Is Bass the Main Difference Between Ety MC3 and HF3?

To me they sound basically the same, but the HF3 distorts much more easily.

Here are some charts so you can explore this for yourself.  It looks like the driver implementation is identical.

Distortion

http://graphs.headphone.com/graphCompare.php?graphType=1&graphID[]=2701&graphID[]=2691

Frequency Response

It does look like the HF3 rides on average +3dB above the HC3, but this could be fit and seal related.

http://www.headphone.com/headphones/etymotic-mc3.php

They dont sound that similar, the MC is more conservative in response due to the lack of treble air. It's also much slower and precise, sounding congested and bland. Been a while since i heard the two, but the HF series was clearly better and worth the price difference imo. 

Not sure that the graphs the user NA Blur is using mean what he is concluding.  I have owned both at the same time and there is a significant improvement in SQ from the MC5 to the HF5.  They do NOT have the same drivers, as the MC series driver is a completely different type of driver that Etymotic created called a "moving coil" driver.  (BTW, a number of other companies have similar cross-type drivers with similar names.)

The HF5 shares the same balanced armature driver as the renowned ER4, but the housing and the tuning are different for each.  The MC5 is much less coherent than the HF5, and on busy music passages, the MC sounds congested and confused.  The HF5 just sound beautiful compared to the MC5.

Save your money and get the HF5 -- it is worth it completely.

Quote:

Originally Posted by ChristmaSFnatic 

Thanks guys. And is the HF5 good for most type of music, esp rock, pop, and Christmas songs? It wont make it sound boring eh?

The HF5's are great all around for all types of music. IMO best earbuds in the $100 price range. Bass isn't huge compared to others but your music doesnt sound like it has a ton of bass anyway.