Loudspeakers Impedance confusion

[Maxxyz]

I know this is very noob of me but I am really unsure and I don't want to fry equipment here. I was handed a Yamaha P7000s amp (4 ohm), two JBL JRX125 duel 15 inch speakers (4 ohm) and two Wharfedale EVPX12’s (8 ohm) for a gig. I would like to add the two Wharfedale EVPX12’s to the system (as part of the PA, not for monitors) but the impedance is confusing me. The JRX 125’s have a parallel 1/4" jack output. I would like to run a stereo output to the speakers. Would I be frying my amp or damaging the speakers if I daisy chain the speakers?

Please help!

 

[WooferHound]

Combining an 8 ohm speaker with a 4 ohm speaker will present a 2.6 ohm load to the amplifier. My experience is that it will work as long as you are using less than half of the capability of the amp and should not be a permanent configuration. Also your 4 ohm speakers will get 2/3 of the amplifier power and the 8 ohm speakers will get 1/3 of the power.

You should not combine speakers of different brands and model numbers as they do not combine very well. Your JBL speakers may even be wired out-of-phase compared to your other speakers which will result in lower output and uneven coverage.

I would advise you to use the 4 ohm speakers only and use the 8 ohm speakers for a different purpous.

Are you trying to get more volume or wider coverage ?

 

[Maxxyz]

Thanks for the advice! You confirmed my suspicions.

I am trying to get max volume out of the system without frying the amp. The venue is quite small (+/- 300 seater). I just thought I would like to add the smaller EVPX12’s as top’s as the JRX 125’s are quite in the low and mid range. I think the best would be to try and find a separate amp and run the EVPX12’s off that? Sometimes there is just no quick and easy way of doing things.

 

[museav]

I know this is very noob of me but I am really unsure and I don't want to fry equipment here. I was handed a Yamaha P7000s amp (4 ohm), two JBL JRX125 duel 15 inch speakers (4 ohm) and two Wharfedale EVPX12’s (8 ohm) for a gig. I would like to add the two Wharfedale EVPX12’s to the system (as part of the PA, not for monitors) but the impedance is confusing me. The JRX 125’s have a parallel 1/4" jack output. I would like to run a stereo output to the speakers. Would I be frying my amp or damaging the speakers if I daisy chain the speakers?

Are you actually going to be able to get stereo? Will everyone, from the people in the middle of the room to those in the rear corners to those right in front of one of the speakers, actually hear the same thing from both the left and right speakers? That is going to depend just on not having left and right speakers but rather on how those speakers cover the listeners and the further you are from everyone hearing the same thing, the less it will be a 'stereo' system.

Running all of the speakers off one amp with one JBL and one Wharfedale per channel would likely make little sense as not only would it be pushing the amp but due to the differences in sensitivity and impedance of the speakers you would also have noticeable differences in levels and response between the two speakers and no way to compensate.

Why do you want to use all four speakers? I could understand using the Wharfedales with sepraate amplification and processing as some type of fill speakers if needed but if the goal is simply greater level then you probably won't get much, if any, noticeable difference in maximum output by using both the JBL and Wharfedale to cover the same area. If you wanted to use the EVPX12s just for higher frequencies than I would use a crossover so that the JRX and EVP each handled part of the frequency range rather than having both reproducing everything.