Zilch's AK Design Collaborative - Econowave Speaker

[borus]

Having studied liquid dynamics so many years ago. I'm not sure I am remembering correctly. It seems to me that unlike cone speakers the voice coil is not the area to be aligned. Within the horn/waveguide the column or mass of air is the substance that is vibrating. So is the opening or mouth of the horn as it transitions and interacts with the air in the room where time alignment should be measured?

Borus

 

[Zilch]

It's the acoustic center, and it's an elusive target.

I recently learned that it moves with frequency.... :yes:

http://www.aes.org/e-lib/browse.cfm?elib=8194

http://www.aes.org/e-lib/browse.cfm?elib=8424

 

[4343]

Blasting the 'Waves!

Well, I finished putting together my test boxes, now I'm trying to break in the new foam on the Advent 10's. Had to dial in a lot of bass boost after disconnecting the 2235's... (Who'da thought a 10" would sound bass shy compared to a 15"r?)

Coltrane "Favorite Things" followed by Black Sabbath "Paranoid" got 'em thumping!

Oh, I played Paranoid BEFORE Coltrane too, loud (wife was out shopping), but had to play it for her when she got back. Playing more Coltrane now after swapping the HF polarity for the JBL driver I used on the waveguides, sax is much better now. I kind of like the rolloff the JBL driver has, sometimes. Hopefully JBL will be getting more soon so's I can go back to the Seleniums and decide which goes where. Looking for some singers now...

Might have to go back to Black Sabbath and see if it still needs the bass boost tomorrow.:scratch2:

Yes, the 10 does end up behind the waveguide lip, and that's as far as I wanted the L-Pad rotated, even though I am running 16 ohm 2420 diaphragms in the drivers.

I'm thinking about getting the bolt on D220Ti's for the QSC WG, is that going to be a standard configuration?

 

[rvsixer]

Envision for the moment and the sake of conceptualization that the eWave dispersion pattern is a hard an absolute 90°. Toed in the Geddes extreme 45°, it's easily seen that the outer edges of the sound field are parallel to the screen and side walls...

For some reason I was thinking 180° dispersion :sigh:. Yes at 90° no first reflection issues with the screen.

...center channel...it may still be, for other reasons.

Do tell...I need to decide on two or more PCB's .

Thanks for your insight.

 

[Duffinator]

With the Econowave, and its CD dispersion, what say 'ye on using them with with said TV? Recommended placement? .....Phantom center or econowave center?

Maybe I need to just buy a wall mount big screen, but I am just recovering from my first ever layoff I don't think that's gonna' happen right now :thumbsdn:. Thanks guys, all experience and ideas and opinions welcomed.

Rob

Rob, are you using an AVR with DD and DTS discrete capability? DVD or BD DVD? In order to hear the full discrete soundtracks you'll need the center channel. It's important to have the same HF source for your three front speakers as sound and voice move from left to right. In order to accomplish this you'll need to build an e-wave center channel for maximum effect. You can read up on this topic at THX. I have been thinking about something similar using JBL L200T fronts and then make a center channel using the same HF butt cheek horn and CD.

 

[Russellc]

I have no idea how this will affect the thread, but I've been sitting on this news since June.

The paper issue will hit the news stands on 11/17 and I urge AK-ers to check it out. This magazine is like Popular Electronics, Popular Mechanics and a science textbook on steroids.

http://makezine.com/magazine/

http://makermedia.createsend.com/T/ViewEmail/r/6FB4B6F20764A504/269FA68AE305A82E44D0DD5392A9C75A

I'll have more to say later, but right now I have a fever & have to go work some overtime.

This should boost it along again I'd think.:yes: Very interested in the Paper version of that mag, I was a real Mechanics lllustrated junky as a kid. Loved the big guy that always test drove cars, forget his name Tom Mcall or McHail or something like that.

russellc

 

[rvsixer]

Rob, are you using an AVR with DD and DTS discrete capability? DVD or BD DVD? In order to hear the full discrete soundtracks you'll need the center channel....I have been thinking about something similar using JBL L200T fronts and then make a center channel using the same HF butt cheek horn and CD.

All good questions. I have a BD player outputting DD 5.1 SPDIF to an older Marantz SR880mkII. According to the Marantz user manual, if CC is set to "none" any center channel audio will be mixed in with the LR mains audio. I take this to mean phantom CC.

