[nodiak]

If I had the capability I would run simulations myself. I just have a macbook and am not very computer proficient.
This is a speaker that has interested me for awhile both for the waveguide and simple crossover - just one passive component on each driver. I have the waveguide and tweeter and one pair of CA18RNX's. I have used them with other bass drivers below. I very much like this TM combo, smooth and seamless. The waveguide makes for a wide treble dispersion that I like alot - no narrow sweet spot. Am currently back to finding another used pair of CA18's to finish the system as Zaph designed it (have been away from audio for 8 months).
When I finish them I will also (carefully) try them on an ob to hear if they can handle coming down low enough to pass off to dual (mono) subs that have highest setting of 120hz/24db ( O audio Bash 500 amp to 2 separate 12's in sealed). If they can't reach that low I may get a different crossover to mate them to the subs (maybe Marchand or similar).
I am curious and appreciative if anyone can run sims given the info on Zaph's site. Maybe a bit much to ask, but am finally asking.
I thought a baffle width of 12-15" might work (but I am a hacker with ideas and no sims). Simply because many use 18" to go lower.
Thanks.

http://www.zaphaudio.com/Waveguidetmm.html

SEAS CA18RNX. FS=35hz. QTS=.31. XMAX-6mm.

Driver heights, center to floor: T - 31.5". Upper M - 24". Lower M - 16".

Don

I'm feeling a little need to try to stop any sims vs. ears debates. I think sims are important, then tweak by ear if wanted/needed. I just don't want this thread to deteriorate into a debate about that issue.

[JohnR]

Are you going to use the Zaph crossover? You're planning to run the panels with no highpass?

[nodiak]

Yes will use some high pass on these. Maybe just a large cap (~100uf or so).
Do ob panel's all have 18db lowend rolloff? If these have 18db then with cap could match the sub amps 24db/4th order. (Not being able to run sims leaves me ignorant of such fundamental info).
Yes to Zaph crossover - minimalist version at this point. Very nice blend at tweeter/top mid. So that's no issue.
It is a 2.5 way so midbass drivers are doubled up, to ~ 400hz. So am hoping that helps power handling enough to work under 200hz.

*edited first post for driver heights to floor.

Don


 

[JohnR]

Do ob panel's all have 18db lowend rolloff?

Only below the woofer's Fs, however usually the panel dominates where the rolloff starts. You'd need to consider the highpass filter as well.

Here's some plots:

Green: 380mm W x 1200mm tall baffle, woofer at 600 mm and horizontal center.

Purple: same baffle but woofer offset horizontally... I forget how much but I think the center was 120mm from the edge.

Red: the response the crossover was designed for (closed box)



You'd get more bass with the second woofer - it looks like you would want to increase the inductor though (L5). It looks like you could cross them to the subs OK, although integrating well is a different story.

[nodiak]

Thanks for that effort.
I wanted to put in that I want to keep baffle height below 40" (typical speaker height for me is best 36-8").
I'll digest your graph. I can see what you mean about larger L5. I have a 6.5mH here I can try when something gets  built.

[nodiak]

I could also replace the lower CA18 with a 12" woofer. Have the tweeter and (upper) midwoofer in narrow baffle, (maybe even 9" as in Zaph's design) for better imaging. Then use larger baffle for the 12. Would go lower with less strain, be easier to reach sub's range. (Zaph's xo on tweeter midwoofer. Large coil on 12" woofer.)
I use another pair of the drivers in the sub's. They aren't truly subwoofers but work well for me with room lift.
As dipoles they may roll off hopefully ~ 100hz.
FS - 29hz. Qts - .4. Xmax - 9.8mm.

Here they are: Post #54 has a members measurements. Unfortunately no frequency response.

http://www.diyaudio.com/forums/swap-meet/156666-50-12-custom-eminence-woofers-sale.html

[nodiak]

I'm fine with this thread fading out, probably best.
Just wanted to post that I've decided to find and make a small 2 way (box) designed by Zaph or someone else with experience to have as a baseline/reference for anything I work on. This 2 way will go with my subs. All I have for tools is an old Audio Control octave analyzer, with warble tones man! It was what I used in the 80's during my first speaker hobby phase. My friends Speaker Builder magazine subscription and table saw kept us both really busy, much fun.
Now the hobby has advanced a lot and there are many folks using excellent computer based tools coming up with some nice designs.  I'll replicate something that interests me.
Here's the 3 driver ob. Scans 9300 in waveguide per Zaph mod, with SEAS CA18RNX, on 10" x 16" baffle with 1.5" radius sides. Eminence 12", on 18" x 18" baffle. Will try some xo ideas and compare to the 2 way. That's about as much as I can do time and effort wise anyway. I think this will satisfy my want to have nicely designed speakers, and my desire to hack around with diy. All in good fun.



 

[MoonUnit]

Here's the 3 driver ob. Scans 9300 in waveguide per Zaph mod, with SEAS CA18RNX, on 10" x 16" baffle with 1.5" radius sides. Eminence 12", on 18" x 18" baffle. Will try some xo ideas and compare to the 2 way. That's about as much as I can do time and effort wise anyway. I think this will satisfy my want to have nicely designed speakers, and my desire to hack around with diy. All in good fun.

That looks great! I didn't realize Zaph posted a waveguide mod for the Scanspeak 9300. I've actually done the mod for the Seas tweeter and have finished the cabinets (sans veneer) and baffles for the Waveguide TMM, but I doubt I'll have time to actually finish the crossovers anytime soon. I have played around with the tweeters in the waveguides with just a capacitor as a crossover though. I think the Scanspeaks would probably be better.

[nodiak]

I modded the waveguide according to Zaph's instructions, then used the 9300 as I had them. He did not post anything about using it. I plan to get the SEAS tweets if I continue with the design.
The 9300's are in my guess a little softer on the high end, which I like, but is maybe less correct. Their parameters are different so would like to have the one's he designed for.
The xo's are pretty simple. Hope you get them done, then let me know how you like them. Or...sell me a pair of CA18's...

[JohnR]

That looks like a very nice platform to work with. It sounds to me like you would really enjoy what you can do with modern software, it's free, you just need to get a calibrated mic and a USB audio interface - around $250 all up.

[nodiak]

I'll definitely look into it, am interested. Will keep scanning similar ideas to this setup and the evolving  solutions.
 
Don

[nodiak]

To get something playing I used the series xo of Lowther's Tiny Baffle OB as guidance. Using parts I had on hand ended up with 100+uF for 12" Eminence ,  and 6.5mH on the 7" midwoofer. Then put a 2 uF cap and 3.32 ohm resistor in series with the tweeter, wired out of phase.
Sounds very listenable, a little excess upper end from the 12, but everything is there down into bass guitar range. Surprised it goes that low. Hooking up subs soon.
edit: hooked up subs. Sounds great, really great. Will use 6x100 channel receiver to try separate ch's for 12's, then wire midwoofer and tweeter as typical tm. And whatever else comes up.