How do I detect slight speaker damage?
Jul 1, 2009 at 3:47 PM Thread Starter Post #1 of 14


New Head-Fier
Jul 1, 2009
Hi all, first time post here.

I recently bought some DT 770 pro 80's and am wondering if I've blown them slightly. On various songs (a mix of 128kbps and higher) via an ipod touch, I can hear an oh so slight crackle/distortion in some high end notes, as well as on the coattails of some low end sounds. Again, these are very slight..I have to strain to hear them sometimes, but they are certainly there. I haven't been pushing the DT's volume-wise because of recent-purchase-paranoia, so I've kept the volume at a reasonable level (2/3rds vol). I have cranked it up once or twice (not all the way) to satisfy my need for louder music, but never to a level I would consider dangerous to me or to the headphones.

Could this be distortion inherent in the recording or compression of the audio?

Or is it a very slightly blown headphone?

Or is this crackle part of the burn in.

Things I believe could have led to a blow.

-Treble booster EQ on higher volumes/without limit or soundcheck
-Ipod's low powered amp causing distortion at higher volumes
-Faulty equipment
-Im just imagining things

Any ideas? Should I return them for a new pair?
Jul 1, 2009 at 3:50 PM Post #2 of 14
It's possible there could be dirt or other contaminants on the drivers. Do you hear the distortion out of both ears, and on particular songs, or everywhere?
Jul 1, 2009 at 3:56 PM Post #3 of 14
It is relatively inconsistent, more so on certain songs. It doesn't seem to pop up on most rock, but maybe it's being drowned out? It's mostly my right channel, but the left bears some of blame as well.
Jul 1, 2009 at 3:59 PM Post #4 of 14
Coming from the exact same problem, with the exact same phones... adding an amp will fix this
If you are really that concerned, you could always open them and take a look at the membrane.
Jul 1, 2009 at 4:06 PM Post #5 of 14
I suppose I can see if an amp resolves the issue. (Am currently looking at the Total Airhead, any thoughts?)

In regards to opening the phones up: Does it void the warranty? Is it hard to do? Is there a decent chance of breaking something whilst doing so? What tools do I need?

Thanks for the replies so far
Jul 1, 2009 at 4:12 PM Post #6 of 14
I have not opened the phones entirely before. Its easy to get all the way down to opening them. I do not suspect that it will void the warranty, as you need to open them to change the foam (which comes packaged with replacement pads). Someone else will have to advise you here.
I cant really comment on the airhead, as I have not heard it.
Contrary to what some will say here, they need an amp and are quite hard to drive (although the 80 ohms is easier than the 250 in non-OTL cases).

Out of curiosity, what soundcard do you have?
If you have something other than onboard, you could give that a try and see if the crackling is less frequent on the soundcard.
I am 99% sure it is an amping issue because i have one of those $5 mp3 players, and it distorts as you describe a LOT. It does it less so on the slightly more expensive clip and even less on my STX (it doesnt do it on the stx, but it sounds sluggish).
Jul 1, 2009 at 4:20 PM Post #8 of 14
I'd say it's definitely an amping problem, then.
Someone might be able to advise you on a portable amp that can drive them if you are using them as your outdoor headphones.
maybe a penguinamp cmoy, but i cant guarantee anything.
Jul 1, 2009 at 6:53 PM Post #11 of 14
The amps in many DAP's, including the iPod line, overdrive easily if a particular song has been mastered/encoded with high gain. This effect can be exacerbated by use of the equalizer, which further boosts certain frequencies.

To determine whether the amp is indeed the problem, choose a song on which the distortion is prominent. Listen to see if the distortion goes away when you reduce the volume on your iPod. If the problem is what I have described, it will not go away because the problem is arising due to the music file's gain, not the output volume. If the distortion does go away, you know the problem is in your headphones.

If it turns out that the problem is file gain, there are two solutions:
1. Turn off your EQ. If this doesn't work, or if you really like the iPod EQ,
2. Download iGain, which can adjust the gain settings on your songs on an album by album basis, making it superior to Sound Check which does not preserve relative volumes between tracks on an album. iGain's gain reduction should definitely clear up any overdrive problems.
Info on using iGain (read this--it's kinda cloogy at times)

I hope it's not your cans. Good luck!
Jul 6, 2009 at 10:40 PM Post #13 of 14
Nice music choice

Theoretically, if gain is your problem, the distortion should be present at any volume level. However, it may be that at such low volume levels you just aren't hearing the distortion.
I'd recommend you try the same tune out on another pair of headphones to be sure--if the distortion persists you know it's gain for sure.
Jul 7, 2009 at 5:39 AM Post #14 of 14
My suggestion is that, fist try your ibuds and listen very carefully to the songs that distorted, you might hear the distortion you didn't noticed before, for it muffled with the backround music and the better headphones dt770 pickup the distortions much easier. Or find yourself a cd/dvd player or even a computer, plug the phones in and listen to the songs that distorted from its original CDs. If the distortions gone then congratulations, you can hear one difference between mp3s and cds. If it is still there, find a friend or the headphone dealer, use their equipments (i.e. cans or amps) to listen to the same songs from cds/mp3s to rule out the amp or phones problems. Only if other people's equipments can't and just your phones can pick the distortion, then it might be your phones that caused the problem.

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