Pa speakers- a general enquiry.

[AJDMGM]

Right, as of previous threads I have started I am interested in building my own SMALL PA system. I mean small drivers, power, everything. This is a project for myself and if it can be of actual use all the better, but its not for anything other than the fun of building it. I have looked into all aspects of
Speaker building but most is aimed at high quality hifi speakers. Obviously I want to be able to hear the music but
I also understand that pa speakers aren't designed to sound brilliant musically. This may seem pointless but I want to do this for myself.

I looked into speaker plans everywhere And all that and into crossovers etc but then I have also looked into pa speakers specifically and found very little in anywhere near as much detail. And have found things like this for sale

PA Knock-Down Trapezoid Birch Cabinet for 12" Driver 245-325

So I got to thinking, how much design goes into it or is it a case of standard cab volume for speaker size and dot give it any further thought?
And pa crossovers don't seem to come into anything much.

Please someone explain all this to me.

Thanks

I built a small PA using a Souncraft Spirit Notepad mixer, a Quad 405 power amp and JBL Control 5s on stands. Sounds excellent and fills a small/medium size venue. Only 4 XLR inputs, but various other inputs for keyboards, etc. I use a single powered foldback wedge. I have 4 Studiospares mic. stands and about 10 different mics. including an expensive Neumann vocal mic. Suits a small folk group in a small venue perfectly. I have run Conferences also using a radio mic. I have. Best advice I had from a prof. audio friend were these two points. Keep everything well maintained and use the PA within its capabilities.

 

[Bob Richards]

Step one would be listing (writing down) everything you want it to do or be optimized for. Step two would be researching every aspect and learning what's involved and how to get it mostly right the first time. PA means high efficiency controlled dispersion speakers, and mixers that have the ability to deal with feedback problems, mix in reverb and etc., durablity, easy to load and unload into a van or truck, etc. Design on paper what you think you want, and let that evolve for a while before building anything, then go out and buy used stuff to save quite a bit of money and time. The controlled dispersion may be the thing most people getting into this understand the least, and it's very important to minimize waste of power and maximize intelligability. If you don't research this fairly complicated subject extensively (PA's in general), you'll regret it later. Hope this helps.

 

[AJDMGM]

Step one would be listing (writing down) everything you want it to do or be optimized for. Step two would be researching every aspect and learning what's involved and how to get it mostly right the first time. PA means high efficiency controlled dispersion speakers, and mixers that have the ability to deal with feedback problems, mix in reverb and etc., durablity, easy to load and unload into a van or truck, etc. Design on paper what you think you want, and let that evolve for a while before building anything, then go out and buy used stuff to save quite a bit of money and time. The controlled dispersion may be the thing most people getting into this understand the least, and it's very important to minimize waste of power and maximize intelligability. If you don't research this fairly complicated subject extensively (PA's in general), you'll regret it later. Hope this helps.

Good advice... AJDMGM.

 

[Nigel Goodwin]

I built a small PA using a Souncraft Spirit Notepad mixer, a Quad 405 power amp and JBL Control 5s on stands. Sounds excellent and fills a small/medium size venue.

I should think it does - top end HiFi amp 😀

Back in the 70's I used to help run a small rock club, and one of the bands who came had 11 or so Quad 33's as their PA - including one with the top all crushed in (made you want to cry). Even worse, they had been GIVEN them all 😱

 

[Jsixis]

I know what pa stands for but in the interest of ease
And the assumption that people would get what I meant I couldn't be bothered to say sound reinforcement system! I know there is a lot of processing involved I just want the 'inside' scoop on the actual speakers.

I have built several pairs of monitors that occasionally get used as small mains.
I started off 15's and a tweeter, then went 12,s 10, and last pair was 8".
Using win ISD they all start to roll off at 100hz but I can play my 5 string bass guitar through them all.

10's and 12's are about the smallest I would go. EV makes a wicked 8" speaker but I haven't found an 8" that does what theirs can do that I could afford.

Using a 10" eminence Alpha in a 13" wide 26" tall and 17" deep box 2 vents 3" in diameter 1.5 inches deep and a tweeter of your choice you can have a nice pair of speakers with 96db @1 watt (or close to it, been a year or so since I made those) out of 1 sheet of plywood. Delta's will work in that box if you really need 400watts RMS but the 200 watt RMS Alphas have survived everything I have thrown at them.

Piezo tweeters work well, I use a 6 ohm resistor in series with a brake light bulb and they last till the amp clips hard.