Speakers need juice

Sgt. Chowder · Post by **Sgt. Chowder** » Wed Mar 04, 2009 11:50 am

So I'm trying to put a sound system on our pedicab. I have two 15 inch subwoofers hooked up to an 800 watt amp, hooked up to a car battery. The system works for a while but then the battery drains fast. does anyone know how I can keep my battery juiced up for longer? What do i need?

klondike_bar · Post by **klondike_bar** » Wed Mar 04, 2009 12:11 pm

um, theres 3 ways:

1) get more, bigger batteries
2) use smaller speakers
3) bring a generator

Post by **Elderberry** » Wed Mar 04, 2009 12:13 pm

or a 4th way...solar panels

JK

Bounce530 · Post by **Bounce530** » Wed Mar 04, 2009 12:58 pm

Unless they're solobaric subs i'd imagine that the box the holds the 15s is going to be really heavy, making a peddy cab pretty hard to peddle through the unpacked playa.
I have two 15's in my suv and the box that I made for them used a full sheet of 3/4"mdf.
Plus you're going to need some kick ass seprates to pick up and make up for mids/highs that the 15s can't produce.
Above all though, make sure to save me a seat!

Toolmaker · Post by **Toolmaker** » Wed Mar 04, 2009 1:21 pm

Put a motor and some alternators on the cab.

ibdave · Post by **ibdave** » Wed Mar 04, 2009 5:12 pm

Sgt. Chowder wrote:So I'm trying to put a sound system on our pedicab. I have two 15 inch subwoofers hooked up to an 800 watt amp, hooked up to a car battery. The system works for a while but then the battery drains fast. does anyone know how I can keep my battery juiced up for longer? What do i need?

http://www.burningman.com/on_the_playa/ ... olicy.html

bdeywoo · Post by **bdeywoo** » Thu Mar 05, 2009 9:12 am

Dont use a car battery, use a deep cycle battery.

gyre · Post by **gyre** » Thu Mar 05, 2009 9:23 am

Forklift battery will do it.
Are you talking about 800 real watts or those imaginary watts most amplifiers refer to?

Doesn't matter how long the power lasts though.
You won't be able to pedal fast enough to outrun the people trying to kill you.

Sgt. Chowder · Post by **Sgt. Chowder** » Thu Mar 05, 2009 1:54 pm

thanx bdeywoo. do you know how much longer a deep cycle battery would last as opposed th a car battery?

dragonfly Jafe · Post by **dragonfly Jafe** » Thu Mar 05, 2009 4:42 pm

have you tried using the search function? this topic has been discussed ad-nauseum many times....

here is one I came up with in about 15 seconds using search;

http://eplaya.burningman.org/viewtopic. ... v++battery

basically your question cannot be answered unless you tell us; charge capacity of car battery, charge capacity of deep cycle, total average watts used (which will be less than 800 unless you play a sinewave at max volume). All of this will greatly vary depending on the batteries you buy and the music you play and how loud you play it.

You probably will not be able to carry enough batteries on a bike to power an 800watt amp for a long enough time....(unless your first name is Lance)

Tips; get the most efficient subwoofer possible. There is a tradeoff- subs that crank out lots of deep bass are usually not that efficient, and subs that are efficient usually have higher F3 cutoffs. Still, I would opt for a high efficiency sub (96-103dB/watt at 1 meter). What this will do is require VASTLY less power for the same sound level (and thus longer play times). The disadvantage is you will not get heart thumping bass.

Dork · Post by **Dork** » Thu Mar 05, 2009 4:51 pm

Deep cycle batteries don't necessarily carry more charge for the same weight. They can just handle being drained all the way more times before dying permanently.

Can you provide more details on the battery you have now and how long it lasts?

Or you can simply buy a small Honda generator and get all the runtime you need. It will likely weigh less than the huge batteries you'd need.

Post by **AntiM** » Thu Mar 05, 2009 5:03 pm

We've been looking at the gel batteries for lights.

gyre · Post by **gyre** » Thu Mar 05, 2009 7:54 pm

To produce 800 watts rms will take much more power.
Depends on the type of amp.

AGM deep cycles are closer to cranking batteries than standard deep cycle.

Antim, I would try for at least nimh batteries.
How much power is required?
Gels are limited in output at a given time and temperature sensitive.
And heavy.

Lithium phosphate is state of the art now.
They are often called slightly different things.
It is a step beyond lithium ion.
Quality varies wildly.
A matched pack is worth the money.
A matched pack for the bike I'm looking at is $400.
Raw surplus batteries maybe a fraction of that.
Hard to compare identical batteries though.
But some are worth what they cost.

