with a default avatar that was a nice looking amplifier I didn't recognize.  I switched it for a funny picture of my dog so I wouldn't get too many amp questions I couldn't answer.   I do look at times, but don't respond as much.

We don't send out ER-4's of any version that have an overall level difference from 100Hz-10kHz of 2dB.  When we do a repair and can't find an adequate match for the other transducer we replace both of them.  If you have a repair in question I think the curves might be retained with the repair...

The current cable is black and has been for over a year. The impedance of the cables has not changed. We may add a red dot on the right side in the near future for color fans.

Looking at returns, and retained samples with different life tests, we have found a couple of runs we are not happy with. The current shell is manufactured differently is not causing problems. It is always possible to crack a plastic part when you insert a metal object into it. If you have a GM...

Quote: Originally Posted by pkshan er4b sounds the most dynamic,detailed & transparent in er4 family IMO,very lively sound. Unlike er4s,the bass of 4b is very deep & punchy,vocals are MUCH better, the sound is very expressive,powerful and muscial. Besides UE10,4b is the only IEM...

Quote: Originally Posted by thevelho Hello, I have a slightly off-topic question: can I benefit from Etymotic's guarantee (and extended guarantee) if I purchased my er4p's on ebay (I bought them new). Thanks! PS: They are wonderful! As long as you keep your proof of...