Crossover designs

[Vladd]

Hello everyone, Horribly new to anything HT related. I had a few speakers setting around and want to do a set of bookshelves with them. My only problem is i have no idea how to design a crossover, if anyone could help me with this or point me towards threads that explain this in a very basic manner i'd be very appreciative.

Just FYI the drivers i have are leftover from an active install i did in my car

2 Ascendant audio Poly mids (4ohm)
2 Morel MDT-29 tweets (8ohm)


I'm building a set of boxes with a volume before displacement of right around .69cubes, hoping to tune somewhere in the 35-40 region depending on what the poly mids can handle.

[cobbpa]

Here's a link I have to ways of designing your own crossovers. I have never done it, but it's all here.

http://www.rjbaudio.com/Audiofiles/FRDtools.html

[Martyn]

For $25 Madisound will design one for you; then you can build your boxes and get your speakers working; then you can read up on crossovers and figure out why Madisound did what they did; then you can try to improve on it yourself. Low cost, low risk, and not as frustrating as trying to start from scratch.

[Mudjock]

Most of the crossover gurus hang out over at the "mission possible DIY" forum. I have used the method suggested above using frd consortium tools(summarized very thoroughly at rjbaudio.com). The first thing you have to do is trace the manufacturers spl and impedance curves using spltrace (found at the FRD consortium web site). Then, depending on whether you want to learn about crossover design or just build a nice pair of speakers, you can either have someone do the process for you or try it yourself and ask for help and/or affirmation along the way. Either way, I would be willing to help.

[Vladd]

Awesome, i'm going to read and hopefully learn right now, since i can't get a impedance graph for the poly mid i might just buy a set of woofers (i wanted more low end than the poly mids can provide anyway)

[Mudjock]

The frequency (blue curve) and impedance (red curve) data are both on the graph provided on Ascendant website. With any luck, the file should be attached to this post. I suspect a lot of smoothing has been applied to this, but maybe it is still useable.