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Drop + THX Panda Review (headphone)

amirm

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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:"

Drop THX Panda Review Wireless Headphone.jpg


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:

Drop THX Panda frequency response measurements Headphone.png


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:

Drop THX Panda relative frequency response measurements Headphone.png


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:

Drop THX Panda THD distortion measurements Headphone.png


Drop THX Panda THD percentage distortion measurements Headphone.png


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):

Drop THX Panda Group Delay measurements Headphone.png


Impedance is flat and low:
Drop THX impedance response measurements Headphone.png


Headphone is very sensitive:

Most sensitive headphone reviewed.png


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:

Drop THX Panda Headphone Equalization EQ.png


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.

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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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  • Drop THX Panda Frequency Response.zip
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sweetchaos

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To import this PEQ profile into 'Equalizer APO', use:
Preamp: -6.2 dB
Filter 1: ON LS Fc 55 Hz Gain 5.0 dB Q 1.0
Filter 2: ON PK Fc 1100 Hz Gain 5.0 dB Q 1.0
Filter 3: ON PK Fc 2500 Hz Gain 5.0 dB Q 1.0

Otherwise, see my PEQ guide.
..................................................................................................................
For those who don't have PEQ-capable app, and want to use GEQs instead.

Preamp: -4.3db
32 2.5
64 -0.8
125 -2.1
250 -2.0
500 -1.6
1000 2.9
2000 3.7
4000 0.3
8000 -2.7
16000 -3.6
Preamp: -4.7db
20 1.3
25 0.9
32 1.6
40 1.0
50 0.5
63 -0.6
80 -1.4
100 -1.5
125 -1.7
160 -1.8
200 -1.6
250 -1.6
315 -1.6
400 -1.4
500 -1.0
630 -0.3
800 1.0
1000 2.6
1250 3.0
1600 2.2
2000 2.5
2500 3.0
3150 1.8
4000 0.1
5000 -0.8
6300 -1.5
8000 -1.9
10000 -2.3
12500 -3.0
16000 -4.0
20000 -4.4
If you want to import into "Wavelet" (Android App):
GraphicEQ: 20 -1.6; 21 -1.6; 22 -1.7; 23 -1.7; 24 -1.7; 26 -1.8; 27 -1.8; 29 -1.9; 30 -2.0; 32 -2.1; 34 -2.2; 36 -2.4; 38 -2.5; 40 -2.7; 43 -2.9; 45 -3.1; 48 -3.3; 50 -3.5; 53 -3.8; 56 -4.0; 59 -4.2; 63 -4.5; 66 -4.7; 70 -4.9; 74 -5.1; 78 -5.3; 83 -5.5; 87 -5.6; 92 -5.7; 97 -5.8; 103 -5.9; 109 -6.0; 115 -6.0; 121 -6.1; 128 -6.1; 136 -6.1; 143 -6.2; 151 -6.2; 160 -6.2; 169 -6.2; 178 -6.2; 188 -6.2; 199 -6.2; 210 -6.2; 222 -6.1; 235 -6.1; 248 -6.1; 262 -6.1; 277 -6.0; 292 -6.0; 309 -5.9; 326 -5.9; 345 -5.8; 364 -5.7; 385 -5.6; 406 -5.5; 429 -5.4; 453 -5.3; 479 -5.1; 506 -4.9; 534 -4.8; 565 -4.5; 596 -4.3; 630 -4.0; 665 -3.7; 703 -3.3; 743 -3.0; 784 -2.6; 829 -2.1; 875 -1.7; 924 -1.3; 977 -0.9; 1032 -0.5; 1090 -0.3; 1151 -0.2; 1216 -0.2; 1284 -0.3; 1357 -0.4; 1433 -0.5; 1514 -0.6; 1599 -0.6; 1689 -0.6; 1784 -0.6; 1885 -0.5; 1991 -0.4; 2103 -0.3; 2221 -0.2; 2347 -0.2; 2479 -0.3; 2618 -0.4; 2766 -0.7; 2921 -1.1; 3086 -1.5; 3260 -1.9; 3443 -2.4; 3637 -2.8; 3842 -3.2; 4058 -3.6; 4287 -3.9; 4528 -4.2; 4783 -4.5; 5052 -4.7; 5337 -4.9; 5637 -5.1; 5955 -5.3; 6290 -5.4; 6644 -5.5; 7018 -5.6; 7414 -5.7; 7831 -5.8; 8272 -5.9; 8738 -6.0; 9230 -6.0; 9749 -6.1; 10298 -6.1; 10878 -6.2; 11490 -6.2; 12137 -6.2; 12821 -6.3; 13543 -6.3; 14305 -6.3; 15110 -6.3; 15961 -6.3; 16860 -6.4; 17809 -6.4; 18812 -6.4; 19871 -6.3
Otherwise, see my GEQ guide.
 
