Zilch's AK Design Collaborative - Econowave Speaker

Perhaps Gordon has some experience with it; I don't know, it could be an E-Wave sleeper in a rational acoustic suspension alignment.... :dunno:

Haven't used it... but, beyond some notching required for the breakup mode at 2KHz, the Peerless SLS 12 looks promising...

Regards,
Gordon.
 
I can't see why THAT wouldn't work. Stack the two 8" woofers as close together as possible, and convert the E-wave crossover low-pass to 4-ohm spec (twice the cap size and half the inductor size, compared to 8 ohms)

I did something similar with my "Dirt-Cheap-O-Wave" cabinets here, and the twin-8" woofers seemed to work quite well. You even wind up with an "elliptical" dispersion (wide in the horizontal, narrow in the vertical) for the two woofers working together, which mates up pretty well with the horn flare (which, for the standard "6512-type" waveguide, is about 90 degrees horizontal and 50 degrees vertical dispersion)...

As for T/S parameters- I'd just put the two woofers in the 1.9 cubic foot cabinet, sealed, and not worry about that. The A60 and A70 used pretty much the same woofers, and the A60 was about .6 cubic feet, while the A70 was about 1 cubic foot. Your cabinets are between these two sizes (per woofer), so that would obviously work...

One thing you would want to ensure- IIRC, some years production of the A60 used woofers that were "closer" to "true" 8 ohms, and some that were "closer" to 4 ohms. You want to make sure the woofers have a DC resistance of at least 5 ohms each. If so, go for it! :thmbsp:

Regards,
Gordon.

Cool. Zilch sees issues though. Apparently two woofers both playing the same program into the midrange don't naturally play nice together, and he said something about problems interacting with the waveguide and defining the forward lobe. But his 'E-wave-mini, in development, will need to solve these problems, so I'll be watching that with interest.

And I'm encouraged enough that I'm going to try to grab that third set of BA-60s....
 
They might. I heard some 801D's about 18 months ago. One of the demo songs was Hella Good by No Doubt which has a killer kick drum track in it. I have that song so when I got home I played it as loud as we did on the 801's that were connected to about $50K worth of electronics. This is one of the songs srbliss heard on my speakers. My speakers would not be embarrassed going head to head with the 801D's.

Thats awesome Duff!!

My problem is the wife really likes the 800's (she also likes the 1400 array) so I have been playing with curved cabs and vacuum presses.:yes:
I may just get this!:D
 
Cool. Zilch sees issues though. Apparently two woofers both playing the same program into the midrange don't naturally play nice together, and he said something about problems interacting with the waveguide and defining the forward lobe. But his 'E-wave-mini, in development, will need to solve these problems, so I'll be watching that with interest.

And I'm encouraged enough that I'm going to try to grab that third set of BA-60s....

Tomlinson Holman (of THX) made it work, with dual-15" woofers and, IIRC, about a 650Hz or so crossover point.

I can't see where everything being scaled up one octave (the woofers 1/2 the size, and the crossover an octave higher) wouldn't work.

Yes, it would take some tuning... but there's precedent for it...

Regards,
Gordon.
 
I need some input on this.

OK, so I just got a really cool idea, but I don't know how it would sound. Parts Express carries these coaxial drivers...

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-502

...which are available in 8", 10", and 12" versions. So I was thinking, why not make a "Coax-i-Wave"? Just mount the D220Ti to the back of one of these Eminence units, and you've just combined the already-wonderful performance of the E'wave with the superb imaging of a point-source arrangement.

I am considering building a pair of these unless there is an obvious flaw in my design that I'm overlooking.

Thoughts?
 
I'm not sure I quite get it. Seems to me the coax full range will have its tweeter intruding into the territory covered by the horn driver. If you were planning to mount only one tweeter driver to the coax you'd be forgoing the horn and the "Ewaving".

Back to my efforts to turn my Klipsch KG 5.5 into a kludge - I'm thinking of ordering the "standard" E wave horn (the 12" by 6.5" one) as well as the Selenium threaded horn to bolt on driver adapter and setting it on top of my cabinet. Then I'd mount my stock Klipsch driver to that, and get some crossovers boards from Zilch and try it out like that. If I feel its a significant upgrade from the stock Klipsch, I'd then try adding an inductor to the lower woofer and begin the process of cutting a bigger hole to mount the new horn in place of the old one. If I'm not impressed I could return them to stock and put 'em up for sale. I'd then decide whether to get the upgrade Ti diaphragms from Bob Crites or order new compression drivers. After that I'd start trying to figure out how to tweak from there. Any flaws in that plan you can see?
 
(caution, longish post with lotsa pics in it..)

Looks like that's going to work.

I've had very good results simming in PCD this year, so I'm a believer.... :thmbsp:

OK, once I got past the fixed circuit layout restriction - which isn't that restrictive as most passive crossovers do follow the same layouts, now I'm impressed.

..so following on from my previous post where I had a prototypical crossover worked from the manufacturers response curve.. of course once I got the eminence Delta 12LFAs and measured them in the real world, the shiny smooth factory curve that was so easy to shoehorn into a flat line turned out to be a lot more challenging, so I had to revisit the crossover, and I was quite stuck for a while using Speaker Workshop to slowly work through different layouts.

SPLtrace data against my measured with cabinet data for Delta 12LFA, scaled so they overlay:
main.php


Part of this was the time and mouseclicks taken to change a component value, recalculate, view response graph on SW, while the same operation in PCW is instantaneous.

new Delta 12LFA and the current Pioneer woofer:
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I also read through some of the existing Econowave designs, loaded in the FRD and ZMA files for the Econowave SR Compact (as my current proposed crossover shows!), this was very informative checking out against another dataset, for instance my measured d220ti + Pyle WG curve pretty much exactly overlays the Econowave SR Compact curve, which is encouraging that my measurements are OK.

