As an owner of a manufacturing firm in the audio industry, I have had the opportunity to work with some truly fine home theaters. The joys of toys with an infinite budget. Life is good, and sometimes it is really good.
A small theater in my home had come together fairly well, and when my partner asked if I could build him a little home theater in his RV Bus, it seemed like the perfect gift. The concept seemed rationale; we would take a couple of components we had hanging around the office and just install them in the Bus. I drew up some plans, and e-mailed them over to Russ Herschelmann to see what he thought. The response from Russ was short and concise, the note was to the effect that I should “Repent Now! and see the evil of my ways.” Russ’ logic was irrefutable, a bus is not a home and the acoustics, if a bus’ interior can even be called that, were simply all wrong for home theater. Russ was of course correct, but being a stubborn sort, we decided to build it anyways.
Our first attempt ran into a few snags. The components were too deep for the shelves already in the bus, but several days of a cabinetmaker cutting all sorts of complex angles resulted in cabinets that looked stock, but which were six inches deeper. Quite delighted with the handiwork, we placed the components into the bus, and used several rolls of Velcro to hold them in place. The bus of course immediately shook the components loose and when a DVD player popped out of a cabinet at 70mph, we decided to get serious and took big straps and big screws and fastened them down hard. Add in some beautiful milled brackets, and it looked great. The result were components which Samson could not have budged. Unfortunately, the impact forces from the bus going down the road immediately broke the solder joints on several of the circuit boards. So, while the components did not move, they also did not work.
At that point in the project we should have quit, but as mentioned above we are rather stubborn. So, we took acoustical foam from our friends out at Auralex Acoustics, and floated the components on a soft bed of foam, and then placed flat rubber bungee cords over the top to tension them into the foam. This system worked well, and at least we could now listen to the system- HUM!!!
While we had carefully arranged the grounds in the system to avoid ground loops, we clearly had a major problem. The problem turned out to be that despite carefully drawn plans for the AC to go through one conduit and for the Audio to go through another, a third party we had hired to help with the project, had decided that it was silly as there was plenty of room in the AC Conduit for the Audio cables, so he “improved” the design and just tie wrapped it all together through 30′ of conduit. Result, remove the screwed and glued ceiling panels and the walls, install the proper cables into the proper conduit, and voila half a week of work later, no Hum. By now the system was looking pretty good. A set of Miller & Kreisel S85 were chosen for the LCR and Surrounds as they make a lot of quality sound in a very compact package. We had planned to use a M&K sub, but a Christmas Gift of a Bag End Infrasub was irresistible. That big bottom end seemed like just the ticket for the wimpy walls found in the bus. We needed a killer first wave, and the Bag End is a veritable lethal weapon.
A Lexicon DC1 slid into the cabinets and while we debated the merits of a projector, the mounting just did not fit the dimension we had. In the end, a Broadcast Quality Sony 2530 Professional Monitor was mounted in the bus, along with six channels of our Gold Line parametric EQ and a indestructible Rane six channel Pro Amplifier for the LCR and Surrounds.
The results were impressive. Not quite high end home theater, but considering that we were inside of a room that bore a striking resemblance to a Godzilla sized beer can, we had pleasant audio with a lot of punch.
Feeling pretty good about the job done, we took it out on the road and immediately started blowing tweeters. A quick spot check with an oscilloscope showed that the problem was that the Bus’ DC converter was sending square waves inductively into our AC, which was then making it to our tweeters. A quick call to Furmann resulted in one of their power regulators. With a coil tap to stabilize the errant voltage and to massage it back into sinusoidal AC, it was time to do some more travel.
With that final piece, we now had a bus ready to travel from coast to coast in comfort with a powerful surround sound system. West Virginia seemed like a great destination in the spring and we were proudly entertaining some friends with the movie Twister. My wife became quite agitated that the bus was rocking, but I assured her that it was normal and that a 400 watts of sub can in fact rock 12,000 lbs of bus. I was quite sure it was ok. The fact that I had missed, was that while we were watching the movie, the local TV station had issued a Tornado Warning. The tornado touched down within a few hundred feet of the bus, and after the movie we emerged to find trees down, limbs blocking the road and a small hole in the side of the bus. She told me so.
We laughed about that one for a while, but when we headed for Georgia it got out of hand. I arrived at a trade show with the top picture window completely blown out of the bus. A 7 foot section of glass was just gone. An individual walked up to the bus to ask me what had happened, and I explained to him that a saucer shaped object had zoomed out of the sky, and fired some sort of a beam at us. Now I could see that he did not believe me, so I confided in him that we had a video camera on the bus, and I had pictures of the attack. He got kind of quiet, and with the trap set, I spooled up a scene from Mars Attacks. As he sat there slack jawed, I paused the movie and told him it was the strangest thing I had ever seen. And, somewhere in Georgia is some guy who will swear that he has seen a bus that was attacked by a flying saucer and that he has seen the video of the little green men with his own eyes. I probably should not have done that. Russ may have been right; I should Repent Now.
For what I did to that poor guy, I will probably get a piece of coal in my stocking this year. To all, best wishes for a wonderful Holiday Season. May you all get the perfect gift for your home theaters.
We removed the bedside table from the bus and replaced it with a 400 watt 18″ Bag End Infrasub. A cast brass elephant lamp gives the subwoofer cabinet a look like a table. A Furmann power conditioner is hidden behind the Subwoofer to provide balanced power for the theater system. The dome above the subwoofer is a rear facing camera, to allow the driver a clear view behind the bus. The cabinets just visible above the subwoofer are filled with absorptive materials and conceal the rear channel loudspeakers.
The original 15″ color TV was replaced with a larger Sony 2530 broadcast quality commercial monitor, which is mounted directly above the driver on a custom steel truss. The truss work is hidden by the cabinets. Below the monitor is the black cover of the Miller & Kreisel S85 loudspeaker utilized for the center channel. A white cover blends the left channel S85 into a custom wall mount. When movies are showing a curtain pulls across the drivers area to provide for dark conditions while screening movies. The modified cabinets contain a Lexicon DC1 Processor, Sony DVD, VCR and DAT Player, six channels of Gold Line parametric EQ and a six channel professional amplifier. Cabinets on the opposite side contain a Gold Line DSP30 analyzer with four channel multiplexer and a TEF20 Analyzer.
Gregory Miller is co-owner of Gold Line, a manufacturer of audio test equipment and digital equalizers. Anyone foolish enough to consider building a home theater in a bus can contact him at email@example.com And, if you happen to be that guy from Georgia, well Uhh, yeah it was a movie.