Zilch's AK Design Collaborative - Econowave Speaker

[Zilch]

I'm not saying "scratch" anything, rather, reminding everyone that, as Russell suggests, there are compromises, and we should remain cognizant of them.... :yes:

I would love to see the TD15S, in 9 cubic feet tuned to 20Hz, anchoring the DE250/QSC.

'Zat what you're gonna build? :thmbsp:

Well it took a little while but I got back around to frequency response measurements.

Those are certainly looking much better, and they clearly define the options in the the crossover region.

I can't guess what's generating the uptick at the very high end, but if it's real, it's adding "air" to the sound, probably pleasantly....

 

[juniorJBL]

I would love to see the TD15S, in 9 cubic feet tuned to 20Hz, anchoring the DE250/QSC.

Sub? Who needs one.

My dual 2242's in 14 cu ft boxes seem to do the trick.


But....... then again my sub1500's in 2.2 cu ft boxes can do very well also.:thmbsp:

 

[hhibrownsbac]

There are several of use doing so, and I havent heard any complaints from those boys!



Russellc

No complaints here, in fact, I have another set of 2225H going out tomorro to be reconed to 2235h for my next project:thmbsp:Maybe that JBL clone Ive been thinking about but what ever it is its gonna rock!!!!

 

[mcmurma]

Sorry; that's why I responded to your question from more of a theoretical design perspective. Waveguides are quite inexpensive, and there's a host of capable compression drivers under $100 that can do a credible job of tweeting mated with them. That doesn't mean that conventional drivers can't do as well or better; it's constant directivity is the worthy pursuit.

RS28Fs came in today, so I may be doing some experimenting with those on ellipticals here soon.... :yes:

I'm curious to see how your experimenting with the RS28F is coming along... as I'm very interested in their performance with whatever elliptical waveguides you are mating them with. Also interested in how they perform raw... sans any waveguide.

 

[Navydoc]

Spent untold hours perusing all the various forums researching the econowave movement (I should have been working, but this is more fun). Ordered three QSC waveguides this morning, will start building the deluxe econowave (2012LF/DE250-8) in a few weeks. Was planning on building my own cabinet, but after looking at some of the builders have done w/ the PE Trapezoid I may just follow along. Have not broken the new to the family comptroller.

SWN

 

[dnewma04]

I would love to see the TD15S, in 9 cubic feet tuned to 20Hz, anchoring the DE250/QSC.

Sub? Who needs one.

Not me, I'll need at least 3.

 

[Schumacher ®]

I'm curious to see how your experimenting with the RS28F is coming along... as I'm very interested in their performance with whatever elliptical waveguides you are mating them with. Also interested in how they perform raw... sans any waveguide.

Check out MarkK's evaluation of the 28F. It is an amazing dome tweeter, usable to 1KHz.

http://www.audioheuristics.org/measurements/Testing/Tweeter6/tweeter_group_6.htm

Check out the IM tests using 1KHz fundamentals. Wow.

 

[drumdude]

15's or no

A ways back in this thread when myself and others were contemplating 12 inch drivers, Wayne popped up with some very good things about two way systems using 15 inch drivers. I'll have to see if I can back track a few thousand posts and find it.
Sure, There's no doubt there may be a little narrowing of lobes and so forth, but it still is one of the most impressive sounds I've had, speaking of both the 2225H and the 2235H.

Lots of love for the 15 inchers! Are they perfect? Hell no! Do they sound great? Hell yes.

I'm sure, as physics requires, there is some lobe narrowing to some degree at some frequencies....so I only get a 5 foot wide sweet spot...not that bad really. For those out there who listen to planer speakers requiring a head vise to stay in the sweet spot, I really doubt you'll complain. Plus, they shake the house! All this stuff is a compromise, and your of course free to use what ever size woofs float your boat, but I wouldnt count out the 2235H or the 2225H for E'waveing. There are several of use doing so, and I havent heard any complaints from those boys!

Russellc

i used 15's on my first ewave project because I wanted more efficiency than I could get from my Advent's. I understood the tradeoffs and I had some pro 15" midwoofers that play up to 2K. I maybe lost a little directivity and pattern control but I gained about 3db over a 12" midwoofer and go deeper too.

Then again I am already planning another set with 12" midwoofers to hang in a music & dance studio already equipped subs. The 15's are great for rockin out but too big to dream of hanging from the ceiling.

 

[Schumacher ®]

'Zat what you're gonna build? :thmbsp:

I figured on going for the TD12 series, but for only a few dollars more, I get an order of magnitude performance gain . . .

I'm a fan of large speakers, and I've dreamed of a big system using a 15. I never imagined that it might be a two way. I had my mind set on a 3-way minimum, maybe 4-way. But after seeing the potential of this setup, a two way with a capable 15 like the Lambda and that QSC/tweeter seems simply dreamy . . .

