T18 and Omni 10.5 review

[RubiconProSound]

Well the first of two weddings is done and the first night went well. I set up two T18's v coupled and a pair of Omni 10.5's at the end of a 25' by 60' room at a local winery/restaurant. I didn't get a chance to RTA or set the EQ so I bypassed the EQ and set the X-over to about 70HZ and did the rest by ear.

The Omni's:
I could definitely hear the spike in the 10K range on the melded array but I just padded it down using the strip EQ on my mixer. The vocals were very clear and overall it sounded very clean. The volume at the far end of the room was still good enough for folks to hear the speeches and background music. I ran the system at about 95~100 dB all night and never really opened it up fo fear of blasting out the folks closest to the dance floor. (I hate long skinny venues...)

The T-18's:
I can't comment on the Vplate since I haven't run the T18's without it yet. (that will be a later SPL day...) I tried to corner load them as best I could but since this was a winery I was stacked next to a monster wine cask. (see photos) Even with the less than optimum loading it still had a nice presence throughout the room even at the other end. The volume certainly wasn't like at the dance floor but the lows were still in the mix. They were very tame during the beginning of the night (Back ground music and program material from the 50's through 70's. Songs like "Brown Eyed Girl" and "ABC"... ) Once I moved into the newer dance stuff that's when the T18's got nice and angry... I put on "My Humps" and I thought the coffee maker behind me was going to fall apart. The groom came in from the bar and said when the song started a number of people looked a little startled and and were looking around the room. The T18's definitely came alive on the newer songs. I had the amp limited to about 22 volts but I don't think I ever got into that range all night. The channel strips hung out in the 4~6 range all night and the amp never broke a sweat.

Overall I was really happy with the sound. (insert a big thumbs up here)The Omni's can definitely run away from the T18's and I had to back them off to even out the mix. I also noticed the transition at the X-over frequency wasn't as smooth as I would have liked, the Omni's didn't seem to pick up on the mid bass where the T18's dropped off. I'm guessing that had more to do with the lack of time available to run a quick SPL and set the X-over up a little better than anything else.

In another hour I'm off to another wedding so I'll see if I can get some more time on the EQ and X-over settings. I'll have more tomorrow....

The set-up:

[RubiconProSound]

Second night went well, although I ran without the subs. It was a tight outdoor patio and I thought it would be an opportunity to run the Omni's full range. I got the EQ dialed in and smoothed the response out on the mids and highs. The arrays work great, no matter where you are on the floor the highs are still there.

The bass seemed a little thinner than I would have liked but considering I was outdoors and without subs I can't complain. I'd like to try the Omni's solo inside before I make a final judgement.

I'm definitely enjoying the smaller pack space of the T18's, the cube size actually makes them a little easier to pack than the long shape of the AT's. (at least in the back of my FJ...)



So does anyone else look at this picture and go Hmmmmm.

I'm wondering what would happen if I just wired the two T18's to the car stereo....

[Sydney]

Nice:

I'm wondering what would happen if I just wired the two T18's to the car stereo.

To your hearing OR the glass?
You did some minor extending right? What's the dims?
* I thought clusters of T18 would be a viable alternative the A/V cart stuff used in schools: Used separately for small class rooms, clustered for events in cafeteria & commons areas.

The bass seemed a little thinner than I would have liked...

Mine likes boundary loading...
Looking forward to SPL day and results of using 4 together.

[jbell]

Are your 10.5's ported? I thought in the first pic, I could see the port?

A couple thoughts, from hearing my dual T18.

Just a 12db cut at 70-80 hz doesn't work well. next octave above that, response really climbs, so you end up getting more 150hz-ish than you want, and then when it peaks and rolls off, response drops like a stone -- so you get a very abrupt cut off that doesn't integrate well with tops. That may be what you heard. I had to stack a 40hz 6db passive with a 12db 80hz active cross to get it to do what I liked. Not sure what eq/crossover options you have, but it is possible to get T18's to integrate nicely.

