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Big 12v amps

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Young Croc
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    Posted: 18 March 2019 at 9:14pm
Hi. Im looking for 12v amps to power big mobile rig which consists of

sub loaded with fane 18xb
mid is jbl 2206
hf is B&C 1" 

what can you recommend?

 thanks :)
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Post Options Post Options   Thanks (0) Thanks(0)   Quote REIER Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 9:46am
Hi! Nice to see more 12v rigs!

You  did not mention how many of each?
If just one of each I would definetely consider Pioneer gmd-8604 or Bassface Black DB4.1. 
They are both efficient bridgeable4 channel amplifiers, and lots of mobile PA have had lots of good experience with them. 

The pioneer will do 100w x 4 in 4 ohms. You can bridge one side to get 300w in 4ohm.
Bassface DB4.1 will deliver 150w x 4 or 2 x 440 bridged in 4 ohms. 

I have used the pioneer, and can vouch for it. Maybe consider Bassface for more juice =)

Of course there are a LOT of other options, but I have had my eyes on these for some time now, and many people report good results with them =)

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Young Croc
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Majestic Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 11:12am
thanks reier.

yes, one stack.

thanks for the info but still not enough power.

need 1k for bass. 400w for mid and 100w for top
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Post Options Post Options   Thanks (0) Thanks(0)   Quote carlosdelondres Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 12:01pm
Look at the Sure Electronics stuff (theri website is very slow today or I would link something specific) http://store3.sure-electronics.com/audio/audio-amplifier-board-output-power-classification/high-power-audio-amplifier-300-3kw-per-channel

but you will need to step the voltage up to 48V at least for a 1K amp. 250W into 2 of your subs will give as much SPL as 1000W into one (less difference once power compression is factored in), and you will save a lot of money on batteries, so worth considering more boxes rather than more powa...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote slaz Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 12:47pm
Originally posted by carlosdelondres carlosdelondres wrote:

Look at the Sure Electronics stuff (theri website is very slow today or I would link something specific) http://store3.sure-electronics.com/audio/audio-amplifier-board-output-power-classification/high-power-audio-amplifier-300-3kw-per-channel

but you will need to step the voltage up to 48V at least for a 1K amp. 250W into 2 of your subs will give as much SPL as 1000W into one (less difference once power compression is factored in), and you will save a lot of money on batteries, so worth considering more boxes rather than more powa...


^^^^ What he said.

All the amplifier options that I know of (and I've scoured quite a bit) for running from batteries are really designed for low impedance loads. Modules like the Sure ones might say "bridgeable" - but usually that means PBTL - i.e. yes - double the power, but only into half the load impedance. There's no extra volts.
Most of the car amplfiers are bridgeable - so bridging 2 channels into a single 8R load will work well - but those kind of amps (to achieve large real-world power) are very thin on the ground.

Another route is to use a large "mono-block" single channel amp (designed for the more ridiculous car sub-woofers) - but you'd need to be looking at ones with a "headline rating" of 10kW or more to achieve a real-world 1kW into a single 8R load. But likely those kind of amps will be drawing several amps dojng nothing .... so not really so power-efficient.

You should find a decent option for driving the mid section OK with 400W or so (a 2 or 4 channel class D car amp with 2 channels bridged) - but driving a CD ?? I doublt if you'll find a car amp with HPF that goes as high as 1KHz or higher, so consider using passive Xover for mid->high.

For bass, consider multiple 12" or 15" boxes (or drivers).

Erm yeah - and don't forget to tot up the weight of the batteries you're gonna need. If you wanna play that for more than a couple of hours .... well you're into fork-lift territory pretty soon.

REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON
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Post Options Post Options   Thanks (0) Thanks(0)   Quote carlosdelondres Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 12:52pm
You can use miniDSP or Sure ADAU1701 to handle processing - a single ADAU1701 can give you 2 in 3 out for a 3 way mono system. Way more flexible than using the built in crossovers in a car audio amp...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Majestic Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 12:58pm
thanks for info guys. much appreciated :)

18xb is 4 ohms which helps. will go for the passive xover for mid top as you suggest staz.

we have one of those b&q type trolleys so weight isnt a big issue. ive got a big varta hobby leisure battery so hoping to just run all off that and may get another for backup. not sure about 48v though.

thanks again 

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Young Croc
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Majestic Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 12:59pm
thanks carlos. good tip

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Post Options Post Options   Thanks (0) Thanks(0)   Quote carlosdelondres Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 1:08pm
How many Ah is the battery? - even a 220 Ah only has ~3.5kWh at most at that sort of discharge rate.  So running ~1kW system, maybe 3-4 hours before battery completely discharged, assuming reasonable duty cycle. And only discharge to 50% if you plan on getting much life out of the battery.




Edited by carlosdelondres - 19 March 2019 at 1:09pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote APW Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 1:42pm
Originally posted by carlosdelondres carlosdelondres wrote:

How many Ah is the battery? - even a 220 Ah only has ~3.5kWh at most at that sort of discharge rate.  So running ~1kW system, maybe 3-4 hours before battery completely discharged, assuming reasonable duty cycle. And only discharge to 50% if you plan on getting much life out of the battery.


^^^^ this ^^^^

Assuming 100% efficiency, at 1500 watts a 110Ah 12v leisure battery (110Ah is a typical size for a leisure battery) will last less than an hour as your amps will be puling 125amp from the battery, however, in the real world your amps are only going to be about 80 - 85% efficient at best so to deliver 1500watts continuous you would be drawing at least 147amps from your 12volt battery, you would get about 45 minutes running if delivering 1500watts continuous into your speakers.

As audio isn’t normally a sign wave and depending on the music content you will probably get about 3 to 4 times this running time…. On a good day with a new fully charged battery you may get about 2.5 to 3 hours until the battery is completely dead.

And also as above... If you want your battery to last any length of time only discharge to 50-60%



Edited by APW - 19 March 2019 at 2:03pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote markie Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 3:03pm
Wouldn't you be better off using an inverter to run a normal mains amp. I'm sure you must have a few lying around.
If it's got wheels or tits it's gonna cost a fortune
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2019 at 6:32pm
Or a gennie!  LOL



Earplugs Are For Wimps!
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