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

[Rickyvt]

Nice progress!

[dheafey]

Nice progress!

Thanks Rickyvt!

I don't have any pictures, but I got the jack plate and L-pad cutouts done, all flanges laminated and lower and upper flanges installed. Today/tomorrow is installation of the remaining flanges and braces, trimming the front of the mid-horn and installing flanges for the full grille.

I was hoping to get this done for a gig on Saturday, but real life keeps getting in the way!

[Rickyvt]

I was hoping to get this done for a gig on Saturday, but real life keeps getting in the way!

I know, I just returned from a trip to Rome and there's a lot to do before I can pick up on my Omni 15. But even now - without braces or insulation and with the back panel loosely in place - it's allready sounding fantastic.
Looking forward to your next pictures and progress, since there aren't a lot of omni threads on this forum...

[dheafey]

After 4 gigs in 8 days (a lot for this old geezer who has a day job) I've finally found some real time to bond with my O12.

Here's the cutouts for a jack plate and L-Pad for the tweeter. I chickened out on making a router guide template and simply mounted a piece of scrap plywood, with the smaller cutout, inside the box. Had I been thinking, I would've hit the edges with a roundover bit prior to putting the scrap piece inside the box as there's not enough clearance for the roundover bit to, well, roundover. A little sanding should do it:


Flanges installed. I messed up the alignment of the bottom left flange and had to dig it out with a chisel, taking a layer of ply with it - proof positive that PL is the bees knees. I'll be doing some minor surgery in the days to come:


Standoffs for the full grille. You may notice construction screws have been removed from the panels and bondo applied (that stuff covers up a multitude of sins :


Band practice for Band #2 and 2 gigs with Band #1 will keep me on my toes, but I think I can get it done by the weekend.

[dheafey]

No pictures today, but bondo/cab sanded and primed, mattress topper installed in cab, non-duratex surfaces spray painted. A gig tonight and tomorrow will keep me away from the cab, though. I have an order into Leland for Duratex rollers, screws and screw covers for the grille.

A number of deadlines have come and gone, so I've decided not to be so impatient. I'm just hittin' the workshop/garage when I have the time. It'll be done when it's done.

[dheafey]

Mattress topper and filters installed:


I prefer using a metal cutting blade on a jig saw for this job:


Unfortunately, while placing the expanded metal behind a few pieces of plywood stock, I dropped the expanded metal, it hit a piece of scrap changing its trajectory, and proceeded to tear up my right index finger. And I had just taken my gloves off. Idiot. I'm a finger style bassist and have a gig tonight; it'll be interesting. Word to the wise - ALWAYS wear gloves when working with this stuff.

[dheafey]

I've recovered nicely and was able to do my gig with little to no impairment. At least, that's what I convinced myself happened.

Like the mid-horn, I stalled MAJOR LEAGUE on the recessed handles. It required I learn a whole new technique that I'd been holding off on: the dreaded RECESSED ROUTER JIG HANDLE TECHNIQUE!! It wasn't that bad, really. It just required a lot of time. Maybe that's why BF says to use surface mount handles.

Anyway, here's the router jig clamped to the box:


Notice the piece of scrap screwed to the middle. You may think, "Cut out the hole for the handle before the recess", but no... The scrap would be to support the router while your routing out the recess.

Here's the result. You did leave extra space for paint and Duratex, right?:


I will admit that routing recesses and cutting holes in a relatively finished cab is nerve racking but measure 15 times and cut once is my motto.

[shawn_g]

Looks good so far. It's nice to see an Omni12 build for a change.

[dheafey]

Looks good so far. It's nice to see an Omni12 build for a change.

Thanks shawn_g!! I'm itchy to make some noise and drive my wife nuts! I've built a pair of Jack 12's for my local High School and will be interested to hear how this compares. Today will be a final, light sanding with 150 grit and some reinforcement on the inside of the cab for the handles to screw into (I missed aligning the screws for the handles with the side braces as the plans state ). Tomorrow is the first coat of Duratex!

[dheafey]

Progress!

After routing out the sides for the handles, I wasn't feeling the love for how much wood was left . I had nightmares of ripping a handle out at a gig, so I PL'd some extra wood on the inside of the cab for the top and bottom of the handle to grab onto:


After a quick sanding with a random orbital sander and 150 grit, I wiped the whole cab down with a damp cloth. First coat of Duratex. I used the foam rollers Leland sells and couldn't be happier with the texture:

[dheafey]

Some nice progress today. As they say, when the sawdust stops flying, your 50% there.

Final coats of Duratex (3 on the bottom where it will see the most abuse), corners screwed on and grille mounted. speakerhardware.com stocks these nifty washers with covers. I have it on good authority that Leland provided parts for the Curiousity Rover:


Another great find, a BF logo badge from Leland. Sup Bill?


I got one of the BP102's mounted, so I'm hoping to get everything wired up and make some noise tomorrow.

[dheafey]

Done!


I haven't gigged with it yet, but have been driving my wife nuts playing around with it. I haven't taken the time to do any voltage measurements but with recorded music, it can easily get louder than I want to listen to. And, best of all, it doesn't fart out. I will say that that mid horn is one efficient mother and, when cranked, needs some EQ to tame it. Not a problem; I'd rather be EQ'ing something out than not having it there.

As a bass rig, its primary use, it's everything I was looking for. Keeping the bass knob at 9 o'clock, I can easily get this thing to volumes it will never see in a gigging situation. Here, the efficiency of the mid horn is exactly what I want. Punchy and articulate with the dual 10's providing some nice bottom end. It won't rattle the nails out of the foundation but as a 1 cab solution, it easily smokes commercial solutions 3-4 times its price.

Once I get more experience with it I'll be writing a thorough review, but right now I am one happy dude!

[Bas Gooiker]

Great to see that you are all done. Nice looking end result.

What did you use before this, and how does it compare tone wise to that?

[dheafey]

Great to see that you are all done. Nice looking end result.

What did you use before this, and how does it compare tone wise to that?

Thanks!

I was using a homemade monitor with an E145 in it and a horn. It wasn't bad but needed significant EQ to sound ok and it was VERY muddy, probably due to a poorly designed cab. However, I've played through a few 4x10" cabs with horns in my day and I prefer this. It can keep up in the "lows" department, but really shines in the mids and highs. I wear IEM's on stage and really need a cab that punches through to add a little extra oomph and this shines for that purpose.

What I like about the O12 is how effortless the mids are presented. I'm certain having a dedicated 6" mid driver from 400-3,500 makes that happen. However, I don't think just slapping a 6" driver in a cabinet would do it. While a b*tch to build, the mid horn must have a lot to do with it. Bill wouldn't put it there if it didn't.

[Bill Fitzmaurice]

I don't think just slapping a 6" driver in a cabinet would do it. While a b*tch to build, the mid horn must have a lot to do with it. Bill wouldn't put it there if it didn't.

One six horn-loaded equals a pair direct radiating, with better dispersion.