Zilch's AK Design Collaborative - Econowave Speaker

[jaybird]

I have another dumb question, earlier today Russell mentioned the low dcr in the coils, would a higher dcr have an adverse effect on the low end output? I believe that would be for L2. ---jay

 

[skywave-rider]

Jay,
I bought the 18 ga Jantzen aircores for the same reason.
They work fine.
.22 (Icore) compared to .38dcr (18g aircore).
Supposedly the air cores have less distortion.
Like Russell says, if you spend more for the larger 14 gauge aircore, you get both benefits.
Pick your poison.

 

[Zilch]

has anybody measured the off-axis of the pt-h95hf against the pt-f95hf?

does the "h" version hold horizontal pattern control any lower than the "f" version? it doesn't appear that there is any benefit as far as the on-axis measurements. maybe there is some benefit vertically? ]

They are equivalent horizontally. The "F" has lower distortion, but less pattern control in the vertical.

See the PT Waveguide white paper, linked in the first post of this thread..... :yes:

 

[publius]

They are equivalent horizontally. The "F" has lower distortion, but less pattern control in the vertical.
See the PT Waveguide white paper, linked in the first post of this thread..... :yes:

thanks. the white paper is where i began. i've read it a couple of times. there are no plots for the "f" version, so that is a little confusing. also, when comparing the "h" version to the old 2381 horn, they switch the drivers from the 2446h to the 2450sl and then make comments about how the new horn has a flatter frequency response. that's not exactly a well controlled experiment.

so, i ended up looking at the plots over at lhf, which directly compare the two horns. :thmbsp: on axis, the "h" version doesn't seem to offer the benefit mentioned in the white paper of "pattern control is extended to a lower frequency," but it is tough to know for sure without polars or some other off axis measurements. anyways, thanks for testing these horns, publishing the results on the web, and helping me decipher the ptw white paper.

 

[Zilch]

I believe our preliminary finding was that the "H" version plays a bit lower. We'd have to do full polars under the same operating conditions to arrive at definitive conclusions.

Suffice it to say that I was not disappointed by Geddes's measurements of the E'Waveguide. The "compact" PT-Fs make for easy builds exhibiting excellent performance.... :yes:

 

[TnT2]

I really don't know how you guys do it, especially Zilch. I think I am going to need a few days just to digest the different horns presented in the last few pages. There is so much to learn and now I need to be aware of the screen effect. Thanks.....

 

[Paratima]

PSA: Ladies and Gentlemen, the beloved Selenium D210Ti compression driver, having flirted briefly with a $40 price tag, is back on sale at P.E. for the low, low price of $29.88.

http://www.parts-express.com/pe/showdetl.cfm?&Did=7&Product_ID=121091

I just ordered another pair (before posting here!). You might wish to do the same. No, they still don't have the 1.5 mH coils in stock.
This concludes our public service announcements for this morning.
(I get no compensation from PE, more's the pity.)

 

[Paratima]

Suggestion from a relative newbie

At 220 pages and almost 3,300 posts, this thread is getting extremely heavy. There is an incredible amount of information here, to be proudly pointed to as a reference in the future. However, I sense that the AK Design Collaborative team has gone well past the original theme of Econo-Waveguide Speaker and is well into the realm of Massive Waveguide Speaker design. This isn't a bad thing, but it calls out for its own thread. Relevant discussion of MWG will be harder to isolate in the future. General discussion and BS is taking over. We are all guilty - it's an easy thing to do, but it muddies the waters of the original concept.

Why not stick a fork in this one and call it "Done"? Otherwise, information actually relevant to EWG and MWG will just become more difficult to find.

 

[skywave-rider]

Warts and all

Where can you get all the information contained herein, enjoy the experience (have fun,) and witness -- or even be part of -- the process?

E'Wave-on, blind alleys and all.
This thread is a beautiful, bloated thing.

 

[Kegger]

Do we have any idea what's pos/neg on the xd-120 drivers?
(meaning forward diaphragm movement)

 

[skywave-rider]

Hi Kegger,
I didn't write that down, I believe it's rev polarity with standard Ewave xo and LPad wiring, but give me a few minutes and I could RTA it.
(I packed up the setup, a little time...)

 

[Kegger]

Much appreciated, Thanks!

Curious how much it nulls when reversed, does it null quite well?

 

[skywave-rider]

Kegger:
Positive polarity (using red 8 Ohm sticker on 18 Sound as pos,) on LE8T-H. This woofer is a backward JBL design -- pos voltage on Neg terminal gives forward cone motion.

Checked against 123A-1 woofer which is exactly the opposite. Confirmed.

On the LE8T-H setup, I find that the waveguide has smoothest response in the crossover region set back about 1/2" from the front of baffle, with woofer flushmounted.

There I get a symmetrical 6dB notch when flipping the polarity.
When doing this at front baffle position, I still see a notch, but the crossover region is depressed a few dB, so it is not so obvious. It's definitely there, though.

I hope this will give you enough info to extrapolate for your design.
Happy New Year!

