Need help on integrated amp ratings and what they mean
Davis
Unregistered guest
Posted on
I have seen some recievers that rate their amplifiers at, for example, 110w x 7ch @ 1000Hz. and others that have ratings of 100w x 7ch @ 20Hz - 20Khz. what are the diferances in the ratings, what do they mean?
Firstly, take all ratings with a pinch of salt - they are just indicators of the sort of performance a particular amplifier will give. Using your figures as an example, the 110w is the peak power the unit will provide, 7 channels is obviously the number of channels (but it will NOT be 110w into each of those channels) and the 20hz-20Khz is the "frequency response" of that particular amplifier - ie the musical spectrum it will reproduce. This won't be "flat" though, ie at the lower end of the spectrum (20hz is right down at the bottom of the bass frequencies) the response will be given as something like +/-4 which (for example) would mean that the lower bass reproduction is a lot quieter than the rest of the spectrum. In real terms what that means is if you had your volume control at a certain level and you were playing music, then a bass frequency really low down was played, it would be a lot quieter than the rest of the music. No amplifier gives a flat response across the whole spectrum but the really expensive ones have a lot better fist at it. Hope this helps.
In addition to what Sun King said, generally speaking the better (more honest?) companies will rate their amps with all channels driven between the 20-20khz band into an impedence load at a rated distortion %. For example, NAD rates their C320BEE as 50 watts per channel into 8 ohms between 20-20khz at 0.03% thd with all channels driven.
If a company is rating an amp at 100 watts per channel at 1000 hz, chances are that they are fudging their numbers to make them look good for an unsuspecting customer. Many people don't look passed the 100 watts figure.
Also look to see if the power increases as the impedence drops. They may say 100 watts @ 8 ohms, 200 watts @ 4 ohms. This implies a stronger power supply.
Many companies also advertise impossible specs. Denon makes an AVR rated somewhere near 170 watts x 7. According to an electricity formula - which I don't know but made a lot of sense at the time - this is impossible from the 120 volts from a standard outlet.
If you have a specific amp in mind, let us know and we'll try to help.
Davis
Unregistered guest
Posted on
I have a Yamaha HTR-5740, and its rated power is 100w x 6ch @ 1000hz @ 8 ohms with a frequency responce of 20 to 20 Khz, I was very suprised to find out that it would not push a pair of 10 year old pioneer 3 way speakers with a 12 inch sub.
so now I am in the market for a new reciever. and again I am leaning twards the Yamaha RX-V 2500. I saw this reciever had a pretty nice review and it has an amp specification of 130w x 7ch @ 20Hz - 20Khz @ 8 ohms. also with a frequency responce of 20Hz - 20Khz.
I am mainly going to use the reciever as a HT setup, but I listen to music alot as well. but yamaha does not use the sub out when listening to music in Pure Direct. I am trying to find a reciever that can push my older pioneer speakers for that reason. space is also another concern, so its pretty importiant that I find a reciever that can handle it with out having to rely on the use of an external amp.
