I've always just assumed that computers send a proper audio signal out on the USB port.  Is that true, or do all USB headphones have built-in DACs and amplifiers?

You're going to have a hard time finding something quite as boomy as the Beats.   The Audio Technica ATH-M50 trades some boom boom for finesse, a lower price, and durability.

Does the same problem happen from different sources?  Is the V6's jack clean?  Have the external cords been worn?

Quote:   Speakers have different efficiencies at different frequencies.  100 mW at 50Hz will not come out at the same loudness as 100mW at 1kHz.  More/less sound out of the same power.  Also, speaker impedance fluctuates depending on what is being played, which raises or lowers the power...

AKG-K550.   http://www.innerfidelity.com/content/wonderfully-competent-akg-k550-sealed-headphone

Here's a nice resource.  The first post is full of great links.   http://www.head-fi.org/t/529144/recommendations-thread-i-e-dont-start-a-new-thread-ask-for-advice-here-please-read-op   There a lot of potentially good choices out there for you.

Audio - Sound Phil(e) - Love   If you want to explore the depths of sound and what it can mean to you, then that's all the reason you need.  Buy whatever you want to do whatever you want with it.  Enjoy yourself.

An amplifier won't change the need to turn up the volume.  It will just let you turn the volume up even more.   Soundcheck should fix your problem.   http://ipod.about.com/od/introductiontotheipod/ht/soundcheck_ipod.htm

Pink noise might accelerate burn-in. But, music is adequate.   Just listen to your cans and leave music playing when you're away.

Quote:   Nope.   As long as you don't exceed their rated power, they will never overheat.

RMS voltage is what directly correlates to SPL (Sound Pressure Level). All loudness is derived from SPL.   Terms like "peak power" and "peak to peak voltage" only exist to impress laypersons with irrelevant information.   If you want to measure the part-volume voltage: 1. Get a...

    Yeah. To swap out devices with subtle differences - all of which are supposed to have no differences - is to miss the biggest source of distortion: the headphones.       Yep.  Yep yep yep.

Just had a listen with some MDR-V6s and onboard Realtek sound.   I spent something like 7 minutes trying.  Couldn't tell any of them apart.   I copied the lossless one and changed its id3 tag to "control."  I named gave the other 4 the same tag info.  In Foobar, they'll all look the same...

Quote: Indeed they did, in 99-2000.  I thought you meant the older generation.  ^_^

(Voltage Squared)/Resistance = Power.  An impedance of 132 ohms will receive about 24% as much power.  That's about -6.2 decibels (65% perceived volume).  To achieve a perceived 50% volume, 10 decibels must be lost, which would require a cable with 288 ohms (10x the resistance, or 1/10th power)...