Flex Your PCD Mettle:

[bwaslo]

Re: EconoWave Mini S-8: Summary

What sort of changes would need to be done to have this design play well when laying on it's side?

Well.... none. Because it won't play well laying on its side, at least if the horizontal constant directivity (kind of the main point of the design) is important to you. Unless the horn and the woofer are one above the other, you'll have a horizontal pattern that is constant for about 20degrees at most and will have holes and other uglies beyond that. You'd have a wide smooth vertical pattern, but that's not usually considered as desirable.

[CZ Eddie]

Re: Flex Your PCD Mettle:

Thanks.
Just one more try at finding dynamic speakers with off-axis response to fit in my 9" height restriction.

[CZ Eddie]

Re: Flex Your PCD Mettle:

So how do I make something like this from Econowave parts?
And 8" instead of 10" woofer.

[bwaslo]

A workable 15" Pro woofer

In view of the exploding woofer prices, I picked up a still-cheap PA-380-8 from Parts Express and did some (relatively crude) measurements, mostly to see how high up it might be used in an Ewave. The larger SEOS waveguides that Erich is coming up with seem like they could be crossed over below below 1kHz when using a B&C DE250, so an affordable 15" would be of interest.

Brian at PE said the data sheet (with a promising looking response curve) currently on the site for PA380-8 is from the manufacturer and let me have a new off the stack unit from stock to check out. I don't have an open 15" baffle or box handy, so I just set it on a pile of blankets on the floor with a book to keep the back vent open... so don't read too much into them, other than the high freq limit which is what I was looking for. I moved the mic around to make sure it was reasonably consistent at distance and near-axis positions. Here is a plot from about 2' away

Looks pretty good to me for crossover even as high as 1500Hz.

I also did a quick check of T/S values with the woofer in the same position and no breakin, here is what WT3 said:


The Vas and efficiency read off from the data sheet, but most values are generally pretty close. Might be all the blankets right behind the basket. It looks like it should work in a reasonably small box though (for use with separate subs, of course). If I get time and energy, maybe I'll remeasure this under better circumstances.

Anyway, just wanted to report a much better-priced option for those who are going for directivity to lower frequencies.

Sof

[donprice]

Re: Flex Your PCD Mettle:

So how do I make something like this from Econowave parts?
And 8" instead of 10" woofer.

Well, by definition eWaves are 2-way designs. So you really can't get there from here...

Back to your previous question regarding how to deal with a height limit of 9"....

Is this for a center channel speaker or your mains? If it is for a center channel, the simple solution is to skip it and use a "phantom" center channel. Properly set-up, the directivity control of the eWave mains should give you a killer center channel sound in phantom mode (of course your HTR comes into play here).

If you need really short mains or surround speakers, you could build the eWave mini S-8 and rotate the horn 90 degrees. Would it work as well horizontally as it does vertically? No. Is it going to be good enough? Excellent question. As bwaslo noted, the you will have a narrow vertical lobe. If you only listen to music/movies from one spot and you aim the speakers properly, you are good (I think). If you move around the room, maybe not so good. By the way, similar effects happen with all (most?) speaker designs to different extents so don't think this is a an eWave specific issue....only that the level of detail in this thread (and related ones) is such that you get measurements and discussion of horizontal and vertical polar responses instead of only on-axis response.

Last but not least, there is a real good chance the speakers will outlive whatever is causing the height restrictions. So build them, enjoy them, and then turn them right side up one day when you can.

[Steve Henry]

Re: Flex Your PCD Mettle:

Last but not least, there is a real good chance the speakers will outlive whatever is causing the height restrictions. So build them, enjoy them, and then turn them right side up one day when you can.

Maybe the best response on this thread. Well said, Don!:D

[CZ Eddie]

Re: Flex Your PCD Mettle:

Well, by definition eWaves are 2-way designs. So you really can't get there from here...

Back to your previous question regarding how to deal with a height limit of 9"....

Is this for a center channel speaker or your mains? If it is for a center channel, the simple solution is to skip it and use a "phantom" center channel. Properly set-up, the directivity control of the eWave mains should give you a killer center channel sound in phantom mode (of course your HTR comes into play here).

If you need really short mains or surround speakers, you could build the eWave mini S-8 and rotate the horn 90 degrees. Would it work as well horizontally as it does vertically? No. Is it going to be good enough? Excellent question. As bwaslo noted, the you will have a narrow vertical lobe. If you only listen to music/movies from one spot and you aim the speakers properly, you are good (I think). If you move around the room, maybe not so good. By the way, similar effects happen with all (most?) speaker designs to different extents so don't think this is a an eWave specific issue....only that the level of detail in this thread (and related ones) is such that you get measurements and discussion of horizontal and vertical polar responses instead of only on-axis response.

