steadyshot
Major Contributor
- Joined
- Mar 14, 2023
- Messages
- 822
This is very serious and wiim (and other class d manufacturers) should respond - the guy says that power specs are met only with 1khz and with other signals it cannot even reach 1 watt power rating when fed with 2.1v signal and channel separation -the test indicated that content from the right channel sounded in the left channel- and the load dependency that indicated that frequency response changes with varying loads. So yes... not good. He tested it with analogue inputs.ok, so now that the dust has settled a bit, thought i'd pop in with an update... please don't shoot me, it's not a snake oil update(one of those is coming very soon, and i promise to anyone who cares it's gonna be a good one!
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more of just an expansion on stuff that keeps coming up in other threads but i don't wanna pollute them with my blasphemous ideas!
to those that are clearly in one church OR other (most people on these forums seem to be measurementphiles), please look away, go "enjoy the music" or whatever you need to do to keep calm before reading this!
(mods please don't ban me and @ WiiM team - the offer to shut me up with free prototype mini v2 or ultra is still on the table)
anyways, been catching up on scientific audiophile's youtube content (will refer to him as S|A from now on - very balanced and quite funny) and he's pointing out an issue that comes up a lot. many people on here seem to completely disregard my point when i refer to the "limitations of measurements" (or how we apply them).
in his videos on the WiiM amp and the Fosi audio za3 + v3 - S|A points out important measurements that many reviewers almost never perform (erin's audio corner does some like the pink noise test on amps) and the ways that manufacturers can "game the system" (does anyone remember the VW fiasco?!!
for example many of these new amps can easily play a 1 KHz test tone at the rated SPL through the speakers as mentioned on the spec sheet, but when a complex signal is used like pink noise (or multitone tests, or actual music) then they are NOT able to meet the specs they claim. obviously this affects every manufacturer to some degree or another - but it's much more rampant in the lower end class D amps than it is in the old-school class A or class A/B ones for example. this is what andrew robinson meant when he says "the problem with measurements is that they tend to show you the best WORST-case scenario" (and sometimes only that) in his "head to head" video of the WiiM amp vs onkyo AVR from @D1N0 's interesting thread...
the reason i need to point this out is because issues such as this would probably be quite apparent if you listened to an amp like this closely enough in a practical and realistc listening environment! you would maybe notice the lack of dynamics at medium listening levels, and obviously the lack of volume when you try to crank it up... i mean shocking, right?!you mean you actually need to listend to an audio reproduction device to evaluate it? haha!!
(as a side note - iDO NOT
. it's worth pointing out much of these specific issues highlighted here might not apply to playing music at "normal" listening levels <70dB)
but anyways maybe these ideas can demonstrate the value of combining both listening and measurements when evaluating equipment, and trying to improve the application of both. and just to remind people that they are NOT mutually exclusive! after all - scientific thinkers must have an open enough mind to discover something new, right? all of this applies to snake oil stuff as well, by the way.
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some of the stuff is scandalous - 
It's like buying a car without a test drive just based on its 0-100 acceleration number. 
