Receiver watt vs amplifier watt (1 Viewer)

[Don K]

I am thinking of adding a 5 channel amplifier to my Nad Reciever and I just wanted to make sure it was worth the money. I understand having a separate amplifier eliminates any electrical distortion that the receiver has but is 100 watts from a hight end receiver different from 100 watts from an amplifier? I have a Hafler amplifier for my sub that weights a ton. What is it that makes it differnet yet rated the same and can you really hear the difference?

 

[Jared_B]

A watt is a unit of measurement, so it can't differ between components. BUT (a big one, too), a watt can be measured in many different ways. For example, amplifier A might be rated at 50 watts, but with 0.10% distortion at 1KHz, where amp B might be 45 watts at 0.04% distortion from 20hz to 20KHz. These numbers can't easily be compared. You must consider the distortion limits as well as the frequency response before looking at just the wattage.

 

[Arthur S]

The 3 things you need to consider are:
1) How efficient are your speakers. For example, Klipsch are very effecient and can get along fine with a receiver. Something like NHT tend to be lower efficiency and might benefit from more power.
2) How loud do you play your material. If it is not loud enough to generate any complaints from neighbors, relatives etc., you may be fine. Before you invest in an amp, you should get a Rat Shack analog sound level meter and see how loud you actually play your material.
3) How large is your room. In a typical room (less than 20X20 with an 8 or 9 ft. ceiling) the receiver may be fine.
I was a little surprised to find that music measured on a meter was very, very loud at 92 db. You might be surprised to hear how loud a system calibrated to 75 db is.
The $30 for the Rat Shack analog SPL meter will both answer some questions and is highly recommended for precise balancing of your HT speakers.