Last but not least, there is a real good chance the speakers will outlive whatever is causing the height restrictions. So build them, enjoy them, and then turn them right side up one day when you can.

Thank you for that post!
This is for front mains L & R built into an entertainment center.

But after some more research this evening, I'm now I'm leaning towards the Eminence Beta 8CX 8" coaxial combined with the Selenium D220ti CD and a Zilch crossover that was designed for the 10CX but should be a good starting point for the 8CX also.

http://www.diyaudio.com/forums/multi-way/133490-need-good-drivers-copper-speaker-cabinet-3.html#post2626851

[stgdz]

Re: Flex Your PCD Mettle:

biggest advantage in switching from the original waveguide to the 152i now that PE has them in stock?


I built a set of SR's with the original waveguide but now that they are back in stock I am thinking of making the switch. Its for the neighbors sound system and he has a three person couch about 13-15ft from the speakers, the center is below the screen and below the listeners by about 2ft.

[NEO Dan]

Re: Flex Your PCD Mettle:

biggest advantage in switching from the original waveguide to the 152i now that PE has them in stock?

IMO
Probably getting away from the D220Ti and it's broadband breakup and going with the DE250, a much smoother less harsh sound.

[mike price]

Re: Flex Your PCD Mettle:

How much of an improvement IS the QSC/DE250 combo , over the standard D220TI econowave? It's certainly a lot more money , but it's something I am considering for my next build.

Would the Delta-12LFA be a good candidate for a woofer in an E-wave?

Also , would two of them in parallel be to sensitive , even after baffle step loss , for the QSC/DE250 top end?

I considered using 2 in each cabinet in a 2.5way configuration , which would get me to about 127db max spl , sensitivity would be around 101db at 2.83 volts , before baffle step.

I know the sensitivity of the DE250 is about 108db , but how much of that is lost to cd compensation?

[donprice]

Re: Flex Your PCD Mettle:

Sounds like a monster, Mike! I don't think anyone has ever returned the DE250 and gone back to the D220Ti. For the effort invested, I would go with the better HF section.

How did you model the efficiency of the 2.5 design? My understanding is that you roll off the 0.5 woofer low enough that you would only have a single woofer running near the crossover....so you get better bottom end performance. I'm not knocking what you are saying, I'm just trying to understand more about it since a 2.5 design/build is on my bucket list. Zilch posted a 2.5 model in the eWave mini thread (?) but I can't seem to find it....

Good luck!

[mike price]

Re: Flex Your PCD Mettle:

Sounds like a monster, Mike! I don't think anyone has ever returned the DE250 and gone back to the D220Ti. For the effort invested, I would go with the better HF section.

How did you model the efficiency of the 2.5 design? My understanding is that you roll off the 0.5 woofer low enough that you would only have a single woofer running near the crossover....so you get better bottom end performance. I'm not knocking what you are saying, I'm just trying to understand more about it since a 2.5 design/build is on my bucket list. Zilch posted a 2.5 model in the eWave mini thread (?) but I can't seem to find it....

Good luck!

I've been skimming through both of those monster threads trying to find info on 2.5 way E-waves myself , no luck yet. I just modeled the 2 drivers in parallel in Bass Box. You are correct on your understanding of the 2.5 way , and I believe it also works out so that the second woofer takes care of the baffle step increasing overall efficiency. If I go this route , I'm pretty sure I will go with the deluxe top end , and yes it will be quite large. The cabinet will be 5-6 cubic feet , but the ones I'll be replacing are 11 cubic feet , so I guess it's all relative. Before I would build though , I'd like to get any feedback possible on the Delta-12LFA's , and any possible problems I may have with the design in general.

[smokarz]

Re: Flex Your PCD Mettle:

looking to build a pair of e-waves mini for surrounds.

anyone built these recently? any build threads? thanks

[tsloms]

Re: Flex Your PCD Mettle:

looking to build a pair of e-waves mini for surrounds.

anyone built these recently? any build threads? thanks

I built a pair of the mini Ewaves using the Beta 8A woofer and XD120 CD/horn but I have not made up a build thread. I put them in the PE .75 cu. ft. curved cabinets and they fit beautifully. They have incredible output for the smallish size.

[smokarz]

Re: Flex Your PCD Mettle:

thanks,

1) is your box sealed?

2) did you use the original e-wave mini xo?

3) any reasons for not using the selenium cd/wg?

4) did you take any measurements?