Zilch's AK Design Collaborative - Econowave Speaker

Round #4

Vertical Map:

Forward axis is dead center between the drivers.


Crossover:

1421 Hz. DC300 does better down here.


Listening ... +/- 2 dB.

Footnote: To locate the forward axis, I invert the HF driver polarity and move the mic up and down to find where the unsmoothed response notch is deepest to the nearest 1/4", my target being -40 or more dB. That's where I measure and adjust the filters and overall response as shown in the crossover plots, with the HF polarity restored to normal.

The vertical polar map is then measured in 3" increments above and below the waveguide axis as reference, +/- 12" each way at a constant mic distance, so that all iterations are directly comparable. Finally, I reconfirm the forward axis location with the HF polarity again reversed.

Rounds #1 - #3 vertical polar maps using driver #1 are linked here:

http://www.audiokarma.org/forums/showpost.php?p=3271615&postcount=8690

And their on-forward-axis crossover responses here:

http://www.audiokarma.org/forums/showpost.php?p=3271677&postcount=8692

I have switched to driver set #2, and yes, there's a Round #5, flattening it a bit more....

Zilch said:

Vertical Map:

Forward axis is dead center between the drivers.

Crossover:

1421 Hz. DC300 does better down here.

Listening ... +/- 2 dB.

Footnote: To locate the forward axis, I invert the HF driver polarity and move the mic up and down to find where the unsmoothed response notch is deepest to the nearest 1/4", my target being -40 or more dB. That's where I measure and adjust the filters and overall response as shown in the crossover plots, with the HF polarity restored to normal.

The vertical polar map is then measured in 3" increments above and below the waveguide axis as reference, +/- 12" each way at a constant mic distance, so that all iterations are directly comparable. Finally, I reconfirm the forward axis location with the HF polarity again reversed.

Rounds #1 - #3 vertical polar maps using driver #1 are linked here:

http://www.audiokarma.org/forums/showpost.php?p=3271615&postcount=8690

And their on-forward-axis crossover responses here:

http://www.audiokarma.org/forums/showpost.php?p=3271677&postcount=8692

I have switched to driver set #2, and yes, there's a Round #5, flattening it a bit more....

Click to expand...

Well, Zilch, I do believe you've done it. A complete Econo- E'wave system. Econo box, combined with econo DC 300, modified E'wave crossover, QSC wave guide, an entire "Econo" system. Granted this is with the more expensive DE 250, but I'm betting the bolt on 220 ti can be adapted here as well.

Russellc

Clarification of "Forwad Axis"

Zilch in post #8861 when you mention "to locate the forward axis" followed by the methodology to do so, by forward axis, do you mean the line that is dead center of the forward lobe?:scratch2: Thanks for the clarification.

russellc

similost said:

From what I understand about the Lambda drivers is that they are so detailed, you're probably not going to hear a different with the Apollo upgrade in the home. Until you start taking them to their limits, they should be insanely clean sounding from all I've read without the upgrade..

However, if you feel you'll hear a $200 difference per driver, it's your money.. You're looking at about $1000 for a pair with the Apollo upgrade from the pricing I've seen.

Click to expand...

Whoa! for 200.00 a driver I wont be hearing the difference! Just hit me that the upgrade price shown for the appollo up grade on Wayne's site is "per speaker"........The AE drivers are pricey enough. Got to have some of those, but not until some of these other projects get finished.

Russellc

Russellc said:

Whoa! for 200.00 a driver I wont be hearing the difference! Just hit me that the upgrade price shown for the appollo up grade on Wayne's site is "per speaker"........The AE drivers are pricey enough. Got to have some of those, but not until some of these other projects get finished.

Russellc

Click to expand...

Yep, it is a big hit for that option. I'd like to have a pair just to hang on my wall. They look like are and it is a shame to cover them with a cabinet. I am going to try and audition a pair of them over the holidays.

I looked the other day, and I believe the Apollo upgrade for the 12" speaker is "only" $100 from AE. Beautiful drivers, almost make we wish I hadn't jumped the gun on some 123-A-1s.

djnagle said:

Yep, it is a big hit for that option. I'd like to have a pair just to hang on my wall. They look like are and it is a shame to cover them with a cabinet. I am going to try and audition a pair of them over the holidays.

Click to expand...

