When someone tells you how amplifiers sound, especially on Head-fi, and especially if it conforms to the Head-fi beliefs that things that are cool or look cool sound cold (like amplifiers that run cool or silver wires) or things that are hot or look warm sound warm (like amplifiers that run warm or copper wires), you should ask yourself a few things before you consider their opinion valid.
Major factors for validity are:
- If they've heard the equipment or not.
- Whether or not they (correctly) volume matched with a meter.
- If they benefit in a major way from reaching a particular conclusion.
- How quickly they were able to switch back and forth for comparison. This type of testing requires rapid switching (within a few seconds due to acoustic memory limitations).
Minor factors for validity are:
- How experienced they are listening for differences.
- How well their hearing works. (Unless they're deaf, but odds are most of us aren't).
- Ambient noise level when they did the comparison.
- Music or noise selection for comparison.
- If they benefit in minor way from reaching a particular conclusion.
- If the meter is calibrated or not.
Most people on here are trying to do science while not having the slightest clue how.
The method is just as important as the observations themselves.
The method should be both
repeatable and
reproduceable.
E.g. if you give someone a room full of equipment and tell them that you think amp A had more bass impact than amp B, they may not hear it unless they are given some details such as what volume level, what music, and with what headphones the observation was made.
But it's absurd to post all this information for a simple comparison between amps, right?
Yes, but there are a few basic things we can include pretty easily, such as "I heard (observation) after volume matching to (sound pressure level) with a (headphone type) in (location) using an A/B switch". That checks off 3/4 of the major factors in one sentence and it's much more likely to be valid than a statement like "If you want more full sound a ___ would do it".