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silentt29

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Billy Budapest

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I wonder what happened along the way as the Panda morphed into its current incarnation from the Oppo PM-3? I was hoping that the Panda was the last remaining way to get the PM-3 sound, but apparently not.
 

respice finem

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Any headphone that isn't comfortable will be collecting dust anyway. And I suspect the good distortion figures would be less good after EQ, esp. in low frequencies. I'm wondering how this thing got THX certified?
 

AdamG

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amirm

amirm

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I have to just ask....

What does "Drop" mean, is this a brand, a company or what..???
As Adam explained, they used to just sell other companies products by collecting a bunch of people buying something together. They then decided to make their own version of some of these products. THey used to be called Massdrop but now just drop.com.
 

PeteL

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Any headphone that isn't comfortable will be collecting dust anyway. And I suspect the good distortion figures would be less good after EQ, esp. in low frequencies. I'm wondering how this thing got THX certified?
THX is not a certification, it's the amplifier used (unused in these tests since they are in wired mode).
 

martijn86

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As an owner I feel like sharing a little.

There is a firmware update out now that'll allow you to upload EQ, straight to the headphones. At that point, whatever you connect to, the EQ will always be applied. I think an onboard EQ, independent of the source, is a great thing to have.

As an early backer, I was a little torn at first. My goal of getting a better Bluetooth headphone was met but they just sounded dull. I tweaked some dials on my phone and got it to be reasonably enjoyable to my taste. The pinnacle of Bluetooth headphones is definitely still a mile away from a Sony MDR-7506 with a proper amplifier.

After the update, I went through the settings of the app SoundID by Sonarworks and, as a baseline, it applies a correction to the headphone that is supposed to flatten the response. After that, I did a hearing test and a preference test. The music samples are terrible but the tests are detailed and can be refined as much as you want. The result is a more lively sound.

There is a tradeoff to the DSP benefit. They seem to combat the distortion in the bass with a band limiter. Past a certain level, the bass starts to get cut off.

Screenshot_20210510-222715_SoundID.pngScreenshot_20210510-222818_SoundID.pngScreenshot_20210510-222827_SoundID.png
 

Jimbob54

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I feared this would be the case- just for the avoidance of doubt though, this is with them wired but presumably active, so the THX amp modules are driving them?

Is there an option to use them passive at all?

EDIT- as has been pointed out below, if they are wired, they are passive.
 
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elliott

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I'm glad this review fell this way. Thanks! I thought I was going crazy. Picked these up used for a great price, but I still didn't understand what all the hype was about.
 

Anmol

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i was thinking to buy this headphone a few months ago due to hype on how good these sound, since it is online shop and cant get a listen, decided against it. dodged a few hundred loss. thanks Amir.
 

Jimbob54

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I'm glad this review fell this way. Thanks! I thought I was going crazy. Picked these up used for a great price, but I still didn't understand what all the hype was about.

I think you answered your own question- it was indeed just hype.

So it looks to me like if you want wireless headphones, go Bose QCor go home (based on reviews on here to date)
 
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