The new HT receiver codecs will require a physical CC as you mentioned. Keep us posted if you do the "butt cheek" center channel (BCCC ), would love to know how it works out.

Rob

 

[Russellc]

Honestly, getting the cat to drop a deuce in the can is far more impressive than than building a pair of eWaves. After 10 years our cat has been trained to get water from the bathroom sink. It jumps into bed and climbs on top of us until we get out of bed and turn on the water for it.

Back to the topic at hand - nearing completion of low power testing...the 35 wpc Denon in the garage is a lot louder than I remember...the bottom end is weak as expected...ZZ Top's "My Head's in Mississippi" comes across as loud and nasty as any sane person would want...from only 35 watts. The high power test (250-300 wpc) should be a blast.

I had a grey stray cat, lived to see 25. she used the toilet, came trained that way or picked it up on her own. One more to wait for to get out of the bathroom!

Russellc

 

[Russellc]

I'm thinking about getting the bolt on D220Ti's for the QSC WG, is that going to be a standard configuration?

I think Zilch has played with that combination a ways back?

Russellc

 

[Zilch]

I'm thinking about getting the bolt on D220Ti's for the QSC WG, is that going to be a standard configuration?

"Standard" eWave will always be the same, I suspect. Once we work through the details, QSC will be an option....

Do tell...I need to decide on two or more PCB's .

Read up in Toole. He devotes a section to it: 9.1.3 - An Important One-Tooth Comb - The Fundamental Flaw in Stereo.

I have been thinking about something similar using JBL L200T fronts and then make a center channel using the same HF butt cheek horn and CD.

Check out Hamilton's HT on LHF - 4430 mains, Zilchified L200t3 surrounds, Zilch-design center channel.... :yes:

 

[Bauhausler]

This should boost it along again I'd think.:yes: Very interested in the Paper version of that mag, I was a real Mechanics lllustrated junky as a kid. Loved the big guy that always test drove cars, forget his name Tom Mcall or McHail or something like that.

russellc

Uncle Tom McCahill. I treasure my dad's copy of his book Today's Sports and Competition Cars, Prentice Hall, 1959.

I've been buying Make on the news stand and just got a subscription. It's a medium format quarterly. Don't blame me if you read it and are suddenly possessed by the desire to build a computer controlled solar water heater or autonomous robotic blimp.

 

[4343]

"Standard" eWave will always be the same, I suspect. Once we work through the details, QSC will be an option....
...
:

Thanks, there's no way I can afford the B&C anytime soon. There is a pair on ebay that need diaphragms, and the (the dias) cost more than the Seleniums!

So far, using what I have on hand is working OK after I remembered that JBL HF drivers are also + to black for forward motion.:thmbsp: Just need more waveguides...

Listening to Tchaikovsky and Sade today, I love the way I can be at the opposite end of the room (14'X40') and still hear the separation!

 

[Zilch]

The bolt-on Selenium D220Ti fits the QSC waveguides.

Not sure that they won't require a filter tweak, but they sound quite good using the standard eWave crossover.... :yes:

 

[Bauhausler]

Fooling around with various crossovers, drivers and waveguides

I've got Kef B110s in LS3/5a sized boxes with the JBL 6" X 6" waveguides and Selenium D220Tis. Here's the crossover and the response for this setup. Looks about +/- 3 dbs from 160 hz to 20K. The scale on the RTA is 5 dbs/division.

Note: when I jumper out the notch filter in the high pass the little dip at 10K goes away.

Later Note: I tried the D220Ti with several crossovers with the PH612 and the B110. This combo, with teh small 6" WG measures flatter than any of the PH612 combos. But I'm just measuring it straight on so I have no idea of the comparisons of patterns. I would expect them to be quite different due to the very different shapes of the waveguides. I was pleased to see that the 6"/D220Ti combo will go low enough to match up with the standard Ewave LP crossover.

Latest Note: I have both channels built, tested and running. They test very very close on the RTA which is a relief. With only a 6" C-to-C distance, from a listening position 20 feet away these approach the ideal of a wide dispersion point source. The soundstage is panoramic and deep with excellent definition.
I suppose I could try the D210Ti drivers in them to see how that works but I don't think there's much point.

