Zilch's AK Design Collaborative - Econowave Speaker

Maybe I E-wave the L-50 with the 127H-1's on the shelf then build NEW boxes for a E-wave LE14 combo? Interior box dimensions of about 12" wide x 18" deep x 30" tall = 3-3/4 cf?

Sounds like a superb plan. The man with the plan!
 
Agree. :yes: The aspect that I was trying to home in on was the observation that the more efficient driver actually sounds different in the midbass. The difference in frequency response is pretty easy to measure and to see. We have a pretty good idea of what the tradeoff is with respect to that.

The efficiency part is less clear though. :scratch2: Lots of folks would just say that the more efficient driver lets you get away with using less amp. However, what has been observed is that there is an aspect, "immediacy" or punch, that is also different between the two drivers. It's probably not a "night and day" type difference, but I don't even know what parameters or measurements to look at in order to have some idea of this difference. That's all I was asking about.

Interestingly, a large part of the Econowave principal is in some sense based on the fact that more efficient drivers sound "better" for some reason. The Econowave doesn't measure as flat as most dome tweeters, but the subjective reports are that it just sounds better; and, not just a little bit better, but *a lot* better. Also, it's not because everybody is actually playing their Econowaves at levels that can't be reached by dome tweeters. Some of it is surely the JBL horn, but reports about Wayne's 4Pi have been in the same vein; music just sounds more "alive" when played on compression drivers/horns.

Maybe Wayne, or someone who is really strong on the technicals, can lend a little insight here. My apologies if this is...:boring:

Most of the imaging magic here as I see it, is due to the "constant directivity"
of the wave guide. Especially slightly toed in so as to cross just infront of the listening position. Image is so stable, and it maintains WAY off axis, unlike any dome tweet could. (Unless mounted on a CD waveguide, of course!:D



Russellc
 
Couple of thoughts on the "Punchiness" of a higher efficiency driver:

Higher efficiency drivers require less power to generate the same output levels (obviously). Less power equals less heat, less heat creates less thermal compression in the driver. Less compression allows more "details" to come through.

That said, low efficiency drivers still allow this punch, so while high efficiency speakers do have their advantages in details, it's not the only thing going on. I believe Ray has made the observation on a couple of occasions that nailing the crossover between the woofer or mid and the higher frequency drivers will often times result in perceptually tighter and better bass response. I first observed this in my car audio days where "slow bass" almost always was due to a lack of midbass or properly positioned midbass. For every beat of the "slow" kick drum, there are high frequency components that give it the "Slam" effect. Well thought out driver selection and crossover design allows those higher frequency components to coherently couple with the low frequency drivers.

YMMV
 
Let's remember that LE14As have limited excursion and power handling capacity using them for extended bass like we are. Tuned higher and in smaller boxes, they're not being "pushed" quite so hard.

JBL clearly liked what they do, and subsequently beefed them up in the three later variants, "H" (L220/2), H-1" (L250) and "H-3" (Array 1400) to play with the big boys, and also build "medium-power" subs. :thmbsp:

..<snip>....

That's what I thought was going on...if they're in those big boxes I guess you'd better be careful if you've got a 200W amp hooked up. I'll stick with the smallish L55 boxes for now. Crossovers are almost done, still waiting for dustcaps.
 
Nice job your your speakers. How do these sound compared to the others that you've built?

As far as for home use, I have built many different speakers using a variety of drivers from Audax, Peerless, Dynaudio, Morel and Focal. The econowaves have nothing to be ashamed of. I am quite pleased with the detail and smoothness of the mid to upper registers. A little more open in the upper registers than the Morel and Dynaudio tweeters that I have used.

The Dayton Classic 10" woofers were a pleasant surprise considering their price. They deliver very respectable bass and do so cleanly. I had no problem filling a very large room with bass. They do quite well with lower mids making it a good woofer for a two-way system.
 
Man I tell yu, anyone thinking of LE10 versions, wow nice bass!
.
.
.
Jack you out there?


I hear ya, Kegger. And I hear that great bass from the 10 inch JBL's as well. They are absolutely surprising little speakers, aren't they?

