Hey I've got some more questions. We're looking at buying a mixer and power amp seperate now to possibly save money. The reason for this is because we only need 2 mic inputs so we could buy a really small mixer for cheap. OK first of all you have to match the ohms of the power amp to the ohms of the speaker, right? So if you need 400W (or 200 for each speaker) you want a power amp with 200W/ch @ 8 ohms, and two 8 ohm speakers, right? But if its 200W @ 4 ohms, can you run that into 2 8 ohm speakers? I guess im asking how the ohmage is supposed to match up.

The ohms should match up.
If you've got a 2x200 @ 4 ohms.
You should use it with 200 watt, 4 ohms speakers.

You can run it through 8 ohms speakers.
But with the higher impedence of the speakers, the wattage output of the head will be somewhat reduced.
So with a 2x200 watt @ 4 ohms amps through 8 ohms speakers. You may be only getting 2x120 or so watts out of the amp.

There are other options open to you. But I think the simplest and the least expensive thing to do would be to buy a poweramp and a pair of speakers that match.

This thread should be stickied i think

[QUOTE=KissMeIamSh*tFaced]This thread should be stickied i think[/QUOTE]
Seconded..
It was at one stage.
It's not up to me tho.

ok guys... what is the cheapest PA you guys have ever seen? I think i saw one for 500$ once (used) with 4 inputs and two monitors.. something like that

$500 used, 4 inputs?

dude, check it.
[url]http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/630130/[/url]
[url]http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/632200/[/url]
[url]http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/608003/[/url]

Those are probably the cheapest you'll find.

o haha i meant 500$ canadian but yea that would be what 325? And i meant like seen in a pawnshop or a store. so i guess 270$ american would be what i should have said

[QUOTE=Gremlin]Those are probably the cheapest you'll find.[/QUOTE]
Yep.. Pretty much.

KissMeIamSh*tFaced, good band man..good band

ok well there goes my feeble attempt to start a conversation

PS: Very good man

my pa is ****e.
 

At the moment i have got a Mcgregor powered mixer (300 watt) that to me looks about 15 years old at the least. And i also have some peavey eurosys III speakers. I have had this for about a year but i am well unhappy with it. It sounds ****E! Do you rekon it'll be the speakers or the mixer that needs replacing coz i can afford to replace both? Whatever i decide to get i'll have a budget of about £400.

HELP!

Narrow down where the problem is. Because it is either a problem with the speakers or with the PA. Either the speaker cones are damaged, or the PA is rooted.

Try it out the speakers through a differnt PA, and try out the PA with differnt speakers.

But guess is that the PA will be stuffed, seeing as it is so old.
Find out the wattage of the speakers, and get yourself a new powerd mixer to suit.

hey aes...my pa just isn't cutting it with only 2 cab's and 1 floor monitor...what do you think would be the CHEAPEST way of making it louder than all the instruments>?....way louder

Pick the speakers up higher, if they are not already. Get some stands for them.
Speakers at ear height sound louder than speakers pointing at your ankles.

Add on more speakers. Doubling your speaker area will give you a similar increase in loudness as you would get with twice the output power. But, of course, watch your ohm loading.

Is the floor monitor ran off the same powered mixer as the FOHs? How is it setup?
You could perhaps use an independant powered speaker for the floor monitor. And dedicate the power to the FOHs. Perhaps you could even bridge it?

You could sell it and buy a larger PA. And of course there are many other options. But it depends on what you've got. What have you got at the moment?

Aes, is there any real disadvantage to using a passive mixer into our PA? Our PA has 2 mic and 2 aux (presumably line, that's the way we've used them) inputs. Could we have a Passive mixer for all the amp mics going into a passive mixer into one mic input, and the vocal mic into the other? and put the line outs of the keyboards into the aux inputs? This would be extremely convinient as when we upgraded our PA we could get a 4 channel one- there seems to be a huge gap between the prices of 4 channel PAs and 6-8.

Yeah. Run the main outputs of the passive mixer into the aux inputs of your powered mixer.

Run all you mics and line level signals into the passive mixer (or into the two spare mic inputs on the powered mixer if needs be). That should be fine.

But, as always. Keep an eye on how you've got your levels set. Watch for clipping, excess noise, etc.

thanks

man, you're quick...

[QUOTE=Aes820]Pick the speakers up higher, if they are not already. Get some stands for them.
Speakers at ear height sound louder than speakers pointing at your ankles.

Add on more speakers. Doubling your speaker area will give you a similar increase in loudness as you would get with twice the output power. But, of course, watch your ohm loading.

Is the floor monitor ran off the same powered mixer as the FOHs? How is it setup?
You could perhaps use an independant powered speaker for the floor monitor. And dedicate the power to the FOHs. Perhaps you could even bridge it?

You could sell it and buy a larger PA. And of course there are many other options. But it depends on what you've got. What have you got at the moment?[/QUOTE]


right now ...its a squier 4 pa with 80 watt mixer with 2 i think 12 inch cabs with a 10 inch floor monitor

80 watts, hmm.. Yeah that probably wont last you too long.

