Who's speaker is this?

[Sibelius40]

I saw this photo posted from Iowa 2010 and this speaker - is the design posted anywhere? Cool lookin'!

Thanks in advance.

[howard]

ed lafontaine

[J_Shea]

That's a mighty handsome speaker all right.:)

[edlafontaine]

I guess I'd better write it up. ;)

I had help. Zilch over on Audio Kharma has a massive thread for the Econo Waves. It is a concept of high efficiency 2-ways using compression driver/horns along with (generally) big mid-bass. Emphasis is given (encouraged) to the re-use of vintage components.

http://www.audiokarma.org/forums/showthread.php?t=150939&page=799

What are there? Almost 12,000 posts in the thread? Just check the first few pages where Zilch has maintained a summary of designs.

Mine is called the E-Wave Delite. It uses the B & C DE 250 cd on a QSC 152i waveguide and an Eminence Deltalite II 2512 mid-bass.

more to come.

[killersoundz]

I guess I'd better write it up. ;)

I had help. Zilch over on Audio Kharma has a massive thread for the Econo Waves. It is a concept of high efficiency 2-ways using compression driver/horns along with (generally) big mid-bass. Emphasis is given (encouraged) to the re-use of vintage components.

http://www.audiokarma.org/forums/showthread.php?t=150939&page=799

What are there? Almost 12,000 posts in the thread? Just check the first few pages where Zilch has maintained a summary of designs.

Mine is called the E-Wave Delite. It uses the B & C DE 250 cd on a QSC 152i waveguide and an Eminence Deltalite II 2512 mid-bass.

more to come.

Ed, Why is the QSC waveguide chosen? Are they that good?

How are the B&C cd's? I've never heard much about them. I assume they are very high quality but have questions about power handling. They seem to be rated a bit lower than others (which I bet B&C's ratings are just more honest) but also require higher crossovers. Absolutely not a concern in your application however for pro audio usage I am curious.

[edlafontaine]

Ed, Why is the QSC waveguide chosen? Are they that good?

How are the B&C cd's? I've never heard much about them. I assume they are very high quality but have questions about power handling. They seem to be rated a bit lower than others (which I bet B&C's ratings are just more honest) but also require higher crossovers. Absolutely not a concern in your application however for pro audio usage I am curious.


Horses for courses. The QSC is economical, less than $15. The profile of the QSC includes a better mouth roundover than either the Dayton or Pyle. That gives it a better diffraction signature. The QSC is made to be flange mounted. That didn't suit my alignment of the Eminence.
There are better waveguides, for significantly more money. I may alter the mouth of these guides. Or, I would like to move on to the Iwata WH4:

http://www.diyaudio.com/forums/attachments/group-buys/187317d1284196568t-waveguides-horns-iwata.jpg

The Iwata WH4 is in the lower right corner, above

http://www.diyaudio.com/forums/attachments/group-buys/187323d1284204217t-waveguides-horns-iwata_gora.jpg

The Iwata WH4 on the right, above

I'm very happy with the B & C DE-250. It is the same as used by Earl Geddes in his Summa and by Wayne Parham of Pi Speakers in his upgrade path. They start with an efficiency of 109 dB/W....more than I need....In combination with the Eminence these are ~ 95 dB.

I'm not qualified to comment on their suitability for pro use.

They are crossed here ~1560 Hz

[ajinfla]

C'mon now Ed, where is the cap hearer in you?;)
How do they sound!!???:D
Seriously. In (size?) your living room? Placed? I'll bet the combined directional characteristics and high eff/dynamic capability makes them...err, slightly different from your typical (tragic?) 7" cone and dome on the face of 2 way box (even those with mustaches:rolleyes:).
Are you doing the full Geddes crossfire/multi-sub thing?

cheers,

AJ

p.s. and where the heck is that Enabl business on the cone, horn, box, your head, etc, etc???:p

[edlafontaine]

I sure am glad I found that "ignore" button...:D

[ajinfla]

Still luv ya Ed :p

[edlafontaine]

The carcases are 3/4" mdf except for the front baffle, the bottom of the slot port and the removable back...those are 3/4" lumber core plywood. Glue blocks run the length of all inside corners, except at the port entry.

Most of the veneer was sawn from ~1" boards, yielding 3 pieces from which to choose/match.

