Crossover Question

[timothy1956]

I want to build another pair of speakers using dayton 3 way crossovers......the only twist is that i want to use 2 tweeters and 2 midrange ( all 8 ohm drivers).......so, what do I need to do to the crossovers since I expect 2 parallel driver/speakers will drop the resistance to 4 ohms? I did this years ago and if I remember correctly, resisters were used......but then again it was along time ago and my memory isn't so good these days....

[billfitzmaurice]

You either need to find off the shelf crossovers rated for 4 ohm loads or design your own. The latter is far preferable. Off the shelf crossovers tend not to work very well, as they're not optimized for the drivers being used.

[Psycoacoustics]

Also two tweeters in one cabinet is almost never a good idea. Keep reading and,,,

Have Fun! Mark

[timothy1956]

batting 0 for 2 so far

[Chris Roemer]

Why 2 tweets?
What drivers?

[timothy1956]

Chris......I'm 63 now.....and I've built dozens of speakers over the years but the set I made in college made me a legend on campus for LOUD music.....My friends still talk about that....The RD use to call me the Kill-o-watt King.......and that set had 2 tweets and 2 mids and a kick ass 15" woofer........This will be the last pair I ever make, and I want to emulate that infamous pair......

[Geoff Millar]

Driver technology has come a long way since your College days (I'm similar age) and you may not need that many drivers to give you volume and quality.

Are you wanting to design a new project, clone your old 15" speakers, or use an existing and proved design? If the latter, PETT members will be happy to make suggestions.

Here are two well regarded projects which will give you volume and quality: I apologise to the many other great designers on this Forum for not mentioning their designs, but these spring to mind as I've considered building them:

https://sites.google.com/site/undefinition/tarkus

http://speakerdesignworks.com/SB6pakproject_6.html



Geoff

[Kornbread]

If loud is the only criteria, just build a pro sound speaker; should be lots of designs out there using multiple drivers. Better yet, loud and quality; line array.

[timothy1956]

Loud is not important.....Looks are important.........I know modern speakers are better than 1975......i want the appearance to look like my old speakers......and sound modern.......it's.the resto-mod of speakers..........

i would have thought the answer would be easier than this is becoming......i'm pretty sure i used resistors way back when but i don't remember the details......i think SpeakerLab helped me out with the details........

[djg]

There must be a vintage speaker forum where old people gather to restore and recreate old designs.

As far as looks, you could build a modern 3 way and add a dummy midrange and tweeter.

On a serious note, Zaph has a huge SB Acoustic 12" 3 way with MTM midrange tweeter arrangement. A well known Madison, WI based speaker supplier has a component kit.,

[djg]

Not what you asked for but still impressive. Available from a well known Cincinnati OH based speaker supplier. Titans.

[Kornbread]

This is close to a generic textbook 2nd order crossover for two theoretical drivers with a flat frequency and impedance response.




Most drivers do not have a flat freq or impedance (ribbons, AMTs?) response. Because of this, real world passive crossovers often become complex, chaotic looking creatures. (XSim 2-way example) See how wildly the freq response and impedance plots vary.

While you may get acceptable to you results using a generic off the shelf passive crossover, we know it is not optimal. This is why many are reluctant in recommending them.

[Chris Roemer]

Do you have a pic of your old fantastic looking speaker (from the '70s)?

[Dave Bullet]

This is close to a generic textbook 2nd order crossover for two theoretical drivers with a flat frequency and impedance response.

... don't forget time alignment of the voice coils relative to listening axis / position.

[Kornbread]

Maybe I was wrong but it felt as if the OP was under the impression that purchasing an off the shelf crossover for a standard 4 or 8 ohm driver, and adjusting with resistors to match the driver's rated ohm load, is the standard. The example was just thrown together with a couple of unobtanium drivers (flat freq. and impedence from 20-20) to show that most of the time, building a proper crossover is not quite so simple. Maybe it is adequate for some but I doubt many on here will recommend that route, at least without some modifications.

And yes, I did recently forget to add in acoustic offset on an old build just recently resumed. The crossover was way off.

Since the OP is no longer posting, I hope he hasn't been scared off.