Omni12 Bass Cab Build - dual 10 BP102, LA6-CBMR, APT80

[dheafey]

Well, it's time to sh*t or get off the pot and I've chosen the former. I've been vacillating for almost 2 years as to what bass cab to build. See, I haven't used a bass amp/cab in years, pumping material direct to the PA and through some beefy monitors. That was ok, but we've recently all gone to IEMs and I miss that bit of thump. Plus, I joined a second outfit where a bass head and cab is my best option. Sawdust needs to be made.

Now, I've read many threads where bassists have swarmed to the Jack series and, when I built a pair for a local High School Drama Club, I was almost convinced that was the way to go. But a pair of unused Eminence BP102s kept whispering to me, "Dave. Dave!!" Hating to see speakers unused, I decided to go the dual 10" Omni 12 route. So let's Get 'er done!!

Time to turn the garage into a workshop:


A little inspiration:


Does anyone need swaybars for an E46 330i?


Kit from Leland. Yeah!!


Prepping the battlefield:


The sawdust will be flying tomorrow.

[dheafey]

First order of business: source some decent plywood. After a half dozen phone calls, I finally found a lumber yard that had 1/2" AC Grade Soft Yellow Pine. I'd mapped out the cut sheet with Cutlist and only needed 1 8x4 sheet, but bought 2 in case. It turns out that was a wise move as I had a few DOH moments.

Second cut of the day was one of the side panels... and I cut it on the wrong side of the pencil line!! I'm going with the full grille option and vacillated something fierce about simply going with 7/8" but, in the end, decided to recut.

I'm convinced Bill's circular saw sled should be the subject of a TED talk. My favorite use for it is to cut panels with an extra 1/8" and "kiss" the side of the panel with the blade until perfect.

Here's where I left off for the day. Unfortunately, when cutting the angle for the front, I messed up the orientation and ended up with the "C" grade side facing out. Bondo is your friend:


Now it's off to band rehearsal to prepare for the weekend from hell: 3 gigs in 4 days. That's a lot for us old geezers.

[dheafey]

Up early and with a sleeping family, I decided to take advantage of the time and wire the filters. The middle filter (midrange) is not me; Leland and Co. surprised me with a pre-wired midrange filter! Thank you, Mr Crooks:


My goal for the day is to get the baffle, second side and midrange horn completed.

[dheafey]

Day 2 saw finishing the filters and external pieces of the cab. I wanted to get the mid horn done, but pooped out. There's always tomorrow:

Here's the finished baffle. I just realized the notes on the baffle are fairly accurate, re: "Front".


Prior to putting on the second side. Note the piece of scrap ply, cut to size, running through one of the driver cutouts; I used it to square things up prior to screwing on the second side:


That's all for now. It's time for a few adult beverages, liquid courage prior to building the mid horn.

[dheafey]

I don't know about you, but whenever I'm in the midst of a project I don't sleep very well. Such was the case last night as I've been cogitating something fierce on the midrange horn. Since the pieces were relatively small I decided to cut the horn parts with my compound mitre saw.

Measure a dozen times, cut once I always say:


Now use my handy, dandy angle measurer thingy:


I then setup the chop saw for that angle and the cuts were much better than this guy could've done with other saws.

The horn mouth required 10 deg cuts on the "not square" sides and I didn't want to do this free hand (ie: circular saw or jigsaw). I took the scrap from the chop saw cut and used it to get the angle right. A quick pass on the circular saw sled and all was well:


I've pooped out from lack of sleep and will probably call it quits. I have 3 gigs in the next 4 days and would prefer to be on my game.

[Rickyvt]

I found the mid horn to be the hardest part... But the way you are making progress, you'll be rewarded with some great sound soon. Enjoy!

[dheafey]

I found the mid horn to be the hardest part... But the way you are making progress, you'll be rewarded with some great sound soon. Enjoy!

Thanks! Agreed, the mid horn is a challenge. It's like building a mini Jack!

[dheafey]

I've completed the mid horn and I need to trim it, but something doesn't seem right. The plans state:

Place the completed mid horn face down on a table saw panel jig and gradually trim the edges, one at a time in sequence, until the horn front reaches its final size of approximately 5 by 7 inches.

I'm assuming 5" is the height and 7" is the width? I took some wood blocks cut to length and the 5" block goes way into the throat. Also, where the throat panel meets the mouth panel is 5 1/4" so I'm not seeing how 5" would work.

I'm definitely missing something.

[Rickyvt]

Do you have any pictures? This is my build thread, there are some mid horn pics there
http://billfitzmaurice.info/forum/viewt ... 30&t=18215

[dheafey]

Here ya go and thanks! I'm just not seeing how the final height dimension of the horn can be 5" when the joint where the throat and mouth panels meet are 5 1/4".

[Tom Smit]

Did you measure in Sketchup and compare? It might help.

[dheafey]

Did you measure in Sketchup and compare? It might help.

Well that's a nifty little tool; I learn something new everyday. The Sketchup has the dimensions at 7" high by 11" wide. That seems to make more sense.

[Tom Smit]

[/quote]

Did you measure in Sketchup and compare? It might help.

Well that's a nifty little tool; I learn something new everyday. [/quote]Don't we all! [/quote] The Sketchup has the dimensions at 7" high by 11" wide. That seems to make more sense.[/quote]
Heh, heh, now you can finish.

[dheafey]

Did you measure in Sketchup and compare? It might help.

Well that's a nifty little tool; I learn something new everyday. [/quote]Don't we all! [/quote] The Sketchup has the dimensions at 7" high by 11" wide. That seems to make more sense.[/quote]
Heh, heh, now you can finish. [/quote]
Awesome. Thanks bunches for the suggestion, Tom.

[dheafey]

Mid horn installed and bracing glued and screwed. Lots of sanding left to do. Those braces look like great places to attach the filters. Hmm... I wonder where I read that...