The rear channel pair in process now will use the LE111H variant, which also sounds very good. But they are only 1.6 cubic feet, so will probably be somewhat limited in LF output. But that is pretty big for rear channel speakers in a HT application where they must be mounted on stands. I can live with that.
 
I've been a little lazy about posting pics of my just finished Ewaves as I've
been too busy listening to them! Well here they are, I still plan on making some grills to cover the LE14A's(they look like white-walls to me). The last 2 months have been a whirlwind of DIY for me as I have built the Ewaves, the 2A3 amp on the cabinet you see as well as the 12B4A linestage to the right of it. I need to complete the Hagerman Bugle phono stage I just received and then I will be focusing on collecting music for a bit.

img0398nb9.jpg


I am passively biamping with the 2A3 amp on top and a Behringer A500 on the JBL's, both driven by the 12B4a linestage. It sounds reeeeaaaaalllly good!:thmbsp:
 
Beautiful. Simple, clean, pretty whitewalls you have there. Get some armor all to make the black part shinier and you'll be pimping. :)

Seriously though, very well done and nice component selection. Worth mentioning again that the amp is stunning. Nice cabinets for the waveguide.
 
Le 10

I hear ya, Kegger. And I hear that great bass from the 10 inch JBL's as well. They are absolutely surprising little speakers, aren't they?

Agreed - Had a pair in diy transmission line towers in the early 80's. Put them to good use rattling pictures on the walls with turntable feedback.
 
Xover mod

Hi All
I'm not sure what it looks like on the scope but I jumped cap c3 (1.5uf)with a wire and it really got the ewave sounding sharper. Now don't get me wrong, they sound great with the cap but I'm going to listen jumped for now. I know I've seen a Xover with an .47uf and if I can find one around here I'll give it a try. It could be that the Altec Madrid has lots o bass and my hearing is going bad (old age :music:)
 

Attachments

  • altech.jpg
    altech.jpg
    49.3 KB · Views: 56
The limiting factor in E'Wave is the Seleniums, actually; check the data sheet for their minimum recommended crossover frequency. Jack was able to have the system cross a bit lower by using a higher frequency highpass as part of the compensation, but still avoiding the resonance peak.

BMS on the same waveguide easily plays down to 1.0 - 1.2 kHz.

Using the 1.5" throat version and a large-format (4" diaphragm) JBL driver, I have been able to play them to surprisingly low frequencies, ~725 Hz, experimentally.

http://audioheritage.org/vbulletin/showthread.php?p=204976#post204976

Geddes teaches us that cutoff in the traditional sense is not a concept applicable to waveguides, but with one this small, there's still likely to be pattern control issues down that low. I have not run the polars to evaluate.

Others far more competent than myself are now working with similar combinations on LHF, so we may see some more information developed in the future over there:

http://audioheritage.org/vbulletin/showthread.php?p=215693#post215693

The 12" square format versions play a bit lower, but I haven't done much work with them other than cursory measurements. RobH is your authority on those, and he has stymied Geddes with them on another forum, well enough so as to elicit a concession that waveguides are not an absolute, rather, a continuum; there are more "waveguidey" waveguides, and also lesser ones, apparently.... ;)


Sorry to drag this out of the past but I have recently come across a econo pyle 22xt+ compression driver /511B /JBL K140 combo (econo @ $100) and wanted to attempt a lower cross over. I tried the <95 db econo cross on these and they sounded pretty good, just not enough top end and maybe a little mid high hole. Without measuring or learning spice is there a econo way to get close enough values for a cross at about 750 - 800 hz. I plan on using Wayne's attenuation and compensation values, but I don't understand how Jack was able to cross the le 14A at 900 hz and the selenium at 3000 and still end up with a flat response.

As far as measurements, Zilch and Dnewma04, I am putting together a Wallin Jig to use with speaker workshop, but I am slow at such things. Thanks for the advice!
 
