Omnitop12 non-spec combat run

[screamersusa]

From someone experienced with EAW and Meyer, and yes glorious old Altecs....
The first 6 went into combat unfinished. Even without the crossovers and throat fillers they performed very well.
A stack of 3 per side at any volume is pleasing and easy to listen to as well as high enough to cover anyones ears.
Compared to a real, massive line array I heard a couple of days later, they filled space so well off-axis that the "real" line array well ...er ...aaah .. sucked.
For the people right on top of the cabs and those directly in front of the stage, the soundfield was very intelligible and full but not as brutal as my expensive bi-amped cabs can be. They take some getting used to as they have a very different sound than most are used to. Ear fatigue at higher volumes is reduced to almost nill due to the smoothness of the boxes and the point source type arrangement. One thing they do not do is overpower the room with that beamy titanium horn sound some people love. The room's acoustics do play a big part in long throw response. They are a very nice fine tool to work with, easy to mix on, and quite transparent. I was taking into consideration the slight upper mid loss due to the lack of the crossover.
I STRONGLY recommend a stack of 3 per side off of a high quality amp for almost any full band playing smallish clubs.Especially top 40. At moderate volume the nearfield dispersion fills that dance floor right in front of you with a curtain or wall of sound that people love because it pulls them into your act. Less ear fatigue means more people staying on the dance floor and in the club. Smoother response and better falloff means the bartenders can talk over or through the system, while the singles can pick up dates, and the club makes money, which is why you are there in the first place.
The final result is more work for you whether you are the band or the sound contractor .

[screamersusa]

Gee it's amazing how fast you can prep 6 of these with a skilled helper. We just finished pre prepping, cutting, and drilling almost everything but the tee nut holes for all 6 in about 5 hours. Tomorrow a little sanding and port routing and assembly begins. Meanwhile i'm off to the tile saw to cut up 72 more piezos.....mmmm glue.

We played with a stack of 2 today in different roles and discovered these things are very usefull. They make great sidefills, keyboard monitors, clean guitar fills, and I even dropped two into my Meyer wedge cradles as long throw floor monitors
with good results. We've given up trying to figure out how many more to build and have decided to just keep turning out 4's and sixes as drivers become available. Actually for plays these might be great monitors.
These are also the first cabinets I am actually considering for a flying rig. I already have flyables but it's too much work for what little I get out of them. A flyable deltalite set of 12 might be interesting.

[screamersusa]

10 to 12 Omnitops w crossovers going out to SF fairgrounds sunday. Will post pics.

[James R]

Just wondering are these the single 12 or double, thanks looking to build some myself.

Jim

[screamersusa]

I chose singles for a number of reasons.
1) Lego block mentality. Build whatever configuration you need with whatever amps you have.
2) Cabinet unity. I want large numbers of the fewest types. Never need to question how something will work or where.
3) Single person setup of large arrays. Since everyone wants to help but never shows up despite GOOD pay....enough said.
4) Ease of construction, ability to utilize my pull saw with 16 inch max for angle cutting. For the 14" and smaller parts.
5) Weight. Even with massive Kappa12a, going up a 6 foor ladder with one cabinet is comfortable.
6) Pack space. Lego lego lego Can stack them in non-square spaces like bricks. (I see a theme here )
7) More forgiving design for sloppy rushed builders.... yeah that would be me.
Reliability . If a driver fails as a Kappa just did (defective), I can grab a spare and or simply bypass the bad cabinet.
With dual drivers in combat.... a dead driver could be shorted so you have to pull the whole box or run the show
holding your sphincter very tight praying it's not a short and your amp wont burst into flames as well because your
running 2 ohms off those lovely AB1100a amps. Happened to me, amp destroyed beyond recognition.
9) Forgiving design for speaker selection. Good results can be had with numerous substitutes while your drivers are bieng fixed. The cabinet can keep working with a comprabable while not perfect temp driver vs maybe a DR which would need the right speaker to work correctly. Easy to swap speakers in and out in the field while the cabinets are IN USE.
Drawbacks.
More materials, more work, and more expensive than doubles.

And Yes.. I'd rather have 6 DR280's, but without a crew... not gonna work at this time.

[screamersusa]

OH yeah... I'm officially up to 12 OTOP12's. And more coming.

