H20 told me about this forum and since i am the owner of ZO2 and C&C BH i can share some thoughts with you.
first of all ZO2 and BH are two different beasts IMO. ZO2 is often advertised as portable subwoofer and this is exactly what it does best. i love ZO2 subwoofer mode to boost bass because it does so across the entire frequency range and you get that meaty rich sound. however... when i tried ZO2 in amp mode i was disappointed. ZO2 lacks instrument separation and is fairly lush and too laidback in amp mode. from my experience with C3 ZO2 is unable to boost clarity and add space, the whole musical presentation remains little big congested. that said IF you haven't heard anything better you will love ZO2. just remember this is more subwoofer than amp just as advertised.
NOW... C&C BH, for me this became a true ear opener, thanks to H20 for suggesting this little gem.
when i hooked BH onto my C3 i could not believe my ears... boy oh boy, i was missing so much in my music. BH immediately added space, separation, 3D stage and highs became so silky smooth. BH also added richer life like mid tones and increased bass immediacy and articulation. what you must remember that BH is not bass booster, so you will not gain earth shaking or head shaking bass... what you will get is air around drums, transient speed and clarity, presence effect. since i do not like woofy bass i much prefer BH handling that fine details to bass boost on ZO2.
that said i agree with H20 about cabling. i tried both stock cables from my ZO2 and BH and can say they are not on par with silver or silver-copper alloy cables. i bought Palic Baloong cable made of silver copper with gold plated terminations and i could not be happier with my choice. i tried this cable against BH and ZO2 stock cables and can report real audible differences particularly in mid and bass area. what a proper thick silver-copper or silver will do is add smoothness to trebles and add even more bass articulation and instrument separation. voices will also sound a bit more clear and closer to you in sense of presence or call it in your face if you want. do not forget cables make difference on this and on high-end gear... if in doubt ask any electrical engineer what high-end fuzz is all about and he will tell you about clean current and so forth. this is why cables surprisingly make sense and difference.
overall BH is a perfect marriage for C3 and adding good silver or silver plated cable (and a thick one) will make this combo a winner.
for what is worth i also note that C3 and BH love balanced armature IEMs.... while dynamic drivers are fine they are consumer sounding IEMs and lack clarity in mids and bass. i tried my Shure se215, Klipsch X10 and none could achieve clarity and detail level that i could achieve with eb50. so i would be considering only balanced armature for this combo. perhaps hybrid IEMs can be good too but i did not have experience to try them.
Edited by Gintaras - 2/12/13 at 11:33pm