Copy-pasta from Carbo Mezzo thread - since many are curious about the Pezzo here as well:
More Zirco Pezzo impressions + Modification:
The Zirco Pezzo drivers are fast and delivery great quality output.
Bass is near perfect, tight and fast with zero bloat. Compared to EPH200, these lack a little bit of bass body, but, sound airier and extract more information in mid-range. Detail retrieval is really impressive although the highs are somewhat thin sounding lacking note weight.
Instrument positioning, again I emphasize, is stellar, and everything is well separated in a wide soundstage.
All said, there's no going around the fact that these are bright earphones. They are really bright, and they do induce listening fatigue after a while.
So, to tame this aggressive treble, I present an easy reversible mod that makes these IEMs sound near perfect!
I use Sennheiser IE Pro tips for this mod, which has a crosshair silicon mesh which prevents the foam or anything stuffed within from dropping through the other side.
Senn IE Pro eartips:
1. Senn IE pro silicon tip,
2. Kitchen towel/dish cloth, made of 35% cotton, 35%Viscose 30% Polyester (cut to fit the eartip bore), I used the same dish cloth for my Grados as well!
3. Foam included in stock IE Pro eartips.
Mod 1: Sennheiser medium tips + 3 included foams
Simply shove in 3 of these foam strips in each of the Senn ear tips, and we get a signature like this
This tames the highs considerably and there is great clarity throughout. Note weight is better with slightly more body.
The overall signature is still tilted towards bright, although they hardly sound sibilant anymore.
I wanted these tamed a bit more for longer listening sessions, and here comes our dish cloth mod!
Mod 2: Sennheiser medium tips + dish cloth + 1 included foam
Carefully cut out a small disc from the dish cloth roughly equal to the inner diameter of our Sennheiser ear tip bore.
It is a little tricky, but shove this piece of dish cloth in first, using the 3.5 mm jack, or small pin.
On top of this shove in one of these foam strips. (using only the dish cloth again brings the treble to near Mod1 range).
Here is how the curve looks now:
Now the sound is near neutral, and it does not sound so bright anymore. Note weight and body are amazing, and the clarity and detail retrieval is still incredile!
This is how i'm listening to my Pezzos since the last couple of days, and i couldn't be happier!
Measurement comparisons:
Pezzo Mod vs
Pezzo Mod+
Stock vs
Mod vs
Mod+
With the final mod (Mod+), the Zirco Pezzos sound like Yamaha EPH200s, with greater clarity and detail retrieval. The male vocals could use just a little more body even with
the Mod+, but i think this is why they are able to extract more mid-range information too.
VS ER2SE
VS Yamaha EPH200
Overall, i must say, if you can do the Mod+ these are an incredible set of earphones regardless of price!