The backs are quarter-sawn sycamore. The balance of the cabinet is covered in cherry, chosen for figure and the presence of gum or mineral streaks. There's also a healthy amount of curl figure in this wood.

The top slope (3" in 12") was chosen to decrease the effective distance between the Eminence 2512 and the top of the case. Simulations done with Martin King's worksheets showed a decrease in ripple as a result. A flat top would have produced ripple ~+/-2 dB. The sloped top is +/- 1 dB in the 650-1K range. I believe the sloped top also makes whatever standing waves do exist more diffuse...

The slot port is sloped 3 in 12 as well. The top of the exit includes a ~4" radius to the front of the case. The bottom goes to the floor with a ~5/8" roundover. There is a mid-slot brace which connects the top and bottom of the port.

There are hard maple stiffeners on all panels except the slot port and removable back. These run diagonally and are tapered, thicker in the middle.

The areas between stiffeners are covered with Owens Corning 703, 5/8" thick. My thumbnail calculations tell me that for this material (3.0 lb/cf) each cabinet has 0.9 lbs. of fiberglass on the walls. Additional stuffing of ~1 lb. of polyfil was in place during the MWAF. I have since reduced this by half and will further cut back on the stuffing once I get used to this level, for comparison purposes.

The B&C DE-250 is attached to a QSC 152i waveguide. The mounting of the combination evolved from an 11th hour query to which Zilch responded: moving the front of the waveguide forward slightly would lower the response tilt from ~5.5 degrees up. The mount rests on the cabinet with no attachment except the wires. The slope of the top resists displacement from vibration. The weight of the CD keeps it in place. I'm very happy with this elegant solution coming out of what was for me a moment of indecision. It works.

I made a wooden taper, attached sand paper and used it to remove the mold marks within the throat of the B&C DE-250. I then used it to match/smooth the transition to the QSC 152i waveguide.
Sanding plastic in a "confined" space required frequent cleaning of the sandpaper, but it got 'er done. I was ever careful to maintain the orientation of the cd while doing this...

Using loudness or bass-boost from my receiver tells me the center frequency of the boost is in the wrong place for these. I have plans to go active. I will explore some bass boost at a better chosen frequency.

I will sketch up a side-view cut-away.

[edlafontaine]

http://i18.photobucket.com/albums/b117/wolf_teeth_speaker/Dayton%202010-MWAF/new022.jpg

[edlafontaine]

bwaslo's comments from Audio Kharma regarding the MWAF showing:
Among the entrants, I would say that Truthseeker's Delites were probably the best sounding thing there, at least to my ears, but then I'm now somewhat tuned to waveguide sound and not much satisfied with cone/dome sound. A few of the winning speakers of the event I actually didn't like at all, couldn't see the appeal.

;)

[edlafontaine]

http://i16.photobucket.com/albums/b31/edlafon/E-Wdlitepottermboard.jpg

The script is easier to read in person. It says: E-Wave (zm) DeLite. That's not a trade mark, its a Zilch Mark! :D

http://i16.photobucket.com/albums/b31/edlafon/E-Wdlitehatch.jpg

These were made to travel, so the terminals were recessed.

http://i16.photobucket.com/albums/b31/edlafon/E-Wdlitehatchcloser.jpg

[edlafontaine]

Wayne Parham's comments from Audio Kharma regarding the sloped top:

Very good. This is something too often overlooked, but very important in larger cabinets used with midwoofers run up high, like all the ones we're using in matched-directivity two-way speakers. It's a good idea to model the internal standing waves, to position the midwoofer and port where the standing waves are zero crossing, not in a peak pressure node. Then it's usually a good idea to put some insulation in the cabinet spanning the cross-section too, not just along the walls. This helps attenuate the lower midrange inside the cabinet.

* http://audioroundtable.com/forum/index.php?&t=search&srch=standing+waves&btn_submit=Search&field=all&forum_limiter=33&search_logic=AND


;)

[edlafontaine]

http://i16.photobucket.com/albums/b31/edlafon/E-waveprogress070610.jpg

Is it just me?...or is something out of order? :D

[erikb]

those are beautiful speakers :)

[edlafontaine]

http://i413.photobucket.com/albums/pp216/arlis/iowa%20diy%202010/IMG_4449.jpg


Thanks for all the comments

[edlafontaine]

Time to weigh in with comments from gurus and all others. ;)

What will be the effect on the imaging by moving the mid-bass forward in the cabinet & adding a larger radius roundover to the edge of the recess???

