I’ve noticed that many Swiftlet farmers don’t know the purposes and usage of capacitor at the Tweeters. They just follow what others did “Monkeys see Monkeys do”. Even those who sell Tweeters with Capacitors know very little about the function and its effect, can’t blame them as most of them are not familiar in sound effect.
If you ask should you add capacitors in all the Tweeters in your Bh? My answer is YES, provided you know how it works and what type of capacitors to be used. Adding capacitors on tweeters improves sound quality, extend the life of the Tweeters, etc by maintaining the flow of electric and sound wave. (Dielectric)
If you simply attached them on the tweeters just because you see many are doing it then my advice is NO .Without having the correct capacitors it would defeat the purposes, furthermore it would have adverse effect on the sound quality and tweeters.
There are many type of capacitors in the market and all of them have different usages, bear in mind not all are for sound purposes. The below would tell you what is sound & it measures.
To make the most of this article it would help if to give you a basic understanding of sound waves.
A vibrating speaker sends a wave of pressure fluctuations through the atmosphere. When the fluctuating waves reach your ears, they vibrate your eardrums backwards and forwards and your brains interpret this motion as sound. We hear different sounds from different speakers because of variations in sound wave 'frequency' - A higher sound wave frequency simply means that the air pressure is fluctuating faster.
We hear this as a higher pitch (or higher note). When there are fewer fluctuations over a given length of time the pitch is lower. These fluctuations are referred to as 'cycles' and measured as 'cycles per second' or Hertz.
Most speakers are only capable of working well over a certain part of the audible frequency which is 20hz to 20khz. Therefore selecting speakers within this range would give you added advantages. (Most swiftlet sounds are between these frequencies.)
Midrange speakers unsurprisingly produce a range of frequencies in the middle of the audible spectrum. It produces best quality of sounds between 100hz and 2khz.
Tweeters tend to be the smallest and lightest speakers and due to the limitations of their mass and size are totally incapable of producing sound frequencies much below 1khz.
I am not going to go into the technical aspect of it which would take pages to finish. (Dielectric loss and absorption, Electrolytic, Electrolytic resonance, etc.)
The common mistake made by most is without observing the polar of the capacitor. It is not advisable to attach the Non-bipolar capacitor to the tweeter +/- plates without observing its polarity it would defeat the purposes of the capacitor. Somehow I discovered many are doing it.
Capacitors have 2 legs the positive and negative. If you ask those who sell tweeters and most of them will tell you all are the same and it could be attached either ways positive & negative. This only applies to bipolar capacitors as both legs can be attached to either side of the tweeter +/- plates. (Non-bipolar capacitor you have to follow the polar +/-)
How do you know which legs of the capacitor is positive? Compare the 2 legs of the capacitor the one that is longer is positive.
For those capacitors that have the same length of legs the side on the capacitors which indicates its specification is the positive side.
Secondly make sure the capacitor value (uf) matches the crossover frequency.
Crossover frequency Capacitor Value (uf)
310 134
402 110
520 80
(You will not always be able to get capacitors to these exact values, look for the nearest value. This is not rocket science and just by fitting a capacitor of approx the right value you will see an enormous difference)
So how to attach the capacitor to the tweeter? The negative leg of the capacitor attaches to the positive of the wire from the amplifier and the capacitor positive leg attached to the tweeter positive plate.
Why want to waste money buying additional capacitors to attached to tweeters if it doesn’t serve the purpose?
Good swiftlet farming all!