 

[skywave-rider]

to be clear

Keg,
to be clear, if you are using a woofer where pos v on pos terminal = forward cone motion, reverse polarity on the 18Sound.

 

[Kegger]

Thanks a bunch!

Let me confirm, (using Econo xover) woofer wired in phase, HD-120 wired backwards
just like the Econo xover does it, provides the correct sum? (Just making sure)

Yes Happy New Year to you as well, going to my brothers tonight. :beer::guitar:

EDIT: Your last post confirms. :thmbsp:

 

[skywave-rider]

Awesome, bring the E'Waves!

Thanks a bunch!

Let me confirm, (using Econo xover) woofer wired in phase, HD-120 wired backwards
just like the Econo xover does it, provides the correct sum? (Just making sure)

Yes Happy New Year to you as well, going to my brothers tonight. :beer::guitar:

EDIT: Your last post confirms. :thmbsp:

 

[Kegger]

I've considered bringing some, but he has a decent system, for a party anyway.

I do the AK'FEST every year halling all kinds of crap there, it is kinda nice not to
have to "Bring the System"

 

[Pio1980]

PSA: Ladies and Gentlemen, the beloved Selenium D210Ti compression driver, having flirted briefly with a $40 price tag, is back on sale at P.E. for the low, low price of $29.88.

http://www.parts-express.com/pe/showdetl.cfm?&Did=7&Product_ID=121091

I just ordered another pair (before posting here!). You might wish to do the same. No, they still don't have the 1.5 mH coils in stock.
This concludes our public service announcements for this morning.
(I get no compensation from PE, more's the pity.)

The D210Ti has been there at ca $30 per for a while, the D220Ti at ca $44 per, OTOH, hasn't been on open deep-discount for a while AFAIK. I don't know what/where the PODRCQ (Point-Of-Diminishing-Returns-Cost-Quotient) would be considered to be by the experts hereabouts relative to one or the other of these two drivers plus the cost of the JBL WGs and/or the on-sale 18 Sound XD 120 at $20 w/WG per, so I can't say there is ca $14 or better of relative improvement to be had between one and the other Selenium or the XD 120 complete at the bargain $20 per plus shipping.
You experts please, what say you, where is the relative PODRCQ between them? Is the D220Ti plus the largest budget JBL WG the biggest bang for the bux qualitywise of the 3 choices?

S.B.

P.S. We see that the XD-120 wants a higher cross-over point than the others noted, so they aren't directly equivalent to the Selenium+JBL WG alternatives. Still at $20 complete and a useful sized potential replacement for smaller boxes, hmmm---.

 

[Zilch]

Why not stick a fork in this one and call it "Done"? Otherwise, information actually relevant to EWG and MWG will just become more difficult to find.

Thank you for your observations, Paratima. Jack and I have discussed these issues at length, and it has been our intent from the outset that E'Wave be more than a cookbook project, rather, instead, a path to discovery of modern loudspeaker design concepts, not merely for others, but for ourselves, as well.

The necessary and sufficient information for participation may be found in Post #1, directly accessible by clicking "First" at the top or bottom of each page.

The rest of the thread comprises the accrued knowledge and experience of its many participants; it goes wherever this unique and, may I say, genuine spirit of inquiry takes it. Yes, it is big, inclusive, and organic, but it is also most assuredly engaging, and I, for one, could not have hoped for a more gratifying result than the continuously expanding knowledge and interest presented here.... :thmbsp:

 

[Kegger]

The XD-120 sure is a bargain at $20.00 each for a horn an driver, tough to beat!

The more I play with them the more they grow on me, I would have no problem in
endorsing them, and Skywave has shown they work just fine on the Econo Xover.

The Econo Xover point is just fine for them, I'm actually crossing over little lower!

Being there a smaller guide they do fit more of the smaller baffle speakers as well. :thmbsp:
(Heck at $20.00 a pop who cares if they get replaced, great drivers to "play" with)

Not advocating one is better then the other, just for the price of admission XD-120
is a worthy contender.

The D210Ti has been there at ca $30 per for a while, the D220Ti at ca $44 per, OTOH, hasn't been on open deep-discount for a while AFAIK. I don't know what/where the PODRCQ (Point-Of-Diminishing-Returns-Cost-Quotient) would be considered to be by the experts hereabouts relative to one or the other of these two drivers plus the cost of the JBL WGs and/or the on-sale 18 Sound XD 120 at $20 w/WG per, so I can't say there is ca $14 or better of relative improvement to be had between one and the other Selenium or the XD 120 complete at the bargain $20 per plus shipping.
You experts please, what say you, where is the relative PODRCQ between them? Is the D220Ti plus the largest budget JBL WG the biggest bang for the bux qualitywise of the 3 choices?

S.B.

P.S. We see that the XD-120 wants a higher cross-over point than the others noted, so they aren't directly equivalent to the Selenium+JBL WG alternatives. Still at $20 complete and a useful sized potential replacement for smaller boxes, hmmm---.