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Sonic Isolation
Old 1st October 2002
  #1
Sonic Isolation

In "normal" studio construction, you build the walls with a couple of layers of dry wall, stud, more dry wall, air gap, more dry wall, stud, more dry wall... and end up with a wall that's nearly a foot thick.

Obviously, you can't do that in a mobile truck... so... how do you build the walls so they:

A) Keep the outside noises to a minimum?

B) Don't crumble and/or disintegrate in transit?

C) Don't reduce the interior volume of the work area?
Old 1st October 2002
  #2
Super Moderator
 
Remoteness's Avatar
Re: Sonic Isolation

Well, back in 1987 when I built my third truck, we used multiple layers of material, but not like your typical recording studio.

It's been a long, long time ago, so I will do my best to remember and explain it to you...

Since we had to start with a truck body, I used it as my frame. The interior side of the aluminum sheets that attached to the truck body ribs were undercoated by spraying this rubber substance. The undercoating really deadened the box very nicely. Then we filled in the spaces between the ribs with 5 LB density fiberglass insulation. We laminated two sheets of 3/4 inch plywood together by spreading silicon across the sheets very thinly, then pressing them together to make one very heavy sheet of wood. Once together, each 1.5+ inch sheet was attached to the truck body's ribs with screws. On top of that, we added two layers of 1/32 inch lead sheet lining. Once the lead lining was in place, we added a rubber sheet layer and a one inch teak wood finish.

We milled all our own pieces. The live side has triangle shaped teak strips and the dead side has 5 LB density fiberglass with angel hair over that for a better feel and to keep you from the insulation. The truck walls are about five inches think. The ceiling was similar to the walls except for the fact that we used one sheet of plywood and added a rubber layer with a leather type of material for a cool look and feel. We lead lined the truck's bed and floated a wood framed parque floor on rubber pucks.

Tommy the Carpenter did an awesome job for me. The huge, thick remote controlled entrance door still works like a charm, even after all this time. I really cannot believe it held up to all the abuse it got over the years. The walls never crumbled or fell apart over time or in transit either.

It did reduce the interior width of the work space, but I worked around that by installing two angled ceiling racks in front and behind you.
Old 1st October 2002
  #3
Lives for gear
 
Fibes's Avatar
 

...and now for the gas mileage.
Old 1st October 2002
  #4
Super Moderator
 
Remoteness's Avatar
Zero gas mileage my man.....




The truck runs on Diesel fuel. heh

About 8 miles to the U.S. gal.
Old 2nd October 2002
  #5
What do you hear in the truck if a NYC emergency 'convoy' of Fire & police vehicles goes right past you?

Old 2nd October 2002
  #6
Lives for gear
 
Steve Smith's Avatar
 

I have used The Aurasonic Truck ( outside in a festaval type setup) about 35 feet behind a full on V-DOSC rig, and let me tell you, the isolation is impressive. I have used trucks that did not have this kind of isloation, and let me tell you , it sucked!

Thanks for the description, I meant to ask you about that when i was there.
Old 2nd October 2002
  #7
One with big hooves
 
Jay Kahrs's Avatar
Quote:
Originally posted by Jules
What do you hear in the truck if a NYC emergency 'convoy' of Fire & police vehicles goes right past you?
Well, with open mics nearby it sounds like a convey of emergency vechices.

Steve, how did you deal with HVAC for the truck? I'd imagine it gets pretty hot in there during the summer with all that gear and people in a small space. It was hot the day I was out with you but I'm sure it's been hotter. Have you ever had problems with heat or other inclimate conditions?
Old 3rd October 2002
  #8
Super Moderator
 
Remoteness's Avatar
Quote:
Originally posted by Jay Kahrs


Well, with open mics nearby it sounds like a convey of emergency vechices.

Steve, how did you deal with HVAC for the truck? I'd imagine it gets pretty hot in there during the summer with all that gear and people in a small space. It was hot the day I was out with you but I'm sure it's been hotter. Have you ever had problems with heat or other inclimate conditions?
Jay,

The day you were out with us, was one of Newark, NJ's hottest days. I think it hit a record that day and it was like a fridge in the control cabin, if I remember correctly.

Keep in mind, I built this truck over 15 years ago and had a slightly different approach to things back then. Economics was key. More bang for the buck ruled back then. Not that it doesn't today, the numbers to play with are much larger for me nowadays.

Back then, we did a lot of recording in places that did not have proper power. Sometimes we could not tie into "real" power and had to modify our power distribution. If applicable, we could use up to six 20 amp Edison plugs right into standard wall outlets. I didn't want anything but 110 - 125 volt equipment in the truck, A/C units included. I decided to use three 117 volt household air conditioners, modified for my needs. One for the equipment and two for the control cabin work space. It's the best $200.00 I ever spent. I bought two $200.00 A/C units and another smaller unit and they are still working like a charm today. I never even recharged them in all these years. They may not be the quietest units but they work perfectly.

Today, with the new expando truck project, it's a totally different thing. We are going all out on this one. High tech all the way in most areas ... but that's another story alltogether.

Back in the old days of everyday use of two inch tape, all we needed to do was turn on the 2" machines and our heating issues were met during the winter season. We carry space heaters that quickly heat up the control cabin. On really cold days, it can take anywhere from 15 to 35 minutes for the truck's control cabin to be at the right working condition. During the hotter seasons, the A/C thing is a totally different situation. The A/C units instantly cool off the truck within 2 to 5 minutes of turning them on. When I had the Harrison MR4 and two Otari MTR90II's on board, we had to have at least one A/C unit on during the winter season. Imagine that...

You could freeze your butt off using DA*8's
Old 3rd October 2002
  #9
One with big hooves
 
Jay Kahrs's Avatar
Quote:
Originally posted by Remoteness
Jay,

The day you were out with us, was one of Newark, NJ's hottest days. I think it hit a record that day and it was like a fridge in the control cabin, if I remember correctly.
Yeah, it sure as **** was. I think it hit 105 or something and the truck was nice and cool.

Quote:
Back in the old days of everyday use of two inch tape, all we needed to do was turn on the 2" machines and our heating issues were met during the winter season. We carry space heaters that quickly heat up the control cabin. On really cold days, it can take anywhere from 15 to 35 minutes for the truck's control cabin to be at the right working condition. During the hotter seasons, the A/C thing is a totally different situation. The A/C units instantly cool off the truck within 2 to 5 minutes of turning them on. When I had the Harrison MR4 and two Otari MTR90II's on board, we had to have at least one A/C unit on during the winter season. Imagine that...
I can. Even in my space with the JH-24, A80, Trident 65 and outboard going there are times when I need to run the A/C in January. Who needs a space heater when you have a big tape deck?
Old 19th October 2003
  #10
Here for the gear
 

Lighter weight compromise

In my small remote truck (http://www.curbside-recording.com/) we used the following technique:

o Foam between the aluminum ribs (blown in in the ceiling and cut blocks on the sides.

o Butyl weatherstripping between the ribs and the plywood sides. I think we used 3/8" plywood.

This gets good isolation at high frequencies, but does very little to block low frequencies. Like I said, it's a compromise... The entire truck is under 10,000 lbs...
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