Go Back   Home > Forums > >

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

Looking for a PA system for my needs
Looking for a PA system for my needs
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
Old 26th January 2021, 11:37 PM   #11
turk 182 is offline turk 182  Canada
diyAudio Member
Join Date: Oct 2012
MP3's , where did the 3 pre-recorded sounds requirement go?
i've a feeling the true intent and purpose is not good...
  Reply With Quote
Old 27th January 2021, 04:27 PM   #12
Flat train is offline Flat train
diyAudio Member
Join Date: Jan 2021
That would be at 1 meter. I know these companies almost always lie, but maybe if I buy 2 of these speakers I could get 120 @ 1 meter? https://www.amazon.com/SoundAlert-Em...ef_=ast_sto_dp
  Reply With Quote
Old 29th January 2021, 02:49 PM   #13
weltersys is offline weltersys  United States
diyAudio Member
weltersys's Avatar
Join Date: Jan 2008
Location: Florida
Originally Posted by Flat train View Post
..maybe if I buy 2 of these speakers I could get 120 @ 1 meter? https://www.amazon.com/SoundAlert-Em...ef_=ast_sto_dp
Flat train,

125dB at one meter within it's limited range of 400 to 4000 Hz appears believable, probably peaking at around 2000Hz, with 400 Hz being 10-20 dB or so less output. A 10dB reduction at 1000Hz sounds "half as loud". Using two horns would increase output around the low frequency cut-off of 400 Hz, but reduce upper off-axis clarity due to comb-filtering. The driver impedance may be low, so adding a second to the SoundAlert unit may not be advisable.
Compression driver re-entrant "speech" horns like this typically can produce in the range of 110dB/1meter midband with just one watt. An example is attached of the Electro-Voice PA-60, which illustrates the response you may see in this type of a device. The PA-60 probably has better low end response than the shorter path length SoundAlert-Emergency device.
The linked SoundAlert unit does not appear to have aux inputs, but as one user wrote:"I soldered the ham radio intercept leads to an aux plug and it plays audio off my phone's headphone jack or my ham radios external speaker jack."

The "Western Safety 50 Watt Megaphone with Safety Siren" (a knock-off of the classic Fanon megaphone which now costs over $200) available at Harbor Freight for $28.99 can put out around 120dB SPL at one meter midband, with a similar peaking response curve. I purchased and tested one of those with the intent of re-using the amp section for a battery operated guitar amp, though ended up selling it after loosing interest in that project..
With a little work, an auxilliary input could be wired to it's microphone input.
It runs on 12V, so it's battery terminals could also be connected (using a fused power point) to a car's battery.

Attached Images
File Type: png EV PA-60 Re-Entrant Horn.png (286.6 KB, 109 views)
File Type: png Fannon & Western Safety.png (734.6 KB, 109 views)

Last edited by weltersys; 29th January 2021 at 03:14 PM.
  Reply With Quote
Old 29th January 2021, 03:35 PM   #14
TNT is offline TNT  Sweden
diyAudio Member
Join Date: Apr 2003
Location: Sweden
Looking for a PA system for my needs
Flat train - if you describe the actual wanted coverage (distance/area) and sound pressure for the furthest listener in your intended audience instead of specifying technical requirements, I think you will get better help.

Music played via Megaphones is not so nice to listen to. Is it music or speech you are planning to perform?

More distortion to the people! Timing . . . . is paramount.
  Reply With Quote
Old 12th March 2021, 10:20 PM   #15
dangus is offline dangus  Canada
diyAudio Member
Join Date: May 2004
Location: Vancouver Island
There are car horns or alarm horns or sirens that play sounds off an SD card. Not high fidelity, but loud.
For example:
Or buy a module like this one and combine with the amp and speaker of your choice:
Switching music module FN BC10 MP3 playback module circuit board 10 channel trigger audio playback board|Replacement Parts & Accessories| - AliExpress
  Reply With Quote
Old 13th March 2021, 12:32 AM   #16
MAAC0 is offline MAAC0  Portugal
diyAudio Member
Join Date: May 2010
50W/100V Music quality outdoor horn speaker, IP66
| Edwards Auckland

...but You need a 100V line amp.
  Reply With Quote
Old 14th March 2021, 11:45 PM   #17
Adam Smithee is offline Adam Smithee  United States
diyAudio Member
Join Date: Mar 2021
Location: Northern 'burbs of Atlanta (East Cobb Co.)
Originally Posted by 6L6 View Post
Where did the 125db requirement come from? That is so loud it will cause instant hearing damage.

Yes, really.

What sucks is that I've done projects for clients who really DON'T understand this.
  Reply With Quote
Old 17th March 2021, 09:01 PM   #18
Mark Tillotson is offline Mark Tillotson
diyAudio Member
Join Date: May 2018
Location: Cambridge UK
mp3 is not a kind of sound, its a format, I think you were being asked "what sound quality and frequency range, especially bass extension, are you wanting?"
  Reply to this post


Looking for a PA system for my needsHide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
My Sound System Needs A Upgrade killsound PA Systems 16 19th November 2014 03:53 PM
Conference room PA system - N00b needs advice Ether PA Systems 51 21st September 2012 01:13 PM
If 4.5" Fostex needs sub & 6" needs tweeter? artfuldodger Full Range 12 4th April 2008 05:41 PM
car audio system needs help stephen22 Class D 14 13th March 2006 06:32 AM
my system needs critiquing joywrex Car Audio 6 18th July 2003 04:09 AM

New To Site? Need Help?

All times are GMT. The time now is 12:08 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio