Zilch's AK Design Collaborative - Econowave Speaker

[DigitalChris]

Okay so in your reverse (or reverse-reverse, as it were) polarity that's a fairly clear notch at maximum driver overlap, so that's good. We should really be focusing on the HF, but just because it's bugging me, your L-pad should be set more like this (not the best mouse-drawn line, but you get the idea):

Thanks for the chicken scratch, nothing more needed to show what you mean

So, if that gets turned down, I'm afraid my rolloff will be that much worse!! The high end already seems to be not so good, nevermind when I put the screen back in front :thumbsdn:

Do you have any links to others posted graphs of their standard e-wave? I'm curious to see their results vs mine.

 

[dumptruck]

So, if that gets turned down, I'm afraid my rolloff will be that much worse!! The high end already seems to be not so good, nevermind when I put the screen back in front :thumbsdn:

Yes, exactly - it looks like something is quite wrong.

Do you have any links to others posted graphs of their standard e-wave? I'm curious to see their results vs mine.

I think there are some around, but you can be entirely confident in Zilch's measurements. From ~600Hz up, this (red line below) is your goal. You may end up with something a little different 1-3kHz due to differences in your driver spacing (front-to-back and/or up-and-down), but we can already tell you're in the neighborhood there, so the HF is the question. You might get a few different ripples, but the average should be just as flat all the way up.

 

[donprice]

Do you have any links to others posted graphs of their standard e-wave? I'm curious to see their results vs mine.

http://www.audiokarma.org/forums/attachment.php?attachmentid=321360&d=1325977635

http://www.audiokarma.org/forums/attachment.php?attachmentid=318902&d=1324741144

These were measured with the centerline between the woofer and waveguide at a distance of 40". No idea if the measurements are good...but I'm seeing a similar 5 dB rolloff between 5k and 15k....

Not the "standard" ewave....

 

[dumptruck]

Indeed, that doesn't look quite right either, but Chris is seeing more like -14dB over that range.

 

[doug s.]

That's going to be too low a crossover point to hold directivity on that waveguide.

Well, a big split between the low and high pass might work, and you don't have to buy crossover parts to try it.

yes, it might be better to find another 12" driver that would go up to 1000-1200hz, and work in that box. i would yust need to find one that was at least as efficient - i am not really interested in anything <97-98db efficiency. low end isn't that important, as i am using subs...

thanks all,

doug s.

 

[DigitalChris]

Could it be a power issue? I kind of doubt it because we're not talking about high SPL numbers here but what else could cause a rolloff in the HF like this? I'm going to double check settings on my AVR, as far as I know, nothing is engaged, as far as AVR EQ goes.

 

[dumptruck]

Try measuring a factory-made speaker that you know goes to 20kHz.

 

[DCinDC]

yes, it might be better to find another 12" driver that would go up to 1000-1200hz, and work in that box. i would yust need to find one that was at least as efficient - i am not really interested in anything <97-98db efficiency. low end isn't that important, as i am using subs...

thanks all,

doug s.

I assure you that woofer is not as efficient as you think it is. By itself, without the midranges playing, it is probably 90 db at 1w/1M or so, at 500-1000hz which is typically where a good speaker manf measures it. I can almost say that I guarantee it is not 94 db or more.

 

[dumptruck]

yes, it might be better to find another 12" driver that would go up to 1000-1200hz, and work in that box. i would yust need to find one that was at least as efficient - i am not really interested in anything <97-98db efficiency. low end isn't that important, as i am using subs...
doug s.

There are hundreds of pro woofers that fit that description.

 

[JohnInICT]

I know there have been a ton of Advents turned into E-Waves. Is this a really good option? Do you use the original Advent woofers?

 

[DCinDC]

I'm doing my NLAs. I've already mocked it up and heard it and am convinced. It will be a GREAT speaker. Everything wrong with the NLAs is cured. I also happen to REALLY like their looks since i spent a lot of time with a friend's powered Advents.

Yes, you use the original woofer.

 

[doug s.]

re: the sp2500, according to the graph prowided by sansui, from above ~80hz, the woofer itself is ~96db. but, as was stated, i should not have any problem finding a 12" driver that is at least 97db efficient and extends to 1200hz.

doug s.

 

[bwaslo]

Digital Chris -- does it sound like the upper treble is gone? Graphs look like maybe your microphone is snookered.

 

[DigitalChris]

Digital Chris -- does it sound like the upper treble is gone? Graphs look like maybe your microphone is snookered.

