My 4-way Crossover Needs Some Sage Advice!

[psarahtonen]

This isn't cross posting! I just have a more specific question now....


I have some Showco S200 "Pyramid" studio monitor/speakers that I'm rebuilding and upgrading the wiring and crossovers.

The crossover points are 200Hz , 800 Hz and 5kHz. Before ordering some ClarityCaps from Parts Connexion (awesome service btw!) I had to draw up a wiring diagram since none are available online.

The photo bellows what I see inside the tower and drew into my diagram. I now know the capacitors' values now but in looking at my diagram it looks like I have 3 problems (indicated by pink arrows in my first crossover diagram below):

ARROW 1- Isn't this connection going to short out the circuit?

ARROW 2- I don't see that these are polarized caps but won't this also be a short circuit?

ARROW 3- Shouldn't there be another component to make a band-pass filter?

A mighty Texas THANK YOU for any help you can give me before I accidentally destroy these beautiful collector speakers!!!


Here's what I **think** I see....

 

[67dylan]

My first question is this: Why spend that much money on caps? Those are not cheap and probably overkill. Just order some Dayton caps: http://www.parts-express.com/cat/me...eca:matches(.,"P_Searchable","1")]&PortalID=1 I'm sure others would agree that there's not really a need to overspend if you don't have to.

Now, to answer what I can. No to the first question. The coil is installed correctly; between the positive and negative, so no short. No, it is not a short, rather a well designed crossover. Third, not necessarily. Those components block certain frequency's (caps high frequency and coils low frequency), in this particular case, they block high and low together. Like I said, that is a well designed crossover and bet they sound fabulous. I googled those speakers cause I never heard of them and looks like they are very rare. Maybe post a pic if you can. I'd like to see what yours look like.

 

[Stuart Pedaso]

1) The coil presents a shunt path for low frequencies, seducing them with an easy, welcoming road, where it sends them to hell instead of to your tweeters. That helps the capacitor which is trying to muscle low frequencies back. Together they keep low frequencies away from your tweeters at a steeper rate than capacitor alone (2nd order vs 1st order filter).

2) Similar principle: 5μF cap is only pulling frequencies above the designed bandpass away from your midrange, where they meet in hell with unwanted low frequencies from 1) above.

3) Cap and coil ARE the bandpass filter. Like tag-team bouncers at a bar. Cap (high pass filter) blocks the low-lifes (frequencies) from entering. Then the coil picks off those that are too high (you know how obnoxious they can be ...). These aren't sent to hell since there's no shunt path -- they just don't get to party in your mid-bass speaker. Midrange bandpass filter above is similar but with addition of the 5μF shunt cap.

The obvious error I see in the top diagram is that bass filter cap only shown connected on one side.