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4 way headphone face off: Drop Seinnheiser HD6XX; Drop AKG 7XX, AKG 702 (Austrian), ATH M50x

dufferdan

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The last two weeks I have been having a nap after finishing work and listening to Apple Music in lossless and hi-rez as I laid on the couch. Setup as follows:

2016 iPad 2 Air as source, via camera adapter to USB input on Topping D70S MQA DAC. Balanced out to DROP THX 789 headphone amp. No EQ.

Music was everything from folk rock, jazz, art rock (RUSH) classical, guitar picking (Lindsay Buckingham) etc, with everything lossless or hi-res up to 96khz.

I spent a week with the Drop Seinnheiser HD6XX. I had picked up a balance cable from DROP and was plugged into balanced output of the 789. As I listened to the music, usually half or fully asleep, but it just didn’t seem alive. Very flat and lifeless, when I realized the treble, on a couple of songs where I would have really expected it, was almost absent. The last straw was two hours ago when Fleetwood Mac Little Lies. That album is full of cymbals and the song was totally flat.

So, I downloaded an app called Sonic Hz, by the way there needs to be better ones, but it was the first that popped up when I searched for Dogwhistle…maybe should have gone with it, but I digress… Now, about 10 years ago, I was messing with my iPhone and the Dogwhistle app and it appeared that I could hear up to about 15,000 hz, give or take. I have had my hearing tested since, and I definitely suffer from some loss (age 60, not a surprise), so I would expect to have had some reduction in ability to hear higher frequencies in the passage of time.

Note I have had covid for the last two weeks, starting last Monday, so stuffed up a lot, sinuses bad, wicked sore throat, and body aches for a few days. Most have subsided and I am on the mend, so my hearing is likely better than last week, and I am more awake after 10 hours at the desk. Hence my noticing things amiss today as opposed to in the throes of it last week.

So I start running thru some frequencies with the HD6XX. 60hz is fine, all the way up to 10,000, then very little at that level. Like wtf? I have lost 5,000hz? Tried and tried, I could get some left ear at 10,700hz, no right ear. I swapped out the cable for the unbalanced cable and had the same results. All other headphones were run via the unbalanced output on the amp….

So I go grab my AKG 702 (Austrian made), probably 15 yrs old. I can clearly hear up to through 16,000hx, though I go have to turn them up. But the hearing is there. Went back to The song, and there was the treble as I remembered it. Wow, OK, emergency over.

Drop AKG 7XX: Less punchy on the music, but the fit was looser and I wasn’t going to fiddle too much, so I kinda held on with hands. BUT, I could hear up thorough 15,000hz with these, so they had some capability. Note, I can’t perceive the flatness of the response, only that I definitely could or could not hear a certain frequency.

Audio Technica ATH M50x: Yep, music was punchy and treble was there. Back to the frequency generator, and could pretty clearly hear to 16,000 hz.

So the Seinnheiser‘s are likely relegated to the junk drawer. Something is defnitely wrong with them. I will have to see when I bought them, but it was likely 4 or 5 years ago. Not sure. My son years ago had broken an earcup mount on a cheaper set of Seinnheiser and they basically sent him a new pair for $50 (full retail was $175, theoretically studio phones for recording work).

I have a pair of DROP Focal Elex on way from their sale (was hemming and hawing between those and the Dan Clark Audio RT) . I am hoping these don’t disappoint!

I will also run the same with my Meze Audio as well. Maybe try my 16 yr old Etymotic ER-4Ps as well…

I may have a headphone problem…
 

ADU

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HD650.jpg


The above is a diffuse field compensated graph of the Senn HD 650, AKG K702, and AT M50X. You can tell which is which with the color key at the bottom. (Oratory doesn't have a graph of the Senn HD 6XX. But the HD 650 should be in the same general ballpark in terms of its response, based on users' comments.)

I have some doubts about the accuracy of Ora's M50X plot. Because it looks like it has a brighter tilt than plots I've seen by some other graphers. And possibly more akin to the response of the original "pre-X" M50, which was a brighter sounding headphone. IAC, I think you can see pretty clearly that there is a difference in the brightness in the treble between the HD 650 in red, and the other two headphones.

None of the above headphones would have what I'd consider to be an ideal response. But at least maybe you can see why you might be able to hear some of the higher treble frequencies on the K702 and M50X a bit more easily than on the HD 650 or 6XX.
 
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ADU

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K7XX.jpg


This graph includes the Drop K7XX, which is in red. (And the Senn HD 650 is now in orange.)

The K7XX is very withdrawn in the upper midrange versus the other headphones. And it must have quite a bit of warmth and also thickness (and muddiness?) in the lower midrange as a result. I suppose you could think it of it as having a "V-shaped" sound, or maybe a W-shaped sound, with the bottom of the V or W in the upper mids.
 

ADU

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index.php


Some groupings of headphones with perhaps a more neutral-ish response imo. That are also very well-extended in the sub-bass for the most part... For comparison to the above graphs.
 
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dufferdan

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Interesting, thanks. I had read reviews of the headphones that were available, and I can understand the differences from design/manufacturing perspective. It was shocking to me the magnitude of the difference in the reproduction of the 10,000hz area. while there are definitely differences in design, I think there is likely pretty wide variability across samples of the same model. I don't know how automated manufacturing is, but variable application of glues, etc could explain a lot of such in-model variation. It really seems like this particular sample is broken, tho the same break on both sides would not be expected...I would expect one side to have a different response than the other. But in my case, it appears consistent.
 