I'm not sure what it looks like on the scope but I jumped cap c3 (1.5uf)with a wire and it really got the ewave sounding sharper. Now don't get me wrong, they sound great with the cap but I'm going to listen jumped for now.
I believe you've defeated the HF comp, and are just listening to the native response of the Selenium driver on the E'Waveguide only.

The curve is posted several places earlier in this thread; in my study of Wayne's eight attenuation component selections being one of them. :yes:


Without measuring or learning spice is there a econo way to get close enough values for a cross at about 750 - 800 hz. I plan on using Wayne's attenuation and compensation values, but I don't understand how Jack was able to cross the le 14A at 900 hz and the selenium at 3000 and still end up with a flat response.
It's the initial cap and inductor in the highpass that set the basic electrical filter characteristics, but it's the acoustic response of the filter and driver/waveguide in combination that matters in the end.

Look back at Post #1, and the earlier 811/511 work, and you'll see that all of these have excess response in the upper midrange, and the electrical filter frequency and slope correct that before the actual HF comp is applied to flatten the higher-frequency response.

You've really gotta have measurement capability to do this stuff, else it's a wank in the dark.... :yes:
 
Sorry to drag this out of the past but I have recently come across a econo pyle 22xt+ compression driver /511B /JBL K140 combo (econo @ $100) and wanted to attempt a lower cross over. I tried the <95 db econo cross on these and they sounded pretty good, just not enough top end and maybe a little mid high hole. Without measuring or learning spice is there a econo way to get close enough values for a cross at about 750 - 800 hz. I plan on using Wayne's attenuation and compensation values, but I don't understand how Jack was able to cross the le 14A at 900 hz and the selenium at 3000 and still end up with a flat response.

As far as measurements, Zilch and Dnewma04, I am putting together a Wallin Jig to use with speaker workshop, but I am slow at such things. Thanks for the advice!

The electrical filters, in this case at 900 and 3000hz rarely directly correlate with the acoustical crossover point, where the drivers response characteristics are entered into the equation. You need solid measurements, either from a reliable party or taken yourself, in order to design good crossovers. You are taking an important step by getting the equipment to measure on your own.

Just to give you an example, if you have a tweeter that is very flat down to 1500 hz and exhibits a natural rolloff below that point and you crossed that tweeter over at 5khz with a second order filter (12dB per octave), your frequency response would very closely correspond to the electrical rolloff (12dB per octave) where at 1500 hz, that rolloff would become steeper because of the natural rolloff occuring from the driver.

Now, if you use that same driver and cross it over at or near 1500hz, you'll see a sharper slope because the two rolloffs are working with each other in the same frequency range.

There are also tricks you can play with the type of crossovers used. Higher Q crossover alignments exhibits rising response as your approach the crossover point before falling off more sharply. So, if you have a mid that dips after 1500hz and a tweeter that rollsoff above 2khz, you can do things like purposely building in a gap in the electrical crossovers to acheive a smooth crossover region acoustically.

Hopefully, that makes some sense.
 
Thanks both of the explanations make a lot of sense. I was planning to buy a variety of coils and caps and then measuring because of my lack of ability/experience to due otherwise.
 
Off topic? How to measure Econo-Wave for absolute beginners... comments on these two perspectives and further suggestions, please.
i) Common Sense: It is imperative to begin by studying an acoustics primer in order to obtain a solid grounding in the subject. Attempting to measure without understanding the basics of the process nor results is pointless.
ii) Lazy/Innumerate/Just-want-'em-to-sound-best Persons: get the testing gear and be walked through the measurement/interpretation process by others, (e.g.)
REQ: http://www.hometheatershack.com/for...nks-guides-articles-stickies-please-read.html
http://www.the12volt.com/installbay/forum_posts.asp?TID=74558&PN=1
Topic has been covered recently: http://www.audiokarma.org/forums/showthread.php?t=200741
http://www.audiokarma.org/forums/sh...equency+response+measurement-+a+first+attempt
 
Could someone give me the outer measurements for the JBL 338800 horn lens? They are out of stock right now and wont have any in stock until next week sometime.


Thanks

Frank
 
Back
Top Bottom