Quote:
Originally Posted by
rawrster 
thanks. the chart by koonhua was helpful :)
Now the real question now is do you hear a difference in the two that is similar to the numbers or at leas how much you can hear. You would need to have amazing hearing to hear 20k :P I'm not an expert on burn in or anything..but what is brown noise?
I don't think I can hear up to 20K but recorded it because the meter was able to get a reading but there was no difference in sound from 17-20K anyway. But those elevated DB values from 9-16K are definitely noticeable. The funny thing is I like that added detail for some things and find it almost annoying for others as I end up getting distracted by it.
Quote:
Originally Posted by
Anaxilus 
Dweaver, great observation and YOU BEAT ME TO THE PUNCH!!
I mentioned a few times around here that I had noticed an anomaly w/ the MD's as well but needed more research. I was fortunate enough to have given in depth listening to 2 different MD's. The first set I used my former typical burn-in process using my SQ playlist increasing volumes each day for 3 days. After extensive listening for a few weeks the mids eventually would become way too forward, loose and bloated on certain songs. I then received another pair of MD's and decided to experiment using the same burn in process but reducing the volume levels w/ respect to each day of burn-in compared to my prior procedure. I was wondering if excessive volume levels or potential clipping had adversely affected driver burn-in or perhaps damaged them. Using this new procedure on the second set I have the MD sound signature but have yet to experience that previous midbass bloat/encroachment issue. The treble also seemed warmer at first than the previous MD's which correlates to your findings on the Coppers. At this point I feel totally comfortable confirming your findings that how you burn-in your drivers can affect the sound signature. Whether the previous MD's had the signature shaped different or the driver got damaged I can't say. I can say they did sound different.
I hear you Anaxilus, I gave my burnin file to another Head-fi member who just got back a pair of MD's from warranty. But suggested he may want to make a modified song that stresses other areas away from the mids such as my suggestion earlier of white - pink - white - brown which may help the MD have more treble presence and ensure the midrange does not become to over powering. The problem for me is I can't affors to buy all these headphones to test my idea out. So I am greatfull when members like yourself help prove/disprove the theory.
Quote:
Originally Posted by
mesasone 
Thanks for posting the data, it's quite interesting. I'm not putting too much faith in the iPhone as a dB meter, but who knows. Perhaps you could contact Tyll and see if he could measure the two earphones with his gear, or perhaps run a similar test on other headphones. Probably busy with CanJam at the moment though.
I wondered about Tyll as well but hate losing my entertainment source for so long plus the added cost. But like yourself I do wonder about the accuracy of the iPhone as a meter. I may see if The Source has a meter I can buy, or a microphone I could possibly hook up to my computer and then I will download a program to do this. I also would love to figure out a way to enclose the tip and have it fed directly to the microphone in an isolating fashion.
What I did for my testing was watch the average DB before I moved the IEM to the Mic and made sure there was enough volume coming from the IEM to move the DB level at least 5DB's before I would record the value which is why I could not get a reading at 20 and 50DB. If I had an isolated tip so most outside sound was blocked I am sure I would have gotten some readings. The other I could not do because I do not have a real lab setup was see which frequencies were the loudest as I had to adjust the volume at different frequencies to get a reading or to bring the reading under 100 so I could capture the variations. So I can't create those cool charts showing the whole spectrum analysis.
Edited by dweaver - 6/6/10 at 8:09am