 

[rvsixer]

Read up in Toole. He devotes a section to it: 9.1.3 - An Important One-Tooth Comb - The Fundamental Flaw in Stereo.

Very interesting, I might have to read the book now :scratch2:. I came away from it that CD, along with a normally reflective room can help eliminate/minimize the effect.

 

[Zilch]

Very interesting, I might have to read the book now :scratch2:. I came away from it that CD, along with a normally reflective room can help eliminate/minimize the effect.

Now that I've found it, I'll have to re-read that section myself, so I can pretend to know what I'm talking about.... :tongue:

 

[MartinV56]

Hi Guys, I will try a woofer tru-sonic 15 "150W with the econowide'm looking tru-sonic specifications, compare against the 420y Altec and the trusonic, some experience,welcome suggestions, thanks,Martin

http://www.hifilit.com/

 

[wushuliu]

Hi everyone. I'm new to this thread and will try to get through as much of it as I can, but I have one question. So far the builds I've been seeing involve older/ used woofers. I have not come across any references to new woofers. What new woofers do people recommend?

 

[Bauhausler]

Hi everyone. I'm new to this thread and will try to get through as much of it as I can, but I have one question. So far the builds I've been seeing involve older/ used woofers. I have not come across any references to new woofers. What new woofers do people recommend?

If you look through the Official Ewavers list (now over 70) on the first page you'll see that several people have had success with the Classic Series Dayton woofers from Parts Express. That's a low-cost option.
Other than that it's pretty much up to you to decide on the following parameters:
How much you want to spend.
What size cabinet.
How low you want the bass to go.
and then search PE, Madisound, etc. for candidates that will play cleanly up to the 1600 hz crossover region.

What a number of us have done is to buy the parts for the conversion, build the crossovers and experiment by substituting this tweeter section into/on top of existing speakers. Once you've heard it a bit you may have a better idea of what kind of 'permanent' speaker you would make.

I've done 2 pairs with Advent woofers. Yes, they're old and they're low-tech but they're cheap, readily available, easy to implement, go low in a reasonably sized box and sound very decent.

There are a few limiting factors to consider in choosing a woofer:
1) the above mentioned 1600 hz crossover point. Woofers designed as subs probably won't play tha thigh
2) the Waveguide is 12" wide, which establishes a minimum baffle size.
3) woofers as large as 15" have issues with the center-to center spacing of the drivers, which should be kept a small as possible if you want a simple build.

Things that are not serious issues:
1) woofer sensitivity. Within a broad range this can be compensated for in the crossover with established parts sets.
2) price/performance. Many very fine sounding systems have been built with modestly priced parts so you're not necessarily leaving a lot on the table if you don't spend hundreds on fancy drivers.

Oh, and welcome to Ewave. Have a good time!

 

[wushuliu]

If you look through the Official Ewavers list (now over 70) on the first page you'll see that several people have had success with the Classic Series Dayton woofers from Parts Express. That's a low-cost option.
Other than that it's pretty much up to you to decide on the following parameters:
How much you want to spend.
What size cabinet.
How low you want the bass to go.
and then search PE, Madisound, etc. for candidates that will play cleanly up to the 1600 hz crossover region.

What a number of us have done is to buy the parts for the conversion, build the crossovers and experiment by substituting this tweeter section into/on top of existing speakers. Once you've heard it a bit you may have a better idea of what kind of 'permanent' speaker you would make.

I've done 2 pairs with Advent woofers. Yes, they're old and they're low-tech but they're cheap, readily available, easy to implement, go low in a reasonably sized box and sound very decent.

There are a few limiting factors to consider in choosing a woofer:
1) the above mentioned 1600 hz crossover point. Woofers designed as subs probably won't play tha thigh
2) the Waveguide is 12" wide, which establishes a minimum baffle size.
3) woofers as large as 15" have issues with the center-to center spacing of the drivers, which should be kept a small as possible if you want a simple build.

Things that are not serious issues:
1) woofer sensitivity. Within a broad range this can be compensated for in the crossover with established parts sets.
2) price/performance. Many very fine sounding systems have been built with modestly priced parts so you're not necessarily leaving a lot on the table if you don't spend hundreds on fancy drivers.

Oh, and welcome to Ewave. Have a good time!

thanks BH!