I can see giving up a bit of beam width, as some others have mentioned.

Here's the 15" Lambda at 40 degrees. (blue line) I can see where there would be a bit of suck out around 1000Hz as you move off axis, but it looks very good up to 20 degrees off axis. A bit of toe in and you've got a very wide coverage zone.

 

[Zilch]

A bit of toe in and you've got a very wide coverage zone.

Thank you for posting the TD15 polars, Pete.

It's not only about "coverage zone," but also uniform power response throughout the design beamwidth to maintain the spectral balance of the reflected field. Toed-in it's less of an issue, but you also have less spaciousness. Extreme toe-in restores that and establishes an enhanced image rendition zone, as well, but the listening axis is displaced relative to the direct axis, 22.5° in the Geddes 45° alignment.

How much compromise is involved, I don't know. Summa uses a 15" woofer, as does Wayne's 4-Pi; it's apparently workable.

I'm curious to see how your experimenting with the RS28F is coming along... as I'm very interested in their performance with whatever elliptical waveguides you are mating them with. Also interested in how they perform raw... sans any waveguide.

Please appreciate that dome-driven waveguides are not mainstream in my efforts here; I am merely a student of the technology.

Same's true of the rest, of course, but I'm somewhat further along in this....

 

[rage]

First measurements.

BMS 4552nd, klipsch forte k23k woofers. 5uf cap, 18db attenuation on hf. 1.5mh and 12uf on lf.

I'm not entirely sure I can't hear that peak around 18k.

These really image well.

 

[skywave-rider]

First measurements.

BMS 4552nd, klipsch forte k23k woofers. 5uf cap, 18db attenuation on hf. 1.5mh and 12uf on lf.

I'm not entirely sure I can't hear that peak around 18k.

These really image well.

What waveguide are you running that with, Rage?

 

[donprice]

I can see giving up a bit of beam width, as some others have mentioned.

Here's the 15" Lambda at 40 degrees. (blue line) I can see where there would be a bit of suck out around 1000Hz as you move off axis, but it looks very good up to 20 degrees off axis. A bit of toe in and you've got a very wide coverage zone.

I think those of us in the "bigger is better" camp believe that the Holy Grail is finding eWave combo that has the XO in the 800-1000Hz range. I think Zilch has been on the trail for 5 years...hunting for the elusive poor man's JBL 4430 killer.

 

[Russellc]

I would love to see the TD15S, in 9 cubic feet tuned to 20Hz, anchoring the DE250/QSC.

Sub? Who needs one.

amen!:thmbsp: I'd like to see that as well! Those AE drivers are the cats meow!

Russellc

 

[Russellc]

'Zat what you're gonna build? :thmbsp:

Definately be watching this one for sure!

Russellc

 

[Russellc]

i used 15's on my first ewave project because I wanted more efficiency than I could get from my Advent's. I understood the tradeoffs and I had some pro 15" midwoofers that play up to 2K. I maybe lost a little directivity and pattern control but I gained about 3db over a 12" midwoofer and go deeper too.

Then again I am already planning another set with 12" midwoofers to hang in a music & dance studio already equipped subs. The 15's are great for rockin out but too big to dream of hanging from the ceiling.

I dont know, I've seen pics of A7s hanging from a studio wall!:thmbsp:

russellc

 

[fastbike]

Fwiw

Well, I have the DC300-8 w/ selenium/Pyle combo in a 2.6 cu ft box. Happy w/ sound. Sealed -3db 45Hz, ported, tuned to 28Hz, -3 db 35Hz
Can't beat the sound/price ratio.

Thanks for the info about 15" drivers. I'll cross them off the list then. I'll probably end up choosing one of these 12"s, although i'm not sure which would work best with the selenium:

Dayton DC300-8
Eminence Kappa
Monacor SPH-315
Monacor SPP-300/AD

 

[similost]

Very very cool to finally see a graph from a TD15... Looks even better than I imagined.. So I take it the red line is on axis?

 

[Schumacher ®]

I think those of us in the "bigger is better" camp believe that the Holy Grail is finding eWave combo that has the XO in the 800-1000Hz range. I think Zilch has been on the trail for 5 years...hunting for the elusive poor man's JBL 4430 killer.

Wouldn't that take one really large waveguide? This QSC barely makes 1500Hz.

 

[Schumacher ®]

Very very cool to finally see a graph from a TD15... Looks even better than I imagined.. So I take it the red line is on axis?

If you click the image, it's linked to Augerpro's test data. He's also got THD and IM distortion data. And while THD is very good across the spectrum, especially down low, it's the IM that really blows me away.

You can navigate to the various test data via links at the upper part of the page.

Remarkable woofer.