Just see if you can stick it through (using those above mentioned methods) with it until you can afford to upgrade.

For an upgrade, a 2x200 watt powered mixer and a couple of speakers would probably be your best bet.
And you could always keep the 2x80 setup to use as monitors.

would mic pre-amps help any..don't they give the kind of boost a guitar efx petal gives a guitar>? or no?

They may boost your loudness a little bit. If you set them properly.
But they can introduce unwanted distortion into your sound if you are not careful with how they are set up.

You can definately give it a try if you wish. Although it is not a long term solution.

Sorry to bother you aes...

were i to use 4ohm outputs of my pa into 8ohm spekaers, would this blow them/ the amp? The amp is only 60w, whereas the speakers are 75w each. with them safe in terms of power rating, is it an issue?

Running 4 ohm outputs through 8 ohm speakers mean that the wattage output of the amp will be slightly reduced.
So if the amp is 60 watts at 4 ohms, then it may only be 40 or so watts while through 8 ohms.
So, power wise, it is not an issue at all.

To get the most out of your PA it is usually best to match your ohm loadings at all times. But, just be sure of the way that your PA works. Running two 8 ohm speakers in parrallel off the one output will have a total load of 4 ohms, for example.
And often, many of those little 4 input mixers are infact just mono PAs, and not true stereo.

I severely doubt its true stereo, but it has 2 4ohm outputs and the speakers i've found are 8 ohm

Its just we were thinking of using it for small venues and then in the future, we'll upgrade everything and use that as our monitoring setup. But 60w wasn't a lot in the first place, will 40w be any good at all, for even the smallest venues?

here they are
[url]http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=23794&item=3749255399&rd=1[/url]

would this plan work? I'm just trying to picture if it was just me with a 40w guitar amp what kinda venue i'd be able to play comfortably. with speaker stands, this might be alright.

Yeah. That's what I was thinking.
And in that case you will be getting the full 60 watts out of the PA. But still, that isn't a whole lot.
They should be alright for practising, and perhaps 'backyard party' sized gigs. But probably not much more
Getting them up onto stands may help a bit. But you really would be better off, in the long run, with a higher powered PA.

With regards to upgrading the whole lot and keeping them for monitors. That is a good idea. And that is what i have done. My older PA is one of those little 4 input 100 watt powered mixers. And since I have now upgraded into these 2x300 watt biamped speakers. I keep the 100 watter and it's speakers for monitoring.

IN my rehersal room at the moment i have a 300watt pa and speakers (dunno the watt of them but its irelevant anyway. But we are soon gonna start sharing with another band and they have a better pa than mine. But my plan is to use MY pa (the crap one) as a monitoring thing and this is how i plan on doing it. Will this work.......?

I will set the good pa up as normal but then from an output on this pa i will then run a jack to jack lead to an input on the crappy pa and use the crappy speakers as monitors. This way i will be able to turn the volume of the monitors up and down.

Any good?

what a convinient time to ask...

look up.

Yeah. That'll work fine. If the good PA has got a line out, or an Aux output. You can run that into the input on the older PA.

DO NOT run a cable from the speaker outputs of the good PA into the older one. This wont be any good for either PA.

Hi, I asked some questions before about how the ohmage was supposed to match up between the power amp and the speakers. I have a few more questions. Ok I understand the the ohmage of the power amp has to be equal to the ohmage of the speaker. And I see alot of power amps that run on 8, 4, and even 2 ohms. So that would mean if I ran the power amp on 2 ohms, I just need some 2 ohm speakers. The problem is, looking throught Musician'sFriend they dont tell you the ohmage of alot of the speakers in there, and the ones they do, all say 8 ohms. So are all speakers 8 ohms? They couldn't all be 8 right, otherwise how could power amps run on 2 ohms? And if not, how do I figure out the ohmage if it doesnt tell me? One other thing, when a power amp is bridged, you have a mono signal, right? So can you only drive one speaker when a power amp is bridged? If so, do you get plenty of sound w/ one speaker? I assume you would because of the increased wattage by bridging. Thanks for the help

1st question. Ohms.

Some poweramps have the abilty to be run at 2 ohms. Yet many (but not all) speakers are only 8 ohms. But. You can wire multiple speakers together. So you can have two 8 ohm speaker cabinets wired next to each other (in parrallel) where the total load of these two speakers would be 4 ohms.

Two 8 ohm speakers (or groups of speakers) in parrallel = 4 ohms.
Two 4 ohm speakers (or groups of speakers) in parrallel = 2 ohms.

So, given this, you can connect up additional speaker cabinets onto the one PA to suit different ohm loadings. Knowing that more speaker area is a good way of increasing loudness. As doubling your speaker area will give you a similar increase in decibels as you would get with an amp with twice the wattage.

Read this article for information about speaker impedence:
[url]http://www.peavey.com/support/technotes/concepts/impedance.cfm[/url]

2nd question. bridging.
When you bridge a poweramp. It is like taking both the left and right channels and combining them into the one mono channel. So a 2x200 watt amp will become a 1x400 watt amp when it is bridged.

