Choosing PA system...

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Hello,
I will be slowly buying components for PA system that I need.
I need PA system for 100m2 outdoors (most people are usually at smaller space, say like 40m2), 50 people maximum, average of 30-40.
I will play electronic, folk, rock and balkan (south european music, lately getting similar to house, sometimes with strong basslines) genres.
Over the day music will be at moderate volumes, but at night it will need to be ready for "banging" for a few hours.

I had already bought Zeck PT7 power amplifier, 2x 700w @ 4ohm, 2x 450w @ 8ohm and 1400w @ 8ohm bridged and it sounds good.

Now I need full range speakers and maybee a sub.
I was thinking of 3-way speakers because of tight budget.

Now my question is how big sub would I need for my for my use. Would say 15" 500w be ok? I can put it in a 20m2 room with window if this would help to get bass louder, I tried this once with car sub and it helped alot.

I can buy passive sub, power it with my zeck amp and buy active full range speakers.

Or I was thinking that I`m better of buying Passive full ranges, because on tight budget I won`t get powered full ranges that would sound as nice as passives powered with my zeck amp and a powered sub because sound quality don`t show as much on a sub that it does on fullranges (my personal opinion).

How much power should sub have according to full range speakers? Saying that sub has the same sensitivity (just for example).

Is it true that speakers should have half the wattage rating of amps wattage rating?

What would be cons of using 4ohm speakers instead of 8, other than need for thicker cables? Is sound quality the same?

What are some PA brands? (I`m searching for used stuff and I get more resoults if I search by brandname)
I already know for zeck, behringer, proel, qsc, jbl, lem, yamaha, yorkville, turbosound, electrovoice, alto, peavey, ksc, celestion, ... i know that`s already alot but trade market is really small in my country...

Thank you for your time and help
 
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your amp will power a pair of 2 way speakers on one side and two subs on the other.
700 watts a side is a lot of power as most speakers reach maximum SPL around 250-300 watts. Works best if the subs are side by side as that gets you a 6db increase


8 ohm speakers give you more flexibility, you can run 2 pairs on each side where if you have 4 ohms you can only run 1 per side.

I am not familiar with Zeck but with the brands I see in America I prefer QSC, Yamaha and Peavey for amps speaker wise I use Peavey but Yamaha Yorkville, Electro Voice seem to be extremely reliable, JBL's are more delicate, stay away from the ION series , I have not seen behringer speakers last at all but in the PA systems a lot of people just buy gear and go do it so it may be user error.
 
Now my question is how big sub would I need for my for my use. Would say 15" 500w be ok?
I can put it in a 20m2 room with window if this would help to get bass louder, I tried this once with car sub and it helped alot.

if you want electronic music with heavy basslines i would say at least two 15/18 or one big 18. The room trick i can't comment on but i imagine it would alter the response and i am pretty sure it will make alignment funny...

I can buy passive sub, power it with my zeck amp and buy active full range speakers.

unless your zeck amplifier provides processing ()at least hi pass and low pass), you would also need a dsp or crossover to separate, level, eq and align bass and mid/highs and send the bass to subs

Or I was thinking that I`m better of buying Passive full ranges, because on tight budget I won`t get powered full ranges that would sound as nice as passives powered with my zeck amp and a powered sub because sound quality don`t show as much on a sub that it does on fullranges (my personal opinion).

passive full rangers, unless they are very big and go very low, would still need to be crossed to the subs, so you still need dsp and some skills/time to learn/help to align it. going with mixed brands will make this more difficult.
nothing impossible but you will be missing a lot without doing it properly, and possibly risking your equipment.
if you have to, i agree that maybe passive sub and active tops could be easier to get right.


How much power should sub have according to full range speakers? Saying that sub has the same sensitivity.
(just for example).

good that you mentioned sensitivity; then you should also understand different kinds of wattage measurements standards so you can compare between manufacturers, watts alone say very little...again, with heavy bassline electronic music i would say at least 6db more subs, or four times the watts - my horn loaded system has got 6800 kw of subs, 2kw mid bass, 900w high mids 200 watt highs and guess what clips first:D


Is it true that speakers should have half the wattage rating of amps wattage rating?
good rule of thumb if you can set good limiters and know your speakers behavior under stress... an amp double the sub rating will fry it with heavy baselines, even one the same rating. if you don't have dsp with good limiting and the knowledge to use it i would say invert that rule for sub and bass heavy electronic, just take an amp half the driver minimum rating (not peak or program), and one with a good peak limiter so that it does not clip.
This should keep your amps safer; for mid highs double the speaker rating is a good suggestion ad the crest factor is higher and you want more headroom


What would be cons of using 4ohm speakers instead of 8, other than need for thicker cables? Is sound quality the same?
mainly that you can hang more 8 ohm speakers easily on an amp; there should be a quality loss that almost nobody could ear unless it's a really bad amp;

i differ from the above suggestion of going mono and hanging 2 subs on one channels and two tops on the other; as this seems a sound for prerecorded music there is a lot of information in the stereo field that would get loss; for live music i find it a more viable option.
i would not search based on brands as there ar a lot of good little or less known ones with good products that often appear at good prices used.


if you feel like building something like your name suggests, just one keystone 18 sub from art welter should do it, a tapped horn project from this site, very cleverly designed and easier to build than many horns, or a couple 15 reflex subs with poles for the tops, and you could buy a couple used 12+1 midtops(more difficult to get diy mid tops right and used cabs often cost less than quality components), another amp, and dsp.
 
