Outdoor T30 setup query (boundary loading)

[commander_dan]

Brains trust,

I am doing a small 2xT30 / 2xOT12 setup in a mates backyard on a rural property this weekend. Examining the low quality pictures below you will see my proposed setup idea.

In the interest of maximising SPL I'll be Vplating the subs, and I'd like to utilise the small stone wall structure seen in the pics, by pointing the subs toward it.

Questions:

1) Is that stone wall (being about the thickness of a double brick wall) substantial enough to create useful boundary reinforcement? (My guess is: probably not).

2) If so, would reflections from the house pose an issue? (My guess is: not enough to notice).

3) If not, would it be OK to setup the subs in front of it firing outwards? (My guess is: probably).

...and go! (Thanks in advance).

[Bill Fitzmaurice]

To provide full boundary reinforcement a wall must be a wavelength wide and tall. At 100 Hz that's 11 feet, at 50 Hz that's 22 feet. You'll get some assistance from that wall, but not a lot. Most of what you get will be from the house.

[commander_dan]

Thanks Bill. Would I be better off then setting the subs up facing the house to fire out onto the grass? Or just setup firing directly out from the stone wall. I could try a few different setups as I'll have a bit of time to play with.

[Bill Fitzmaurice]

The main concern is keeping the sub mouths less than 1/4 wavelength from the house. viewtopic.php?t=398

[commander_dan]

Yeah ok. So at 35hz that's about 2.5m.. I'll see how viable it will be to aim at the house.

Cheers!

[Bruce Weldy]

Yeah ok. So at 35hz that's about 2.5m.. I'll see how viable it will be to aim at the house.

Cheers!

You're only thinking about the lowest frequency of the sub. If it's low passed around 100Hz, then it needs to be within about 2 ft from the wall....or at least 8 feet away. That's off the top of my head, you can do the math to be more exact.

[commander_dan]

Hehe guilty as charged.. I definitely am more biased to the low frequencies

If I do setup against the house, the subs will be a foot from the wall.

[Bill Fitzmaurice]

A foot is fine.

[commander_dan]

Just a quick review on this. I ended up loading the subs against the house as planned and it worked out perfectly. Plenty of headroom with the pair of V plated T30s. Didn't get many photos of the setup but can see it below.

[Bruce Weldy]

I bet it shook everything in the house....

[himhimself]

Backyard parties with tubas are always fun! While boundary reinforcement is awesome (I've done it countless times using 12m high concrete tilt-up building walls - wow) even without, the tubas can do an admirable job. I have four, and v-plate them in a pile. Usually someone ends up asking to turn them down anyway
Was just in Perth a couple weeks ago. Did the tunnels tour under the Fremantle prison and hung out in Northbridge for a night. Was hoping for some better music venues but oh well, still had a good time.

Oh, complete aside. I stopped off in Phuket for a few days between work stops and spent several nights until close at Illuzion. OMG, first I've been able to hear a Funktion One system install. Like my tubas and o-tops on steroids, just huge sound with effortless bass that doesn't tire your ears out even after hours at full tilt. Their engineers had it dialed in really well.

cheers all!!

[dlv]

Nice set up for a great party!