Another thing you have to think about, when you bridge the poweramp, you have to double the speaker ohms.
So if your amps is 2x 200 watts @ 4 ohms. Then when bridged it'll be 1x 400 watts while at 8 ohms.

Bridging a poweramp is commonly done when using the poweramp do drive a subwoofer (in a biamped / triamped setup). Because of the lower frequencies, subwoofers require the extra wattage to stay clear and undistorted. And also, because bass frequencies are omnidirectional (you dont need a left and right channel). It doesnt matter that you dont have a left and right channel.

So, if you are thinking of adding on a subwoofer to your setup. Get back to me. But for now and for your specific situation, I dont think there will be any advantage in bridging your PA. Just leave it how it is.

hey aes, rather than spending £60 on some small speakers when they'rre only a temporary solution that'll be used ofr monitoring

My dad has some hifi speakers claiming to be 80w each (yeah right) but still likely to be able to handle 60w between them. They're 8 ohm, the lil' pa we have, as you know, has 2 4ohm speaker outputs. buuut...

they are connectied with wire terminals, not jacks. So, how could i wire them together to get my 4 ohms? wiring something like that into parallel is easier said than done. I have a soldering iron and stuff, and could get some of those connector things if that would help.

Also, they are either 6" or 8" speakers with a 1" spekaer- is this likely to cause any problems? Will the spekaer be so small it will distort, or have trouble reaaching the bass notes? It says it has a minimum frequency response of like 70-80hz i think. I know A is 440, but don't know how the system works form there.

thanks,

moaner

Minimum frequency response refferes to the lowest bass note that those speakers are able to handle.
The human ear cannot hear anything under 20Hz. Everything under that, you stop hearing and start 'feeling'.
Often PA speakers only handle down to 80Hz or so. Leaving everything else to be handled by seperate amplifiers and low range drivers called sub-woofers. If at all.

Some sound techs just flat out ignore all frequencies below 40Hz, and dont let them be amplified. Claiming that everything under this is just a waste of headroom, and is more of a cause of unplesant 'rumble' than it is actual sound.
Meaning, why would they waste amplifier power tyring to reproduce frequencies that dont really need to be there in the first place?

Those stereo speakers of your old mans will have an internal passive crossover.
Which is a small piece of circuitry which seperates your audio signal into differnt ranges of frequencies. The low frequencies will be sent to the woofer. the Mids to the mid range, and the highs to the tweeter.
This passive crossover will prevent the low frequencies from trying to pass through the tweeter, which will in turn prevent damage due to cone distortion.
(bare in mind there is a differnce between a passive crossover and an active crossover)

I would only suggests you use your old man's speakers if you are confident that they wont be damaged. Given their wattage rating, it seems obvious that they will be fine. But I still dont want to encourage you to go ahead and use them, just incase you ruin them. It shouldn't ruin them. But yeah. I hope you know what I mean. As long as it is okay with your dad. Then yeah.

You can wire them up just by cuting the ends off a speaker cable and stripping the wires so that they can fit into the wire terminals.
Taking note of polarity. Positive to red, Negative to black.

You should know the differnece between parrallel and series connections by now.
If not read these pages:

[url]http://www.termpro.com/articles/spkrz.html[/url]

[url]http://www.avatarspeakers.com/wiring%20diagrams.htm[/url]

yeah, i got that, my dad said you can just put 2 wires in 1 termiinal to give parallel

the speakers are already dead old, and he's planning on replacing them, so thats why i was asking

thanks

Aes, if my band bought a decent powered mixer but it was only 200w, could we, in the future, add a power amp between the powerd mixer and the speakers, without worry? I guess the real question is, can you plug a very high power signal into the input of a power amp?

No. You cannot plug the output of a power amp into the input of another amp.
(unless it is attenuated - with a dummy load or something)

What you could do. When you upgrade. Is use the main speakers in that PA for monitors. and run the auxillery output of that PA into another poweramp to use as FOH speakers

ok...

do powered mixers have stereo line level outputs that bypass the amplification section?

i was considering something today... is it possible t use guitar amps as monitors... or jsut guitar cabs... or something

[QUOTE=moaner]do powered mixers have stereo line level outputs that bypass the amplification section?[/QUOTE]The vast majority of them do. They are usually called Auxillery outputs. Not all of them are stereo, but they'll have them none the less.
[QUOTE=KissMeIamSh*tFaced]
i was considering something today... is it possible t use guitar amps as monitors... or jsut guitar cabs... or something[/QUOTE]Um. I guess you could. I dont really see why tho. I think you would get better results using a proper monitoring system.

if I end the auxillary outputs to the poweramp, I could then use the normal speaker outputs as monitor outputs...


aes, good sir, you are a genius.

[QUOTE=Aes820]. I guess you could. I dont really see why tho. I think you would get better results using a proper monitoring system.[/QUOTE]

We lack monitors at the moment