This is a review and detailed measurements of the Drop + THX Panda wired and wireless headphone. It was kindly loaned to me by a member and costs US $399 from the company.
While the feel of the pads is nice, I am not sure I got any cuteness inferences from the name "Panda:"
The spring tension is extremely progressive going from little resistance to massive amounts. The soft pads help a lot but I did not like wearing them. They bothered me from start and stayed that way. The small cups and heavy weight of the unit despite its size do not help in this regard. We are at 380 grams with inside cup dimensions of 59x40x20 (Height x Width x Depth).
A removable 3.5 mm cable is provided for wired connectivity. Online measurements and reports indicate the same response wired and wireless so I did all of my testing wired (lossy codecs can change the frequency response).
The measurements you are about to see are made using a standardized Gras 45C. I searched for any and all measurements I could find online. Alas while a number of them are close to mine, none are using the exact fixture down to coupler and pinna. As you will see, I have confirmed the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers specially in bass and a few kilohertz so keep that in mind as you read these tests.
NOTE: I had a hell of a time getting consistent measurements out of this headphone. Slight touch to the headphone would often send the response in one channel down by 20 dB! I thought the cable was loose or broken but moving that alone did not help. After many tries, I got lucky and got one consistent measurement you see below. After I did the measurements, I read the note from the owner that indicated people complaining about this very thing. I am thinking there is a design problem in the wired pass-through mode of this headphone which needs to be addressed.
Drop + THX Panda Measurements
Let's start with our usual frequency response measurements:
As usual, I try to sync up the measurement to the frequency of 425 Hz which is the zero reference for the preference curve. Doing so shows the good compliance to target from 80 Hz to 700 Hz. Other measurements I have seen online sync up to 1 kHz and as a result show sub-bass and 1 to 5 kHz much closer to target with a massive boost showing between 80 to 700 Hz. Remember, this is just a visual aid. The measurements and what the headphone is doing is the same either way.
You can see the broad deviation in relative graph just the same:
In my book, this kind of response is a mistake. Deep bass is a fundamental advantage a headphone can have because it is free of room modes that speakers suffer from. And at any rate, speakers struggle to reproduce sub-bass. Headphones if designed well can do this with ease. The broad dip between 1 and 6 kHz suck the openness life out of a headphone and is another sin in my book. Drop raves about not having DSP in there to process the sound. DSP is exactly what this headphone needs to produce anything close to preferred tonality.
Distortion is quite low:
Then again we need to boost the very areas that are highest in distortion so above graph is somewhat misleading if you are going to use EQ.
Group delay is very clean except for bass (which is typical):
Impedance is flat and low:
Headphone is very sensitive:
Although subjectively I kept turning up the level to compensate for frequency response errors.
Drop + THX Panda Headphone Listening Tests and Equalization
I couldn't listen for more than a few seconds to Panda before reaching for EQ. So much of the life of the music is sucked out in mid frequencies without it. A quick fix for that region with a single filter improved things but not remotely where it needed to be. Took a good half of hour of tuning with more filters to get reasonable sound out of this headphone:
With all these fixes, the sound was quite pleasant and much more open with far better spatial qualities. Still, I was not in the mood to listen much to the headphone and took them off.
Conclusions
The Panda gets so many things wrong here. It is not comfortable to wear, and has very poor frequency response curve. Equalization helps a lot but in my attempt at least, could not remove the bad tastes of the sound without EQ. There are so many other choices of headphones out there that I don't see a reason to use this headphone. Equalization is a must for this headphone and needed to be there day one (I understand they are releasing an App with EQ soon). Given how much experience Drop has with selling other headphones, I am so surprised that their internal process did not catch the many flaws this headphone has. Yes, there was a time that having "THX" on any audio gear was a major advantage. But that technology is of no use if you get the basics of the design wrong.
Needless to say, I can't recommend the Drop + THX Panda. If you have it, you need to use EQ and put pressure on Drop to investigate whatever is wrong with signaling of this headphone in one channel.