[killersoundz]

Time to weigh in with comments from gurus and all others. ;)

What will be the effect on the imaging by moving the mid-bass forward in the cabinet & adding a larger radius roundover to the edge of the recess???

Ed I am curious as the reason you chose to rear-mount the woofer.

Here are the pro's and con's how I see it:

Pros:
-Looks good
-Time aligns the woofer closer to the horn (in most cases)

Cons
-diffraction

I'm not sure if there would be any realistic difference between the current configuration, a larger radius, and even flush mounted. But I don't know, and I'd like to know for sure.

By the way I think a 12" woofer is beaming starting around 1000hz. This is one (of many reasons) I'm messing around with a design using a 2" exit compression driver & horn that can be crossed over as low as 600-800hz. Having that extra bit of midrange on the horn has to sound spectacular (in my imagination).

How do you like the sound of these? They are clearly a different animal than what would be considered normal home audio speakers. Accordion surround woofers and horns are incredibly efficient, that's nice ain't it?

[ajinfla]

I highly doubt it's (HF) diffraction.
At the frequencies that woofer operates, it will be quite directional where edge diffraction will be any concern (well below 1k).

[killersoundz]

At the frequencies that woofer operates, it will be quite directional where edge diffraction will be any concern (well below 1k).

Right that's what I was kind of saying. It's getting directional probably an octave below crossover which is below the important 'imaging' area so it can't make too much impact.

One drawback I'd like to point out (and have confirmed by others) is since the woofer is directional right at and below the crossover, then it kicks into the horn which is pretty wide coverage at the crossover and a bit above, is this an off-axis nightmare?

That's the benefit of being able to use a lower crossover point with a larger format horn (and a larger woofer) I think.

[Æ]

I don't know, WHOSE speaker is it?

[killersoundz]

I don't know, WHOSE speaker is it?

I don't know, I think it was a BOSE prototype. Following tradition, the production model will be 100% plastic.

[ajinfla]

Right that's what I was kind of saying. It's getting directional probably an octave below crossover which is below the important 'imaging' area so it can't make too much impact.

One drawback I'd like to point out (and have confirmed by others) is since the woofer is directional right at and below the crossover, then it kicks into the horn which is pretty wide coverage at the crossover and a bit above, is this an off-axis nightmare?

That's the benefit of being able to use a lower crossover point with a larger format horn (and a larger woofer) I think.

I'll admit that I haven't followed the Econowave (etc)threads (not my bag). I imagine that Zilch crossed where there is a decent directional match between the horn and woofer. That's the whole idea (at least horizontally :)).
The z offset will affect phase match, or time alignment (my favorite) or whatever you want to call it. The main effect is the frontal lobing angles of the non-coincident driver combined outputs.

cheers,

AJ

[killersoundz]

I'll admit that I haven't followed the Econowave (etc)threads (not my bag). I imagine that Zilch crossed where there is a decent directional match between the horn and woofer. That's the whole idea (at least horizontally :)).
The z offset will affect phase match, or time alignment (my favorite) or whatever you want to call it. The main effect is the frontal lobing angles of the non-coincident driver combined outputs.

cheers,

AJ

I haven't followed the e-wave threads either...only because there are so many posts I don't have the time or patience to start reading.

[Æ]

I haven't followed the e-wave threads either...only because there are so many posts I don't have the time or patience to start reading.

Zilch was present and displayed at our last DIY.

[killersoundz]

Zilch was present and displayed at our last DIY.

Honestly I don't even know who Zilch is. :(

[edlafontaine]

killersoundz posted:
Ed I am curious as the reason you chose to rear-mount the woofer.


Originally Posted by Zilch:
...get the offset aligned properly. We've reduced the center to center distance between woofer and waveguide in Deluxe to the absolute minimum and achieved a +/- 15° (-6 dB) forward lobe. Farther apart, the lobe gets smaller, and the axis must be aimed more precisely.

It's a somewhat esoteric point that matters hugely; the height of the QSC waveguide is against us in this....


Originally Posted by Zilch:
Delite was prototyped with rear-mounted woofer and front-mounted waveguide on a 3/4" baffle. With that relationship, and using the crossover as designed, the forward axis came out at +4.66°, suggesting that the waveguide could come forward a bit, relatively.

http://techtalk.parts-express.com/showthread.php?p=1637407#post1637407

[fastbike1]

Since you don't want to do any reading of the EconoWave "theory", the simple answer is that the design works.

