Help with 3-way crossover. Dayton Reference drivers w/ 27TDFC. Zaph? Others?

[wigginjs]

I built this 3-way speaker with the hopes of doing a completely active digital pc-based crossover with all sort of neat digital corrections. Well, this technology is a little more complicated that I originally anticipated and I'd like to take my time with it. In the mean-time I have these speakers I'd REALLY like to listen to, but they don't have passive crossovers. I really only know the first few things about designing passive crossovers and I would really appreciate some help from more experienced designers. I've attached pictures and what I think is all of the relevant information. Not shown in the PDF diagram are 2 braces (above and below the 10") as well as a fair amount of poly-fil. Some of you guys have quite a bit of experience with this driver set because you've measured them (Zaph comes to mind). I'm not looking for a masterpiece of a crossover here, but more than just simply plugging nominal impedance into a formula and getting a cookie-cutter x-order crossover. Thanks in advance, discussion and suggestions are really encouraged.

[cotdt]

nice cabinet work!

good job!

[BobEllis]

http://www.htguide.com/forum/showthread.php4?t=11873 might help

If you have the amps ready, we are about to embark on an analog active XO group buy Here

[DIY_newbie]

Or jump in on the DCX bandwagon with the rest of us DSP jockies

--Chris

[wigginjs]

Thanks all for the compliments or suggestions.

Bob:

I can see the similarities between the speaker you've mentioned and mine, but I'm not sure how it will help me develope my crossover other than, perhaps, choosing crossover points. I definately do not have the time to start another electronics project at this point, so the analog active xo is out, thanks though.



DIY_newbie:

Ahh, I had originally planned to use the DCX, but the supposed advantages of a PC-based crossover still seem too great. I'm really just interested in developing a quality passive XO at this point. I believe this combination of drivers has great potential, but I need some help unlocking it.



To anyone who has the expertise to help, I don't mind compensating you (monetarily) for your time and knowledge if the work is of high enough quality.

[DIY_newbie]

RE: Advantages of PC crossover..

I played with KX drivers and my audigy card.. IMHO the DEQ + DCX combination gave me better results and are much easier to use.

The only problem with the DCX is they're not available for a bit longer...

--Chris

[sliceofhogan]

You might find some inspiration here.....RS series three way

[BobEllis]

Originally posted by sliceofhogan
You might find some inspiration here.....RS series three way

HEY - that's my link! I did the same thing - the driver compliment is the same, but that design uses 2 woofers and mids. redesigning the XO for single drivers isn't straightforward.

m0tion - you could do worse than a 4th order LR with a notch for the breakup modes (using the XO frequencies suggested in the thread or, say, 300 and 1800. I am using an RS150 and 27TDFC in my home office with an LR4 active XO at 2400 that sounds quite good (because it was built for another project, and like you I wanted to listen in the meantime.).

You can import PE's CLIO data into Speaker workshop by renaming the CLIO files *.frd and *.zma and play with its XO functions. Better would be to measure the driver responses in your box. You can use SW's network optimize function to tweak values and it ought to be a listenable start. Be sure to download. See Claudio Negro's site for a tutorial, and search for the manual. I found it fairly easy to follow the directions in the manual and come up with passive designs. It even seems to model the Cauer-Elliptic filters that are so popular over at the site linked above.

The active XO is not a major project - I've got a spreadsheet in the thread that will let you calculate filter and notch component values. An hour or so messing with that and ordering parts and I'll bet you can have the XO's up and running in a day. Certainly less than a weekend if you don't get carried away with an artistic case. If it's just temporary, you can just mount the boards on a piece of mdf and hide them somewhere away form power cords. Then if you decide you like it enough to keep a while, Par-metal cases are relatively inexpensive and decent looking.

If you want I can post or email you a schematic and component values for a 1500 Hz XO that rolls off initially at LR8, ending up at LR4 when 55+ db down. That and a W-M LR4 would probably get you going in style. I should have a Mouser parts list by the end of the week.

There is also a Foobar XO plug in (http://sourceforge.net/projects/xover/) that works pretty well, although I haven't done any serious listening to with it.

[wigginjs]

Interesting side note:

I contacted Madisound because they offer a crossover design service using LEAP. The guy who answered was really friendly about helping me design a crossover even though they didn't carry some of the drivers until he found out that two of them were from Dayton. He said "Thats a Parts Express brand, we can't help you with those". After that he was really short. I think thats absurd.

[cotdt]

Originally posted by m0tion
Interesting side note:

I contacted Madisound because they offer a crossover design service using LEAP. The guy who answered was really friendly about helping me design a crossover even though they didn't carry some of the drivers until he found out that two of them were from Dayton. He said "Thats a Parts Express brand, we can't help you with those". After that he was really short. I think thats absurd.

Wow... I guess they don't like Parts Express!