Ohms, Amps and speaker confusion

[browniebrett]

Finally I believe I have found a forum with all the experts! Ive got alot of navigating to do through this site but appears to be promising. Ive always been into the music, but am upgrading to DJ'ing small parties and what nots. I had a small 4 channel mixer with a small amp and a couple of speakers. Ive now picked up a Behringer Europower PMP200 800W 14 channel mixer. This thing has me somewhat confused as I am trying to understand the ohms against my mixer/amp as not to blow the thing up. A quick history I have the following. The Mixer: Stereo Mode: 225W @ 8ohm/350W@ 4ohm(4ohm min load) In Bridge mode:800W @8ohm (8ohm min load) Ive got two older Peavy's at maybe around 200W at 16ohm each. these are the bass with probably tweeters or horns? Ive also got two smaller Kustom speakers that are maybe 200W as well and 8ohms each. I run out of my mixer right and left to the PEaveys, out of them to the kustoms. These all sound just fine and can crank the music nicely. Every once in awhile my lights may flicker at th emonitor level around zero.. But typically its at -24 and -12 when playing.

Ive been trying to determine if I can add any more speakers to this setup? or am I pegged? Im assuming my behringer is at its peak at 4ohms? So if I have (2) 16 ohm speakrs do these then drop to 8 ohms per? and my other (2) small speakes that are 8ohms each do they drop to 4ohms? This is where Im as confused as a baby racoon... I still have two original speakers from my old setup I would like to add to my current speakers but am affraid I will blow something up. They are both 8ohm speakers as well. But not sure of the wattage. Since my Peavys are 16ohm would these even put much load to the mixer/amp? this seems like a rare ohm rating from everywhere Ive read or just obsolete. I would think the higher ohms the more speakers you could hook up to. Keep in mind Im not even using the bridge port.. Thats another learning lesson in itself. Anyway some basic insight would be much appreciated,!

[Jazz P Bass]

Quote:"Im assuming my behringer is at its peak at 4ohms? So if I have (2) 16 ohm speakrs do these then drop to 8 ohms per? and my other (2) small speakers that are 8ohms each do they drop to 4ohms?"
I would not take the Behr below 4 ohms.
The answer to both speaker questions is YES.

[g1]

Sounds like you have mixed speakers on each side? The Kustoms will be getting more power than the Peaveys. If you have an 8 and a 16 connected to each side of the mixer that becomes 5.3 ohms per side, with the 8ohm cabs "hogging" the power due to their lower impedance.
Ideally you would want to swap the Peaveys for 8 ohm cabs, then, combined with the Kustoms you would have 4 ohms per side, and each cab would be getting the same amount of power.
Alternately, you could get rid of the Kustoms and run 3 more 16ohm cabs per side along with the Peaveys for a total of 4ohms per side.
As JazzP stated, do not go below 4ohms per side.

[techineer]

This should help you figure it out:

Speaker Impedance Explained - Ohms

[Brad1]

Something else to consider is that using dissimilar brands/models of speakers from one output will make it impossible to get the best sound out of either set of speakers. Besides the fact that you are already depriving one speaker of full power by using different impedance speakers, each speaker has its own sensitivity and frequency characteristics. That means that if you try to get the best, smooth punchy sound out of one set, the other set will likely object in some manner. Probably, one won't take as much lows, or the highs will sound brittle...even though you got the other set perfect. You'll likely NEVER get the most out of EITHER set, because each is compromising the other.

If you are going to use multiple speakers from one output, they should be the same brand, same model, and of proper impedance to, combined, match the ideal output impedance of the amp.

Since that Behringer has only one set of outputs (stereo mains, or main/monitor), you COULD run, say, the Peaveys through the Main output (paralleled to achieve 8 ohms), and the Kustoms through the Monitor output (paralleled to 4 ohms). That way, you can EQ the Peaveys with the Main section's EQ, and the Kustoms with the Monitor section's EQ, to get the best sound out of both sets. You can get (or build) a speaker-level "Y" cable that would let you run parallel to stage left and stage right, "Y"ed at the back of the amp, if you wished. Or, just run the cable from one speaker to the other, but that would probably have to run across the front of the stage.

The main problem you may find with that is that is it can NOT be stereo with that particular Behringer. You've traded the stereo capability for more control over each set of speakers' for better sound quality.

One other problem may be the Behringer may, or may not, like to be pumping out dissimilar loads from each amp section...8 ohms Main to Peavey/4 ohm Monitor to Kustom. (Of course, Behringers have enough trouble being reliable on even the proper loads, so who knows if they are crappier with mismatched loads than matched...they're crappy anyway.)

Can you live without stereo, for better sound from each set of speakers? May try it to see what you think, unless some of the techs here who consistently deal with the well-known poor quality of Behringer products knows something about mismatched amp-loads in those, and advises against it.

And, before you ask...yes, you COULD conceivably run 'stereo' by running only through the left channel to the Mains/Peaveys and the right channel only through the Monitor/Kustoms. But, it will be wonky, if you think about it. Just imagine running a stereo signal ONLY through one Peavey and one Kustom. It'll be imbalanced because of the different speaker characteristics...no matter how much you EQ them both....and if you have to EQ them both so much to get them anywhere similar, you've just compromised both sets' ideal characteristics, anyway. No point in that, huh? And, you'd likely not want both Peaveys to one side of the stage, and both Kustoms to the other side, anyway. That would look silly, and be imbalanced. Furthermore, if you put one of each on each side of the stage, the left and right are then together, anyway, on both sides of the stage. You'll have no 'stereo spread', so you've gained nothing, in terms of 'stereo'.

Anyway, unless someone here knows of a reason to advise against running 8 ohms Main/4 ohms Monitor through that Behringer...you may consider that scenario to see if you can get each set of speakers sounding their best? (I advise never running ANYTHING though those ripped-off design, cheap-Chinese-crap Behringers full of bad workmanship and lousy components...but, that's just me.) The point is, you'll NEVER get two different speakers sounding their (respective) best through one set of volume/EQ controls of an amp channel. BOTH will be compromised.

Brad1