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Zilch's AK Design Collaborative - Econowave Speaker

EconoWaveGuide Utility Large Advent Conversion Unit II Done

I now have a pair of my converted Utility Large Advents playing.

I am required by the conventions of speaker building to declare them The Finest Loudspeakers That I Have Ever Heard.

I'll put as many hours as possible on them before the 12/13 SMAC Meeting and I hope that as many AK-ers as possible can hear them then.
I expect them to change in character somewhat as the freshly re-foamed woofers break in but one thing I know for sure is that nobody is going to complain that the tonal balance is thin and lightweight.

Right now I've got them about 4' away from the back wall and 18" off the ground. This seems like a good place to start. Most speakers would lose all bass in that position in this room.

The last step is documentation. I'll take a copy of the crossover on paper and add a description of the parts used. I'll also write out the URL of the construction thread. This will be placed in a Ziploc bag stapled to the back. Just in case someone has to service them some day or I forget what's in there.
 
Bauhausler said:
I now have a pair of my converted Utility Large Advents playing.

I am required by the conventions of speaker building to declare them The Finest Loudspeakers That I Have Ever Heard.

I'll put as many hours as possible on them before the 12/13 SMAC Meeting and I hope that as many AK-ers as possible can hear them then.
I expect them to change in character somewhat as the freshly re-foamed woofers break in but one thing I know for sure is that nobody is going to complain that the tonal balance is thin and lightweight.

Right now I've got them about 4' away from the back wall and 18" off the ground. This seems like a good place to start. Most speakers would lose all bass in that position in this room.

The last step is documentation. I'll take a copy of the crossover on paper and add a description of the parts used. I'll also write out the URL of the construction thread. This will be placed in a Ziploc bag stapled to the back. Just in case someone has to service them some day or I forget what's in there.
Click to expand...

Excellent work, ULA owners can now E'wave! I assume all this is going into the seperate thread? I'll have to get reading, I know a few ULA owners out there.

russellc
 
marantzfan said:
Did y'all hear that?? That was the sound of Andyman raising the bar for the rest of us...:yes:
Click to expand...

And a high bar it is. I would like to veneer my JBL 4647 ( 4507 ) boxes, would be a first project venner wise, and a fairly large cab. Have been reading threads over on LH forums where members have veneered some of the larger JBL monitor boxes. I may have to practice up on something smaller
to get my feet wet. I'm sure there is a learning curve.

Andyman, was this a first project, or are you a seasoned veneer man?

Russellc
 
Looking forward to hearing the B. I have a great pair of cabs that would make LE10 eWaves. Of course that would be after building two amps and a turntable. Cheers.
 
Russellc said:
And a high bar it is. I would like to veneer my JBL 4647 ( 4507 ) boxes, would be a first project venner wise, and a fairly large cab. Have been reading threads over on LH forums where members have veneered some of the larger JBL monitor boxes. I may have to practice up on something smaller
to get my feet wet. I'm sure there is a learning curve.

Andyman, was this a first project, or are you a seasoned veneer man?

Russellc
Click to expand...
First project, but brutal.

I've built and finished a lot of things in wood, but this was my first shot at veneering. FWIW, go with the paperbacked veneer in the large sheets, pre glued if you can. I used raw flitches I picked up dirt cheap, but quite honestly, what I saved in initial outlay was lost to extended time in prep, matching, filling, gluing, etc, etc, Matching up 5" x 22" sheets, squaring edges, then backfilling seams where they shrank, and repairing small chips with a blend of shellac and sawdust and or slivers all took a ton of extra time.
It literally cost me about $14.00 total for the veneer, but I spent hours dealing with it. Then again a 4'x8" sheet of Rosewood veneer from Oakwood is about $200, but I could get 4 faces out of it, so that works out to about $50 face. The sides are birch-ply and actually turned out quite nice; a lot better than I anticipated with some very nice grain patterns.

Here's a link to Oakwood. It's local to me and I found out about it from Grumpy; he got his cocobolo there for his AudioNotes that Billfort built. Check out the samples and the prices, but realize one has to buy a whole sheet so 32x those ft2 prices before you get too excited :yes:

Oakwood Veneers
 
Bauhausler said:
I am required by the conventions of speaker building to declare them The Finest Loudspeakers That I Have Ever Heard.
Click to expand...
Heh, heh. Ain't THAT the truth?

The best speakers ever conceived by anyone, anywhere, are ALWAYS whatever ones I'm working on right now.... :tongue:


SPAM said:
It says 92, but is that correct?
Hasn't Zilch confirmed Jack's high sensitivity (>95dB) network for that driver?
Click to expand...
Yes, I was myself surprised, and don't know the answer. This experience has been confirmed by several E'Wavers now.... :dunno:
 
SPAM said:
It says 92, but is that correct?
Hasn't Zilch confirmed Jack's high sensitivity (>95dB) network for that driver?
Click to expand...

I believe that driver had its own crossover, 900 hz on the bass driver. It was crossed over a little sooner to help with its "hump"....

Russellc
 
Russellc said:
I believe that driver had its own crossover, 900 hz on the bass driver. It was crossed over a little sooner to help with its "hump"....

Russellc
Click to expand...

Yep, that's they way I built mine.
900 and 3000 are the points IIRC...
 
