Omnitop 12

[gdougherty]

So, after cannibalizing one tweeter array to get a full working set as I await additional tweeters for my second pair of OT12's, figuring out that the tweeter array shouldn't be wired in after the inductor, and sealing everything up I plugged a newly completed OT into one side of a Denon home theater receiver, threw in a CD and cranked it up.
Then I cranked it back down, because dammmmmnnnnn, those puppies were loud. The 1802 I used only runs 80watts per channel and while the amp reads +10db at a max, if I turned it up past -10db it became deafening in the living room. Most amazing though was how clear it was. No matter how loud I had it, it never broke up, never fealt painful. Can't wait to run it on a proper amp in a good sized room at full war volume.

[Strapping Young Stu]

Have you got photos?

Nice review, can you say any more about the sound quality rather than volume quantity?

Stu

[gdougherty]

Sound quality:
Bear in mind this is without any break-in period. Generally that smoothes things out, but I've never heard a night-and-day difference either after a break-in period. Of course I've never done an objective test with recording the fresh vs broken-in output.

Without eq there's a minor touch of the midrange "honkiness" you hear the audiophiles talk about when they discuss horn loaded home speakers, but it's nothing at all like the wedgehorn, and it's more a distinctive colouration that may or may not disappear with the application of the autoeq in my DEQ. The wedgehorn lost almost all it's "honkiness" after a proper eq, so I'm thinking I'll see the same thing with the OmniTops. I'll make sure and include that info in a follow-up.
From 100hz on up, the 12" driver is strong and effortless delivering smooth mids and a reasonable amount of bass. When I turned the bass tone control on the Denon up to +6 it actually sounded like it may do acceptably well for a full range PA at moderate volumes on accoustic music where deep bass isn't necessary. Running with a moderatly powerful 12" B&W home theater sub I could tell I'll want to use a sub in most of my applications.

The highs out of the 6 GT1016 array were incredibly clear and detailed. I've read all the rave reviews of coupled piezo tweeters and the 4 in my wedgehorns keep up effortlessly with the 6.5" driver, but they've never really been cranked up to high volumes either. Until now though, I'd never experienced this marvel of Bill's designs for myself. I was blown away by how clear and smooth the highs were at any volume with the limited power I had available. As a reference, I own a pair of B&W602S2's which are a wonderfully detailed and articulate bookshelf speaker and the Omnitops were easily as good. When people say hi-fi in describing these and the DR's they're not off the mark. My father asked if he could have them to replace his Boston Accoustics satellite speakers in his living room.

I've not run it side-by-side with my Peavey SP2x, but having used the Peaveys just that morning my impression was that the OmniTops are more clear than the Peaveys and I imagine they have an advantage in high-output clarity given their serious advantage in sensitivity.

[Strapping Young Stu]

Cool let us know how it sounds with the auto EQ and/or proper EQ engaged and if you can figure it out, where the honkiness lies

Is it a 1x12" or 2x12"?

Stu

[EW]

What's your intended use for your OTop 12's?

Also, could you post your EQ settings for those of us without an RTA?

Thanx!

[gdougherty]

These are Deltalite II 2512 loaded 1x12's with the 6 piezo tw. I plan on eventually building 3 pairs. For when I really need it, I can stack 3 per side and cover up to 500 people, or I can add an amp and run 2 pair up front with the third as a rear delay for a long venue to avoid having to deafen the front row to cover the back. I can also split off a pair, have 2 for my mains and use another pair at a different venue with a powered crate mixer.

I'm waiting on another 20 1016's to complete my second speaker and get me set for building the second pair. I do need to put some absorbtive material right behind the driver and do something to extend the throat braces out to the side. I'm now thinking it's possible that the "honkiness" is just some midrange distortion caused by those two issues. Once I've got my first pair completed I'll hook them up outdoors and get a basic EQ on them (I do the autoeq with the room correction enabled which gives a slightly more pleasing sound). I'll post that over in the EQ section rather than here.

