OK I know that burn-in is a touchy subject for some but I want to state at the start, I have been monitoring the actual decibal levels of Monster Turbin Copper 2 at set frequencies as they have been burning in and they have definitely changed as the headphones have burned in. So for the purposes of my discussion I am going to speak about burnin as if it exists. Please don't derail the discussion with comments about how burnin is bunk, if you don't believe in it please just skip this thread.
OK to set the stage for this discussion let me explain what I have been doing and why.
I have been a member of Head-fi for about a year and half now and like many other members have been caught by upgraditus a few times as I try and find the perfect IEM/headphone. My journey led me to buying a apir of IE8 which I liked but ultimately found unsatsifactory. So in a bold move I sold my IE8 and bought a pair of Monster Turbine Coppers from a fellow head-fi member. When they arrived I really liked their sound but found them a bit dry due to them being very balanced. The sense of dryness became worse after reviewing a warm mid centric IEM for MP4Nation (M2). Then I recieved an unexpected but welcome invite from Monster to review their Monster Turbine Copper and they shipped me a review pair.
So I started to wonder about the burn-in process and whether I could affect the sound of the new MTPC coming in. My thought was can I make the midrange better and improve the bass in any meaningfull way. So I started to research the various burnin noises used. I had been using pink and white noise plus just using my music all played at a slightly louder than normal volume for burning in my past headphones and IEM's. But my research lead me to Brown Noise a noise like pink and white noise but more bass and midrange centric from what I read. I downloaded a sample and found it to be alot warmer sounding.
I then created a master wav file that was 1 minute brown noise, 1 minute pink Noise, 1 minute brown noise, and then 1 minute white noise, I then looped that file for 48 minutes and finished with a 12 minute silece to give the IEM a break. My thought was that by doubling the amount of brown noise I would ensure that the bass and lower mdirange would get a heavier work out ensuring the bass was massaged heavily to get rid of the excessive boominess and the lower midrange would become prominent through heaveir use. The pink and white noise would then work the upper midrange and treble. This versus my old method which due to a prominence of rock music and only pink and white noise only heavily worked the upper midrange and treble and moderately worked the bass and lower midrange.
So after a very quick in initial listen of the new IEM which revealed much whast I expected in regards to an fresh IEM (bloated bass, rolled off treble and and over all sense of congestion). I set up my computer and amp to play my special file and let the new IEM cook over night. The next day I was amazed at the sound, the midrange was much more forward than my original MTPC and so was the bass. It was like Patricia Barber was sitting in my living singing as compared to the original MTPC where she sounded much more distant. At this point I was not trying to actually measure much because I knew the new IEM would change more, but the difference was astonishing. I then let the new IEM cook each night for 2 more days and each day while there was small changes in the sound that prominant midrange and added bass never really left. I then put the IEM on to cook and left it for 24hrs straight and still the same result. So after another 12hrs of burnin and no real change in sound I then decided to compare the decibel reading of the new vs the old MTPC using set frequencies and the following is the actual reading difference for each frequency I tested in decibels. I do not own a real decibel meter so I used my iPhone and a decibel program for the test. Here are the results:
|Frequency in Hz||20||50||100||250||500||1000||2-5000||6000||7000||8000||9000||10,000||11,000||12,000||13,000||14,000||15,000||16,000||17-20,000|
Note I was unable to get an actual reading for 20 and 50Hz but I could hear a difference of about double the sound, basically on the old MTPC I could barely hear 20Hz and got only an extremely faint buzz at 50Hz whereas with the new MTPC the 20Hz was audible and could be felt (very low hum) and the 50Hz was more like a humm vs a faint buzz. From what I have read about decibels, if the difference is only 1-2 decibels you can't really hear the difference, 3 decibels difference you can hear a faint difference, 5 decibels you hear a definite difference, and 10 decibels is basically twice as loud. So based off that info the bass of the new MTPC is basically twice as loud, the midrange up to 1000Hz is noticeably louder, then the sound essentially stabilizes between 2-8000, then has a faint change and swing in loudness from the new MTPC to the old between 9-11,000, and an increased swing in loudness to the new MTPC from 12-16,000 and then a final leveling off from 17-20,000.
So at this point a conclusion can be made that Monster has changed their design of the Copper or that the burnin process has made a difference. I asked SoundMatters if Monster has changed the MTPC design and his responce back was no and I do believe him, and here is why. If Monster deliberately made this type of change in the sound signature of the MTPC they would alienate users who buy the Copper for it's balanced sound plus they would effectively lessen the reason for anyone to buy the Mile Davis model as it's forte is the midrange tweak.
Is my testing done? Not really as I do think the treble is the hardest aspect of an IEM to break in, so I expect the treble may actually slowly achieve a similar decibel rating between the two IEM's. To this effect I will not be subjecting my old MTPC to this new burnin process as I want them to stay a reference set for now. Plus I like having two unique sounding IEM's that address different sound needs.
So should everyone do this process during burnin? The answer to this is yes IF you want your MTPC to be warmer sounding with a larger bass presence. Otherwise I would think you might want to burnin your MTPC with whatever music you like to listen to as it will probably not stress the areas I did as much and will give you a more "balanced" sound. For me though I love this different sound as it gives me most of the thingts I loved about my IE8, the area I loved in ther M2 in regards to a forward sounding midrange that is slightly warm, plus the detail I love about the MTPC and I am fortunate enough to have my original MTPC's to listen to when I want that more balanced sound.
I will be meeting up with a fellow Head-fi member in the near future who owns a pair of Miles Davis, I am more than a little curious how close this specially burned in MTPC sounds to the MD's. I will be posting my results after that meeting and will get the other Head-fi member to post his experience after listening to my two Copper's as well.
Edited by dweaver - 6/5/10 at 11:14pm