Build some plexiglass boxes to show them off. You can get a 4' x 8' sheet 3/4" thick for about $700... :thmbsp:

Zilch said:

Your crossover boards are set up for biamping without an active electronic crossover. All you need is a second pair of input terminals:

http://www.audiokarma.org/forums/showthread.php?p=2636636#post2636636

Unbolt the pair on the boards, separate the wire lugs already installed, connect to the new terminals, and reinstall the orignials to the boards. Your new terminals will connect to your low-frequency amp outputs, and the originals to your high-frequency amp outputs.

Read the Application Note regarding biamping with tube amplifiers driving the high frequency section:

http://audiokarma.org/forums/showthread.php?p=2416284#post2416284

Click to expand...

Thanks Zilch,

Last weekend I did the separation of LF and HF for bi-amping

LF 300B
2A3 HF

All ok, again thanks

Russellc said:

Zilch in post #8861 when you mention "to locate the forward axis" followed by the methodology to do so, by forward axis, do you mean the line that is dead center of the forward lobe?

Click to expand...

The acoustic center.

It can still be asymmetric about that axis.

Russellc said:

Granted this is with the more expensive DE 250, but I'm betting the bolt on 220 ti can be adapted here as well.

Click to expand...

I'll be trying that, yes.

cheapowave

Hi guys,
amazing work here! well done.

I've just gotten to a listenable stage (after a steep learning curve) my speaker project.. I'm nicknaming this one cheapowave as I've used some of the ideas of the econowave project but with much less expensive drivers.. a Pyle PDS221 compression driver on a Pyle PH612 horn, with a 12" Pioneer PA driver gotten from "a popular auction website" as the woofer.

Sound is big, warm and pleasant, maybe a little bit of graininess in high end, and very HF response tails of quite a bit..

After a few false starts attempting to work out a crossover myself from scratch I've gotten some great results with a modification of the econowave circuit, but adjusted the values so they work with the PDS221 response as modeled by Speaker workshop. I also went for a first order LP stage to help taper off some bumps in the response of the woofer:



.. also there is a fairly obvious upgrade path for these when I get upgradeitis...

zog666 said:

Hi guys,
amazing work here! well done.

I've just gotten to a listenable stage (after a steep learning curve) my speaker project.. I'm nicknaming this one cheapowave as I've used some of the ideas of the econowave project but with much less expensive drivers.. a Pyle PDS221 compression driver on a Pyle PH612 horn, with a 12" Pioneer PA driver gotten from "a popular auction website" as the woofer.

Sound is big, warm and pleasant, maybe a little bit of graininess in high end, and very HF response tails of quite a bit..

After a few false starts attempting to work out a crossover myself from scratch I've gotten some great results with a modification of the econowave circuit, but adjusted the values so they work with the PDS221 response as modeled by Speaker workshop. I also went for a first order LP stage to help taper off some bumps in the response of the woofer:

.. also there is a fairly obvious upgrade path for these when I get upgradeitis...

Click to expand...

Very nice speaker!

zog666 said:

... also there is a fairly obvious upgrade path for these when I get upgradeitis...

Click to expand...

Yup. Those cabs look sweet and will probably stick around for years. Nicely done! :thmbsp:

I'd like to do a cheap-o-wave setup with my spare horns and datyon woofers, but those pyles you used are nearly half way to the Selenium.

I think my best bet is to buy DE250s or BMS and use the Selenium in my L26 cabs.

No curves published, so I can't tell how well they might fare with the eWave crossover....

Just for the heck of it, hooked up a selenium/pyle waveguide biamped along with my center channel woofers.



Wow! 3 biamped waveguides across the front sound AMAZING! Now my surrounds are standing out with poor sound.

Fedex delivered the 6 Dayton RS180s today. Plan is to build some Dave Brown transmission line towers with JBL 6x6 waveguides and a waveguide equiped center. Each cab biamped with 2 RS180's. This is going to be one great system!

vlad335 said:

Just for the heck of it, hooked up a selenium/pyle waveguide biamped along with my center channel woofers.
...
Wow! 3 biamped waveguides across the front sound AMAZING! Now my surrounds are standing out with poor sound.
...

Click to expand...

That's my plan as well, although not biamped. Ordered 4 more 6X6 yesterday, and finally the order from October has shipped. Held up due to the 6X6's being back-ordered.

Going to use the 6X12's as LCR, 6X6 as rears.