First ever post on DIY, please excuse the intrusion

This JBL Cinema Horn rig is 100dB efficient for the first watt at 27Hz and beyond 1200Hz 117dB efficient with beryllium domes in the JBL Compression Drivers.

To drive to 110dB, 100W, 1 bass unit
For an out door venue, I wouldn't bother with a sub, silly idea as you just soak wattage in infra bass for no good results

The Twin 21" reflex cab's go down to 24Hz -3dB and are perfect for application here

This Rig is an out door field system run from a battery, efficiency is the key to a successful set

15" subs, you are barking up the wrong tree

Just out of interest I run a DMX RGB rig with this, run at a solid 115dB for about 2 amps on 230vac or less than 500w for the whole rig in total (sort of ground breaking stuff and a throwback to the early cinemas)
 

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For a Cinema speaker with millions of dollars worth of development in design, deliberate narrow beaming propagation, I don't think so actually, I just state stuff from the book of JBL4632 Specifications.

The paint is still drying on the Twin 21's and I've only had the horns for a month, today just purchased the DSP, currently on a miniDSP. Have done a test Gig

A bit happy to say the least, it's due out to the first gig in the end of March
 
being the Cinema install series is meant to to be "mounted into a wall" what sort of baffling system are you going to use?
if you plan to make this into a mobile rig i'm interested to see what you come up with to retain the pattern control without a wide baffle.

Actually in the Owners Manual for the Cinema Series there is no mention of such additional baffle/boundary effect as an aid to specified pattern control, and in actual fact are tested without such, boundary aids for directional sound propagation. I believe this may well be an assumption on your part w/o correct research with all due respect of coarse for your experience

I have contacted JBL Professional in USA to confirm access to spare parts and specifics of mounting my JBL Horns and as a little fun the application bestowed upon them

They can and will stand alone in field and play effectively to their specifications. Just like any other horn speaker with their new friends the Twin 21" bass Reflex Cabs.

Next !
 
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well i've installed a few in theaters locally but what i know is irrelevant.
if you where interested in discussing your system why didn't you start your own thread?

Is Ok, Champ, I don't want any beef, this is my 4th post in this Forum and it's obvious already that anything I have stated directly from User Guides/information directly from Manufacturer itself will be challenged to what end, amusement I guess.

As far as I'm concerned "Photos or it is a lie/didn't occur"
You are entitled you your own opinion but not your own facts.

I have nothing further to add to this Forum and will be deleting my User Name and Profile directly/
 
This JBL Cinema Horn rig is 100dB efficient for the first watt at 27Hz and beyond 1200Hz 117dB efficient
I just state stuff from the book of JBL4632 Specifications.
Actually, JBL 2425 driver in JBL 4632 high section has 116 dB/2.83V/1m sensitivity, which is very high, indeed:
http://www.jblproservice.com/pdf/Theatre Series/4632M-HF.pdf

Probably at 3 kHz. 6 dB less at the low corner of the horn, and 6dB per octave less above 3k.
And a very narrow pattern horn......
No, at all accounts.
Horizontal dispersion is 90 degrees, and vertical is 50 degrees (in-wall mounting). No surprise, it has to cover all seats in the cinema!

This Rig is an out door field system run from a battery, efficiency is the key to a successful set
Very interesting idea! Yes, it is very efficient (106 dB mid section sensitivity), but 4632 mid/high section is very cumbersome (61"x30"x18"), heavy (125 lbs) and fragile for handling. You have to build appropriate cabinet to mount the 4632 mid/high section in it.
Did you examine Dynacord FX12-PRO horn mid/high section with the same 106 dB sensitivity, but with very compact dimensions (24"x24"x32") and 109 lbs weight?

being the Cinema install series is meant to to be "mounted into a wall" what sort of baffling system are you going to use?
if you plan to make this into a mobile rig i'm interested to see what you come up with to retain the pattern control without a wide baffle.
Without additional baffle (wall) there may be some loss of control between 250 and 600 Hz, but nothing serious because mid horn section is huge, 30" wide.
A year ago I checked a JBL 5732 (smaller brother of 4632) in one small local cinema - it is mounted in front of the wall (not into it), but it covers all seats without problems. Outdoor field is different, of course, but I think it will be OK.

if you where interested in discussing your system why didn't you start your own thread?
I can concur with you that 125dbmonster made some sort of threadjacking here, but his use of cinema speakers for battery powered outdoor system is very interesting.

I have nothing further to add to this Forum and will be deleting my User Name and Profile directly/
No need for such drastic actions, please start another thread for your system.
 
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I need PA system for 100m2 outdoors (most people are usually at smaller space, say like 40m2), 50 people maximum, average of 30-40.
I had already bought Zeck PT7 power amplifier, 2x 700w @ 4ohm, 2x 450w @ 8ohm and 1400w @ 8ohm bridged and it sounds good.
Any pair of 8-ohm boxes with 15" plus 1" exit driver (with 44/50 mm voice coil) will do it, even Behringer.
Jsixis posted a good idea: your Zeck amp on one channel feeding one pair of 15"+1" and other channel feeding two subs (18"). You need one cheap active two-way crossover to make this working.
 
No idea how to start a thread, sorry. Forum new person, post 5

On the left column "Forums" chose appropriate theme, say Multiway. Up on the left corner click the button "New thread".


Dunno, no idea. is Ok, I lived to now happy with what I do W/O this Forum, so not a big deal, no loss to anyone

Have fun. Bye.,


MODERATORS PLEASE DELETE MY PROFILE AS I HAVE NO IDEA HOW
 
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