How do you wire to different ohms?

2 speakers 8 ohms how best to wire power amp?

• I just bought two new speakers and need to learn how best to wire them, as to not have them catch on fire. This is PA audio, not car audio, but its mostly the same, right? Speaker Specs: PV115 8 ohm load 400W program, 800W peak Then, it says 5.4 ohm minimum, which is the bit I'm scared about. There are two inputs wired in parallel on each cabinet, 1/4inch standard mono plugs. Power Amp Specs: QSC RMX 1450 Per channel stereo: 8ohms 260W 4ohms 400W Bridged mono: 8 ohms 800W 4 ohms 1400W Real question being, (do I need) or (can I) to wire these speakers in series or parallel? Should I just try regular stereo wiring? Do I need a bigger power amp to properly push the speakers? Thank you so much!

• Answer:

  That's not the ideal amp for those speakers, so you're gonna have to choose if you want to overpower or underpower them (note, if you drive the speakers too hard you can ruin them but they won't catch fire). I don't know WTF that 5.4 minimum ohms thing is...according to the specs online they are 8ohm speakers, so they should be, well, 8ohm speakers. Sometimes speakers won't test for the exact impedance they claim to be (i.e. a 4ohm speaker might be 4.3 or 3.8 etc), but I've never seen a speaker deviate from its rated impedance by more than about 0.3ohms...so I'm gonna assume that your speakers are just 8ohms (you could check them with a multi-meter if you wanted to find out for sure). Wiring the speakers in series is out of the question because that would give you a 16ohm load which would result in your amplifier outputting very little power. So basically here's your two options: 1) Wire each speaker to it's own channel. That amp is gonna put out about 260W RMS (program) to each speaker...you'd be underpowering each speaker by about 140W. I would expect you to get pretty good volume still, but the sound may be a little sloppy/distorted and you certainly won't be able to drive the speakers as hard as they are designed to be driven. 2) Wire them in parallel which gives you a 4ohm load and then bridge the amp. This will give you an impressive 1400W RMS but that means each speaker is receiving about 700W which is close to double what they are designed to handle. I assume PA amps are like car audio amps wherein they have gain control, so you would need to keep the gain fairly low so as to not blow the speakers. If it were me, I'd trying to get an amp that more properly powers the speakers. But if you are stuck with that amp, then I would probably opt for option 2 (although option 1 is safer). Ultimately your call though. Maybe check PA forums and see if people have had issues when putting a lot of power to those speakers...in car audio there's some speakers that don't seem to be able to handle the RMS power they are rated to handle, whereas others can take double or triple their rated power before developing problems. If it is ill-advised to overpower the speakers, then go for option 1. Ultimately your best though would be an amp that is 400x2@8ohms or 800x1@4ohms (or a 4ohm version of those speakers).