[screamersusa]

Another reason for singles.
Overheating amp running 2 ohms, disconnect one cabinet for 2.9 ohms, lower the gain for a few till the amp cools down.
Then bring it back up for the rest of the show with 3 cabs only on that amp channel(s).
Works better than just letting the amp cool a few and bringing it back up again because the heat will build faster in some amps at 2 ohms vs 2.9 (or is it 2.6?).
This way you still have 3 cabinets per amp channel going the rest of the day vs either only 1 double or a system that keeps shutting down. I get really annoyed at big shows when I hear amps cutting on and off in the line arrays run by pros.

[Chris_Allen]

Come in Screamer, get us some pictures of your lego brick army

[bgavin]

Why not build a series/parallel wiring box so you can avoid the 2 ohm problem? Otherwise you need six amp channels to stay at 4 ohms with 12 cabs.... an expensive solution.

In a series-two configuration, your amp will probably produce at least 62v, which gives 31v (125w) to each driver. Any more than that is wasted in heat and power compression. You could wire the box for 3 parallel groups of series-two. This gives a 5.33 ohm impedance with six drivers. One amp channel.. happy amp.

[Tom Smit]

Why not build a series/parallel wiring box so you can avoid the 2 ohm problem? Otherwise you need six amp channels to stay at 4 ohms with 12 cabs.... an expensive solution.

In a series-two configuration, your amp will probably produce at least 62v, which gives 31v (125w) to each driver. Any more than that is wasted in heat and power compression. You could wire the box for 3 parallel groups of series-two. This gives a 5.33 ohm impedance with six drivers. One amp channel.. happy amp.

Recently I had been thinking about this, and my brain won't let me see it configured. Do you have a diagram (and photo) for this?
TomS

[bgavin]

No.

First, there are three circuits. Each of the three is a series circuit, with two drivers.

RedWire (+) --> (R) 2512 (B) --> (R) 2512 (B) --> BlackWire (-)

RedWire (+) --> (R) 2512 (B) --> (R) 2512 (B) --> BlackWire (-)

RedWire (+) --> (R) 2512 (B) --> (R) 2512 (B) --> BlackWire (-)


Next, each of these three circuits is connected to the jack in the cabinet.
All three (RED) to +
All three (BLK) to -

******

Now this is nice and tidy if all done inside a single box. That is not the case for us.
Each external speaker connects through a jack to your series/parallel box.
The serial wiring as shown above is done inside your box. Standard cables connect each of the cabinets.

******

I should probably build and sell these on my (upcoming) eCommerce site.

[Tom Smit]

bgavin, thanks. So, if I'm right, each circuit in the box must have a minimum of two cabs plugged in for the speakers to operate. And, as more cabs are added/needed, then the next circuit is used.....and finally the last circuit if more yet.

TomS

[screamersusa]

Pics...



more pics here.
http://www.screamersusa.com/BFM/OT122.html

The Omnitops performed amazingly well. Considering we were so totally undersized for this venue, the sound filled the space remarkably well. Very consistent throughout the venue and only slightly better in the center. Compared to the last couple of line array's I heard, the coverage was far superior. Thankfully it was more of a hi-class show and not a punkfest.
Inital tests with a cd going were jaw dropping. The greatest part was the breathy sound of the wooden flute, the timbre of the wooden drum, and the buzzing and subtle wood tones from the marimbas came through so well it raised eybrows.
You could tell that the real classical music lovers were really enjoying the quality of the sound by their body language and an occasional goose bump attack during the flute solos. The only problem we had was with getting the vocals clean which is being worked out now. I believe it is a crossover problem because I didn't have the probem as bad before crossover changes were made. Great little usefull boxes ya got there Bill.

[Tom Smit]

Wow, you been busy! And how was the sound quality?

TomS

[screamersusa]

A friend of mine from Kravitz Center was at both shows. I asked him to be brutally honest. We both agreed the system needs some tweaking. Compared to the new Meyer arrays and delays they installed there he said this, "The dispersion is really quite amazing" "I've never heard a small portable system sound that close to our installed system or fill a room this big with only two stacks".

The main act consisted of Professors and PHD's of music from various universities in Guatemala.
To say they were impressed is an understatement. These guys tour the world and play places like Lincon Center and Carnegie hall. Not the gig I expected!.

The Venue manager suggested I build a bigger system and give him a call.