该帖子解释了一个简单的低通滤波电路，可以与subwooferamplifiersfor acquiring extreme cuts or bass in the frequency range 30 and 200Hz, which is adjustable.
How it Works
一些low pass filter circuitsfor subwoofer application are presented all over the net however this one is an upgraded example.
此处提供的电路利用了ST微型电子产品的高效率Opamp TL062。TL062是双输入阻抗J-FET OPAMP，表现出最小的功耗和较大的回能速率。
The opamp possesses outstanding digital attributes as well as being exceptionally compatible with this circuit.
在TLC062内部的两个操作流程之间，一个与放大器阶段的混合器形式连接在一起。左/右通道链接到用于混合的IC1A的反转输入。
The gain of first stage may be tweaked utilizing POT R3.The output of the 1st stage is hooked up to the input of next stage via the filter circuit containing parts R5,R6,R7,R8,C4 and C5.
可以在TLC062的引脚7处获得第二个OPAMP（IC1B）作为缓冲区以及过滤后的输出。
If you are interested to create your own low pass filter with a single IC 741 and customize it, then the following discussion might help!
使用IC 741的简单主动低通滤波电路
In electronics, filter circuits are basically employed for restricting the passage of a certain frequency range while allowing some other band of frequency into the further stages of the circuit.
Types of Low Pass Filters
Primarily there are three types of frequency filters that are used for the above mentioned operations.
These are: Low pass filter, high pass filter and the band pass filter.
As the name suggests, a low pass filter circuit will allow all frequencies below a certain set frequency range.
A high pass filter circuit will allow only the frequencies which are higher than the preferred set range of frequency while a band pass filter will allow only an intermediate band of frequencies to flow to the next stage, inhibiting all frequencies which may be outside this set range of oscillations.
Filters are generally made with two types of configurations, the active type and the passive type.
Passive type filter are less efficient and involve complicated inductor and capacitor networks, making the unit bulky and undesirable.
However these will not require any power requirement for itself to operate, a benefit too small to be considered really useful.
Contrary to this active type of filters are very efficient, can be optimized to the point and are less complicated in terms of component count and calculations.
In this article we are discussing a very simple circuit of a low pass filter, which was requested by one of our avid readers Mr.Bourgeoisie.
Looking at the circuit diagram we can see a very easy configuration consisting of a single opamp as the main active component.
切断50 Hz的电阻器和电容器被离散地尺寸，这意味着不允许高于50 Hz的频率通过电路进入输出。
Circuit Diagram
Subwoofer Low Pass Filter using Transistors
电路图显示了一个活跃的低通滤波器布局，可以通过计算四个电容器的几个幅度来轻松地分配任何首选的截止点。该过滤器包括RC -NetWork和一对NPN/PNP BJT。
The transistor specifications shown could be straightaway substituted by some other varieties without altering the circuit's functionality. The supply voltage utilized must be between 6 and 12 V.
The capacitor values picked out for C1 to C4 establish the cut-off frequency. These magnitudes could be acquired from the below given two formulae:
C1 = C2 = C3 = 7.56 / fC
C4 = 4.46 / fC
在这里，FC提供了所需的截止频率（在Hertz中）。在此公式中，振幅响应下降了3 dB，C1至C4的值是在Micro Farads中计算的（如果我们在KHz中使用该单元，则结果将以纳米法拉德值表示，并将MHz置于Picofarad单位。）一个示例，指示了用C1 = C2 = C3 = 5N6和C4 = 3N3构建的过滤器。
The '-3 dB point' in this scenario develops at 1350 Hz. One octave greater, at 2700 Hz, the attenuation is already 19 dB.
For technical explanation of the circuit you may refer to the data providedhere。
What is that part of resistors r6 and r7?
those are pots….variable resistors
非常有用的电路，尝试尽快构建这个问题的唯一问题是缺乏晶体管2N3905，我可以用两平行的BC547替换这些BJT吗？
Hai sir
In my area shop 0.47uf available only in 400v 474code….
