Hello people of AAC! I hope this post doesn’t break any rules right off the bat as it is my first. I am what some would call a Carpenter but in my free time I like to listen to music, quite loudly. In the past I have had many vehicles with pretty nice aftermarket stereos, mostly installed by other people (read: professionals).


Now I've done some quick reading on this site and it seems like its very much geared towards the engineer, so I hope Im not wasting anyone’s valuable time with this nonsense. Anyways to the point. So my largest system to date included some hefty components, 2 12" 750w subs, plus 4 150w speakers, with separate amps to run both. I also had a capacitor in the system to help with the massive draw I was taking to help with headlight dimming. Now all that considered it was a great setup and it outlasted the car it was put in. So some time has gone by and Ive removed the whole works from the car and its all sitting in storage, other then the subs, they are being used as my tv stand. After looking at my glorious subs for a few weeks, the idea to wire the whole mess up and build a custom enclosure to fit everything inside, subs amps speakers, all in one dolly-mounted setup, has become increasingly hard to ignore. I want to have it all built into a tall box, dolly-mounted so its portable. That for me is the easy part.


The part that I have come here to find help for, is getting a big enough transformer to power it all! Ive done some research into people doing similar things, but not one single person has done it to this scale. Every time I find someone who has done this, they only ever seem to have a deck and a couple of small speakers hooked up to a re-purposed x-box power supply. Now that’s all great and everything but I need something bigger. Much bigger. Like, 2500w total power bigger. Unfortunately all of my internet sleuthing has brought me nothing in the way of hardware big enough to do the job. I need something that will power the head unit (deck), both amps, the capacitor, both subs, and all 4 speakers. If need be im more then willing to run it to a 240v wall plug, like for my dryer for instance, if the 120v standard just wont cut it.


Again Im just some goofy journeyman woodworker so if I come across as less-than informed please go easy on me. Its my first time.

 

What do you want to make, a super ghetto blaster?

 

You're in the right place!

I did the repurposed car audio as home sound system thing more than once.granted its been about 20 years now but I did it in excess just as you did!

Despite your big amplifiers you don't need a proportionally equally sized power supply to feed them if you cheat a bit and do what your vehicle does and use a good deep cycle battery as an intermediate power stage. With that you can easily run a multi kilowatt soundsystem off a common 120 VAC 20 amp circuit being the average power consumption is not the same as the peak power.

In fact all you would need is a good high capacity battery charger like a commercial unit with a 50 or more amp continuous rating and your big capacitor as the charging source for the battery. It would be about the same working capacity as your stock 75 - 100 amp alternator had for reserve power above what the vehicle used.

That's the cheap and simple power system I used but I put the battery charger guts plus capacitors in a smaller case made up to look like some fancy high end custom power supply when the reality was it was just a garage sale battery charger I got for $10 because the power cord and leads were junk .

 

+1
That's exactly what I was thinking. Just get a 12V deep cycle battery, a battery charger and you're set to rock, rattle and roll!

 

This all seems far to easy to be true. Just a high capacity battery charger and a fresh battery? But what about run times? Will something like that power it for a couple hours at a mid-high volume output?

Thanks for the quick replys!! I think I came to the right place for answers for this finally.

 

This all seems far to easy to be true. Just a high capacity battery charger and a fresh battery? But what about run times? Will something like that power it for a couple hours at a mid-high volume output?

Thanks for the quick replys!! I think I came to the right place for answers for this finally.

It will power it continuously for as long as you keep it plugged into to your wall outlet.

The battery is like your capacitor and the battery charger is like the alternator/rectifier on your car.

Easy as 3.14

 

Soo something like this?
https://www.batterystuff.com/power-supplies/load-bearing-chargers/power-max/powermaxpm3-35-12.html

Why didn't I think of that?? I was overthinking this for sure. It all seems so simple now, just a battery and a charger. So easy.

Of course now this begs the question of if I will need to swap in a bigger amperage breaker into my house pannel and wire in a dedicated circuit to an outdoor plug

I dunno if anyone would appreciate a build follow up to this as I put it together, will update as things go together. The thread will get buried over time but I'll share it.

 

Soo something like this?
https://www.batterystuff.com/power-supplies/load-bearing-chargers/power-max/powermaxpm3-35-12.html

Why didn't I think of that?? I was overthinking this for sure. It all seems so simple now, just a battery and a charger. So easy.

Of course now this begs the question of if I will need to swap in a bigger amperage breaker into my house pannel and wire in a dedicated circuit to an outdoor plug

I dunno if anyone would appreciate a build follow up to this as I put it together, will update as things go together. The thread will get buried over time but I'll share it.

You can post your follow ups here and, when finished, you can make a new thread in the "completed projects" subforum. Fewer of those so it doesn't get buried so quicky.

 

Soo something like this?
https://www.batterystuff.com/power-supplies/load-bearing-chargers/power-max/powermaxpm3-35-12.html

Why didn't I think of that?? I was overthinking this for sure. It all seems so simple now, just a battery and a charger. So easy.

Of course now this begs the question of if I will need to swap in a bigger amperage breaker into my house pannel and wire in a dedicated circuit to an outdoor plug

No need to upgrade your house wiring. The charger draws only 6A, not 35A.

 

Of course now this begs the question of if I will need to swap in a bigger amperage breaker into my house pannel and wire in a dedicated circuit to an outdoor plug

NO! NEVER "UPGRADE" THE BREAKER. It's designed to meet the capacity of the wires. If you have a 15 amp breaker then it should - by code - be a 14 gauge wire (or bigger). A 20 amp breaker must be on no smaller a wire gauge than 12 gauge. If you were to put a 30 or 40 amp breaker on a 12 gauge wire and something were to short out you'll have a gigantic electric heater cooking the studs in your walls. Good news is that that will only be the case until the house burns to the ground.

