Increased power available when listening to music only? (1 Viewer)

[Brent_N]

Forgive me for this dumb question...

I am planning a budget conscious home theater system and am looking at the Onkyo TX-DS494 receiver which is conservatively rated at 55 watts per channel x 5.

If I am listening to music CDs using only the front two speakers, am I still only gettings 55 watts per channel or is the power that is not being sent to the surrounds and center speaker available to drive the front speakers (i.e., ~137.5 watts per channel)?

Having never had a home theater system, I don't really know how this works.

Thanks.

 

[Brian Crowe]

I know there are some receivers that list wattsx2 vs wattsx5. Some technics models have 100x5 or 120x2. My guess is that if it doesn't say this in the documentation then it's just a straight 55 all the time.

~Crowe~

 

[Wayne A. Pflughaupt]

Actually, from what I read in the magazine tests, many receivers deliver less peak power with all five channels driven simultaneously than they do with only one channel.

Since you say the Onkyo is rated conservatively (an hallmark of Onkyo), it’s reasonable to believe you will get more than the 55 rated watts in two-channel mode.

Regards,

Wayne A. Pflughaupt

 

[Bob McElfresh]

This IS a confusing question.

Even a receiver rated for XX watts per channel WILL provide more power than that if you crank the volume control up. But the distortion starts to increase dramatically. You dont usually have to go too far above the max point to start hearing the distortion.

So yes, a receiver rated a 50 wpc X 5 channels driven is a power-plant than can sustain 250 watts at a time. But while you CAN get 125 watts using the L/R channels only, you would not like the results.

 

[Shad R]

Onkyo RULES! Honestly, when I was purchasing my surround reciever about 3 years ago, at Soundtrack, they had an Onkyo 75x5, and a Sony 100x5 hooked up in the middle of the room as "demo" theaters. I listened to both tomarow never dies and Lost in space on both systems(same speakers all the way around). Well, I went with the Onkyo(and still have it), it just sounded smoother on pans and was crystal clear at high volumes. The Sony sounded good, but it didn't sound as clear. I didn't understand why the Onkyo, rated lower watts, sounded better, and I got the guy to admit that Sony cheats on watt ratings, and Onkyo under-rates their amps. Goes to show you that watt ratings aren't always accurate. Your Onkyo probably sounds as good as the Sony Onkyo just makes good products, IMO.

 

[Bob McElfresh]

(Since we are drifting this direction and the question has not been answered in a while...)
Receiver Power Ratings
When a salesman brags about a receiver having 120 watts-per-channel, experienced guys will immediatly ask:

Whats the distortion of that amp at it's maximum output?

A 50 wpc receiver can/will give you 70/80/100 watts for some ammount of time. But the sound is distorted. The better companies will tell you that their "max power" is at a given distortion level. These numbers are something like 0.03/0.05/0.08% (I'm pulling from memory so dont shoot me if I'm off )
Cheap companies will brag about 100 wpc and have "1% distortion" burried in the fine-print (or not shown at all). This is a HUGE ammount of distortion and you should RUN, not walk away from this brand.
The good companines (Yamaha, Dennon, Onkyo) tend to always report:
XX watts per channel into 8 ohm resistive load
All Channel Driven
20-20,000 hz
Distortion less than 0.03%
The better ones (Yamaha) will also report:
YY watts per channel stereo/2-channel mode
Which will help you compare things properly.
Shad: this is why that "lower-power" Onkyo sounded better than the Sony. I'll bet if you looked at the details, the numbers used different resistive loads or 2-channel vs 5-channel measurments so the Sony looked more powerfull, but not when you read the fine print.
Brent_N: A quick search of OnkyoUSA web site shows for your selected receiver:
Power Output (8 ohm): 55 wpc
Power Output (6 ohm): 70 wpc
Dynamic Power -
- 8 ohm: 75 wpc
- 4 ohm: 110 wpc
- 3 ohm: 140 wpc
At a Total Harmonic Distortion (THD): 0.08%
20-100 khz
(I'm assuming all these apply at once).
Despite the fact I'm explaining all this stuff, It's been a few years since I've receiver-shopped.
I'll go on a limb and say that this is a solid unit with decent numbers. It's NOT pushing the high-end at a budget price, but the reporting is honest and Onkyo as a brand tends to be good, if not great quality.
Hope this helps.