This is a review and detailed measurements of the Bose QuietComfort 35 II noise cancelling headphone. It was kindly purchased new by a member and drop shipped to me. It costs US $299 on Amazon including Prime shipping. It has an incredible 44,000 reviews on Amazon averaging 4.5 stars! Are the masses right? We are going to find out.
The 35 II doesn't feel fancy, nor cheap:
The cups are on the smaller side but fit my ears fine:
They are on the softer side and seal well which means they wear warm. Fine right now in winter but I suspect they may get too hot in summer.
I briefly tested the noise cancelling function using my Audio Precision fan noise as stimulus. Just wearing the 35 II was enough to kill 90% of the noise. Turning it on removed the last bit but really, it was fine without it. Noise sources with lower frequency content will likely show off the effect more.
Note: The measurements you are about to see are preformed using standardized GRAS 45CA headphone measurement fixture. Headphone measurements require more interpretation than speaker tests and have more of a requirement for subjective testing as a result. In addition, comparison of measurements between different people performing it using different configurations requires fair bit of skill. So don't look for matching results. Focus on high level picture. Listening tests are performed using RME ADI-2 DAC and its headphone output.
Bose QuietComfort 35 II Measurements
Let's start with frequency response of 35 II and comparison to our preference target to figure out tonality of the headphone, with the unit bot on and off:
I first ran it with it powered off and was surprised how bad the response was. Equally so, I was impressed once I turned it on and it not only flattened the variations in bass and mid-range but also pulled up the bass response to below 20 Hz! Here is the powered on response again:
That is pretty good tracking of our target response! It is essentially perfect to 1 kHz. Here is the relative variations:
Good news extends to very low distortion at decent levels:
Considering how much bass we already have -- so we don't have to boost it -- that is excellent level of distortion in that region.
Here it is in absolute level:
Again, remember that this is to be compared to post EQ for other headphones that are weak in bass.
Clean, not fuzzy group delay shows that we have one radiator doing its job, not a bunch of other resonances mixing in:
The entire curve is lifted up from 0 degree indicating a constant delay of about quarter of a millisecond.
Impedance radically changes when the unit is on or off:
Paradoxically, even though we are using the internal amplifier when the unit is on, it is not the most efficient headphone to drive:
Bose QuietComfort 35 II Listening Tests and Equalization
I was instantly at ease with the tonality of the 35 II. The clean and appropriate bass response was a delight. Spatial qualities were a bit light and higher frequencies a tad dull so I put in a bit of salt and pepper on it:
Once there, toe tapping started and I could listen endlessly to my test tracks. So much so that I did not want to take them off to take the pictures for the review!
As an aside, here is the EQ that I applied to AKG K371 headphone:
So darn close! Indeed the Bose could also use that broad light boost in pink filter I had in K371. I wonder if Bose measured the response of the K371 and used that as the target for 35 II. Anyone know which came first?
Conclusions
Amazing what happens when you follow the science and tune a headphone to proper target curve. You get a happy Amir who loves the 35 II with just a bit of EQ. What else is there to say?
The Bose QuietComfort 35 II gets my high recommendation if used with recommended EQ. Without it, it is still recommended but just not as highly.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The 35 II doesn't feel fancy, nor cheap:
The cups are on the smaller side but fit my ears fine:
They are on the softer side and seal well which means they wear warm. Fine right now in winter but I suspect they may get too hot in summer.
I briefly tested the noise cancelling function using my Audio Precision fan noise as stimulus. Just wearing the 35 II was enough to kill 90% of the noise. Turning it on removed the last bit but really, it was fine without it. Noise sources with lower frequency content will likely show off the effect more.
Note: The measurements you are about to see are preformed using standardized GRAS 45CA headphone measurement fixture. Headphone measurements require more interpretation than speaker tests and have more of a requirement for subjective testing as a result. In addition, comparison of measurements between different people performing it using different configurations requires fair bit of skill. So don't look for matching results. Focus on high level picture. Listening tests are performed using RME ADI-2 DAC and its headphone output.
Bose QuietComfort 35 II Measurements
Let's start with frequency response of 35 II and comparison to our preference target to figure out tonality of the headphone, with the unit bot on and off:
I first ran it with it powered off and was surprised how bad the response was. Equally so, I was impressed once I turned it on and it not only flattened the variations in bass and mid-range but also pulled up the bass response to below 20 Hz! Here is the powered on response again:
That is pretty good tracking of our target response! It is essentially perfect to 1 kHz. Here is the relative variations:
Good news extends to very low distortion at decent levels:
Considering how much bass we already have -- so we don't have to boost it -- that is excellent level of distortion in that region.
Here it is in absolute level:
Again, remember that this is to be compared to post EQ for other headphones that are weak in bass.
Clean, not fuzzy group delay shows that we have one radiator doing its job, not a bunch of other resonances mixing in:
The entire curve is lifted up from 0 degree indicating a constant delay of about quarter of a millisecond.
Impedance radically changes when the unit is on or off:
Paradoxically, even though we are using the internal amplifier when the unit is on, it is not the most efficient headphone to drive:
Bose QuietComfort 35 II Listening Tests and Equalization
I was instantly at ease with the tonality of the 35 II. The clean and appropriate bass response was a delight. Spatial qualities were a bit light and higher frequencies a tad dull so I put in a bit of salt and pepper on it:
Once there, toe tapping started and I could listen endlessly to my test tracks. So much so that I did not want to take them off to take the pictures for the review!
As an aside, here is the EQ that I applied to AKG K371 headphone:
So darn close! Indeed the Bose could also use that broad light boost in pink filter I had in K371. I wonder if Bose measured the response of the K371 and used that as the target for 35 II. Anyone know which came first?
Conclusions
Amazing what happens when you follow the science and tune a headphone to proper target curve. You get a happy Amir who loves the 35 II with just a bit of EQ. What else is there to say?
The Bose QuietComfort 35 II gets my high recommendation if used with recommended EQ. Without it, it is still recommended but just not as highly.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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