Not sure how your single driver T18's coupled compares to my dual cabinet. If it's any better, you've got a winner for a small set up. Makes me think of trying a couple 10.5's with a dual T18, and one of samsons 1U amps /small behringer mixer for a complete school set up.

It'd be cheap, and would have to kick the stuff out of the plasti-boxes/powered mixers I see.

Any spl readings from your pair?

[RubiconProSound]

To your hearing OR the glass?

Either...

You did some minor extending right? What's the dims?

I added 1" to the width and 3" to the depth. The cabinet is now 21X19X19 so I guess it's officially a T19.67

I added the 3" to the depth so I could add the speakon connector to the front and not worry about leaks in the horn. The pic below gives you an idea of the "dead space" where the speakon and T -nut for the V plate go.

[RubiconProSound]

Are your 10.5's ported? I thought in the first pic, I could see the port?

Yup, I forgot to paint the foam on the inside of the cabinet... good eye.

A couple thoughts, from hearing my dual T18.

Just a 12db cut at 70-80 hz doesn't work well. next octave above that, response really climbs, so you end up getting more 150hz-ish than you want, and then when it peaks and rolls off, response drops like a stone -- so you get a very abrupt cut off that doesn't integrate well with tops. That may be what you heard. I had to stack a 40hz 6db passive with a 12db 80hz active cross to get it to do what I liked. Not sure what eq/crossover options you have, but it is possible to get T18's to integrate nicely.

I've got a dBX 223XL, I can't change the slope and I think it's fixed at 12dB... I'll get it on the RTA in a week or so and dial it in better. (getting ready for Memorial Day now so I won't have time...)

Any spl readings from your pair?

not at war volume, I kept the volume down because it was a wedding reception. I've got a regular party coming up in a couple of weeks with club and newer dance material. I'll open them up then and see what they can do.

For smaller events I think I'm really going to like the portability of the T18's. They seem to do just fine and I don't need the trailer like I do with the T30's.

[klocwerk]

keep us posted on your progress working out the kinks!
I'm considering a T18 to put under my O10.5 for a fuller mini upright bass rig, so I'm definitely interested in how they mesh.

[RubiconProSound]

"Part deux" is scheduled for today...

I have an outdoor party and I have enough wall at the back of the house to load the T18's against. I'll have the mic and the True RTA with me today so I should be able to get more specs. I also get a chance to try out a new amp. I picked up a QSC CX404 from a buddy for a steal. It's 2 rack spaces, 4 channels, and a total weight of 21 lbs. Perfect for the 10.5 + T18 set-up. (and my back...)

Specs and pics to be posted on Sunday....

[Harley]

Careful, one of my THTs cracked my windshield right down the middle...

[RubiconProSound]

part deaux...the more I listen the more I like. I got to do an outdoor party for some friends of ours that we DJ for every year.

So I got to try out two arrangements in one night. I began the party with the system set up on the back patio. The Omni's were against the back wall of the house (about 2~3' from wall) at just above head height. The two T18's were loaded against the rear wall of the house under the balcony. I had planned to V-couple them but the space available for me to walk would have been to small so I just laid them on thier sides bottom to bottom.

I did a quick RTA from the patio and the sound was reasonably smooth with a small bump in the 8k range. I went back the to EQ and smoothed out the upper end a little and all was good.

In short, the sound was great. In the past I used to run some JBL TR225's for these party's and the bass had a nice kick but never really had the bottom end. (No real surprise given the enclosure for the TR's was way too small for two 15" woofers...) There was plenty of bottom end even out at the end of the patio. I was sitting around 106 dB at the "booth" during the louder portions of the evening and hovered in the mid to low 90's on the patio depending on where you sat/danced. I didn't really have the volume up loud enough to get any real "kick" out on the patio but it was perfect for the night. (Although under the balcony the T18's gave me a nice massage all night...) The T18/Omni combo is also much easier to haul and takes up less space in the back of the FJ than the TR's did.

