0dB and above is the point where equpment clips.
You should ideally try to set your signal to as close as possible to this 0dB limit without ever peaking over [B]for recording[/B]. As you'll ensure the best possible recording quality.

With regards to PAs. Adjust each channels input gain so that is never peaks over this 0dB limit, like said above.
And then use the mixers main output slider to control overall loudness, (not the volume knobs on the poweramp).

If you are loud enough with just having the mixers main output sliders up quarter of the way. Then that's all well and good, that's all you'll need.

If you slide the main output sliders nearly all the way up, so your signal occasionally peaks. Then when it does peak it will be sending a clipped signal to your poweramp and this will introduce an unpleaseant sounding distortion. Too much of it can even damage your equipment.

Alright thanks, but I don't think you answered all of my questions. In another post this guy had two 100W RMS speakers at 8 ohms. And you recommended a 2x100 watt at 8 ohm poweramp or a 2x200watt at 4 ohm poweramp. I was under the impression that if you had two 100W 8ohm speakers hooked up in parallel, the most each speaker could receive was 100W. So if speakers are wired in parallel, the wattage being put into them can be doubled? And is there any more specific things I need to know about what to do and what not to do while setting up a PA?

Well. think of it like this: You are doing sound at a gig, controlling the mixer. It is right in front of you. But the poweramps are right up the other end of the room, next to the stage. If you want the band to be a little louder you'll have to get up and walk all the way over to the stage, where the poweramps are, and then turn them up there. A much simpler way of making the whole band louder would be just have the poweramps volumes up nearly all thew way all the time, and slide the main output slider on the mixer up a bit.
This is generally how it is done, for reasons of simplicity.

There are other reasons too. On account of the whole clipping thing, if a rogue sine wave gets through and clips over this 0dB limit, then you will get distortion. Because, you can't predict what the person on the stage is going to do.
Say you set their levels suitable for a normal singer and the gig is going well. But suddenly the singer decides that they want to bring the mic right up to their face and give it a huge death-metal like growl. You dont have time to react to this and suddenly you've got red 'clipping' lights flashing up all over the place. This doesn't sound good.

You'd want to set your levels appropriately, so you'll always have enough headroom to do the job and to eliminate the risk of unwanted distortion due to clipping.


I reccomend a 200 watt at 4 ohm poweramp in that instance. Because running an 8 ohm speaker off a poweramp rated at 4 ohms will give you a slightly reduced output power. If the poweramp was rated to pump out 200 watts per channel at 4 ohms. Then it may only be able to pump out 100 or 120 watts or so per channel while at 8 ohms.

And, I mean, per channel. Most poweramps are stereo, meaning they have a left and right channel. You'd run each channel into its own respective speakers.
You can [B]bridge[/B] some poweramps, to convert the left and right channels into the one single channel. But this is a little more complex. I should have coverd bridging poweramps somewhere else in this thread. Although I wouldnt reccomed you worry about it for now.

When you combine additional speakers together, regardless of if they are in parrallel or series, you combine each of their rated power dissipating rating to claculate their new rating. Remembering to take into account their impedence and the loading they'll have on the poweramp.
So, two 100 watt 8 ohm speakers wire together in parrallel will be like one 4 ohm 200 watt speaker.

Ok I think I get it. I've got a few more questions, though. How do you wire speakers in parallel? Is there just another output on the speaker that goes between two of them? We just got two squier loudspeakers that are 300W RMS. If they can be wired in parallel, then the biggest power amp we could get would be 2x600W @ 4 ohms, right? Also, you've said before that you should buy a power amp w/ a little more wattage than the speakers so clipping doesn't happen. Is there a certain percent that the power amp is supposed to be over the speakers? Basically, I'm trying to figure out the right size power amp to get the most volume from our speakers and the right amount of headroom, and they only have one input so if there's a seperate one you have to have for parallel, we can't do it. But please tell me what size would be right for both if we could and couldn't wire in parallel. Thanks for the help.

im so happy today i bought my first ever pa (well our band did) its a jade 150 watt powered mixer and 2 jade 75 watt speakers so it suit our band well. i paid 300 australian so im happy

Yea I'm the wreck that started the live sound thread. God knows I need help. I just need the bare minimum for a live show if you guys could let me know what i need and an idea of good quality item that wont cost me a million dollars that would be huge. Thank YOU!

[QUOTE=dRvthruRkr]Yea I'm the wreck that started the live sound thread. God knows I need help. I just need the bare minimum for a live show if you guys could let me know what i need and an idea of good quality item that wont cost me a million dollars that would be huge. Thank YOU![/QUOTE]
As mentioned before in this thread: Have a look on Musiciansfriend, or around in local music stores for Packaged PA Setups.
Where you get a Powered Mixer and a couple of speakers all in one package.

I sure will, thank you

Its time for a p.a. upgrade.

I was wondering if I could just buy another power amp instead of having to replace the one I have now with a bigger one, meaning I could use them at the same time. Is there a way to use multiple power amps to get more power? If so how?

