关于单只全频音箱相位问题。为此烦恼已久，请教下老师们。

tz139161

相位。。我前段时间拿相位仪测试，一只音箱咋高音+ 低音-啊  这怎么处理

xycad

这是正常的现象，也是很常见的想象。你能说出你的困惑具体是什么吗？

038948qing

为什么会是这样呢

tz139161

回复 2# xycad


    大家都说相位应该全是+（正）才对啊。一只音箱中分别高音是+（正）  低音是-（负） 这样相位不就是一正一负吗？准确的说不就是低音和高音的相位反了吗？这样不影响吗？？？

xycad

低音肯定是不能搞错的，也就是说低频任何时候都得一直，即+
但是高频就不一定了，高频有时测量时发现就是反相。这个问题之前我也曾发过类似的帖子请看：
http://www.xycad.com/bbs/thread-47988-1-1.html

tz139161

好的。谢谢。老师。我去看看。

声斗士

低音一定是+的，现在的2分频音箱高音一般是-,为了解决相位问题。

声斗士

小伙子头像不错。

tz139161

谢谢楼上的解答和分析

葛亮

是不是需要反相，要看具体使用的是哪种形式、何种阶次的滤波器，下面是国外的参考文献资料：

24dB/oct Linkwitz-Riley filters are the industry standard, the easiest to use, and the filter type recommended by Ashly.
Other filter types are available, but may require polarity switching or other adjustments for proper results. The following
paragraphs offer a summary of the three filter types as used in the 3.24CL crossovers.
Butterworth
Butterworth filters individually are always -3dB at the displayed crossover frequency and are used because they
have a "maximally flat" passband and sharpest transition to the stopband. When a Butterworth HPF and LPF of the same
crossover frequency are summed, the combined response is always +3dB. With 12dB per octave Butterworth crossover
filters, one of the outputs must be inverted or else the combined response will result in a large notch at the crossover
frequency.
Bessel
These filters, as implemented on the 3.24CL, are always -3dB at the displayed crossover frequency. Bessel filters
are used because they have a maximally flat group delay. Stated another way, Bessel filters have the most linear phase
response. When a Bessel HPF and LPF of the same crossover frequency are summed, the combined response is +3dB for
12dB/oct, 18dB/oct, and 48dB/oct Bessel filters, and -2dB for 24dB/oct Bessel filters. One of the outputs must be inverted
when using either 12dB/oct or 18dB/oct Bessel crossover filters or else the combined response will have a large notch.
Linkwitz-Riley
The 12 dB/oct, 24dB/oct and 48dB/oct Linkwitz-Riley filters individually are always -6dB at the displayed crossover
frequency, however the 18dB/oct Linkwitz filters individually are always -3dB at the displayed crossover frequency.
The reason for this is that Linkwitz-Riley filters are defined in terms of performance criterion on the summing of two
adjacent crossover HPF and LPF filters, rather than defined in terms of the pole-zero characteristics of individual filters.
The 18dB/oct Linkwitz-Riley individually are 18dB/oct Butterworth filters in that they have Butterworth pole-zero characteristics
and also satisfy the criterion for Linkwitz-Riley filters.
When a Linkwitz-Riley HPF and LPF of the same displayed crossover frequency are summed, the combined
response is always flat. With 12dB/oct Linkwitz-Riley crossover filters, one of the outputs must be inverted or else the
combined response will have a large notch at the crossover frequency.

为了便于阅读理解，我把它整理成了表格的形式

滤波器类型	分频点处衰减	特征	相同频率组合叠加后的响应	特殊斜率相位变化	具体表现
Linkwitz-Riley	-6dB、（18dB /Oct为-3dB）	24 dB /Oct Linkwitz–Riley 滤波器是工业标准滤波器	0dB( 平坦 ）	12dB/Oct	一个输出必须被反相
Butterworth	-3dB	最平直的带通、最尖锐的过度衰减带	+3dB	12dB/Oct
Bessel		最大的衰减迟滞、最大的线性相应	+3dB、（24dB/Oct为-2dB）	12dB/Oct、18dB/Oct