-----------
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/
While the feel of the pads is nice, I am not sure I got any cuteness inferences from the name "Panda:"
The spring tension is extremely progressive going from little resistance to massive amounts. The soft pads help a lot but I did not like wearing them. They bothered me from start and stayed that way. The small cups and heavy weight of the unit despite its size do not help in this regard. We are at 380 grams with inside cup dimensions of 59x40x20 (Height x Width x Depth).
A removable 3.5 mm cable is provided for wired connectivity. Online measurements and reports indicate the same response wired and wireless so I did all of my testing wired (lossy codecs can change the frequency response).
The measurements you are about to see are made using a standardized Gras 45C. I searched for any and all measurements I could find online. Alas while a number of them are close to mine, none are using the exact fixture down to coupler and pinna. As you will see, I have confirmed the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers specially in bass and a few kilohertz so keep that in mind as you read these tests.
NOTE: I had a hell of a time getting consistent measurements out of this headphone. Slight touch to the headphone would often send the response in one channel down by 20 dB! I thought the cable was loose or broken but moving that alone did not help. After many tries, I got lucky and got one consistent measurement you see below. After I did the measurements, I read the note from the owner that indicated people complaining about this very thing. I am thinking there is a design problem in the wired pass-through mode of this headphone which needs to be addressed.
Drop + THX Panda Measurements
Let's start with our usual frequency response measurements:
As usual, I try to sync up the measurement to the frequency of 425 Hz which is the zero reference for the preference curve. Doing so shows the good compliance to target from 80 Hz to 700 Hz. Other measurements I have seen online sync up to 1 kHz and as a result show sub-bass and 1 to 5 kHz much closer to target with a massive boost showing between 80 to 700 Hz. Remember, this is just a visual aid. The measurements and what the headphone is doing is the same either way.
You can see the broad deviation in relative graph just the same:
In my book, this kind of response is a mistake. Deep bass is a fundamental advantage a headphone can have because it is free of room modes that speakers suffer from. And at any rate, speakers struggle to reproduce sub-bass. Headphones if designed well can do this with ease. The broad dip between 1 and 6 kHz suck the openness life out of a headphone and is another sin in my book. Drop raves about not having DSP in there to process the sound. DSP is exactly what this headphone needs to produce anything close to preferred tonality.
Distortion is quite low:
Then again we need to boost the very areas that are highest in distortion so above graph is somewhat misleading if you are going to use EQ.
Group delay is very clean except for bass (which is typical):
Impedance is flat and low:
Headphone is very sensitive:
Although subjectively I kept turning up the level to compensate for frequency response errors.
Drop + THX Panda Headphone Listening Tests and Equalization
I couldn't listen for more than a few seconds to Panda before reaching for EQ. So much of the life of the music is sucked out in mid frequencies without it. A quick fix for that region with a single filter improved things but not remotely where it needed to be. Took a good half of hour of tuning with more filters to get reasonable sound out of this headphone:
With all these fixes, the sound was quite pleasant and much more open with far better spatial qualities. Still, I was not in the mood to listen much to the headphone and took them off.
Conclusions
The Panda gets so many things wrong here. It is not comfortable to wear, and has very poor frequency response curve. Equalization helps a lot but in my attempt at least, could not remove the bad tastes of the sound without EQ. There are so many other choices of headphones out there that I don't see a reason to use this headphone. Equalization is a must for this headphone and needed to be there day one (I understand they are releasing an App with EQ soon). Given how much experience Drop has with selling other headphones, I am so surprised that their internal process did not catch the many flaws this headphone has. Yes, there was a time that having "THX" on any audio gear was a major advantage. But that technology is of no use if you get the basics of the design wrong.
Needless to say, I can't recommend the Drop + THX Panda. If you have it, you need to use EQ and put pressure on Drop to investigate whatever is wrong with signaling of this headphone in one channel.
-----------
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/