[QUOTE=iron_lion]Its time for a p.a. upgrade.

I was wondering if I could just buy another power amp instead of having to replace the one I have now with a bigger one, meaning I could use them at the same time. Is there a way to use multiple power amps to get more power? If so how?[/QUOTE]

we'd need to know your current setup. Chances are if you need more volume you also need bigger speakers, at whoich point a full new system would probably be better anyway, for the extra channels.

Okay, I have 2 200 watt Kustom Speakers, a mixer with 8 inputs, and 1 400 watt power amp, i was wondering if I could buy for example, 2 100 watt monitors or something, would i have to buy a 600 watt power amp, or could i buy a 200 watt power amp and like run one power amp to the other and have them like combine power, or something.

[QUOTE=iron_lion]Okay, I have 2 200 watt Kustom Speakers, a mixer with 8 inputs, and 1 400 watt power amp, i was wondering if I could buy for example, 2 100 watt monitors or something, would i have to buy a 600 watt power amp, or could i buy a 200 watt power amp and like run one power amp to the other and have them like combine power, or something.[/QUOTE]

You could use your current speakers on stands as monitors, and use your current poweramp to power them. You could then guy some bigger speakers and a bigger poweramp, probably have to be getting towards 2x300 for it to be worth it. I presume you have enough mixer inpus for your needs?

help....
 

would it be better (in the long run) to buy a mixer seperately ,and then some speakers, or a whole PA system
were looking at:
[url]http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/630130/[/url]
or,
[url]http://www.behringer.com/UB1202FX/index.cfm?lang=ENG[/url]
with 2
[url]http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/609000/[/url]
would i need a power amp?

should i get a subwoofer or a bass cabinet....


(please help us)

If you got the mixer and speakers, you'd need a power amp.

you wouldn't need a subwoofer, those aare full range cabs. Using one COULD improve your sound, but there are more important things to buy at your level.

The package should do you fine, but in the long run, you might be glad you bought the seperates. Its up to you.

Have a powered mixer(200 watts), and 2 amps(15 and 20 watt)...

Can we make the pa-mixer output to them instead of speakers for a couple of months?

[QUOTE=LivingDeadBoy]Have a powered mixer(200 watts), and 2 amps(15 and 20 watt)...

Can we make the pa-mixer output to them instead of speakers for a couple of months?[/QUOTE]

no, it'll burn out without a correct speaker load attatched.

you can get speakers very cheap on ebay (£100 for a pair of 1x12s BIN, i once did see).

but we tried it yesterday evening and it all worked O.o...
the problem is... right now we got -200$..

[QUOTE=LivingDeadBoy]but we tried it yesterday evening and it all worked O.o...
the problem is... right now we got -200$..[/QUOTE]

shame.

The poweramp is always operational in your PA, so it is slowly melting it. the only way it would work would be to disconnect the speakers form the practice amps, fit a jack plug to the end and plug them in like that. But, you wouldn't be able to turn the amps on, and also, you could blow the speakers, from too much power.

jack socket sorry.

gah **** that sucks... must get speakers... fast...

wait.. How does that happen???

[QUOTE=LivingDeadBoy]wait.. How does that happen???[/QUOTE]

the amp doesn't know that you've got no speakers plugged in, since its designed only to be used with speakers. so it tries to run, but there's no speakers to go to, so it just starts to fry itself.

[QUOTE=moaner]you wouldn't need a subwoofer, those aare full range cabs. Using one COULD improve your sound, but there are more important things to buy at your level.[/QUOTE]

could a bass cab work like a subwoofer?

but wait... we take the speaker outputs and direct it to our amplifiers(combos), so basically the thing that should fry after time is the amplifiers of the combos. not the pa system..

[QUOTE=LivingDeadBoy]but wait... we take the speaker outputs and direct it to our amplifiers(combos), so basically the thing that should fry after time is the amplifiers of the combos. not the pa system..[/QUOTE]
There is a very large chance you could do damage to both.
I would not reccomend it.
I would only reccomend you run the speaker outputs of your powered mixer into suitable speaker loads.

wuold this be a good pa system?
2
[url]http://www.musiciansfriend.com/srs7/g=live/s=packaged/search/detail/base_id/88745[/url]
with
[url]http://www.musiciansfriend.com/srs7/g=live/s=packaged/search/detail/base_id/88618[/url]
and
[url]http://www.musiciansfriend.com/srs7/g=live/s=packaged/search/detail/base_id/118900[/url]


please help we dont really want to waste our time or money....we have little money to spend

I've got a few questions that no one answered before. How do you wire speakers in parallel? Is there just another output on the speaker that goes between two of them? We just got two squier loudspeakers that are 300W RMS. If they can be wired in parallel, then the biggest power amp we could get would be 2x600W @ 4 ohms, right? Also, you've said before that you should buy a power amp w/ a little more wattage than the speakers so clipping doesn't happen. Is there a certain percent that the power amp is supposed to be over the speakers? Basically, I'm trying to figure out the right size power amp to get the most volume from our speakers and the right amount of headroom, and they only have one input so if there's a seperate one you have to have for parallel, we can't do it. But please tell me what size would be right for both if we could and couldn't wire in parallel. Thanks for the help.

