crossover system? I wanted to install components but would rather not pay the high prices if I don't have to. I've done some research on the net and found its a matter of getting the slope angles right and matching the x-over system to the characteristics of the speakers. Yes it would probably be way easier to just buy some, but what's the fun in that?? Also, do you guys run x-overs for your subs? I was planning on just using 1 10" to just fill in some low end.

 

Most of us just use the crossovers built into the amps or one in an EQ or active crossover for the subs. For more guidance on building a x-over check madisound's web site. And yes, it probably is cheaper to buy a component set with crossovers than it is to buy the same drivers and build a crossover with the same capabilities as the factory tuned system.

 

You mean like this?
<img src=http://www.ee.utulsa.edu/~mblehm/pics/home_stereo/home_stereo_crossover.jpg>

Yup.. it's possible, but expensive. Those cost me about $200.

 

was that $200 just for the parts? how long did it take you to get the frequencies tuned right? any pointers for a novice besides telling me to just go and buy some?

 

yeah, the $200 was just for parts.. of course these are in a set of bookshelf speakers that'd cost about $2500 if you bought them from a dealer. I used high quality $$$ parts in them.
you could probably build the same thing for $50-60 if you went with cheaper stuff.

as fas as the design, the guy that I bought the drivers from did the design for me. The frequencies are the easy part. the hard part is impedance correction, resonance notches and level matching between drivers.
here's the diagram of those crossovers:


on the midrange (the Dulcet/HiVi Research F6 in that diagram), the frequency part of the crossover is the 1mH coil and 11uF capacitor on the far left. the conjugate is an impedance compensation/Zobel network. This stuff can't really be designed correctly without some $$ test equipment, as you have to know some stuff about the speaker itself, not just looked up in a spec sheet (those values can change as much as 300% from their spec value).

on the tweeter (Focal TC90TD), the first three components are for cutoff frequency (3.6uF, 0.7mH, 5.5uF), the 6 ohm resistor is for level matching to the midrange (tweeters are generally quite a bit louder than the rest of the system unless you add something like that), the resonance notch is designed to filter out a spike in the responce, due to the tweeter itself (again, something that much be tested on an impedance analyzer, not looked up in a book), and the conjugate is to help stabilize the impedance for more even frequency response and an easier load for the amp to drive.

now for the GOOD news. this system sounds absolutely gorgeous. every bit worth the $600 they cost me for the entire speaker.
on your end of things, you CAN build a simple 2 way crossover.. the frequency is the easy part. you look at up in a table or have a computer program do it. the zobel networks are the fun stuff, and I wouldn't really worry about resonance notches. most people can't hear them, but the ones on these drivers were pretty nasty due to the titanium domes.

hope that helps.

 

Funny this topic comes up. I'm in the process of building a pair of Dynaudio bookshelf speakers, and am designing the x-overs as we speak. Righ now I'm using Solen caps, and Goertz Copper foil inductors, and once I have the system tuned right, I'll replace the Solen caps, with Hovland. I'll snap soome pics once done....

 

yeah, that helps a lot. its tells me that i need to have the guy i get the speakers from design the crossover network for me. as far as the system you have in your car, are you running component or coaxial speakers? i remember from the other board that you made your own speaker pods, but can't remember what kind of speakers you were using.

 

I'm using FOCAL Component speakers. I'm also running active crossovers (before the amps) on everything. then just for safety, I put the FOCAL supplied crossovers on the tweeters- that way I can't fry them by pushing the wrong button. been there, done that. $200 mistake.



Whitemax, the Solen caps are already excellent quality. you may get a little better sound out of the Hovland, but there's maybe 0.0001% of the people in the world that can hear a difference between different caps in the system. If you DO hear anything, it will more likely be from the difference in tolerances between the Solen and the Hovland caps. (1 0.5uF cap isn't exactly 0.5uF. they generally have tolerances of 10-20%. )