dod9
New Head-Fier
- Joined
- Aug 1, 2005
- Posts
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(Read bold for quick version)
Just bought some second hand DT 770 Pro's (80 Ohms) for £95 (I wanted them asap).
They were apparently brand new unwanted extra pair for his friend, never even taken out of box and came with invoice from 2nd Jan 2015, they appeared factory packed.
Anyway I quickly tested them with one song and the guy seemed legit and I was in a rush so I bought them. - lesson learnt, test as much of the spectrum as you can.
Turns out the right speaker (cup/driver/phone? excuse my terminology) has a very audible buzz like distortion, more easily heard at lower frequencies like bass/low synths etc.
Very annoying, very prominent and I can't use them like this.
That was on my phone, so I thought maybe it's the source or I need an amp, but then tried in PC, and although the PC powered them better (could go louder), the same buzzing distortion occurred in the same places.
Using audacity on the PC I played each songs left tracks (which had not buzzed), solo through the right speaker, and they distort just as the original right tracks had.
The right track (which sounded distorted on the right speaker) sounds fantastic when played solo through the left speaker, so much so that I am really happy to hear how they should sound (ie, left playing only without the contamination of the right side).
I tested using a tone (sine wave) generator (http://onlinetonegenerator.com/) and I could hear the buzzing clearly all the way from 1hz up to about 200hz (harder for me to discern around there and upwards).
It almost flaps about at low frequencies then turns more buzzy and high pitched buzzy as you go up the freqs.
I read all these threads about the known DT 770 hair problem, ie a hair can get in the driver and make it 'rattle' and you can remove hair from the inside areas to fix it.
http://www.head-fi.org/t/560330/dt770-pro-80ohm-bass-crackle
http://www.head-fi.org/t/594553/bass-distortion-crackle-on-dt-770-pro-250-ohm
http://www.head-fi.org/t/353097/solved-rattle-with-dt770-pro-80-removed-hair-come-and-go-solution-used-warranty-got-new-pair
http://forums.guru3d.com/showthread.php?t=344368
https://www.gearslutz.com/board/so-much-gear-so-little-time/876056-dt770-pro-headphones-damaged.html
I recorded sine wav upward sweep playing out through each speaker into a mic so you can hear the problem in the right spaker for yourselves in the links below:
Both are the same wave sweep for same duration, 20 seconds, 1hz to 200hz:
http://208.53.158.159/gd7/rising-freq-sine-wav-1hz-to-100hz-20s-LEFT(good)-phone-to-mic.mp3
http://208.53.158.159/gd7/rising-freq-sine-wav-1hz-to-100hz-20s-RIGHT(bad)-phone-to-mic.mp3
I just want your guys opinion:
1. Is this 'rattle'?
2. Should I open them and investigate/clean or just call the shop tomorrow and let them sort it out? (they are 22 days old and i have invoice). - I don't want to risk losing any return-ability.
3. Any other comments/tips etc?
Thanks!
Just bought some second hand DT 770 Pro's (80 Ohms) for £95 (I wanted them asap).
They were apparently brand new unwanted extra pair for his friend, never even taken out of box and came with invoice from 2nd Jan 2015, they appeared factory packed.
Anyway I quickly tested them with one song and the guy seemed legit and I was in a rush so I bought them. - lesson learnt, test as much of the spectrum as you can.
Turns out the right speaker (cup/driver/phone? excuse my terminology) has a very audible buzz like distortion, more easily heard at lower frequencies like bass/low synths etc.
Very annoying, very prominent and I can't use them like this.
That was on my phone, so I thought maybe it's the source or I need an amp, but then tried in PC, and although the PC powered them better (could go louder), the same buzzing distortion occurred in the same places.
Using audacity on the PC I played each songs left tracks (which had not buzzed), solo through the right speaker, and they distort just as the original right tracks had.
The right track (which sounded distorted on the right speaker) sounds fantastic when played solo through the left speaker, so much so that I am really happy to hear how they should sound (ie, left playing only without the contamination of the right side).
I tested using a tone (sine wave) generator (http://onlinetonegenerator.com/) and I could hear the buzzing clearly all the way from 1hz up to about 200hz (harder for me to discern around there and upwards).
It almost flaps about at low frequencies then turns more buzzy and high pitched buzzy as you go up the freqs.
I read all these threads about the known DT 770 hair problem, ie a hair can get in the driver and make it 'rattle' and you can remove hair from the inside areas to fix it.
http://www.head-fi.org/t/560330/dt770-pro-80ohm-bass-crackle
http://www.head-fi.org/t/594553/bass-distortion-crackle-on-dt-770-pro-250-ohm
http://www.head-fi.org/t/353097/solved-rattle-with-dt770-pro-80-removed-hair-come-and-go-solution-used-warranty-got-new-pair
http://forums.guru3d.com/showthread.php?t=344368
https://www.gearslutz.com/board/so-much-gear-so-little-time/876056-dt770-pro-headphones-damaged.html
I recorded sine wav upward sweep playing out through each speaker into a mic so you can hear the problem in the right spaker for yourselves in the links below:
Both are the same wave sweep for same duration, 20 seconds, 1hz to 200hz:
http://208.53.158.159/gd7/rising-freq-sine-wav-1hz-to-100hz-20s-LEFT(good)-phone-to-mic.mp3
http://208.53.158.159/gd7/rising-freq-sine-wav-1hz-to-100hz-20s-RIGHT(bad)-phone-to-mic.mp3
I just want your guys opinion:
1. Is this 'rattle'?
2. Should I open them and investigate/clean or just call the shop tomorrow and let them sort it out? (they are 22 days old and i have invoice). - I don't want to risk losing any return-ability.
3. Any other comments/tips etc?
Thanks!
