A couple questions - Page 2

Regarding crosstalk, I've created some test files: http://rapidshare.com/files/430363572/pink_r_mp3.zip

http://hotfile.com/dl/82209444/1704ee3/pink_r_mp3.zip.html

 

Read up on crossfeeding here: http://www.linkwitzlab.com/headphone-xfeed.htm, if you want to know the technical details.

Edited by xnor - 11/12/10 at 3:57pm

 

When I swap headphones during listening sessions, sometimes I cannot hear a difference and other times it does seem, dare I say say it, clearly different. I also think mood is important and whether i can be bothered to listen to the differences or not.

If it makes any sense, I owned the DT880/32 ohm, and I SWEAR that it sounded just weak when I hooked it up to my netbook directly. I added a simple E5 without even adding the Bass Boost, and it was (to me) better. Either my netbook's HPO can't handle 32ohms at that level of sensitivity, or there is a real improvement with amping. Less noticeable was amping other 32ohm headphones that I owned, but with the DT880, I could easily tell when it was amped, unamped.

I'm just trying to find logical reason, and not just "OMFG PLACEBOZ LULZ". Even straight off my Sansa Fuze, the DT880/32 didn't sound anywhere near satisfactory to me. It was only after adding a seemingly crappy E5, that it sounded fuller to me.

Believe me, I would rather not add an amp when using a portable, but I KNOW I needed it with my 880s.

Let me also mention the D2000 and XB700 which are on paper both easier to drive than my old DT880/32, yet the majority of head-fiers who own either agree almost as a whole that they both benefit from amping.

I'm all for proving that bull**** is bull****, but I refuse to believe that the DT880/32 didn't have any benefit in amping vs leaving it unamped. Sure it sounded fine if you didn't own an amp, but having an amp pretty much highlighted the lack of body that it missed for me.
Edited by Mad Lust Envy - 11/13/10 at 3:08am

What people are referring to when the mention using a better amp than what's inside a portable player is, the ability to reproduce a highly complex signal and drive a load with frequency-varying impedance in a linear manner.  This is not the same as a test program playing a frequency sweep through the device (though the measurements do have some relevance).  I agree though that the improvement may not be noticeable with all music. Fast and complex music will become noticeably congested when the amplification can't keep up.  Tracks where the recording has a wide soundstage will sound like everything is coming mostly from the middle. Instruments and voices will be blurred together when you try and visualise the performance.  With higher-end equipment the audible soundstage appears wider and individual instruments or performers appear more as distinct entities on the stage.  It's not to say, however, that one can't enjoy music with it all blurred together, as this is what most people are used to.  Hearing music you've always listened to on the work radio on a high-end hi-fi system can be a shock, as it sounds totally different.  Whether or not this is more enjoyable or not is subjective.

Replies in bold.
Edited by xnor - 11/13/10 at 7:04am

 

There are certainly differences in demand between a sine wave and music (which is the statement you are responding to).

 

Imagine a sine wave signal of 100Hz at an amplitude of 28V RMS. For an 8 ohm load, this equates to about 100W (98 actually). The same amplitude at 1000Hz will be exactly the same power. Now add the two signals together, in the same way that signals add together in music. We are interested only in the peak amplitude, the RMS value indicates that the power is only 3dB higher, but it is only when an oscilloscope is used that the true picture emerges.

 

We will now see a low-frequency waveform, with a higher frequency waveform superimposed - the high frequency signal will be riding up and down the path of the low frequency signal. If we were to perform a calculation (or simply measure the combined signal with an oscilloscope), we will see that the peak amplitude has doubled. The effective RMS value (most multimeters will get this wrong unless they are true RMS types) is 40 Volts, and this would imply 200W. Although this is the real RMS voltage, it totally underestimates the amplifier power needed to reproduce it cleanly. An oscilloscope shows 80V peak for the same waveform, so the amplifier must be capable of passing an 80V peak signal - a 400W amplifier.

 

Personally: I think too many things are attributed to crosstalk.

 

That said: the interaction of an amplifier and speaker is more complex than it might first appear. The amplifier, for example, acts as a damper: it is responsible both for extending the speaker but also pulling it back in place. Also, as ohm load changes, the voltage required to keep the magnets energized increases. An amp which cannot keep up, even if not clipping, will create poor sound. Most times I've heard this the result was "harsh" mid-range and "loose" bass.

 

While many of the claims of amps are snake-oil... it is indeed very easy to under amp a demanding speaker (I'm still trying to get enough to properly drive my N801's). I would not at all be surprised if one change is a better soundstage.