At about 10:30 the neighbor came by and asked us to turn it down so we moved inside. I brought the Omni's in along with 1 of the T18's. I loaded the Tuba against the wall (no corner available) and stacked the gear on top of it. No real surprise, the system rocked inside. In both cases I don't think I had the amp over 1/2 what it could give and it cruised all night long.

Settings:
Both my EQ and amps have low cut filters on them so I just went with the filter on the amp at 33Hz. The limiters on the QSC were also on but I don't think they had to do anything all night. The sound seemed happiest with the X-over set around 70Hz. The 48dB slope on the dBx seemed to work out ok. The next step is to get a DCX so I can dial in the delay...

All in all I'm very happy with the sound. This will be my regular wedding and house party rig from now on. It might be a tad small for larger halls, but at wedding receptions I only really need the spl at the dance floor. Nobody at receptions likes to yell over the music, I think more DJ's need to get this clue. It's not a rave, it's a reception.

Pics....

The patio: I was set up under the balcony, you can just make out the Omnis under the balcony.


The Tubas: Did I mention how much I like having the speakon jacks on the front as well as the back? Look Ma, no wires...


After the move inside: I found another benefit to the additional 3" I added to the T18...My gear stacks on top nicely.

[klocwerk]

looks awesome!

So they're standard T18's? WHat's the extra 3" thing?

[RubiconProSound]

I added the 3" to the depth so I could add the speakon connector to the front and not worry about leaks in the horn. The pic below gives you an idea of the "dead space" where the speakon and T -nut for the V plate go.

see the post about a 1/3 of the way down the thread...

[klocwerk]

I added the 3" to the depth so I could add the speakon connector to the front and not worry about leaks in the horn. The pic below gives you an idea of the "dead space" where the speakon and T -nut for the V plate go.

see the post about a 1/3 of the way down the thread...

Ah, rgr.
T18s it is for me too then, once I'm done moving.

[RubiconProSound]

Some information from our RTA party yesterday (Kaptain John and I)

Disclaimer: the SPL readings are subjective as are the TrueRTA plots since I was using a Radio Shack Digital SPL meter as the Microphone, and the testing was done outside. (John's backyard) The AC compressor kept kicking on occassionaly and a light breeze picked up near the end of the testing.

The Omni was tested on a tripod about 4~5 feet above the grass and the RS SPL meter was also mounted to a tripod roughly a meter away. I wouldn't put any stock into the SPL readings listed on the TrueRTA screen shots since I didn't calibrate the mic to the program. We used the Binks test CD and set the pink noise track for 2.8 volts (no load) then plugged in the Omni and ran three plots. This is an average reading from the three.

The Omni 10:



I now see why I thought the bottom end was a little thin...because it is. I strayed from the plans and added a divider behind the melded array because I had some leaks. I'm guessing maybe I ate up a little too much airspace in the process and killed off some bottom end. I'm not too worried about it since I'll always be using these with the T18's anyway. (Now that I've seen the light and given up the dream of tring to have "full range" cabs 20 feet away from each other...)

I can also definitely see the spike at 8Khz I was hearing. This is also tamed with a little eq and I figure it's just a byproduct of the Melded array. I'll take the great wide dispersion of the melded array over a more even RTA plot any day.

The T18:



The SPL is off a little from what is published on the site but I do know the SPL meter was reading 103 overall. We set the output voltage to 2.8 volts using the 1K test tone on the binks CD, then ran pink noise through filtered at 33~125 Hz. I have heard that the radio Shack SPL meters are notriously bad in the lower frquencies so I can't wait to get my Behringer RTA Mic and try the plot again...

Here's my AutoTuba just for comparison. Same voltage, same pink noise. We just unplugged the T18 and swapped in the AT...

[Bill Fitzmaurice]

You won't get the same measurement from an O10, or any cab, on a stand versus half-space. When measuring with a noise source it will come in 6 to 12dB lower than with a swept sine wave, depending on the resolution used.