Actually the impedance does NOT determine how hard they are to drive (ala if you need an amp or not, or higher quality amp, etc. etc.). As an example, my daily drivers are a pair of Beyerdynamic DT990 600ohm, I can run them at reasonable sound levels off my phone.... Albeit lacking a bit of detail. About the Sennies though, no, you absolutely do NOT need an amp. However, if you want to bring out a little more from the headphones, I would definitely suggest an amp.
Taken from over at
Head-Fi:
SanjiWatsuki said:
I've been seeing this myth floating around a lot and I feel like I'm constantly correcting posts about how hard it is to drive a headphone on this. The worst part is that new users read this generalization and then start telling other people that impedance is how hard it is to drive a headphone, and then more new users read those posts...
Well, it actually comes down to a formula.
Power in Watts = ( Voltage * Voltage ) / Impedance
dB SPL = Sensitivity in dB/mW + 10 * LOG ( Power in mW)
As impedance goes up, the voltage squared is divided by a bigger number, but sensitivity gives a higher starting point for that dB SPL calculation. They both work together to determine how hard it is to drive a headphone, but the sensitivity is probably the more important component.
Now, as far as HEADSETS, when it comes to wired, under $100 the Skullcandy SLYR is the best priced at $70 with the Sennheiser G4ME One/Zero at $180 being my PERSONAL choice favorite for headsets in regards to quality, then you have the AudioTechnica ADG1 and AG1 for $220~, and then Beyerdynamic MMX300 for $300+.
Now, the question you asked regarding sound quality between open and closed, this is a tricky one. GENERALLY open designs tend to sound better than closed simply thanks to the design of being open-air. The open-air design of headphones can help give the impression that sound is coming from around you, as opposed to emanating from your head, which is a characteristic of closed-back and in-ear headphones. So if you want absolute sound stage alongside the best sounding, it will be open-back without a doubt. And the larger sound stage lends itself best for FPS games and positioning.
On the other hand, you have the downsides of open cans, which are noise leak both in and out alongside what I can only describe as bass that does not quite have that impact provided by closed cans. The pros to closed though are noise isolation alongside a generally more impactful bass. Of course, the sound stage tends to shrink considerably, so if you are worried about positioning, you need to get a set of open, if you are more worried about noise isolation and don't NEED the best sound positioning, closed is the way to go.
Now, if you want to save a little but love the general awesomness Sennheiser tends to provide, you can just buy a pair of the
HD 598 for $150 from Amazon. The G4ME One/Zero use the same drivers as found in the 598, you are paying a little more for the microphone convenience. Then of course attach a modmic to it and have a detachable mic for whenever you want
Of course, if you actually plan to make use of the attached microphone on the G4ME headset, then go in that direction as a modmic will cost you around $40~, tipping the scale in favor of the G4ME headset.
