the Fly Clone Project

True confession: "I screwed up!" Stepping out of the Deep Bandini pile, I'm looking to get cleaned up with a little advice. I wanted to run my Parkers through after market speakers for more enhancement. I knew the impedance rating of my amp and it should have been the very first thing to consider along with the following info. This 4 OHM rated amp has 2-12" speakers and I bought two 4 OHM rated speakers for it. Here is the hard truth I learned. Connecting two 4 Ohm rated speakers in parallel gives a 2 Ohm impedance to the amp. Connecting them in series gives an 8 OHM impedance to the amp. With a 4 OHM rated amp, the lesser impedance of power into the speakers with 2 OHMS will drive the amp to put out much higher power with higher volume and possibly/likely amp failure. The greater impedance of power into the speakers with 8 OHMS will drive the amp to put out higher power with less volume at the speakers without amp failure. The only workaround I have found is a Weber-Z Impedance Matcher for $200. For an additional $75, I could get the right matched set and use these speakers in my 4 OHM single speaker amps. None of this stuff costs a King's ransom. It just leaves a nasty thorn in my side.

I hereby confess my sin and ask for a remedy!

After exhausting everything under the Sun for an answer, I have a reasonable accommodation for this OHMS mismatch.

A 4 OHMS speaker wired in parallel with an 8 OHMS speaker will produce a 3.428 OHMS impedance to the amps speaker output leads. It does not matter which of these two speakers is first in line to receive the amp output. The 3.428 OHMS is the constant average.

The aftermath of the sonic aspect is that there is a +/- 15% increased drive to each speaker which will result in some volume increase and will also produce a slightly brighter speaker voicing.

The aftermath of the electronics aspect will be a potential overdrive of +/- 15% at max settings for a 4 OHMS rated amp. This might or might not engage the amps overdrive protection and shut the amp down due to overheating the internal components. If the amps volume/gain/drive controls are maxed or very close to it, that is where this condition would occur.

Frying the amp in this example depends on how good the quality and endurance of the amp components are. Running the amp at 80%-85% max should keep this overdriven power source from becoming destructive. My gut feeling is that there will be an indistinguishable volume difference due to the mixmatched impedance. I was told that on the zero point of a sine wave on a scope it will show a very slight distortion but nothing a human can hear.

Do this at your own risk. I will be testing this with my equipment.

The source of all of this comes from the most advanced individual I know who I rarely tap. He has maintained and programmed the atomic particle collider (atomic bomb testing) and created and programmed all components of the recently built observatory for the University of California. It was like trying to get a casual conversation with Einstein on steroids.

Good Luck! Hope this helps someone.

July 17th Addendum: All of this has worked out exceptionally good for me. My huge surprise was my choice for Emimence Texas Heat speakers. The enhanced voicings for my Artist, Deluxe, and Mojo running these speakers with solid state has completely blown my mind!!!

I rest my case.

Thanks for sharing your research, @Soloaxer. I'd been following from the first post, but don't have comparable gear to contribute anything more than encouragement. Coming out the other side with those "Eureka!" moments when new combinations of gear end up sounding better than expected have a way of making the previous headache seem worthwhile.