Omni 10 Airhead

[DaveK]

I built an Omni 10 with the airhead option to mount an amp head and use as a bass combo.



I needed something to bridge the gap between a small home practice amp and a T39+O10.5 stack. This seemed like just the ticket. Small enough to be reasonably portable, but still able to keep up with a rock drummer and a couple guitarists with 1x12 amps. I had previously tried an O10.5, but it was not enough.

I tried it out at band practice and at a rock gig with PA support for bass. At practice it had no trouble keeping up and gave me great tone. At the gig I used it as my stage monitor. Again, no trouble being heard.

Others have reviewed the Omni 10 tone for bass guitar so I'll just say that I'm also very happy with it. This review is about the airhead option. That option is not in the plans, but is easy to figure out. I decided to go with a 2U head so I added 4 inches to each side panel (3.5 for the 2U space and 0.5 for the top panel). I mounted 2U rack rails in the opening and then screwed the amp to that.

I also added some other options that are a little more advanced, but definately worth considering. First, I wanted wheels in the lower back corner to move it around. I used the 2" recessed casters from PE. To mount them I added a fixed 2.5" strip along the bottom of the back panel opening and then a flange to screw the back panel into.

Second, I wanted a handle on top to pull with. A retractable suitcase-style handle would have been great, but mounting and sealing it seemed too complicated so I went with a flip handle recessed into the top panel.

Third, I wanted recessed steel bar handles on the side to lift with. The only challenge here was notching the horn braces to fit around the recess pocket.

Fourth, I've always had trouble sealing around the tweeters so I added a divider to give them their own chamber and isolate them from the woofer rear chamber. To compensate for the lost volume I extended the cabinet depth by 1/2 inch.

Finally, since I was using a bass head with bi-amp output, I wired the tweeters to be switchable between the main woofer channel or the bi-amp channel. Quite frankly I can't hear any difference for bass guitar use, but I did it anyway just for fun.

Dimensions: 20W x 30.5H x 16.5D
Weight: 80 lbs (40 for the Baltic Birch carcass, 20 for the GK amp, and 20 for all the other hardware)

[john101]

That looks great. I'm planning to do the same thing except with a 10.5 and an Ashdown Mag300 head.

John

[MYork]

That looks great! I enjoyed reading how you installed the recessed casters. MY

[Harley]

I built an Omni 10 with the airhead option to mount an amp head and use as a bass combo.

Great looking unit!

Well done.

[Marko Rooseno]

I built an Omni 10 with the airhead option to mount an amp head and use as a bass combo.

I needed something to bridge the gap between a small home practice amp and a T39+O10.5 stack. This seemed like just the ticket. Small enough to be reasonably portable, but still able to keep up with a rock drummer and a couple guitarists with 1x12 amps. I had previously tried an O10.5, but it was not enough.

Beautiful. Simply beautiful.

[vlad335]

Wow DaveK!

That cab looks magnificient.

I now remember seeing your wedgehorns on Frapper. You do some nice work sir.

[DAVID_L_PERRY]

Very nice looking build !!

What are the small holes directly above the piezo array for ?

Dave

[MYork]

Fourth, I've always had trouble sealing around the tweeters so I added a divider to give them their own chamber and isolate them from the woofer rear chamber.

I think it was a way to attach the "tweeter chamber." MY

[Mikey]

What are the small holes directly above the piezo array for?

I think those are the tweeter switches, recessed to avoid being accidentally tripped.

[DaveK]

I was asked a couple questions in PM that I thought were worth answering publicly. I also just noticed that Dave Perry asked a question earlier that I missed and never answered.

I like your mod of sealing off the tweeters so that leakage is not an issue. Did you find that the additional 1/2 inch of depth offset the lost internal volume adequately?

I did the math and the extra 1/2 is not quite as many cu.in. as the lost area behind the tweeter baffle. However, the net loss is about 1% of the overall cabinet volume so I don't think it makes any real difference.

The other reason I extend the back by 1/2 inch is that I like to build the baffle differently. I make the baffle the full width of the cabinet and glue it in place. That means I can't use a circular baffle cutout, but must use a spacer ring. That, in turn, means a 2510 driver does not have enough clearance from the back panel. Please note that this is a DEVIATION from the plans and probably not what you want to do.

Similarly, since I would be using a GK head I would also be thinking about putting the tweeters (switchably) on a second circuit.

This was hashed out a while back, however that thread may have aged out by now. The summary is that GK crosses over at 5KHz, but 10" drivers roll off around 2-3KHz. If you run the piezos off the GK tweeter channel you probably have a hole between 3KHz and 5KHz.

In my case, it's really a moot point for bass guitar use. There just isn't any content up that high, at least the way I play. I could have left the tweets out entirely, but put them in just for fun. I wanted to practice making a 1016 array and wanted to be able to use the cab for PA in a pinch.

What are the small holes directly above the piezo array for ?

Those are low profile rocker switches from PE. One selects between the GK tweeter channel or the main channel. The other turns off half the tweeters. There is also a third switch in back to put the woofers in series or parallel.

[Ron K]

Very nice!

[greg]

I just received my omni 10 plans and want to try this. Did you paint the inside of the port white?

[DaveK]

I just received my omni 10 plans and want to try this. Did you paint the inside of the port white?

That's the inside of the back panel you see through the port. When I took that picture I hadn't installed the port tube yet (still haven't, actually ). I also hadn't lined the back panel with foam yet.

[joelc1319]

I just received my omni 10 plans and want to try this. Did you paint the inside of the port white?

That's the inside of the back panel you see through the port. When I took that picture I hadn't installed the port tube yet (still haven't, actually ). I also hadn't lined the back panel with foam yet.

Port tube ??? Am I missing something?... Also, I was going to ask if you had a grille on your box? If so, what did you make it out of?

[greg]

The Omni 10 is ported when used as a full range cab