EtymoticFilter Tuning Kit - Designed for ER Series Earphones - Includes 4 Filters of Each Color (White, Brown, Green, Red & Orange)

I have recently purchased several pairs of Etymotic ER4XR's when they went on sale; couldn't pass up the deal as I have been a longtime fan of Etymotic IEMs - something like over a decade. But it was somewhat of an on/off relationship where I would go from Etymotic to another IEM or headphones and back.But recently, I have discovered by accident how to make everyday use more comfortable and enjoyable. One of the most common issue I had was that the stock tips that were provided were not very good in the past. But I had not been using them properly. When you use the double or triple flange ear tips is that you rotate them an an angle (parallel to your ear canal) and point the tale down as you insert them. It will complete isolate outside noise and it will be very comfortable at the same time. It also vastly improves the frequency response and make it sound exactly how the IEM was tuned from the factory.But here's the rub. Ety's typically have a flat frequency response graph or neutral sounding signature and it limits the colorization of the original work hence called audio monitors. Because of this, I did not use them consistatly in the past. However, I think Etymotic engineers heard me (and many others) and came up with the 'XR' series which has a slight low end bias. This did the magic for me. It has just enough low frequency bias and it punches hard. Wait, I am not finished yet LOL.Okay, now that the low end is covered, now the high-mid highs were not high enough for me like the previous generations. This is where these filters came in. Originally, for years, I thought that the "filters" were just to protect the drivers from ear wax contamination. I was sorely wrong on this one, well sort of. Well, it does both. It provides ear wax protection AND also slightly modifies the frequency response curve. ER4XR's comes stock with green filters, which is mentioned as being neutral. This kit, comes with 5 different type of filters; white, brown, green, red, orange. As you go from left to right, it filters least to most. White is most bright, and orange is most dark or warm. I guess you can call them 'passive band pass filters' in nerdy speak.I find that my ears like the brown, which is slightly brighter than the stock green filter. It actually made me appreciate this IEMs even more. I am hearing things now I have not heard on the tracks before. If you're an audio head like me, I highly recommend you trying out these filters. You'll very likely be surprised at what it can do to an already an excellent IEM in stock form.

I wanted to get more out of my ER2XRs than they offered out of the box. They're great, don't get me wrong, but I was looking for more - more evenness in the tuning, and more bass detail. Ety describes the different tuning filters by impedance. I found that the brown filters gave these IEMs the character I was missing.Mind you - I listen almost exclusively to classical music, especially large orchestral works like Mahler and Bruckner symphonies. You will have to find out what you want and how to best get it.I do wish Etymotic would sell the filters, besides the green one, separately.

This kit allows you to try out different filters and find the one that best suits your combination of player, earphone, hearing, and preferences. With my FiiO M11s player, ER3SE, and balanced cable I found the red filter to be the most natural sounding. Of course, your preference may differ which is the beauty of this sampler.

Not all filters fit exactly the same, and the price seems unnecessarily high for those who already own an Etymotic IEM. Nevertheless, each color filter dampens treble as displayed, and the differences are audible.

My ER4XRs are too sterile and suck all personality out of any music I throw at them. The orange filter helped a lot with adding some warmth and removing the "space" in between sounds (because the decay is near-instant).

Product came missing the orange filters. Awesome.

Great product to tune the earphone to suit my taste better

It doesn't add clean treble - only peaky points. I'd advice against it.