Open Baffle/"dipole" Build

[ocdSCHACK]

I love seeing build threads, and I know I will have questions for the electronic experts as I get closer to finishing.... so, I'm posting these to inspire any experts to answer any "newbie" questions should they arise. I'm also putting them up for those, like myself, who just like to see stuff built.

This is an ORION clone/ripoff. My ending goal turned out to be a speaker that could rival or contend with the ORION for under $1200. I don't think they'll sound as good or better, but for the money, I hope they are a much better value with similar sound quality.
To make the woofer frame/baffle, I chose a self developed "Z-frame." No, I have no Idea how it will sound, but the crossover is active.

[MSaturn]

I assume you're going the opposing-woofer route?

[ocdSCHACK]

Then I measured and marked a MTM(mid-tweeter-mid) outline that would fit on the remaining top part of the speaker.
I have to mount the tweeter overlapping the mid-woofers, because of the non existent surface area that is needed.

Here is a pic during the routing:

A pic after routing.

I got lucky; the hole for the mid woofers was exact. It is 8.75" diameter for the outer circle and 7.25 for the hole cutout.

[ocdSCHACK]

I assume you're going the opposing-woofer route?

Yes. I hope it will sound alright; It will be unmounted to the top part of the speaker, so if it sounds like a*s, I'll build one with a different design.

[ocdSCHACK]

Before the holes were cut, I took these pics to inspire me to finish in a timely manner. This is all I have so far, but I'll keep it updated as I move along with the build.

[blair]

I may have missed it, but what drivers are you using for bass? Is it all four hi-vi?

Thanks, and please keep us updated on your progress.

Blair

[MSaturn]

probably gonna have some nasty diffraction issues mounting the tweeter on top like that, though.

[ocdSCHACK]

I may have missed it, but what drivers are you using for bass? Is it all four hi-vi?

Thanks, and please keep us updated on your progress.

Blair

Bass: 4 x Peerless XXLS 8 ohm woofers
Midrange: 4 x 8" Hivi M8N woofers
Highs: 2 x or 4 x Vifa DX25 neodymium tweeters (Parts Express Buyouts from ProAc speakers)

[ttan98]

Bass: 4 x Peerless XXLS 8 ohm woofers
Midrange: 4 x 8" Hivi M8N woofers
Highs: 2 x or 4 x Vifa DX25 neodymium tweeters (Parts Express Buyouts from ProAc speakers)

Very nice looking speakers. You must be very good with your hands and lots of patient.

Do you intend to use passive or active x-over? Any details available yet?

[nick29498141]

OOO I want an update...

NK

[ocdSCHACK]

Very nice looking speakers. You must be very good with your hands and lots of patient.

Do you intend to use passive or active x-over? Any details available yet?

I'm going to use the Behringer DCX2496 for the crossover.
I'll post some updates if I get anything good done this weekend.

[ttan98]

I'm going to use the Behringer DCX2496 for the crossover.

I use a similar arrangement, quick and effective and more importantly the sound will not disappoint. I am thinking of using passive in the longer term.

[ocdSCHACK]

I got some more work done, and here some of the pics. I'll post more when I have time.

I added sides to the front baffle, but they were too big, so I had to make some adjustments.


I marked the part to rough-cut.





Then I routed them flush.

[ocdSCHACK]

Next, I used the router to put an angle on the edges of the baffle back. I didn't want the piece look like I meant to combine it with the side panel.





I used a cheese-grater type of file/rasp to get the end edge but sandpaper works too.

[MSaturn]

your woodworking prowess really makes me wish you were using a nicer 8" midbass .. say, the peerless HDS?

[ocdSCHACK]

your woodworking prowess really makes me wish you were using a nicer 8" midbass .. say, the peerless HDS?

Thanks for the compliment. Maybe I'll upgrade later, but I've spent too much money too fast lately. I decided to build the speakers separately because it was becoming overwhelming having to do so much twice. I couldn't decide what I should do next with so much stuff scattered in front of me. Here are some more pics of what I've got done:

The speaker I brought inside to test and learn how to use the DCX2496 active crossover.


I primed everything with with shellac...Bad choice.




The Primer wouldn't sand correctly and started gumming up on the sandpaper. It was so bad I sanded 95% of it off with 60-80 grit.
So next, I re-primed the wood with Evercoat "DURA BUILD" high-build primer using a gravity feed spray gun. Then sanded it flat with a sponge pad and 320grit sandpaper. I may have skimmed over it with a higher grit just to be safe.





My assistant said it looked good, and was ready for paint.

[ocdSCHACK]

For the black, I used Cheap black lacquer from Pep Boys and then covered it with 2-part automotive clear coat.

Here's a pic of the products I used


Here's a shot of painting with the lacquer. That thing on my face is a gas mask. I recommend you use one if you do any painting with these chemicals.


One of the air nozzles got clogged on the paint gun when I was painting the clear coat and it put huge streaks of excessive "orange-peel." It looks awful, but luckily it will be sanded away.
Here a picture with the orange-peel on the sides and the front baffle painted with Rustoleum epoxy paint.




When the clear coat hardened, I wet sanded it pretty flat with 1000grit. I then used 1200 and 1500grit. Any sandpaper scratches from paper lower than 1200 grit is almost impossible to remove, but the poor paint job needed something rougher. The goal is to sand until the entire coat is flat and dull.


Using a a sanding pad makes it easy. The low spots are the dark and shiny specs in the finish. The dull part is where the sandpaper has sanded.


A close-up of the specs where the low spots are:


I used a finishing sander for the 1200grit paper. It's not required or recommended, just a little faster and more dangerous.




Keep sanding until the high and low spots are gone and the finish is completely dull. Here's a piece that's now ready to be buffed/polished... no more glossy specs.

[ocdSCHACK]

After (hopefully) sanding out all the scratches from lower grit sandpaper with 1500 grit, the finish should be ready for polishing. Here's a shot of the tools needed. 1) rotary polisher/sander- this needs to be one that is strong enough to eat through the paint if you use it wrong. A little dual-action Porter Cable sander will never work. 2) buffing pad. 3) real compound polish, not Meguier's or Turtle Wax. 3M is your best bet if you buy it locally.


The shine is starting to come back

One side finished with the Compound I used. It's Transtar "Super Kut Compound" It's aggressive and it will probably need another polish with something that is a finer compound to make sure any "holograms" won't show up in the finish.



And now they both are shiny again.


A quick recap of the paint job for you or your car painter.
1) Coat with High Build primer
2) Sand flat with 220-320 grit. Finish sand it with 320 or higher.
3) Paint the base coat
4) Paint the clear coat
5) Sand the clear coat with 1200 until it's a totally flat surface.
6) Sand the clear coat with 1500 until it has removed all scratches from the 1200.
7) Polish/Buff out the 1500 grit scratches with compound and a buffer.
8) Polish/Buff out the compound scratches with swirl-remover(or similar) and a buffer.
9) Ask yourself if it was worth the hassle, time, or money.

[christianb]

I'm not seeing any of the pictures.

[jimlg]

Me either?