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dufferdan

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Update: I initially contacted Seinnheiser who indicated DROP serviced their own products. I then contacted DROP and instead of reading my outline of the issue, they replied with a boilerplate litany of frankly dumb suggestions to check cables, when I had clearly done that and tested against other cans. When I replied somewhat sarcastically to that note, they came back saying they didn't service out of warranty items (2 yr warranty on the HD6XX, which isn't bad overall, I bought in 2018). So I have sent a note back to Seinnheiser to see if they can do a driver swap. I will see what comes back. I know Seinnheiser was great about repairing/replacing my sons out of warranty studio cans that had a broken ear cup mount ( a known weakness), I was happy to pay the $50 cost of that one.... so I am hoping for something here. If they cannot do anything, I am going to be hard pressed to buy from DROP again if there is no way to get something repaired, even if out of warranty....note , I am fine to pay, my fault for not recognizing the issue sooner...
 

_thelaughingman

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Update: I initially contacted Seinnheiser who indicated DROP serviced their own products. I then contacted DROP and instead of reading my outline of the issue, they replied with a boilerplate litany of frankly dumb suggestions to check cables, when I had clearly done that and tested against other cans. When I replied somewhat sarcastically to that note, they came back saying they didn't service out of warranty items (2 yr warranty on the HD6XX, which isn't bad overall, I bought in 2018). So I have sent a note back to Seinnheiser to see if they can do a driver swap. I will see what comes back. I know Seinnheiser was great about repairing/replacing my sons out of warranty studio cans that had a broken ear cup mount ( a known weakness), I was happy to pay the $50 cost of that one.... so I am hoping for something here. If they cannot do anything, I am going to be hard pressed to buy from DROP again if there is no way to get something repaired, even if out of warranty....note , I am fine to pay, my fault for not recognizing the issue sooner...
Terrible that you’re having to go through all this with Drop.
I’ve said this before here on ASR, DROP is not worth the hassle to purchase products from because of their lack of support and Warranty for products. It is one of the reasons why I have not purchased a HD6x from them even though the headphones are reputed.
 

ADU

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Interesting, thanks. I had read reviews of the headphones that were available, and I can understand the differences from design/manufacturing perspective. It was shocking to me the magnitude of the difference in the reproduction of the 10,000hz area. while there are definitely differences in design, I think there is likely pretty wide variability across samples of the same model. I don't know how automated manufacturing is, but variable application of glues, etc could explain a lot of such in-model variation. It really seems like this particular sample is broken, tho the same break on both sides would not be expected...I would expect one side to have a different response than the other. But in my case, it appears consistent.

A bad unit is always possible. It has happened to me a couple times with other audio products. I've also never purchased from Drop though. And have no idea what their QC record is.

Based on the above plots though, there are some fairly glaring differences in the brightness and treble response between the HD 650, and some of your other headphones.
 

ADU

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This is a recent raw (rather than compensated) FR plot of an HD 6XX made by the SoundGuys on the new HBK 5128 HATS in-ear measurement system btw...

drop-x-sennheiser-frequency-response-chart.jpg


And these are a couple estimated plots of the raw in-ear responses of some neutral loudspeakers that I recently put together for the same system...

index.php


The above in-ear speaker plots were derived by combining the speakers' diffuse sound power curves with the HBK 5128 HATS diffuse field response curve. So they are only approximations, which are rather generalized in the treble. And I'd expect to see a few more peaks and dips in the actual responses of headphones in that range, as on the SoundGuys graph of the HD 6XX.

The HD 6XX appears to be tracking the overall levels of the above speaker approximations pretty well though, in both the midrange and treble. Which suggests to me that it has a fairly "flat" and neutral response. The only area where the 6XX seems to be falling short is in the bass.
 
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dufferdan

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This is a recent raw (rather than compensated) FR plot of an HD 6XX made by the SoundGuys on the new HBK 5128 HATS in-ear measurement system btw...

drop-x-sennheiser-frequency-response-chart.jpg


And these are a couple estimated plots of the raw in-ear responses of some neutral loudspeakers that I recently put together for the same system...

index.php


The above in-ear speaker plots were derived by combining the speakers' diffuse sound power curves with the HBK 5128 HATS diffuse field response curve. So they are only approximations, which are rather generalized in the treble. And I'd expect to see a few more peaks and dips in the actual responses of headphones in that range, as on the SoundGuys graph of the HD 6XX.

The HD 6XX appears to be tracking the overall levels of the above speaker approximations pretty well though, in both the midrange and treble. Which suggests to me that it has a fairly "flat" and neutral response. The only area where the 6XX seems to be falling short is in the bass.
Yeah, as I said, I think mine are faulty. Need to check them as another poster on a different site suggested…
 
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dufferdan

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As update, I went back and forth with DROP and given the phones were purchased in 2018, out of warranty, they had no way of servicing out of warranty items. So I went back to Seinnheiser and they suggested they could sell me the earpieces and phones for the HD 650 and show me how to install them myself. They don’t have any of the HD6XX cans in stock. Given what I paid for the HD6XX and the cost of the new earpieces/drivers, I will have something akin to the HD650 for less than the cost of the HD 650’s in Canada. I have zero issues with this alternative.

My Drop Focal Elex arrived today and had an hour and a half to listen to them while having a bit of a nap. Really nice soubnd across the spectrum, with a pretty full lower end at very modest listening levels. While heavier, I would say more substantial, I didn not find them at all uncomfortable. More to come on those…
 
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