question about speaker crossover

[SentinelAeon]

I am making a really simple cheap speaker (consisting of bluetooth amplifier ZK-502C, Dayton audio TCP115-4 and Dayton audio ND16FA-4) and i need a capcitor to cut low frequencies for tweeter. Usualy i used a electrolytic or ceramic capacitor to cap it at around 3500Hz. But today i read a guide on crossover and both types of capacitors are said to have negative effect on audio quality. The summary of the guide was that it is best to use film capacitors. Since i never dealt with them before i am looking for some help in choosing the right one.

 

[SentinelAeon]

Yeah, amp shutting down is another issue and i will open its own thread cause its really interesting that its DCing even without speakers connected.


I kind of dont like adding resistors to the speaker because number 1 priority is loudness, then its bass and everything else is like number 10. Speaker is used in loud environment where you wouldn't be able to tell the quality of the sound anyway.

So right now i set it so the resistor on each channel is like 10 ohms so i lose as little loudness as possible. Though i always wondered, why not just use 1 resistor in the place where i connect 2 channels together ?


Btw is there a better way to connect the channels together, without using a resistor ? Because the bluetooth chip and amplifier chip are on top of the board so i could connect 2 legs together there if that would be better.

 

[rjenkinsgb]

Are you saying you are connecting the outputs together as well as the inputs? That's different to the original setup, as I remember it?
It is not a good idea as different tolerances in the filters could cause current between the two amps.

Sticking with an "Active crossover" setup would be better - dedicate the amp channels to main and tweeter, and add appropriate high impedance crossover filtering at the input of the two channels, so they only get the frequencies the speakers can respond to.

Audio crossover - Wikipedia

en.wikipedia.org

 

[Nigel Goodwin]

Post a drawing of EXACTLY how you're wiring everything, your descriptions make little sense.

 

[audioguru]

You are using the stereo to mono resistors as a simple audio mixer circuit feeding amplifier inputs but your resistor values are so low that you are overloading the output of the Bluetooth receiver which might cause it to fail with high sound levels. Of course a mixer circuit reduces the levels a little so simply turn up the volume control a little.
I think a mixer would normally use 2k to 10k resistors and not less resistance.

 

[audioguru]

A volume control and the voltage gain of an amplifier are designed so that very loud signals can be turned down and not loud enough signals can be turned up.
Since you use the volume control always at maximum then the amplifier voltage gain is too low or the bluetooth receiver output level is too low.

Most audio mixer circuits do not overload anything and have no voltage loss because they use an opamp.
Your extremely simple passive mixer using resistors causes overloading the input and attenuating the output.

 

[SentinelAeon]

I actualy made a new thread for the stereo to mono since this thread was about a crossover.

https://www.electro-tech-online.com/threads/stereo-to-mono-problem.163860/