[QUOTE=BlinkRockr41]Also, you've said before that you should buy a power amp w/ a little more wattage than the speakers so clipping doesn't happen. Is there a certain percent that the power amp is supposed to be over the speakers? Basically, I'm trying to figure out the right size power amp to get the most volume from our speakers and the right amount of headroom,[/QUOTE]


what if your power amp is exacly the amount of watts as ur speakers(at the same amount of ohms)

Yay I took apart my home entertainment system speakers, since i didn't use it in years. So now i have 2 100 watt speakers...

Connected it all, now this is how it runs:
Instruments>>Mixer>> Speaker Outputs(1 and 2) >> Speakers
\
\_>> Monitor Output >> Amp1 >> Line out of Amp1 >> Amp2
--------------------

Works awesome... :) Is it good?

[QUOTE=meizmatt]wuold this be a good pa system?

please help we dont really want to waste our time or money....we have little money to spend[/QUOTE]
Yes, That will work.
But for your money (also including the mics and necessary cables to plug everything in with). You may be able to get a very similar packaged setup for less.
If you are on a budget and want to go for individual units. You could see how you go on Ebay?

[QUOTE=BlinkRockr41]I've got a few questions that no one answered before. How do you wire speakers in parallel? Is there just another output on the speaker that goes between two of them? We just got two squier loudspeakers that are 300W RMS. If they can be wired in parallel, then the biggest power amp we could get would be 2x600W @ 4 ohms, right? Also, you've said before that you should buy a power amp w/ a little more wattage than the speakers so clipping doesn't happen. Is there a certain percent that the power amp is supposed to be over the speakers? Basically, I'm trying to figure out the right size power amp to get the most volume from our speakers and the right amount of headroom, and they only have one input so if there's a seperate one you have to have for parallel, we can't do it. But please tell me what size would be right for both if we could and couldn't wire in parallel. Thanks for the help.[/QUOTE]

Do a google search for the difference between parrallel and series circuits.
Many speaker cabinets have both an input and an output, these are usually wired in parrallel, and to connect up addition cabinets you simply daisy chain this output into the next cabinet.

Then you have to work out your ohm loading. You add the reciprocols of each of the loads, which equals the recipricol of the total load.
S1 = First speaker, S2= Second Speaker T = Total impedence.
(1/S1) + (1/S2) = (1/T)
Two 8 ohm speaker in parrallel = 4 ohms.
An 8 ohm speaker in parrallel with a 4 ohm speaker = 2.6r ohms


'Clipping' only refers to the poweramp. It has nothing to do with the speakers. If you run your rig up loud you may start to experience clipping. Most poweramps have a red LED light that indicates this. Keep an eye out for it and make sure it doesn't happen. If it does happen then make sure it is minimal.

Running it up extrememly loud will make it clip, regardless of what speakers you've got running off it.

I'd only reccomend buying an amplifier with enough headroom (watts) for you to do what you need it to do. Then, choose your speakers accordingly.
If you buy a 500 watt per channel amp and only need to run your volume down low in rder to be loud enough, then that's fine.
If you have a 100 watt per channel amp and you are running it up into clipping, then this is where problems occour.

[url]http://www.kustom.com/products/pa/kpa100.asp[/url]

For those new, is $399. Is this a good deal? Or is this Kustom PA package sh[i][b][/i][/b]it?

[QUOTE=][B]Kustom KPM 4100[/B]

100 Watts RMS Output

4 Channels

4 Balanced XLR Inputs/4 Line Level Inputs

5-Band Master Graphic Equalizer

Built-in Reverb/Echo Effect

Tone Control for each Channel

Phantom Power

[B]Kustom KSE 10 - Speakers[/B]

10-Inch High Efficiency Speaker

Power Capability: 75 Watts RMS/150 Peak

Frequency Response: 75-18K

Sensitivity: 93 db

Impedance: 8 Ohms[/QUOTE]

What if your speaker doesn't have an input and an output...

BWD: They do the job. Good for garage bands practising, and 'house party' or backyard sized gigs. But not much else.
You do get what you pay for.

LivingDeadBoy: You could wire one yourself, Or use a Parrallel splitter box. But always take note of the total ohm loadings. I'd suggest you read up on this topic further, do a google search for resources.

Well I guess that's pretty much just what we need. Just for practices or parties, because venues have PA's usually, right?

Often venues do have PAs, yes. Or you could hire one for the night.

i need some general info on on a P.A. for vocals thanx

i need some general info on vocal P.A. thanx

I'm not sure if this has been asked or not, but the search isnt working right right now and there are too many pages to look through. I just but a small 230 watt PA to mix our instruments and record to cassette with when we jam. The speaker cabs have outputs on the back of them labeled "extension"

My question is:

Is this a line out or a speaker level out?

For some reason since the board has been screwed up today this didnt go to the front.

Hopefuly now it will.