The cheapest PA system - diyAudio
Go Back   Home > Forums > Live Sound > PA Systems

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

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
Reply
 
Thread Tools Search this Thread
Old 1st December 2008, 06:45 PM   #1
diyAudio Member
 
Join Date: Nov 2008
Lightbulb The cheapest PA system

Hi guys!
i'm here to show you my new project: a PA system with a super performance/cost quotient.

target:
- f. response: 45hz(f3) - 16000hz circa
- hi max spl (near 140dB)
- stack use (0.5phi)
- low cost


after some ideas i have realised that to contain cost i have to create a 2way system:

- low frequency: 45hz to 500hz (if it is possible highest, like 800hz but i will test it)
- hi frequency: 500hz (800hz)to the highest possible frequency
- eventually piezo tweeters

to have a very high SPL i decide to use horns: frontloaded horn is probably impossible (due to freq. range), so i will project a rearloaded horn, i don't really like rearhorns but in this case i will use!

the driver that, in my opinion, has the best performance/cost quotient is the Skytronic 902.442:

http://export.skytronic.com/product/....php?s=902.442

a cheap 12" whit big voice coil (100mm) and good t&s for a horn.


Here is the project using HornResp:

Click the image to open in full size.


and here is the project using AJhorn:

Click the image to open in full size.


GOOD! (in my opinion)


i would create 4 scoopbin, so i can create a stack and work in 0.5phi... probably i can get 140dB whit only 1.2KW from this bass system...



for the high frequency i probably use this compression driver (but i don't know if they can go to 500hz):

http://www.usblaster.com/Products/DJ...ers//USB%20387

or this:

http://www.usblaster.com/Products/DJ...vers/USB%20384

(probably the first)

in my opinion i need 4 compression driver with few watts: so i can improve the durability of the system.


what do you think about this crazy project?
  Reply With Quote
Old 2nd December 2008, 11:24 AM   #2
diyAudio Member
 
Join Date: Nov 2008
no opinions?

  Reply With Quote
Old 2nd December 2008, 05:58 PM   #3
HK26147 is offline HK26147  United States
diyAudio Member
 
Join Date: Jan 2008
My opinion - though you may not not want to hear it is:
A 2 way PA with a clean output of 140db is a lofty goal. I won't say it's impossible, but you want it cheap as well?
I am unfamiliar with those drivers you mentioned, nor have I seen any feedback on them... Based upon the pdf specs:
The 12" driver has only a 4mm excursion - Excursion limited and Insufficient to generate that sort of SPL before mecahnical damage or thermal failure, I'm guessing.
It's been my experience that a PA made from cheapest parts can not be made to sound good, and will not be very durable and robust.
There is a huge sonic difference in a PA made with cheap parts and one made with name brand drivers.
You pay a lot of money for a driver like a 2206 or a 2226, but after over 8 years and thousands of watts they still sound better than new OEM drivers.
I repair drivers and so I would rather repair a used/damaged ( cone tear etc ) JBL then buy a new OEM despite price.
  Reply With Quote
Old 2nd December 2008, 06:21 PM   #4
diyAudio Member
 
Join Date: Nov 2008
probably 140dB is too high for my application... and this is impossible for this kind of product...
I will test the woofer and the driver, after this i will decide...


thank you for your opinion!
  Reply With Quote
Old 2nd December 2008, 06:52 PM   #5
diyAudio Member
 
Join Date: Nov 2008
anothor thing, what do you think about my rearloaded horn project?

thanks
  Reply With Quote
Old 2nd December 2008, 06:59 PM   #6
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
By the time you reach 140dB your nose starts to bleed.

I agree with HK, 140 is a bit lofty. I run 6 15" horn loaded Selenium PA woofers plus 2 horn mids and 2 horn tweeters and expect a clean 125 dB with 1.5K of power.

Tell us what these are for, maybe we can help.
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 2nd December 2008, 07:03 PM   #7
diyAudio Member
 
Join Date: Nov 2008
i have calculated a theorical spl at 1 meter in a 0.5phi emission...
so real 115-120dB are enoght!

i would create this system for a carnival wagon...
  Reply With Quote
Old 2nd December 2008, 07:37 PM   #8
HK26147 is offline HK26147  United States
diyAudio Member
 
Join Date: Jan 2008
Forum member Davygrvy built 6 horns each with an Eminence HL10 ( Total Driver cost $780 ). These horns formed a fairly small stack.
And when given enough power produced painful SPL.
I used to set up a parade float sound system myself, and I'm guessing his stack would fit your carnival wagon system.
But not as a 2 way.
  Reply With Quote
Old 2nd December 2008, 07:45 PM   #9
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally posted by HK26147
My opinion - though you may not not want to hear it is:
A 2 way PA with a clean output of 140db is a lofty goal. I won't say it's impossible, but you want it cheap as well?
I am unfamiliar with those drivers you mentioned, nor have I seen any feedback on them... Based upon the pdf specs:
The 12" driver has only a 4mm excursion - Excursion limited and Insufficient to generate that sort of SPL before mecahnical damage or thermal failure, I'm guessing.
It's been my experience that a PA made from cheapest parts can not be made to sound good, and will not be very durable and robust.
There is a huge sonic difference in a PA made with cheap parts and one made with name brand drivers.
You pay a lot of money for a driver like a 2206 or a 2226, but after over 8 years and thousands of watts they still sound better than new OEM drivers.
I repair drivers and so I would rather repair a used/damaged ( cone tear etc ) JBL then buy a new OEM despite price.
my metod to have an approx of the max thoerical output,

Click the image to open in full size.


i use it to note the difference between different thorical project...
isn't correct but for approx the difference between project is good...

  Reply With Quote
Old 2nd December 2008, 07:50 PM   #10
diyAudio Member
 
Join Date: Nov 2008
another simulation...

Click the image to open in full size.



140dB was refered to these simulations...



  Reply With Quote

Reply


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
Cheapest USB DAC kit? Spasticteapot Digital Source 0 16th November 2006 04:56 AM
Cheapest kit or project? yamski Tubes / Valves 14 26th May 2006 12:59 AM
Cheapest Solution bjackson Solid State 3 2nd August 2005 03:18 AM
Cheapest 12" Sub seangoesbonk Multi-Way 15 11th December 2004 08:15 PM
cheapest good sound system possible? r3n0 Car Audio 6 14th October 2004 05:28 PM


New To Site? Need Help?

All times are GMT. The time now is 03:51 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2