New 12 volt amp rack for remote location work...

[RubiconProSound]

I threw together a couple of cheap 12 volt amps and a preamp for doing remote location stuff. I mounted both amps vertical in the cabinet and put air inlets and outlets in the hopes the heatsinks will act like a chimney and keep things cool. I've run the system for a couple of hours in the garage off my MP3 player and so far so good. I'm curious to see what kind of run time I can get out of it at war volume with the laptop and mixer hooked up. I have a small 400 watt invertor to run the mixer and laptop.

With it hooked up to a pair of T18's and Omni 10.5's it has plenty of volume. The last photo is with the Omni and T18 for scale...

[DJ Big Ronn]

Thats pretty nifty, kinda similar to the bass cart. You may need to put a small 1 or 2 inch computer fan if the amps start to get hot. Just a suggestion, the Optima batteries are a bit pricey, but will outlast those regular car batteries by a fair margin. If you have an extended job, just add a second battery.

[Tim A]

Just a suggestion, the Optima batteries are a bit pricey, but will outlast those regular car batteries by a fair margin. If you have an extended job, just add a second battery.

Also look into a 'deep cycle' battery, such as one for a boat or RV. They're designed to be charged and discharged over and over, whereas a standard car battery is designed to remain charged for most of its life.

[RubiconProSound]

The battery in the photo is a deep cycle...see the wing nuts on the posts?
I've got two from my travel trailer that I can parallel if I need to.

+1 on the red tops, I used to sell a bunch of those when I was installing car audio.

I'm doing a new years party so I think Ill bring the "12V suitcase" along with me to see how it does against my normal 110V rack. I'll have plenty of time before the party to play around and see what kind of SPL I can get out of it.

[jcmbowman]

Looks great!

A couple of minor suggestions:
If you're looking for maximum thump on the low end, think about adding a 1/2- to 1-farad capacitor into the power supply system. It's a trick from the car audio side of things, and it will also prolong the life-span of your battery because it helps limit the spikes on the power load and keep it a more steady demand on the battery.

Also - if you turn this experiment into something that you find yourself using regularly you may wish to do some serious research into which 12v amplifiers are the most efficient. Just the same as the difference between a Crown Macrotech and a Crown Xti, there are car audio amplifiers that are designed for raw output, and there are newer designs that are designed to barely sip at your batteries' output. I've worked with some friends who attend the burning man festival in nevada every year and are very concerned with power draw since they spend a week a year living entirely off-grid. The difference between a cheap amplifier and a well-designed newer digital switching amplifier is the difference between measuring runtime in hours or days off the same power source.

Last thought - if you plan to use this setup regularly - think about picking up a couple of solar panels to feed your batteries during the day. You're in California so you get some great incentives from the state govt. to get them, and it keeps you from having to worry about plugging them in when you get home... Just a thought.


As always - some top-notch implementation of a very innovative idea.... bravo!

[RubiconProSound]

Thanks for the comments...
I thought about throwing a stiffening cap in there but I wanted to keep the overall package small. I chose the amps because they were cheap. (59.00 each at Kragen near the house...) There a number of "digital" or "D class" car audio amps out there I could have used but in my experience they don't live up to the hype.
I installed car audio for 15 years and even did the whole IASCA competition circuit for a few years (as a judge and competitor) so I'm very familiar with car audio.

This rig will get used when our 4X4 club goes wheeling out into the boonies or for outdoor wedding ceremonies. I did a wedding last year where the ceremony was out in the garden about 100 yards from the reception hall. (No 110V and a generator would have been too loud, even a little Honda 2000i) This package fits the bill perfectly. I'll use the solar panel idea, I don't think I'll need it for the occasional ceremony but for the back woods it will definitely come in handy.

My New Years party will be in a barn at a vineyard my friend owns. I'll be staying the night there and hanging around the next day to help clean up. I'll run the "suitcase" to my T30's and tops and see how much we can get out of it (time and SPL) over the course of the day on Thursday.

[DJ Big Ronn]

Hanging around to clean up, or sober up . I've certainly found out how diff. things are between auto and pro sound. Like you, I competed in the whole IASCA, USAC and Thunder on wheels circuit and thought I knew it all, this site has sure changed my outlook. I'd be willing to bet, that the cabin of my astro van loaded with Autotubas rather than 8 eighteens, would have turned some pretty impressive numbers without having to use six batteries and a 200 amp alternator. Like the elders say " If i'd have known then, what I know now".

[Tom Smit]

Your set-up looks real good to me! ....gives me some ideas. Looking forward to your results!

TomS

[RubiconProSound]

Big Ronn...

Hanging around to clean up, or sober up . I've certainly found out how diff. things are between auto and pro sound. Like you, I competed in the whole IASCA, USAC and Thunder on wheels circuit and thought I knew it all, this site has sure changed my outlook. I'd be willing to bet, that the cabin of my astro van loaded with Autotubas rather than 8 eighteens, would have turned some pretty impressive numbers without having to use six batteries and a 200 amp alternator. Like the elders say " If i'd have known then, what I know now".

Answer to the first question: Both...

You took the words right out of my mouth in regard to discovering this site and what I thought I knew from the car audio world...If I knew then what I know now. This site made me realize just how much guys like Richard Clark and Tom Nousaine contributed to car audio from the Pro Sound side. I had no clue when I started installing in 85'. MECP and RTTI didn't teach me much more either...

I'm still tempted to roll into a competition with a couple of Auto Tubas and some rediculously small amp just to see the puzzled looks.