Andyman said:
Yep, that's they way I built mine.
900 and 3000 are the points IIRC...
Click to expand...

That's what I remembered, not sure about the high frequency end compensation, I dont remember if it was different as well, or if only the low frequency leg was different. I'd have to wade back through to see....

Incredible job for a first time on the venneer!

Russellc
 
Comments:

Bauhausler said:
I now have a pair of my converted Utility Large Advents playing.
Click to expand...
Damping: I believe I'd move to higher-density fiberglass rather than overstuffing, though Advents with foam were certainly full of that. R-15 for 2x4 walls is the same thickness as R13. If your home center doesn't have it, check with the local lumber yard that construction contractors frequent.

HF response: D210Ti is a bit rolled off at VHF; Jack designed the HF comp for flat response with D220Ti. If you want to switch from "sweet" to "bright," swap in D220Ti rather than giving D210Ti more HF boost. I'd trust Mrs. Bauhausler on this one; the fair sex hears more acutely up there.... :yes:
 
Zilch said:
Damping: I believe I'd move to higher-density fiberglass rather than overstuffing, though Advents with foam were certainly full of that. R-15 for 2x4 walls is the same thickness as R13. If your home center doesn't have it, check with the local lumber yard that construction contractors frequent.

HF response: D210Ti is a bit rolled off at VHF; Jack designed the HF comp for flat response with D220Ti. If you want to switch from "sweet" to "bright," swap in D220Ti rather than giving D210Ti more HF boost. I'd trust Mrs. Bauhausler on this one; the fair sex hears more acutely up there.... :yes:
Click to expand...

Thanks for the recommendations. Before making any decisions about changing the damping I want to make sure the woofers are fully loosened up. Also I should listen to them in at least 3 different environments & get different opinions. I expect them to cound quite different @ Dennis's house on Saturday.

One major improvement is dispersion. I work in this large room and I'm moving around a lot. One of the things I like about the Linn Isobariks is the coverage. These waveguides have a similarly even change in timbre as you move around. I hadn't been expecting that, as my previous horn experiences in here were La Scalas, Khorns, Altec Valencias, M19s and various 811A and 511 setups. These WGs are much smoother off axis. WAY off axis as far as I can tell.
 
Bauhausler said:
One major improvement is dispersion. I work in this large room and I'm moving around a lot. One of the things I like about the Linn Isobariks is the coverage. These waveguides have a similarly even change in timbre as you move around. I hadn't been expecting that, as my previous horn experiences in here were La Scalas, Khorns, Altec Valencias, M19s and various 811A and 511 setups. These WGs are much smoother off axis. WAY off axis as far as I can tell.
Click to expand...

Andyman said:
Kegger and I noticed the same thing here in the garage tweaking my set.
Click to expand...
I'm surprised y'all are surprised. Look again at the polars Geddes measured for us. It's what constant directivity and uniform power response are about. Even the reflections from stuff off-axis have the same timbre as the on-axis response:

http://audiokarma.org/forums/showthread.php?p=2302942#post2302942

That's what makes the imaging precise and stable.

You can also do Geddes's recommended 45° toe-in thing for a sweet spot that's two yards wide.


Bauhausler said:
Also I should listen to them in at least 3 different environments & get different opinions. I expect them to cound quite different @ Dennis's house on Saturday.
Click to expand...
That may surprise you, as well.

Because of uniform power response, you're hearing the speakers, not the room.

Whether absorbed, diffused, or reflected, the spectral balance remains essentially constant.... :yes:
 
Off axis- ATM, the cabs are pointed toward the centre of the room, bi-secting three feet in front of the listening position (as a lot of you blokes found, too). The WG is sitting on top of the cab, the inner right hand corner of the WG about 1cm back from the baffle edge and the left, outer corner directed slightly outwards, about 2cm back from the baffle edge.
 
Had my first taste of econo-wave last night :thmbsp:
For initial testing bass bin was a sawed-off end from a console that's been with me for twenty-five years since high school. Wish I had a camera--you'd laugh.
Only gotten one network Zilch-nutted so far, and don't own any mono LP's, so for source I used a recent mono Pepper 'drop from bit torrent. Wow! Some of those sound effects on side two (cock clucking &tc) really sprang to life through the waveguide.

I like the sound of it . . . better than paper cone tweets in L50 I've been listening to for several months, that's for sure. :yes:
Like it so well I'm gonna have to wire the other network and then try some of my own LP's in stereo. :D

With the big inductors back-ordered, next step might be to try Decade 36's stock low-pass circuit (nominal 1500Hz crossover.)
 
A note to E-Wavers considering the Utility Large Advent for conversion. When I took out the stock crossovers I found that the woofer inductor measured around 1.58H. It was also of adequate size and wire gauge for the ewave crossover application. This would indicate that if you have a decent stock of C's and R's around you might get away with building a pair of crossovers with only the addition of the .6mh inductor, saving considerable cost.

I've been listening to this pair of E-Waved Large Advents for over a day and the woofers have smoothed out and de-boomed a bit. There's plenty of bass but it's not all in one resonant peak now.

One thing I need to do is make some impedance measurements & fake up some kind of graph. This would be useful to those considering driving a pair with a tube amp.

Hey. Maybe I should take this other pair of Advent cabs & woofers and build up another complete pair. Then I can stack them & see how that sounds. It would have to be an improvement. Right?...
 
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