DE250/QSC/DC300/Trap Cab L-Pad Attenuation

Round #5:


Top to bottom: Max (5:00), 3, 1, 11, 9, 7, Min (Off).

Yeah, +/- 1.5 dB @ 1:00, yellow.

I'll build it final tomorrow.... :yes:


XO:


Vertical Polars:


Quite subtle, but there's 2 dB less energy at 3 kHz, now, and 1 dB more in in the last octave, clearly audible. Open these two as tabs and click between them to see the difference between Round #4 and #5:

http://www.audiokarma.org/forums/attachment.php?attachmentid=185652&d=1261384011

http://www.audiokarma.org/forums/attachment.php?attachmentid=186056&d=1261619308

Polar maps here, same drill:

http://www.audiokarma.org/forums/attachment.php?attachmentid=185651&d=1261384011

http://www.audiokarma.org/forums/attachment.php?attachmentid=186057&d=1261619308


Schematic:


Yes, I punted and added that -3.88 dB fixed L-pad at the HF driver as opposed to taking C3 down to 0.1 uF and reworking the attenuation, reason being I don't have a low-DCR inductor for L3, and I may have overdone the BSC (Baffle Step Compensation) with L2 = 2.0 mH.

Bottom line: not final, but it illustrates what I've done to "tame" DC300, i.e., convert C2 to a conjugate and add a tank filter to the lowpass output, and how I lowered the highpass frequency with different values for C1 and L1.

I'd prefer if the forward axis were tilted upward rather than normal to the midpoint between the drivers, and there is a bit of phase interference at 3 kHz yet to be resolved, but overall, this is performing well.


Lowpass:

Zilch said:

No curves published, so I can't tell how well they might fare with the eWave crossover....

Click to expand...

Here's some info I measured myself in ARTA, drivers in cabinet - not calibrated to SPL or anything but enough for me to run some stuff through speaker workshop:

PDS221 in PH612
http://pix.minirig.org.au/main.php?g2_itemId=1694&g2_imageViewsIndex=2

Pioneer A30GC50-52F-Q-1 woofer
http://pix.minirig.org.au/main.php?g2_itemId=1699

variation of the Econowave Xover - some of the values chosen more due to the parts on hand (4.4 uF cos I had 2 2.2 uF caps avail)
http://pix.minirig.org.au/main.php?g2_itemId=1707&g2_imageViewsIndex=1

I stepped through your entire photo series beginning here:

http://pix.minirig.org.au/main.php?g2_itemId=1470

Beautiful job on the cabinet build; I savored every pic. :thmbsp:

The PDS221 curve looks like classic power response above a 3.5 kHz mass breakpoint. It's linear monotonic, and should be amenable to Wayne's Pi-speaker HF compensation approach. Parse it out. Start with just the comp cap; if that's an 8-Ohm driver, your 2.5 uF value is too high and not rolling off the response high enough; pick a value that starts at just above 20 kHz, then set the slope with the resistor in parallel. That'll give you a perspective on how it works. Then add the resistor to common and adjust the pair according to what is required to balance with the core highpass filter and the woofer output. Refer to his attenuation chart here:

http://www.audioroundtable.com/PiSpeakers/messages/1278.html

Read through his tutorial if you haven't done that, and his posts on the subject in this thread, accessible via Advanced Search This Thread on his ID.

With 8-Ohm Selenium drivers, 1 uF is about the max value for C1, eWave's C3. Above that, there's no comp happening at the 20 kHz high end.

Footnote: One of your early schematics had the highpass inductor to common before the series cap. Not surprising that didn't work....

4343 said:

That's my plan as well, although not biamped. Ordered 4 more 6X6 yesterday, and finally the order from October has shipped. Held up due to the 6X6's being back-ordered.

Going to use the 6X12's as LCR, 6X6 as rears.

Click to expand...

Funny. I called JBL yesterday and was told that they havent had any 6x6's and don't expect to get any till mid Janurary at least. (Called Friday as well.) Not saying you are not telling the truth... The guy I was directed to was kinda rude right off the bat and seemed bothered by my call. Basically was told to quit calling till next month. He ended the call with, "Good luck." (I thought at the time that was a strange thing to say.)

Maybe I need to get someone to order me three of these or look into something like the QSC's. Don't want to get all conspiracy theory about this but you saying you ordered some yesterday makes me think I need to look elsewhere. I think maybe I will contact some JBL dealers after the holiday and see what they can do. I don't care if I pay more for them.