Crossover mod question

[byron]

I have some speakers that someone gave to me. I have some extra caps and I have been experimenting around with the crossover. It is a two way design crossed at 2K according to the sticker on the back of the speakers. The capacitor values for both are 4.7uf. I have swapped the caps out for some spares that I have laying around. I am swapping them with smaller values such as 4.0uf,3.3.uf,2.7uf. I know what the sound results are since I have been playing music and making comparisons. What is the effect on what I am doing when to the slope and other output characteristics? Am I creating a gap in the output frequency? I imagine that I am certainly changing the xover frequency, most likely increasing it.

[philiparcario]

> I have some speakers that someone gave to
> me. I have some extra caps and I have been
> experimenting around with the crossover. It
> is a two way design crossed at 2K according
> to the sticker on the back of the speakers.
> The capacitor values for both are 4.7uf. I
> have swapped the caps out for some spares
> that I have laying around. I am swapping
> them with smaller values such as
> 4.0uf,3.3.uf,2.7uf. I know what the sound
> results are since I have been playing music
> and making comparisons. What is the effect
> on what I am doing when to the slope and
> other output characteristics? Am I creating
> a gap in the output frequency? I imagine
> that I am certainly changing the xover
> frequency, most likely increasing it.
you are changing the freq. how much depends on a lot of factors. the drivers impedence is 1 factor. what type of crossover 1st order 2n order 3rd order 4th order. in a first order crossover 2000hz hi pas for a 8 ohm is 5.7uf in a 2 order crossover more parts are needed both high and low have a 4.97uf cap (at 2100hz a 4.73 uf cap) (at 2300hz a 4.32 uf cap) (at 3000hz a 3,315uf cap). this explaination is very bare bones. the inductors would be changed with those freq not just the caps. here is a link for a calculator

<A HREF="http://www.mhsoft.nl/CrossoverNetwor...udspeakers.asp">http://www.mhsoft.nl/CrossoverNetwor...udspeakers.asp</A>

this is a basic program. you need to play with some numbers to see things change you need to read some books. please give this questioner a few books to read

[unknownuser]

Lowering the cap value will raise the cut-off frequency, and alter the slopes. How much, and in what way, depends on the topology...whether it's a 1st or 2nd order network, and the parameters of the drivers. It must be a 2nd order network on the woofer. Beyond a certain margin, you will noticeably mess up the shape of the roll-off.

If you do it to just the tweeter, you should gradually get a hole in the response.


(Originally posted by: BFB)