Shall i use it sir…
音频收益是否损失
嗨，Kesav，它会起作用，但看起来很笨重……。您可以使用它，音频不会受到影响。
谢谢你先生…
先生，一个怀疑…
I see one low pass filter circuit past 1 year back
使用0.56UF，0.47UF和39NF ..
In my area shop there is no 39nf till now…is there any alternate…while using alternate any effects will be loss or not..
Kesav, the capacitors in a filter circuit determine the range of the input frequency, if you change it the outcome might get affected…you can learn more about it here
//www.addme-blog.com/2016/01/design-low-pass-filter-circuit-quickly.html
d函数双锅22 k是什么?我可以使用10k, 50k,100k dual . *(sir or I can series 12k+ 10k)
it is probably for controlling the high frequency range, you can use 50 k pot or 10+12K pots in series.
我需要你帮助我建立一个金属探测器。555年智慧nd it work but my problem is I need d out to be either high or low state. I even couple d o/p to op-amp no response. but there is variation in d 555 o/p .what I don’t like is that the sound is on always… *irritating * .help me out o
which circuit did you make?
help me I want to make metal detector wit high sensitivity. ( that is when ever it detects metal an indicator will glow only.) thanks in advance
sorry jack, I do not have any practical experience with metal detectors.
尊敬的先生
低通滤波器的低通滤路电路
请请求答案
1.电阻四分之一瓦的瓦数足够了吗？
2。22k pot is dual gang stereo type?
3。What is the output woofer impedance and watt ? 4ohm 50w is enough ?
4. l in和r在线中与地面连接吗？（输入）
output other wire is taken from ground isnt it ?
Thank you sir
Dear Jayanth,
I think the R2 link must be removed, the input cannot be dual if the output is a single output.
因此，请忽略R2链接
1) all resistors are 1/4 watt 5%
2）22k锅是一个双帮派锅
3) impedance will depend on the type of amplifier used, it is not related to the above circuit
thanks for early reply sir
ok i will do same.
我最近将制作该巡回赛，然后让您知道先生。
Sure! Wish you all the best!
sir circuit is working perfectly. thanks
Glad it is working jayanth, keep up the good work!
R1和R2充当两个L＆R通道的混合器，当您构建2+1系统时，它很重要。
OK, but how can we get a stereo response using this circuit?
sir this circuit is working fine with 100w amp.but i want to increase the bass effect further more. for that what are the components and values to be change sir?
您好Jayanth，有关定制设计，您可以参考以下文章，并根据您的喜好调整值
//www.addme-blog.com/design-high-pass-filter-circuit-quickly/
请我需要一个用于逆变器电路的活动过滤器。谢谢
Sorry, I do not have the necessary calculation for it at the moment, I’ll try to get it if possible
使用此C4，C5 R，5,6,7,8值。范围为18至105 Hz，而不是30至200Hz
Is it possible to get both high and low pass using this circuit for bass speaker and mid-range speaker? How?
The above circuit require a dual power supply?
您也可以使用带有单个电源的最后电路。在PIN3和C1的连接处添加一个电阻分层。可以使用两个10K电阻器串联制成电阻分隔器，其末端可以在电源的 +/0V上连接。
Sir,after integrating this low pass filter to an already working amplifier with base and trebble controls,will the controls still function as they used to? Or the whole amp output will be a bass amp? If so what can be done to have a distinction between bass and trebble in the same amp using the above filter idea?
埃文斯（Evans），您说您想要一个sub Woofer过滤器，因此上面是推荐的滤波器……如果您想要低音和高音，那么您将需要以下文章中解释的电路
//www.addme-blog.com/small-stereo-amplifier-circuit-with-bass-treble/
Got you
先生，如何在放大器输出下切断低频信号？我的意思是B/W放大器和扬声器。
嗨，Aju，对不起，我对此一无所知！