Need to power this massive system... - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 25th September 2007, 07:16 AM   #1
diyAudio Member
Join Date: Sep 2007
Default Need to power this massive system...

I have this 18 sub system that I am running off of batteries but I need the system to be able to hook up to a generator so I can run it for an extended period... Please let me know if you have any idea's...

I have 8 amps total... I was thinking of maybe hooking up a battery charger to the batteries and at least this would make the batteries drain slower...?

Thanks for your help,

  Reply With Quote
Old 25th September 2007, 07:42 AM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
sell off all those speakers and buy some Labhorns.
You will need about 10% of the power and thus 10% of the battery capacity.
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 25th September 2007, 05:04 PM   #3
Eva is offline Eva  Spain
diyAudio Member
Eva's Avatar
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
I've ran into the same problem, but power conversion from mains to 12V is not that hard, see the power supply that I built in this thread:

0-15V 0-120A adjustable PSU attempt with average current control.

Also, the power efficiency of those JLs in sealed boxes is quite low (not that low because there are a lot of them placed together and benefiting from mutual coupling). However, the mid-bass, mids and highs performance of your system is likely to be very poor. For compact and efficient subs (20 to 80Hz), you can consider placing some JLs in tapped horns (see the subwoofer forum), maybe 4, 6 or 8 of them and selling the rest. You would get the same SPL that way, but with much less power.

If your amplifiers are not class D, sell them and buy class D because in practice they produce the same output power with less than half the input power.

For mid-bass and mids consider some PA drivers loaded with horns, and for highs a pair of compression drivers with suitable horns would do. A digital crossover like Behringer DCX2496 (and somebody skilled enough to find the optimum parameters) is required to get the best out of such a system.

See my DIY horn loaded mid-high (250Hz-17Khz @ 106dB/W)
Click the image to open in full size.
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 5th October 2007, 04:40 AM   #4
diyAudio Member
Join Date: Sep 2006
But class AB is like 90% efficient?

I would mount a few alternators under the hood with a removable belt. Three big ones should do 400 amps @ 12v which is 4800 watts. The only other way to get large amounts of power is 220. By the looks you need 4800 watts...

Edit: Or just use horns or other such devices. Might be easier.
  Reply With Quote
Old 6th October 2007, 10:44 AM   #5
Gordy is offline Gordy  United Kingdom
diyAudio Member
Join Date: Nov 2006
Default Re: Need to power this massive system...

Originally posted by tnptruck
I was thinking of maybe hooking up a battery charger to the batteries and at least this would make the batteries drain slower...?
For a small investment you could have two sets of batteries arranged such that one set is on charge while the other set is in use. Then all you need is a simple switching system to change from one set to the other, so as the fresh set is switched in the drained set is switched onto the charger.
  Reply With Quote
Old 6th October 2007, 02:15 PM   #6
Warp Engineer
On Holiday
AudioFreak's Avatar
Join Date: Oct 2001
Location: Queensland, Australia
Originally posted by ak_47_boy
But class AB is like 90% efficient?
No. Typically more like 70% from memory.
- Dan
  Reply With Quote
Old 6th October 2007, 03:00 PM   #7
Did it Himself
diyAudio Member
richie00boy's Avatar
Join Date: Nov 2003
Location: Gloucestershire, England, UK
tnptruck are those pics from the Love Parade?

I would look into running mains powered amps and hook up to a mains voltage generator. The current draw running that lot off 12 volts will be staggering and cause a lot of problems.
__________________ my website for UK diy audio people - designs, PCBs, modules and more.
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Will F4 have enough power in this system? ro9397 Pass Labs 11 18th October 2007 12:37 AM
Massive GC? Suggestions please Nicks Chip Amps 46 16th August 2005 01:38 PM
2 way + sub PA system: what power for each way? Bricolo Everything Else 1 29th June 2004 01:57 PM
DIY sub: massive driver needs big amp for cheap! levine Subwoofers 6 22nd March 2002 06:52 PM

New To Site? Need Help?

All times are GMT. The time now is 02:30 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2