impedance question

[g1]

But wouldn't the lower ohmage of the resistor mean that the speaker will actually be dissipating LESS than half the power where it's impedance is higher than the resistor?

This is a series circuit. Power dissipation in either component will be IsquaredR. Current will be the same through each so the higher resistance component will "hog" the power.

[Alan0354]

I used to have to do that all of the time when people were mixing brands of stereos and speakers back in the old days. Many amps didn't like some expensive speakers that would drop below the rated lowest load for some solid state amps of the time. Yamaha and Infinity were famous for it. People would burn the amps up over and over. And .... I had to make what the sales people sold them work no matter what. So I would take the speaker apart and add a 2 ohm 20 watt ceramic resistor in series to the positive terminal inside. No body ever noticed a difference except their amps quit blowing up. And these were the "Golden Ear" crowd.

It is very hard for me to believe that it does not affect the sound. Speaker impedance varies with frequency and is reactive, you put a resistor in series, you change attenuation at different frequency and you change the power level of different frequency to the speaker.

In all do respect, Yamaha and infinity is no high quality speaker. They don't even make medium level speakers. Not mean to be offensive, we don't talk hifi with those commercial stuffs. You need to have the high quality amp, high quality preamp and speaker to even hear the difference. I had a pair of Kef which is two level higher than Infinity and Yamaha. I used an Acurus amp which is at the level of Kef. I use one pair 14 gauge cable and it's good enough already. Then I bought a pair of JM Lab Focal which is audiophile quality. It sounded terrible. I was so distressed. Then I started experimenting with Monster type cable with 12 gauge thin stranded wires. It started to open up. I then experimented by adding the second pair of cable, it improved, then a third pair. It topped out on the 4th pair. Then I can't hear the difference with the 5th pair. I know I hit the quality ceiling of the power amp as it's only at the low end of audiophile. Quality is like all of a sudden, I hear something and I turn around thinking the sound is from somewhere in the house. When the phone ring in the video, I turn and look at my phone, that's the quality I refer to............Those are the things that get lose first.

The point I am trying to make is you have to consider the quality of the whole system, the system is limited by the weakest link. For Yamaha or Infinity, together with the unknown setup, maybe the 2 ohm resistor is not even the gating factor.

I am no golden ear and my wife doesn't know anything about audiophile. If both me and my wife can point out the difference in sound with different number of pairs of 12 gauge Monster style cable, you bet that made a difference. Can you imagine how low the impedance of 10' 12 gauge cable? not to mention 4 pairs in parallel!!!

[Alan0354]

I don't want to make the other post too long. I am experimenting in how to lower the loudness of my 40W Pro reverb. It never cross my mind to put any series combination using resistor. Instead, I disconnect one of the two speaker and put in place a resistor in parallel with the one remaining 8 ohm speaker. I definitely can hear the difference in sound. More obvious is the bottom( low frequency end) got attenuated. I even verified by changing the resistor from 10 ohm down to 4 ohm. I really lose bottom using a 4 ohm. at 10 ohm, it's much less obvious. I cannot not turn the bass knob up to compensate, it would be too easy.

I used my THD Hotplate to be one of the speaker load also. It change the sound even more than the resistor.

I even started a thread in making a load that act like a speaker to minimize the affect of the original sound. It's not that easy.

Like I said, the quality of the sound is limited by the weakest link of the signal chain. My 73 SF Pro Reverb is relative high quality clean amp in all do respect. I can sure hear the difference. It's not just the bass or treble. It's the transparency, openness, sound stage that distinct the quality of the speaker/amp combo.....how "big" it sounds. That's when things become critical.