[shoeblade]

Intro

Here is a guide on how to slightly modify your ER4 custom IEM tips to make them sound much better.
 

Background

Some others on Head-Fi had mentioned decreases accuracy and shrill sound after installing the custom tips on their etymotics.
I recently bought a pair and also noticed a dramatic change in sound. I would personally describe it as if someone had put hand over my ears and decreased the treble and made it shrill.
Symbols and S sounds had a harsh TSSSSSS quality which I have never encountered with over a decade with this headphones with various tips.
Needless to say, I was not very impressed.
 

Analysis

I came to the conclusion that either the bend in the sound bore of the molds was modifying the sound or the fact that the volume of air in the bore now was greater than that of other tips.
 

Notice the steep bend in the sound bore
 

Solution

The solution to this problem is to remove the filters from the tip of the headphone to the tip of the mold.
In this way, the sound is not filtered until it gets closer to the eardrum.
I also guess that the sound has more power with the filter removed and therefore can easily move the air in the sound bore before the filter.
Whatever the effect of this modification, the results speak for themselves with my ER4 sounding better than I have ever heard it.
 

Step 1: Remove Filters From Earphone

Use the filter removal tool to remove the filter from the headphone.
This will destroy them, so you will need 2 fresh filters after this step.
You may want to remove the green fabric from the center of the filter and replace the empty filter "can" into the headphone.
 

Step 2: Find Some Pens, Remove Ink Tube

Gather a few pens and pull the ink inserts out of them.
Compare the opening of the pen insert to the filter size.
Pick a tube which is slightly smaller than the filter.
 

Notice that the tube to the left is a better fit than the tube to the right which may be too small
 

Step 3: Cut Tube

Cut the end of the tube so it is slightly longer than the filter.
 

 

Step 4: Insert Filter

Insert filter into tube.
Turn tube upside down and press filter in.
 

 
 

 

Step 5: Insert Into Mold

 
 
Let me know how this works for you and if it improves sound any

 

[mchang]

Thanks for sharing, shoeblade.
 
I'll definitely explore the mod should my custom tips degrade the sound. I'm waiting for a re-make on right ear from Microsonic, but I too wondered if that sharp bend would have sound consequences.

 

[luisdent]

See my last post here. Do you think this would matter in my case? I don't hear anything abnormal, except the slight sibilance...

http://www.head-fi.org/t/550773/etymotic-acs-or-microsonic-for-cutom-fit-program#post_9338275

UPDATE: See this thread for details:
http://www.head-fi.org/t/538615/if-you-still-love-etymotic-er4-this-is-the-thread-for-you/1245#post_9338889

 

[markanini]

That's a clever mod. The improvement treble is expected as the tube creates somthing of a resonant lowpass filter. Westone used to offer mold setup like that:

 

[luisdent]

Quote:

That's a clever mod. The improvement treble is expected as the tube creates somthing of a resonant lowpass filter. Westone used to offer mold setup like that:

 
Wait they used to put the filters right in the mold for you?  I wonder if I can ask them to do that...

 

[markanini]

No one else tried this yet? losers

 

[luisdent]

Quote:

No one else tried this yet? losers

 
Ha.  Mine were far too "off" for that to fix them.  Etymotic had me send them in and they're going to compare the response to that of the triple flange and go from there to see what needs to be done.  Probably partly fit, partly depth, partly filter...
 
Ironically, I read somewhere that they used to put the filters like that for you when you ordered the custom tips.

 

[markanini]

Let me guess: There wasn't enough room for the filters to be placed outside the er4 nozzle yet remain within the mold? You could have pulled out the ER4 from the mold a bit. OTOH it'll be interesting to see what Etymotic says about your molds. Keep us posted.

 

[luisdent]

Quote:

Let me guess: There wasn't enough room for the filters to be placed outside the er4 nozzle yet remain within the mold? You could have pulled out the ER4 from the mold a bit. OTOH it'll be interesting to see what Etymotic says about your molds. Keep us posted.

 
I've tried pulling the er4 out a bit and a lot.  Nothing changes the sound much.  I haven't tried the filters on the end of the tips, because I don't want to waste two filters just yet. :-o

 

[OJNeg]

I imagine this would work with the MC5 and other models as well. I'm going to have to get a new set of filters to try this mod.
 

 

[markanini]

Quote:

 
I've tried pulling the er4 out a bit and a lot.  Nothing changes the sound much.  I haven't tried the filters on the end of the tips, because I don't want to waste two filters just yet. :-o

Pulling out the ER4 in the mold alone can only make the sound worse. Got to move the filters for the mod to work.

 

[luisdent]

Pulling out the ER4 in the mold alone can only make the sound worse. Got to move the filters for the mod to work.

Ah, gotcha. I'll see how the molds are when I get them back or whatever they send me, if they still aren't good ill try the mod.

 

[luisdent]

Update.  I talked with Etymotic, and they measured my custom tip's frequency response.  They said there was a huge spike in the treble.  They think it might have to do with the sound hole being too large.  They were very good about the whole thing.  They said they tried a few things such as putting the filters in the molds instead of the nozzle, which required extra tubing.  They said that helped the treble, but caused other unwanted changes like a suck out of some frequencies.  They are going to try and work with microsonics to fix this issue and get back to me.  I have my fingers crossed...

 

[markanini]

Wow, which other manufacturer would go that far?

 

[luisdent]

Quote:

Wow, which other manufacturer would go that far?

 
I know.  Etymotic seems great.  Everyone I've talked to has been knowledgable and helpful.  Now let's hope microsonics is half as good...