A good charger is key.
And important with anything past lead.
The nicad pack on the scooter I was given blew up and took out a shop.

Bob · Post by **Bob** » Thu Mar 05, 2009 9:24 pm

I recommend cranberry juice.

Igneouss · Post by **Igneouss** » Fri Mar 06, 2009 7:03 am

The small/quiet honda 1000W generator is the way to go. Smaller and lighter and probably cheaper than all the other options you are discussing.

Toolmaker · Post by **Toolmaker** » Fri Mar 06, 2009 8:39 am

Igneouss wrote:The small/quiet honda 1000W generator is the way to go. Smaller and lighter and probably cheaper than all the other options you are discussing.

Small lawnmower motor=Free (salvage)
4 Alternators=10$ each (junkyard)
Belts and pulleys=20$ total (junkyard)
Plate to mount everything=Free (cut from scrap)

I doubt that a honda generator of any sort is cheaper than 30 bucks and a Saturday afternoon worth of labor.

Igneouss · Post by **Igneouss** » Fri Mar 06, 2009 9:37 am

Definately cheaper if one has the resources to make the 'alternator' version work.

Bob · Post by **Bob** » Fri Mar 06, 2009 8:33 pm

Plus lawnmowers run real good on concentrated cranberry juice.

Bounce530 · Post by **Bounce530** » Fri Mar 06, 2009 11:01 pm

2 Orion 15" dvc's @ 300 watts equals 152 db on the dashboard.

gyre · Post by **gyre** » Fri Mar 06, 2009 11:29 pm

And Orions aren't very efficient. are they?
Maybe 87 db/watt?

Toolmaker · Post by **Toolmaker** » Tue Mar 10, 2009 1:30 pm

Igneouss wrote:Definately cheaper if one has the resources to make the 'alternator' version work.

Its not that hard.. a few youtube vids will give you enough knowledge. There's pully calculators online that are free. If you went with a diesel motor for the contraption you could use more fuel varieties for even further reduced operating costs.

If I could afford it I would get a decent quiet honda.

Sgt. Chowder · Post by **Sgt. Chowder** » Thu Mar 19, 2009 8:34 am

i'm diggin the cranberry juice. but i'm leaning more towards the alternater route. sorry i've been a little vague as far as wattage and stuff. i need to get on that because i'm not really sure myself. i just got the speakers and a cheap amp and got a boner.

Ugly Dougly · Post by **Ugly Dougly** » Thu Mar 19, 2009 9:22 am

Does that mean that there won't be a Quiet Side of the playa anymore?

munney · Post by **munney** » Sat Apr 18, 2009 7:11 pm

Muchos Soluciones

There is so much LOUD music already out there, how about if you bring your mp3 player and some 9volt powered mini speakers from some cheap shit shop, and Zip Tie that mess to your pedi cab

Then you and your peeps can hear your tunes, others may also as well

Everyone will be happy and there will be One less Mobile Thump Factory parked outside my tent

La Segunda Solucione' Make an Impact and get a cheap Generator, get More Bigger Speakers and Blast them and Us and as a finale to the Awesome sounds that have come from your Most incredible Tune vehicle, Ride it into the Man just as it crashes down from his pedestal, letting the flames engulf your artwork as a symbol of the limited time we have here on this planet

Plan 3, Sing, Listen, and just cruise around and be a part of the scene without the doppler effect

I vote for plan #2

EspressoDude · Post by **EspressoDude** » Sat Apr 18, 2009 7:19 pm

Sgt. Chowder wrote:So I'm trying to put a sound system on our pedicab. I have two 15 inch subwoofers hooked up to an 800 watt amp, hooked up to a car battery. The system works for a while but then the battery drains fast. does anyone know how I can keep my battery juiced up for longer? What do i need?

get a sexier charger.....or viagra

or, give your passengers pedals to crank connected to alternators.....

If nobody rides, nobody listens

munney · Post by **munney** » Sat Apr 18, 2009 7:43 pm

Right on Espresso Dude, Make them work for their tunes, No Glove No Love, No Pumpin' No Humpin', Mo Peddling Mo Meddlin'

Sure to give new meaning to "Kick out the Jams"

Elorrum · Post by **Elorrum** » Sun Apr 19, 2009 7:15 pm

If the sonic experience is mainly for the riders, (800 watts, not likely) you can get some "tactile transducers" that don't draw as much power and put them under the seats of the pedicab. Parts express had a diy project where they put these inside a couch for watching movies.

http://www.parts-express.com/wizards/se ... N=25000647

Speakers need juice

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