Author Topic: Econowave Speakers  (Read 96746 times)

Offline richidoo

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Re: Econowave Speakers
« Reply #30 on: March 08, 2012, 10:17:14 AM »
The contact cement is working well, one done, one to go. But it really stinks, even outside. I'm taking a break to sober up.  Should finish the cabinet damping today, then the rest can be done indoors.

mgalusha

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Re: Econowave Speakers
« Reply #31 on: March 08, 2012, 12:52:53 PM »
That stuff is evil, I bought a chemical respirator for working with things like contact cement, acetone, keytone and other nasties.

I'm looking forward to your thoughts. I suspect the CD could really use some impedance compensation. I know you have read Wayne Parham's crossover 101 stuff and he is pretty adamant about the need for zobel's and other comp networks.

Offline BobM

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Re: Econowave Speakers
« Reply #32 on: March 08, 2012, 01:26:39 PM »
Rich ... Rich ... wake up!!!

Someone call the paramedics.
Laugh and the world laughs with you. Cry and you'll have to blow your nose.

Offline richidoo

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Re: Econowave Speakers
« Reply #33 on: March 08, 2012, 01:28:08 PM »
Hi Mike,   Yes, I used a respirator for the second speaker, didn't smell a thing, and didn't get stoned.  MEK is not good for you. Thankfully, the damn roofing membrane is all used up and may never return. Such a pain to work with, but it does take down the wood ring a lot though...  They make a self-adhesive version, but I bet it doesn't stick good enough for vertical applications of small pieces.

In the Tech Talk discussion that created this crossover, there was talk of notches and impedance correction, but Zilch didn't choose those for the final XO. The rising CD impedance's effect will vary with the damping ability of the amps, so it might benefit the HF to leave it untamed for the SS amp, and add it for the tube amps. Flattening woofer impedance will change the crossover parts values, but might sound better by making less woofer in the upper mids.  It's all out there to try.

Are you still planning to build 4pi Mike?

Offline richidoo

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Re: Econowave Speakers
« Reply #34 on: March 08, 2012, 01:31:09 PM »
Rich ... Rich ... wake up!!!

Someone call the paramedics.

 :D

Offline richidoo

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Re: Econowave Speakers
« Reply #35 on: March 08, 2012, 03:06:09 PM »


Proof I can count to 22.

Next up is adding FG insulation as acoustic damping to stop the echoes.

Offline hometheaterdoc

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Re: Econowave Speakers
« Reply #36 on: March 08, 2012, 05:32:24 PM »
in my best Count from Sesame Street voice "1.. bwah... ha ... ha ... ha"  :)

Looking good, Rich!  Looks like a little gluing on the front panel and some parts attachment and they're almost ready to make some noise!

Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

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Re: Econowave Speakers
« Reply #37 on: March 08, 2012, 05:48:30 PM »
Yup, getting close now! At least to the first draft.

mgalusha

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Re: Econowave Speakers
« Reply #38 on: March 08, 2012, 07:50:11 PM »
Are you still planning to build 4pi Mike?

Good to hear you went with the respirator, we don't want you to drop.  :shock:

Yes, at some point I will build a pair just so I can hear them. I have 4 of the JBL 2226H woofers, so I need the wave guides and B&C drivers. First I will likely build a pair using one of the 2226H and a Beyma TPL-150, sort of e-wave/four pi like but with more top end extension. I know there will be a lot of work to get the crossover correct but I'll keep them outboard and build/measure/listen until I get them right.

This project is certainly moving along nicely, I am enjoying the build from here.  :thumb:

Offline richidoo

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Re: Econowave Speakers
« Reply #39 on: March 09, 2012, 08:34:08 AM »
Pics:







Mess... 

The horn is plenty strong enough to support the DE250 CD without a rear brace. The other CD we have is the Radian 475PB. It is larger and heavier (PB = plubum?) but I think it will not need a brace for normal use.

Remaining: build the ports and glue baffle to box.

mgalusha

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Re: Econowave Speakers
« Reply #40 on: March 09, 2012, 08:54:25 AM »
Looking good Rich!

Offline richidoo

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Re: Econowave Speakers
« Reply #41 on: March 09, 2012, 11:48:43 AM »
Thanks Mike

Ports built. 3.25 inches long extensions made from 4" PVC pipe, added to Parts Express 4" diameter flared port makes a 6.89" effective port length. I machined them on the table saw using the crosscut sled and twisting them through the blade by hand - fun! Taped them to the Parts Express flared ports on the inside of the tube with 2" aluminum metal HVAC duct tape. Turns out, two of the PE flared ports taped together back to back would be almost perfect length, with flares at both ends, and cheaper.

Now to try to find some 5 min epoxy to glue them to baffle.

Offline richidoo

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Re: Econowave Speakers
« Reply #42 on: March 09, 2012, 01:50:03 PM »
I painted the inside of the ports black because the white PVC pipe and shiny aluminum tape were visible from the front of the ports. The ports are epoxied in. I will seal the back of the port mounting with caulk, then I'm ready to glue the front baffles to the box.  I think it will take a little massaging with the sanding stick to get it to fit perfectly, then clamp it into submission.  :twisted:
Hopefully, the miters will line up close enough to be within range of a 1/8" roundover bit.

A buyer review on the PE website of the i152 horn complained that the DE250's threaded studs are too short for the thick mounting tabs of this horn. To fix this easily without cutting bolts, I bought four M6x1.0 x 40mm metric bolts from Home Depot, $0.60 iirc. Screw one of the nuts that come with the DE250 all with way to the head of the bolt, then slide on a lock washer and a flat washer. Screw the bolt through the horn tab into the CD, bottoming the bolt in the CD bolt hole. Then with a 10mm open wrench, tighten the loose nut that's on the bolt down toward the horn tab to gently squeeze the lock washer almost flat.

Offline richidoo

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Re: Econowave Speakers
« Reply #43 on: March 10, 2012, 02:48:46 PM »
The first box is glued. They should be playing tonight, with a little luck...   [-o<

The front baffles lined up perfectly, no sanding or cutting needed. I love when it all comes together.

jianghai

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Re: Econowave Speakers
« Reply #44 on: March 10, 2012, 05:05:05 PM »
Looks amazing! Soo jealous of your DIY chops. Can't wait to hear em.