Try thinking in terms of watts. 12 VOLTS (corrected, thanks #12) at 35 AMPS (corrected, thanks #12) is 420 watts. Your standard 15 amp circuit at 120 volts will deliver 1800 watts. 20 amp circuits on 120 volts will yield 2400 watts of power.

Your amp may be capable of pushing a peak of 1,000 watts, but it's sustained output may be more on the order of 400 watts. And often the rating is divided by the number of speaker circuits. Stereo's rated at 400 watts are 200 watts per channel. To get the higher wattages they use lower voltages and much higher amperages. Speakers are coming in lower ohm ratings. Resistance (ohms) multiplied by amperage equals voltage. Voltage times amperage equals wattage. You can work the numbers both ways. You can start with known wattage and voltage and determine how many amps the circuit is drawing by dividing watts by volts to get amps. OR watts divided by amps to get volts. Either way, once you know volts and amps you can calculate ohms (resistance).

All things balance out. Aside from some level of inefficiency, 250 watts at 120 volts is the same power of 250 watts at 12 volts. Amperage and voltage differ, but the "Power" measured in watts (or in some cases VA - or VoltAmps) is the final outcome of what you're doing.

When your speakers go BOOOOM they draw a lot of power. That's where the reserve of the battery comes into play. But when they're just humming along they use far less power (there's that word again) and the battery and charger can more than sustain the humming along part. In fact, the power supply can recharge the battery when the music is more subtile. Now, if all you do is go BOOM BOOM BOOM BOOM BOOM BOOM then you're going to drain the battery. HOWEVER, if the battery is big enough it will handle the load and recover later. Smaller batteries just won't hack it. Depending on the numbers, your battery needs to be of sufficient size and all will be absolutely fine. Guaranteed.

 

12 amps at 35 watts is 420 watts.

You have a typo.

 

You have a typo.

Of course, he meant 35A @ 12V = 420W.
And if one battery cannot supply 35A continuous, just put another battery in parallel with the first battery.

 

Not the first or last time I did or will do that. Thanks #12. Corrected in post. I get this from my mother. All my life I didn't know (growing up) what my name was. "Ralph - Lewis - Frank - ANTHONY! GET OVER HERE!"

And for a while all of us didn't know who was Geesus Kryste and who was Gaud Dammit. Especially when the two oldest moved out.

 

if all you do is go BOOM BOOM BOOM BOOM BOOM BOOM then you're going to drain the battery. HOWEVER,

That's what nerds are for. If we were up close and personal, most of us would know how much capacitance and how much battery, and where to place them, but it's complicated. So we're going to give you some basic outlines of the power/time requirements and stomp that, "over-thinking it" out of you.

"Normal" music typically has peaks at 10X the average power. Automotive rust removers are run at lower numbers than that, but the point is, you can slam some serious amps with a battery or a capacitor and the power from the wall outlet will catch up in about 17 milliseconds. Start by reading all the labels for watts, volts, amps, and ohms. Write them down. From that, almost everything else can be calculated.

 

And of course !
Really serious heavy gauge wiring too.

 

Oh yeah, I came to right place. This is all great information. power supply is in the mail! And I would just be re-using my wiring kit i had the stereo installed in the car with, and it has some 0 gauge power wire im pretty sure. Its fat. This whole system ran beautifully when it was in the van so I figure if I can get the supply of power worked out all will be right in the world.

I like being told not to do stuff, its better that way.

If I had neighbours Im sure they would just love me once this is finished. Thankfully i own a big chunk-o-land at my own dead-end street.

 

Oh yeah, I came to right place. This is all great information. power supply is in the mail! And I would just be re-using my wiring kit i had the stereo installed in the car with, and it has some 0 gauge power wire im pretty sure. Its fat. This whole system ran beautifully when it was in the van so I figure if I can get the supply of power worked out all will be right in the world.

I like being told not to do stuff, its better that way.

If I had neighbours Im sure they would just love me once this is finished. Thankfully i own a big chunk-o-land at my own dead-end street.

I'm half deaf from similar antics when I was younger. Don't sacrifice your hearing (which lasts the rest of your life) for a few hours/days/weeks of head-banging. No joke. It is a pain to deal with hearing aids and even more painful not to hear grandkids say the funniest things.

 

I'm half deaf from similar antics when I was younger. Don't sacrifice your hearing (which lasts the rest of your life) for a few hours/days/weeks of head-banging. No joke. It is a pain to deal with hearing aids and even more painful not to hear grandkids say the funniest things.

Sorry... could you please type louder? I can't quite read you....

 

Don't sacrifice your hearing (which lasts the rest of your life) for a few hours/days/weeks of head-banging. No joke.

Dead serious here! When young (long time ago) I played rock & roll drums - without hearing protection. Gave them up to become a family man. Years later (and a new wife) my wife bought me drums because I loved them so much. Played them almost a year before I sold them. The reason? My tinnitus was getting worse. Even with hearing protection. I literally cried when I sold them to a young man (probable age 16). Gave him some advice, and it went like this: "I'm going to give you some advice. If you take my advice you'll never thank me. But if you don't - you'll wish you did. WEAR HEARING PROTECTION!" Then I told him about my tinnitus and how I forever more hear several pitches of ringing in my ears and that was the reason why I was selling my drums.

DUDE - PROTECT YOUR HEARING. You'll never thank us if you do. If you don't - - - . Yup! You guessed it.

 

Sorry... could you please type louder? I can't quite read you....

Sure, act all brave and make fun of me while you are protected by your fence. Our fence... Our wall? Your ...?