# Powered mixer question



## smorgdonkey (Jun 23, 2008)

I have a powered mixer with plenty of power on tap...130 watts per side into 4 ohms. The trouble is that I have 8 ohm speaker cabinets rated at 200 watts each. That drops the power output of the amp down to about 90 watts per side. I have to push the powered mixer pretty hard to get any volume. 

I'm thinking that 4 ohm speakers are in order.

Is that the general opinion of most of you? Any recommendations for 4 ohm speaker cabinets? It would be nice if they had 15 " speakers as well as horns or other...possibly 12" speakers +...

Direction?


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## smorgdonkey (Jun 23, 2008)

Yeah...I pretty much have my answer here...if I go from 8 ohm speakers to 4 ohm speakers then the mixer goes from 90 watts per channel to 130 watts per channel. Pretty much explains itself I guess.


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## allthumbs56 (Jul 24, 2006)

You may not get an appreciable increase in volume for your troubles though. The difference between that 130 and 90 (?) watts will more likely just result in a small boost in clarity. If I recall, you need to double the RMS (all other things being equal) to gain a 3db increase.

As an FYI, there's a great P/A booklet available at Yorkville in their downloads that gets in to all kinds of stuff like that as well as SPL over distance, and power loss over cable lengths and thickness.

"Volume" can be a very complicated matter.


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## Andy (Sep 23, 2007)

That's not much power -- I use a 200W powered monitor for band practice, and wouldn't want anything less.

My opinion? Do it right. Get a good mixer, a pair of 15s and a power amp that can put out serious volume and stay clean. There's nothing worse than the sound of an overdriven PA, and you can easily blow your speakers if the power amp clips too much.


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## Milkman (Feb 2, 2006)

If you're using the mixer for playback (recording) that amount of power is fine. 

If you intend to rehearse or play a gig, my opinion is that you should be looking at a minimum three times that (600 watts minimum) and that of course will only allow you to amplify voice and acoustic instruments.


That's not meant to be critical of what you have, just my opinion based on many years of experience.


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## smorgdonkey (Jun 23, 2008)

All good points guys - some obvious and some not so...I have two plans:

Plan A: exchange the powered mixer for one that gives me 215 watts per channel.

Plan B: keep the one that currently gives me 90 watts per channel and add an amp which gives me 280 watts per channel more. 

I think both set ups will work for me but I am leaning toward B...my error was not looking into the ohm issue earlier. Most amps and powered mixers are touted for having all of this power but typically they are referring to power at 4 ohms or bridged power...yet most speakers are 8 ohm. It is a bit ridiculous if you ask me.


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## RIFF WRATH (Jan 22, 2007)

why not get a couple more 8ohm speaker cabs and parallel off the original 2 8 ohm speaker cabs, bringing you down to 4 ohms per side.........perhaps face the extra 2 speakers towards the band as monitors...........this is what I do but with a passive mixer and a power amp........looking at your total of 200w you might get away with two house sterio speakers for now.............your 200 w will be OK for now in a smaller space.....


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## smorgdonkey (Jun 23, 2008)

Well, I'm going with 450 watts per side (at 8 ohms) I believe. More power is always better...to have it on tap even when not pushing it...in my opinion anyway.


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## Milkman (Feb 2, 2006)

smorgdonkey said:


> Well, I'm going with 450 watts per side (at 8 ohms) I believe. More power is always better...to have it on tap even when not pushing it...in my opinion anyway.


More power IS always better in PA terms.

You can use 1000 watts to drive 200 watt speakers and as long as you don't push them to clipping you'll be fine. I always use more power than my speakers are rated to handle.

As guitarists we tend to think in guitar amp terms when it comes to power. A 30 watt guitar amp is PLENTY loud enough to play even large rooms and yet a "PA" with less than 500 ~ 600 watts is barely adequate for rehearsal.


It's all about headroom.


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