OTop8 dispersion angle and Bi-amping

[Keryn O'Shea]

Ok great, thank you very much for your help gentlemen.
Could you confirm these values being safe please:
If l were to set the HP at 45hz, a 50v limit,
and a 35hz HP, a 40v limit?

[Seth]

Keryn, will you remind me what we're talking about... it it 3015LF loaded T48's?

[Keryn O'Shea]

Yes mate, there's a mixed bag of drivers
2x LAB15, 2x 3015LF and 2x 3015CX in T48s, one of each on two channels, and setting the limiter for the weakest driver being the 3015CX, depending on content HP at 35hz or 45hz. Xmax is 8.7mm

[Seth]

I'm not sure what year your plans are, but my set from last year has this as the voltage limit recommendation:

There's no official voltage recommendation for different high pass frequencies, other than the one stated above.

The recommended high pass frequency is (as stated in the plans) "Groups of less than four cabs should be high-passed at 40 Hz. With four cabs or
more 35 Hz is acceptable"... same voltage limit.

I'm thinking somewhere around 50v would be sufficient.

[Keryn O'Shea]

I have 2013 plans, which talk about the LAB/LF drivers at 60v, though that table you referenced must be in later plans.
I'm glad to learn how impedance doesn't enter into limiting, l missed that in the forum discussion.
50v it is! Thank you.
Would l be missing out on any noticeable output on the times when l can't stack & V-plate with the six cabs?
My guess is no.

[Seth]

Are you asking about limiting the LAB and 3015LF loaded cabs to 50 when they could technically be run higher in a case when you're not utilizing all 6 cabs, and missing out on potential peak output?

If so, the difference between 50 and 60 volts is only 1.6dB. If you did a side-by-side A/B comparison of a sine wave tone, you might hear the difference. But, if you pulled the volume down 1.6dB mid-show or even at the peak of the performance, not a single person in the audience would even have a clue that the volume changed.

Your guess is correct.

[Keryn O'Shea]

Are you asking about limiting the LAB and 3015LF loaded cabs to 50 when they could technically be run higher

I had wondered about that, and it's great to know l'm not missing out there.
More asking if when running 6 cabs, whether there would be a noticeable difference in output between stacked with the V-plate like this

Or set up next to each other in a line when l dont have help setting up. l was guessing with two cabs yes, but not a large difference with six.

[Bill Fitzmaurice]

Stacked gives more efficient coupling of the individual cabs into one larger source.

[Seth]

Bill, I forget at what point the v-plate offers no benefit... was it 8 cabs?

[Bill Fitzmaurice]

I wouldn't bother with more than six.

[Keryn O'Shea]

I wouldn't bother with more than six.

Great, thank you.
Today there was a reprieve from the rain, so this happened finally..

Just myself for setup, as it's a Monday, next time there'll be help to stack & V-plate. It's not like I'll be looking for more bottom end though. My mate visited for a listen & we ran it up to just barely brushing the limiter with a Psy Trance track & we were both astounded with the strength of Bass.. & we were standing 90ft away
The system was faced the opposite direction from my sons bus stop, which is 0.6 of a mile away, & they could hear Van Halen clearly when they stepped off the bus, with the fader at 60%. The OT8s are silky smooth all the way into ridiculous volume levels,
We ran four Psy tracks loud & the 10 amp breaker didn't trip... very happy indeed!

[himhimself]

That looks amazing! Wish I could hear your rig.

[dlv]

Now that is impressive!!!

[Tom Smit]

Awesome!

[Seth]

Keryn, that looks so darn good. Everything square, symmetrical, evenly spaced, and identical from cab to cab. Ultra professional. I'm super impressed. It's been a long project, congratulations on completion and a successful test run!

Which amp/s did you run it all on?