most people tend to stick with the same impedance for all of their speakers, as it puts less strain on the amp. the 7100 is a particular amp that does not struggle with different impedances from the speakers. however if the speakers have different impedances they are probably different brands; mixing brands of speakers is not usually advised either as echoing can occur due to the nature of different tweeters being in the speakers. so if you are going to mix brands be sure to listen and make sure that they sound good together. the sub, being low frequency, can be a different brand w/o any side effects. as far as efficiency/sensitivity, higher dbs are more efficient and therefore require less power to produce the same spl. that is taking into account that they are both rated exactly the same, and if they are different brands they most probably are not. with a pre/pro that has channel gains, etc. its not a big issue because you can get equal sound out of your speakers by making adjustments to the gains. youre not going to find the answers to all your audio questions in a forum though. sound needs to be heard. hopefully this reaffirmed/cleared up the previous posts and you understand a little more. im sure soundhound will disagree with me as he is prone to do. :-)

it looks like youre going to be listening to mostly music??? the power handling is pretty low for your rears, and would not be the best for the 7100 which is 100w channel, it seems like. center and sub are most important for ht, fronts (sub could be) are most important for music so keep that in mind with buying. from what you have been posting it seems like you havent gone into any stores to demo products, you may want to try that, albeit a place with competent salesmen. take in a couple of demo cds so you can see what you like about particular products.

I have Klipsch Speakers and they are very efficient. Those speakers also sound great.

In general, efficiency is defined as desired output divided by required input. In the case of speakers, the desird output is acoustic power (sound) and the required input is electrical power (from the amplifier). So speaker efficiency is defined as acoustic power out of the speaker divided by the electrical power into the speaker.

A typical speaker has an efficiency of about 1%. So for 100 watts of electrical power into the speaker, it is putting out 1 acoustic watt. 1 acoustic watt does not sound like much, but in a typical home environment, is is quite loud.

As I said, the speaker puts out acoustic power. Speaker specifictions usually give specs on sensitivity, efficiency, or whatever term they use, as XY dB with 1 watt of input power (electrical) at, typically, 1 meter (and, technically, an acoustic environment should be specified, such as an anechoic chamber, "typical" living room, or whatever, but often the environment is not specified).

One needs to know the acoustic environment in order to translate from acoustic power (watts) to sound intensity level (dB).

My electrostatic speakers are probably on the order of 1/2% efficeint. Large horn type speakers can be vastly more efficent. I have read that large Klipsch corner horns are about 40% efficent. The horn acts sort of like an mechanical-acoustic transformer, matching the mechanical impedance of the moving driver cone, dome or whatever to the mechanical impedance presented by the air the speaker is trying to move (vibrate).

Paul


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the 1derful1