J. Vigne is correct. "Yes" you can use the speakers. "No" he has no suggestions.
The "max 100 W" on speakers means don't give them more than that.
Manufacturers often seem determined to make everything more complicated than it really is. There is always the owner's manual! I would say, if the manual does not make things clear, don't buy the unit it comes with. That's me.
J. Vigne
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John A. - Thanks. You are correct.
J. Vigne
Unregistered guest
Posted on
By the way, does it seem like no one can or will read an owner's manual? I've come across innumerable occassions where I have read the owner's manual and it makes no sense or doesn't clearly address the issue at hand; but, so many of the questions posted on this forum could quite easily be answered by spending less time typing them out and instead just reading the owner's manual. They might even learn something they didn't expect to find. There are no stupid questions. There are quite frequently easy to find answers. To answer the question posed to us: Yes, wattage is the result of amps (current) divided by Ohms (impedance). Wattage is therefore changed by the variant of impedance. In a perfect world (we wouldn't be in Ir..., never mind) as impedace drops, wattage increases. As impedance increases, wattage drops. Every speaker system has a swing in the impedance it shows to am amplifier. Look at a speaker review and you will see a graph which shows the impedance at different frequencies. This plot for any given speaker is a function of the drivers (woofers and tweeters, etc.), the crossover components (resistors, capacitors, inductors and internal connections and cables) and the enclosure type (ported, sealed and so on). What your speaker is indicating by 4~6 Ohms is a swing between those two points. In reality the speaker probably goes above and below those points (it certainly does if it is a ported design) and the amp has to deal with those highs and lows in impedance also. But you have a nominal 4~6 Ohm speaker. The power rating is a suggestion to how much power can be applied to the speaker before damage is likely to occur. In truth, the power rating is as illusionary as the value of the dollar. You can use a very clean, well designed and constructed amplifier with very high wattage that will put peaks of several hundred watts into most well designed and constructed speakers without damage. It is far easier, though, to blow up a speaker with a low powered amplifier that gets very dirty (clipping) very quickly. Power handling, in a speaker, (I know what you're thinking, John A.) is a subject that would take several pages to begin to assess. In short, your 90 watt amplifier is fine if you do not clip the amplifier. The author accepts no responsibility for yada, yada and so on.
The other general point, often unappreciated to judge from this forum, is that an amp/receiver "max power output" is obtained with a large signal coming in, and/or high gain (volume up high). You can always decrease its power ouput just by turning the volume control down. As J. says, I think, a more powerful amp with the volume turned down will do less damage, and sound better, than a less powerful amp at higher gain and struggling to drive the speakers. Other things being equal.
"90 W" amp with "100 W speakers" is probably a good match in most cases, and those impedances are probably matched OK, too. The speaker impedance can be higher or about equal to the amp recommendation, but should not be significantly lower. "4 Ohm" speakers with an "8 Ohm" amp might work OK, but it is taking a risk.