[Minibear453]

I read somewhere that noise cancelling headphones have worse SQ than normal headphones... why? Simple as that.
 
P.X. What's a good day-day headphone for $50 ish?

 

[QuantumXL]

uumm Well from what I understand is that a lot of the highs and mids are muffled out due to the Noise Canceling (which is the purpose of many noise canceling headphones; to cancel out the surrounding high and mid frequencies). So what you hear is an overwhelming amount of lows. As far as sound quality goes... It all depends on the technology. If the headphones are able to reproduce the sounds perfectly with the noise canceling, than yes... However, from my own experiences... I have no luck. So I stick to IEMs.

 

[Sardonyx]

Because they are noise generators.  There is a microphone to monitor ambient sounds, and some electronics to analyze & modify the signal so the headphones will output sound waves 180 degrees out of phase.  But the small, cheap, low quality components are far from accurate, so (for example) instead of 5 + (-5) = 0; you get 5 + (-4.5) = 0.5.  Audible hiss and/or masking of music frequencies. 

 

[Trysaeder]

A lot of it is because the wavelengths of higher frequencies are very short. Simply one centimetre of difference in positioning can put the noise cancelling signal out of phase.

 

[patwoltenholme]

It's actually a pretty complex issue. A lot of it relates to how accurate the microhpones that pick up the noise are as well as how fast the circuitry can analyse, EQ and reverse the phase of the noise to add back into the main signal. You see, often these external little mics are pretty crappy so they aren't getting an accurate picture of the noise first of all. Secondly, no digital circuitry can perform all the DSP fast enough to incur 0 latency. It's just not gonna happen. So what ends up happening after all this is that due to these inaccuracies, some of the normal music signal is cancelled too along with the noise.
 

 

[High_Q]

Well, using a mic would be a bad idea if a sensing system is used as there would be latency in the system's reaction.  Since all noise that needs to be cancelled is in the audible range, it would not be that simple to implement the cancellation.  I see noise cancellation as sending out wave of the same frequency as the wave, but with 180 phase shift.  But, phase is time dependant, so if there is latency, it will not cancel out at perfect 180 phase.  

 

[Prog Rock Man]

I would recommend the Goldring NS1000 for NR headphones. They are amongst the cheapest you will get, they work well at isolating you from outside noise even when switched off and they still work that way when batteries run out. Some NR headphones produce no sound at all when the batteries run out.
 
I find the SQ lowers when NR is on as there is the itroduction of background noise, a faint hiss and the treble is enhanced.