To be honest, I'm not sure what I'm listening for. I do feel that some of the crispness of the sound isn't there. I played part of Transformers 2 upstairs on my paradigms and I think I'm hearing some more crispness to the track. I have not run Audyssey yet downstairs but have upstairs, could this be the reason?

I can bring my microphone upstairs and do a sweep to my Paradigms and see what they bring to the table, with and without Audyssey engaged.

 

[skywave-rider]

OK DigitalChris, you should get the protection cap tomorrow. So I did my measurements today for the comparo.
Specs:
-1 meter on axis with JBL standard PT EWaveguide, windowed (rectangular) to .66ms (1520 Hz.)

I did 2 measurements. One with the EWave crossover (original version.) The other with only a protection cap (33uF NPE, what I sent you. But it actually measures about 38uF.) All measurements are with "horn on top," not mounted in baffle, though flush with it.

For the crossover measurement I put an 8 Ohm dummy noninductive resistor in place of the woofer. I also tried it without one, and the measurements are identical in the region of interest. Not sure if it matters, but If you do it without the resistor, run the test at a low volume first to make sure your amp is ok with it. I did the 2 types of measurements so we can test the driver baseline, and then driver plus x-o.

Blue: D220/EWaveguide/no crossover other than protection cap.
Green: D220/EWaveguide/EWave crossover.

To me, the green looks +/- 2 dB across the range. The peak at the top is the breakup. The blue shows the characteristic big 2k peak at the bottom of the range.

Since I was testing and had stuff apart, I threw on the 6x6 PT (RED) and the 8x8 (BLUE) on the crossover here (D220Ti):

http://www.audiokarma.org/forums/attachment.php?attachmentid=355243&d=1339360790

And this is the D210 on the Standard EWaveguide and crossover:

http://www.audiokarma.org/forums/attachment.php?attachmentid=355244&d=1339360790

 

[DigitalChris]

Thanks sky, I got the cap yesterday, I appreciate it

Because you did the tests with the horn out of the box, should I as well? Also, what does 6x6 and 8x8 mean? What range should I run my sweeps and and what scales did you use on your graph? I only ask about the scales because your graphs look different than mine, not REW I take it?

 

[4343]

Thanks sky, I got the cap yesterday, I appreciate it

Because you did the tests with the horn out of the box, should I as well? Also, what does 6x6 and 8x8 mean? What range should I run my sweeps and and what scales did you use on your graph? I only ask about the scales because your graphs look different than mine, not REW I take it?

8X8:

http://techtalk.parts-express.com/showthread.php?p=1655955#post1655955

from Zilch's Summary (linked from page 1):

6X6:

"Alternate "Mini" PT waveguide for smaller projects, Part# 364914-001, 90° x 90° dispersion pattern, flange dimensions 6" x 6", 4" deep to rear of flange with D220Ti driver, 3.375" using D2500Ti-Nd, $6.00 each."

8X8:

"Also for smaller projects, PT-D95HF-1 waveguide Part# 364700-001, 90° x 50° dispersion, flange dimensions 8" x 8", 7.625" deep to rear of flange with D220Ti driver, 7.125" including D2500Ti-Nd, $14 each."

 

[skywave-rider]

Thanks sky, I got the cap yesterday, I appreciate it

Because you did the tests with the horn out of the box, should I as well? Also, what does 6x6 and 8x8 mean? What range should I run my sweeps and and what scales did you use on your graph? I only ask about the scales because your graphs look different than mine, not REW I take it?

Hey Chris,
I just did the 6x6 and 8x8 measurements because I had the rig set up, but it has nothing to do with your setup. Sorry for the confusion.

I really do not think you need to take the waveguide out of the box.

I ran the sweeps from 20Hz - 20kHz. I could have started a lot higher, of course. Maybe 500 Hz? You're running through a cap or the crossover anyway.

We are never going to get our graphs to match perfectly. So we'll do our best to look at the trends and particular points of interest. (I can supply "graph extents" numbers, but I am not sure what those numbers mean. Let me know if you want them.) I try to make the vertical scale so that I can easily read single dB increments. I thought the ones you posted looked good.

I am using Fuzzmeasure.

 

[DigitalChris]

Great, thanks for clearing that up. I should be able to take some measurements for you tonight. I'll post them before work

 

[DigitalChris]

Geez, I'm such a liar

Tonight, promised, I will have some graphs for you

EDIT: No I won't, who am I kidding. Sunday nights have been the worst times to work downstaits lately, by the time 930-10 comes, I'm ready for bed when I should be getting ready for work. I wanted to take the measurements tonight but I was beat and not to mention irritated, so I didn't make it down there. Tomorrow I should be back on schedule so measurements will be on the list of things to do