Longer answer: using a woofer that meets the general spec (i.e. can cross @ ~1600Hz), and mounting the woofer as close as possible to the wave guide, will give good to excellent results depending on your tastes and ears. This is the basic EWave w/ the generic crossover and PH612 waveguide (or JBL equivalent). . Several more specific designs have been developed for certain CDs, waveguides, and woofers. These are primarily crossover variations. One of the original design parameters is smooth off-axis response. Several variations (tests) have demonstrated limited to no effect from cabinet edge diffraction or woofer mounting style. These demonstrations are via response measurements rather than strictly subjective accounts.


I haven't followed the e-wave threads either...only because there are so many posts I don't have the time or patience to start reading.

[edlafontaine]

Zilch's prototype with 3/4" z-offset resulted in a forward lobe axis of +4.66 degrees.

My build increases the z-offset by ~0.78". My thumbnail trig tells me this lowers the forward lobe to durn-near horizontal. :rolleyes:

If I move the mid-bass forward in the cabinet, I could move the waveguide with it to retain the z-axis relationship...or decrease it to restore some upward tilt. :confused: choices, choices...

Another consideration is that the current y-axis offset could be reduced...That would be a good thing, as it would increase the breadth of the (-6 dB) forward lobe. :confused: choices, choices...

[Zilch]

By the way I think a 12" woofer is beaming starting around 1000hz. This is one (of many reasons) I'm messing around with a design using a 2" exit compression driver & horn that can be crossed over as low as 600-800hz. Having that extra bit of midrange on the horn has to sound spectacular (in my imagination).The woofer is omni at low frequencies, whereas the waveguide is constant directivity (loosely) at some beamwidth. Key to a successful design is achieving a smooth transition between these, taking advantage of the woofer's "beaming" you mention. It's largely a function of the woofer diameter, the waveguide design dispersion, and the crossover frequency.

Wayne Parham (an EconoWave collaborator) did much of the groundwork defining these variables, and the prescription for making it work. The considerable leeway he describes is evident in the directivity maps I have provided for several of the designs in the "Flex Your PCD Mettle" thread here on Tech Talk. Those aren't sims, rather, the real deal, comprised of 19 discrete response measurements taken at 5° increments from 0° to 90° off-axis; for asymmetric designs, it's 37 measurements.

There are many designs targeting lower crossover frequencies, which generally mandate larger waveguides. Geddes's Summa, for example, uses a 15" woofer and similar-dimension waveguide to cross below 1 kHz. He runs DE250 down that low in this "flagship" design. I've designed with the 30" JBL Screen Array waveguide running at 800 Hz using their TOTL large-format (4" diaphragm) compression driver and 1.5" throat diameter. As in all of this, there are tradeoffs -- with larger than a 1" exit, directivity control drops below 20 kHz, and at 2", below 10 kHz. To get the low end down to 500 Hz virtually necessitates a 3-way design approach using a separate midrange driver and waveguide with associated "complications."

Ed has incorporated many of the principles we have been working through and refining over the course of the last three years. EconoWave did not start from scratch, however; the concept began with Altec's Model 19 ca. 1975, and was firmly established as "worthy" in the JBL 4430 using Keele's now-familiar "baby cheek" constant-directivity horn in 1980, which product is acknowledged as the font of subsequent designs by Parham, Geddes, et al. Clearly, Ed's design belongs to Ed, however, it is most gratifying for us "facilitators" to see it garnering such widespread appreciation here.... :)

[edlafontaine]

killersoundz posted:
How do you like the sound of these? They are clearly a different animal than what would be considered normal home audio speakers. Accordion surround woofers and horns are incredibly efficient, that's nice ain't it?

I like them very well. I had Modula MTM's set up in the room where these are now. The range covered by the DE-250 is much better than that which was covered by the Seas H1212. The efficiency contributes to a greater sense of realism. It is nice...better than what I've had.
Yet, they remain a work in progress. Twiddling with the x-y-z orientation is hoped to help them merge better than they already do. I may even offer someone a bargain price for a pair of 2512's so I can try other mid-woof's. ;)

[killersoundz]

Hey there Zilch, I appreciate you giving me the run down as by my fault I was too lazy to start reading into those threads.

Ed - Try out some B&C woofers?? :)