[vlad335]

Thanks for the review. I would be interested in pics of your cabinets if you could post them.

[gdougherty]

I'll see about getting pics. I just got my second speaker fixed with 6 working tweeters. They look pretty much like just the other OT12's on the Frapper banner, duratexed with Penn-Elcom corners. Only difference is I only have a 2 speakon plate, no 1/4" jacks and they're mounted on the bottom of the back rather than the top. I built mine with the full front grill arrangement to eventually have a foam backed mesh grill to protect them a bit in the rain. It also eliminated the need to cut a 50 degree angle on the horn sides. The horn necks I also cut to 45 degrees insead of 65 and just caulked over the resulting gap. I was all about the simple cuts on this build.

[djshortpaul]

The horn necks I also cut to 45 degrees insead of 65 and just caulked over the resulting gap. I was all about the simple cuts on this build.

Are you glad you did this? Does it seem to have any adverse effects? I'm about to start building some OT112s and if I can avoid any >45 degree cuts that would be nice but I don't want to compromise performance.

Cheers. Paul.

[gdougherty]

I'd say it doesn't look quite as nice right now since I don't have the transparent foam and grill on, but otherwise it will eventually be covered up. I ran them at full War volume outside and the midrange sounded beautiful. I got a number of comments that everything sounded so incredibly clear and people were amazed that I was pushing enough volume to cover a baseball field with just two subs and these tiny little tops.

I have a feeling that a number of people probably had an unexpressed thought of "You gotta be shitting me if you think those tops will cut it out here." All that was expressed to me though was astonishment at how good they sounded after I made another tweeter swap to eliminate another bad tweeter revealed at the higher volumes.

I've got some questions I'll be making in another post, but I'm wondering if the 6 tweeter array is the best option for outdoor work at max volumes. The 2512's seem happy to push everything to incredibly high volumes, but the additional power handling from a crossfired array may be the best option, unless my gear was a problem.

[djshortpaul]

Thanks for your reply. I think I'll give that a go unless someone tells me its not a good idea. I'm starting the build this week and I'll be sure to take lots of pictures and write a review up when I'm done (whenever that is )

[Ron K]

The horn necks I also cut to 45 degrees insead of 65 and just caulked over the resulting gap. I was all about the simple cuts on this build.

Are you glad you did this? Does it seem to have any adverse effects? I'm about to start building some OT112s and if I can avoid any >45 degree cuts that would be nice but I don't want to compromise performance.

Cheers. Paul.

Easy way to cut greater than 45 degrees on a table saw is to make a "T" out of ply about twice the height of your rip fence. Then rest the "T" on top of the fence. Now clamp your piece to be cut to the "T". Adjust the fence inward till your edge is lined up and push through the saw. Simply use the difference of the degree greater than 45 degrees.

Example: You need a 65 degree cut. Set the blade angle at 25 Degrees and use the "T" to steady the piece vertical on the saw. Clamp the piece with the bottom edge against the table top and 90 degrees to the fence. Set the fence the distance of the ply thickness past the edge of the blade. "cut your piece"

[Bill Fitzmaurice]

There are instructions in the plans how to cut angles in excess of 45 degrees with either a table or circular saw.

[danest]

I`m planning on building a few OT12s.How many of them can be stacked per side for an audience of say 2500,and how are they to be stacked,straight or vertical?

[SoundInMotionDJ]

I`m planning on building a few OT12s.How many of them can be stacked per side for an audience of say 2500,and how are they to be stacked,straight or vertical?

Stacked vertically.

For a rock concert for 2500 of your closest friends, I'd look for a setup to have between 16 and 24 OT12's. I'd build the same number of DR280's.

If you go with the DR300, you'd need between 8 and 12 of them.

Subs for a venue that size would be:

8-12x T48
8-12x T36

16-24x T39
16-24x T30

But, with an audience that size, the DR300 + T36 makes a whole lot of sense.

--Stan Graves