I also switched to Holmimpulse for measurements, to use its gating function, and made a set of measurements outside. My back yard is not huge, but with the speaker on its back there is no "back wall", and hopfully the irregular shape of the vegetation diffused some of the reflections.

main.php


After trying all sorts of layouts with the resultant data in both Speaker Workshop and PCW I'm currently tending towards a variation of the Ewave SR compact crossover but using a Zobel impedance correction on the woofer.

response in PCW:
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circuit in SW:
main.php


response in SW (some smoothing applied):
main.php


I got the Eminence Delta 12LFA from local (Melbourne) dealer Essential Audio. The hard bit was having to enlarge the hole by 2mm around to fit, which was done by running around the inside of the hole with a jigsaw twice:

main.php

..luckily the screw holes lined up from the previous driver exactly.

.. now the next step is to adjust the above circuit to use values available from combinations of Jantzen components or similar, and price up a list.
 
Mighty close, looks like to me, via the process we have taught for optimizing custom EconoWave designs.

I am very pleased to see others digging deep to make this happen for themselves.... :thmbsp:
 
Mighty close, looks like to me, via the process we have taught for optimizing custom EconoWave designs.

I am very pleased to see others digging deep to make this happen for themselves.... :thmbsp:

Thanks.. and I have yet to get more advanced as I'm working mainly with basic frequency data here taken from one point.
I already noticed one minor error in the speaker workshop circuit.. I'd swapped the values for the Zobel..
now looking a bit flatter with:
Rz1 as 7.6 ohms and Cz1 as 13uF.. thinking of running with 8.2 ohms and 15uF as they are available stock values that also graph out ok.
 
followup: tidied it up a bit

corrected and cleaned up crossover using component values I can buy (using Jantzen components for pricing it up):
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And the modelled PCD response:
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I've specced a pcore inductor for the lowpass.. I see none of the econowave designs I've looked at bother with the extra expense of aircores so it's not worth it?

Also rather than a proper LPAD I'm just using a resistor in parallel to attenuate the d220ti.. but both the modelling in PCD and speaker workshop show it working out OK.
One idea I'm turning over in my head is replacing it with a wirewound pot like this, though I might just leave it at a fixed value.
 
We used air cores where they matter. It's EconoWave -- use inexpensive I-core for the lowpass; the PC board is laid out for them, and accepts all of the available values.

Put in the L-pad -- you won't regret having the capability to dial the HF level up and down without altering the response. Board's laid out for that, too. Zobel you wire external across the woofer output. Put it on a couple of solder terminals you secure to the board mounting holes at that end of the board. Do the same with a notch or whatever in the highpass you might add at the other end of the board.

I don't want to discourage anyone from doing their own thing here, but we have years' of work invested in making this easy for everyone with proven designs and construction tools, and it's foolish not to take advantage of that, in my view, even with custom designs. Your circuit will fit nicely; the boards are $20/pair -- be slam-dunk done with it.... :yes:
 
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I'm not sure I quite get it. Seems to me the coax full range will have its tweeter intruding into the territory covered by the horn driver. If you were planning to mount only one tweeter driver to the coax you'd be forgoing the horn and the "Ewaving".

The Eminence drivers do not include tweeters. Instead, you purchase the tweeter separately and attach it to the back of the coax. The tweeter would be the Selenium D220Ti, in this case. With this arrangement, there is no separate waveguide, so it's technically not a "true" E'wave. It still uses the same driver and crossover, however. I don't know that it would sound quite as good as the original E'wave, because there is no large waveguide, but I would think the imaging would be excellent.
 
Nick, I think you may be missing the main point of the ewaves, which IS the particular waveguides (constant directivity types with rapid flare). The idea is to have controlled directivity so the HF response is very similar at all angles, only dropping off in strength off-axis.
 
Nick, I think you may be missing the main point of the ewaves, which IS the particular waveguides (constant directivity types with rapid flare). The idea is to have controlled directivity so the HF response is very similar at all angles, only dropping off in strength off-axis.
I realize that you need the waveguides to get the constant directivity, but aren't the E'waves pretty good in the frequency response department, too? I realize my design won't yield the uniform sound dispersion, but in an application where there is only one listening spot, I would think that coaxially-mounted E'wave tweeters would take advantage of the actual quality of the sound while providing EVEN BETTER imaging.

I am, however, planning on building conventional E'waves soon. Very soon. I couldn't be more excited to hear them, since I haven't seen a single bad review on them. My coaxial design was only intended as a possible follow-up to this current project, but if it's a bad idea then I won't waste my money and just enjoy the conventional design, which I hear is great.

What I'm saying is that it was just a concept, and it seems that it's not worth the effort.
 
Been a while since I've been in here but it's good to be back. My e-waves have been in storage the past year but we are about to become re-united.

I've come across a local set of cabs that look perfect for the E-wave and I was looking to get some expert advice.

The cabs are Tannoy Royale's. The current owner gave me interior dimenssions of 14"x22"x38". I have an extra set of JBL 2225's that I thought would be a good mate to this cab with the JBL waveguides, Selenium 220's and the E-wave x-over.

Looking for thoughts on mating this cab with the 2225's and what tuning would need done.


Looking forward to your responses. Thanks in advance. :thmbsp:
 
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