另類的開箱

ackcheng

另類的開箱

ackcheng

剛剛閱讀完這篇文章,

http://www.libinst.com/accel.htm

就買下了所需要的硬件

ackcheng

首先量度的是DAC sound card.

ackcheng

First the yellow line - no spikes, no air con, speaker turn off
You can see the the noise floor is quite low and all the high frequency noise is not there. Well, the speaker is off!. You can also see the noisy area corresponds to 120Hz, 110 Hz and 100Hz. I think this must be coming from the transformer as the main frequency out from PPP is 60Hz. But I am not sure why 100Hz and 120 Hz is there!?

The red line - with spike, no air con
this should have been the second best, but when I did the measurement, the escalator outside my home is moving!!

Green- no spike, air con on

Blue - with spike, air con on

Now you can see the clearly the effect of spike on the body vibration!!!

More testing to do in the future

jackt

究竟係量度 Ground Noise 定 Vibration Noise 或者是其他呢？

ackcheng

If ground noise means electrical noise, then it is not picked up from the accelerometer. You can see that when speaker is on, then the noise cut off at 20KHz which indicates that it is speaker effects

turboturbo

ching, what kind of spikes will you test in the future? would be interesting to AB test the high end spikes in the market, as well as the hifi shelves.

nicknick

arthur兄，第一次見張相時，還以為是Pizza Hut薄餅外賣開箱呢！（digikey上面有單張）

nicknick

ackcheng 發表於 2013-7-31 00:37
First the yellow line - no spikes, no air con, speaker turn off
You can see the the noise floor is q ...

有機會的話好想你幫忙試試test“妹釘”，因為它是我暫時試過最冇音染同時在諧震上極大改善的釘腳。

ackcheng

冇問題，隨時帶來試試！

ackcheng

Turbo hing, 其實我是主要用來測試speaker baffle 的。