[AntonZ]

DIY switch mode amps are available from http://www.41hz.com , very efficient on power. No idea how they perform on piezo systems like the Omnitops and DR's, these tend to be picky on switch mode amps.

[DJ Big Ronn]

Big Ronn...

Hanging around to clean up, or sober up . I've certainly found out how diff. things are between auto and pro sound. Like you, I competed in the whole IASCA, USAC and Thunder on wheels circuit and thought I knew it all, this site has sure changed my outlook. I'd be willing to bet, that the cabin of my astro van loaded with Autotubas rather than 8 eighteens, would have turned some pretty impressive numbers without having to use six batteries and a 200 amp alternator. Like the elders say " If i'd have known then, what I know now".

Answer to the first question: Both...

You took the words right out of my mouth in regard to discovering this site and what I thought I knew from the car audio world...If I knew then what I know now. This site made me realize just how much guys like Richard Clark and Tom Nousaine contributed to car audio from the Pro Sound side. I had no clue when I started installing in 85'. MECP and RTTI didn't teach me much more either...

I'm still tempted to roll into a competition with a couple of Auto Tubas and some rediculously small amp just to see the puzzled looks.

Richard was way ahead of his time. Whoever heard of putting 12 inch mid bass speakers and diamond impregnated diaphram horns under the dash. The fact that he was a Alpine product tester and had a lot more money than us kids, didnt hurt either. While we were loading as much gear as possible, he was preaching less is more and building his own super efficient speakers, that is very similar to Bill's philosophy. Great minds do think alike ! Back then I didnt have the benefit of the knowledge, because as you know auto comp. was a very secretive world. I feel fortunate to be able to use all the knowlege on this forum and stun people with the small system that I have. The, why cant my multi thousand dollar yorkies and Mackies sound like that keep me building. LOL

[Connif Boudoin]

Wow Ronn, another thing that you never talked about. I was big into car audio in the late 80's early 90's. I went to the nationals for IASCA 2 years consecutively in Oklahoma to get ideas but never competed. These guys had money or did nothing else. I knew Mark Fakuda and seen his Yellow Blazer compete. That's where I saw the Stealth alarm system that I wanted. Bought is and automated a few things on my car. Windows, Locks, Hood, Motorized Trunk, change amp mode and impedance to 4 ohm or 8 ohm, turn each amp off independtly and a few other things. He never could beat Richard in the IASCA contest and Richard would never do TOW or USAC. They were mostly SPL. It was fun to watch a USAC or Thunder on wheels contests but most of those guys were looking for pure SPL. I liked Sound Quality and thats where IASCA was. USAC had some of both. Met Richard there also and got on a mailing list. I Sunk a lot of cash into a DIY car system. I did have some nice stuff. Precision Power amps, Pioneer premier headunit, JL and MB Quart speakers. 1000 watt and up class. I was getting all the tech notes from Richard Clark on how to approach competition. He was also using noise gates which was unheard of in car audio. He always scored perfect on his noise tests. I really enjoyed and learned a lot from those tech notes. A lot of it applies to what I do now with live sound. I bought a phase tester which I lost, and the test CD which I still have from Richard. I swore I would never sell my amps after I built that car because when I went to buy another vehicle I had to buy all over again. Well I still have the small amps but my 600 watter got stolen when my son had it. I kinda figured it wouldn't last him very long.

Oh well. Moved on to bigger and better things. Actually went back to bigger and better things. My first PA was Peavey Lips/Horns, JBL horn loaded 15" mid bass, Peavey FH-2's(huge 200lb.) all peavey amps. this was early 80's. This was one rocking heavy PA. Used it for a lot of Parades and Parties. Had lots of fun too. Later.

[DJ Big Ronn]

Happy New year Connif, Sorry that I havn't been in touch. I've been having a little trouble with cellulitus in my legs and have been a little out of pocket (Hospital). Things are starting to get a little better, even tho I'll probably be admitted again this weekend for another round of IV antibiotics. The doc. is keeping me home to let the swelling down, but since I started another set of T-48's, I'm having trouble staying out of the shop LOL. Isn't it amazing how the sound and music bug travels down the line. I would bet that most prosound guys at least dabbled in car audio at some point in their life. Anyway, I'll get back to you later and see if you may be able to do a little tweak session with me at the sugar festival building for project graduation. I'll be there on May 11 thru 14th. Thanks, Ronn.

[jcmbowman]

Isn't it amazing how the sound and music bug travels down the line. I would bet that most prosound guys at least dabbled in car audio at some point in their life.

Actually, I'm amazed that more prosound guys don't get into car audio. One of my easy gauges for other sound guys is what their car sounds like. I've never met a sound guy who was truly passionate about good quality sound that could tolerate a factory car system. OTOH, I've met plenty of sound guys who could care less about how their system sounds as long as it's loud and they can get drunk with really BAD car systems. The "well what does your CAR sound like" question is one of my easy litmus tests for new people. It's not foolproof, but so far it's been right at least 9 out of 10 times.

[Sydney]

The "well what does your CAR sound like" question is one of my easy litmus tests for new people. It's not foolproof, but so far it's been right at least 9 out of 10 times.

Not to pick a fight, but to play advocate for those ( who for a variety of reasons ) choose not to bother with hopping up their car sound system:
I know many who are very serious about sound, but don't bother with auto sound.
It's hard to make assumptions about the Ph level from location to location for effective litmus tests.
As Ron K mentioned on another thread, I am always suspicious of the individual who insists on bragging on their car system, or their other efforts.
Practically speaking it usually only takes a few seconds of listening to the individual or their work to form a fairly accurate judgment. It speaks for it's self.

Syd