刚买了个earthworks M23，需要下载校准文件，由于网上无法注册直接下载，我发了个email给earthworks官网，回复了一个TXT的文件，再附上一段说明：
Your ECF is attached. Please read the explanation about setting up the low frequency data below.
EDITING THE ECF CURVE TO 10Hz & BELOW:
Using the magnitude value found at the lowest frequency value (approximately 790Hz) in your ECF, you can edit the ECF, by adding coordinate points (as needed) to the .TXT file for the frequency values you require, between ~790Hz & 10Hz. For example, if you copy and paste the 790Hz line of the .TXT file into the line preceding it and then change the frequency value to 10Hz, you will have a curve with < +/-0.25dB of error between 10Hz & 790Hz. To get accurate measurement to the -3dB roll-off point of the specific model (5Hz [M30, M23], 4Hz [QTC40], 3Hz [M50] & 9Hz [M30BX]), enter the 790Hz value, less 3dB, at the specified low end frequency, for a near vanishing error.
大致读了下并百度翻译验证了下，我理解的意思是：ECF文件里只对790Hz附近以上的校准数据，790HZ以下的中低频数据可能官方没有测那么多点，默认没有给出，因此他让我直接在ECF校准文件里直接添加一个10Hz，然后幅度值与文件里最低端频率保持一致，这样就拉平了10HZ到790Hz的曲线，然后又说如果要精确修正3dB滚降点数据，再添加一个5Hz点，然后幅度值减去3dB。
我打开他提供的ECF文件，发现确实最低端频率只给到了765HZ，于是我在原来的数据点基础上添加了两个点：
原始文件的前几行如下：
"Transfer Function Mag - dB volts/volts (0.10 oct)(eq)(eq:aux)"
"Hz" "Data"
765.4139, 2.502037
818.201, 2.52134
870.9882, 2.546939
950.1689, 2.596001
我修正以后的前几行如下：
"Transfer Function Mag - dB volts/volts (0.10 oct)(eq)(eq:aux)"
"Hz" "Data"
5， -0.497963
10, 2.502037
765.4139, 2.502037
818.201, 2.52134
870.9882, 2.546939
950.1689, 2.596001
。。。。
不过隐约有点疑问，感觉前面700多Hz，只填写2个点，能像他说的保证全频段精度吗，那其他频率点呢？声学测试软件会自动给他填进去吗或者做某种平滑处理？
不知道我的修正方式对不对，理解上有没有错误，请有经验的大侠指点，谢谢
本帖最后由 天戈 于 19-6-15 00:31 编辑