How Important Is a Receiver’s Power Output in 7-Channel Mode?

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Q I love Sound & Vision’s reviews for the objective bench tests, though the results often don’t seem to sync up with the reviewer’s opinions. I’m looking to replace my damaged but terrific sounding Pioneer A/V receiver with a Yamaha RX-V773. The RX-V773 and its siblings get stellar reviews, but they exhibit a huge power drop-off when driving five or seven channels compared with their two-channel measurements. Pioneer’s VSX-52 receiver delivers around three times the power as the Yamahas into seven channels, though this doesn’t seem to make a difference in the subjective part of the review. Here’s my question: Is a receiver’s power output in seven-channel mode not an important factor when it comes to sound quality? Just looking at test results, I would have expected the Yamahas to get a poor rating for sound, but their reviews are consistently excellent on that point. &mash;Jonty Rees / Austin, TX

A It’s rare for an A/V receiver to achieve anything close to its two-channel power spec during five- or seven-channel tests with all channels continuously driven. One reason is that a particular model may lack a sufficiently robust power supply to allow it to match its measured two-channel performance on such tests. Another is that many receivers incorporate protection circuits that limit their output when pushed to deliver power to all channels simultaneously.

While the gap between an A/V receiver’s two-channel and multichannel measured performance no doubt looks bad on paper, the reality of the situation is that receivers are almost never called upon to deliver full power for all channels—let alone continuous full power—during real-world listening. In other words, those five- and seven-channel measurements are in reality torture tests that have little to do with actual music or movie content. That explains why you’ll sometimes see a discrepancy between the numbers in the Test Bench and the subjective comments in a review’s main section: It’s easy for most receivers to perform within their linear operating range on regular program material played at a sane volume level, particularly stereo music.

So, while one receiver’s ability to deliver more power continuously into multiple channels doesn’t necessarily equate to “better sound,” better measured performance can provide increased comfort that it will handle whatever you throw at it. And also that you’re getting your money’s worth, particularly with more expensive models.

COMMENTS
pw's picture

So now you know the secret. Dump that receiver for separates, monoblocks if possible.
It's time you stepped it up.

Sonodyne's picture

I would say, if you can, separate into pre & amp. At the very minimum you can run the centre and surrounds using your current receiver and use a reasonably powered 2 channel (Parasound Halo A23 or the A21, even better/ Emotiva as a less pricey option). A better option will be using a three channel amp for the centre and fronts with the receiver handling the surrounds. Ideally, use a pre/ pro with single or combination power amps. Remember – a receiver is always a compromise.

Goodfellow's picture

How many people that are in the market for a receiver are willing to do all of that do you think? Oh about zero I would think. The difference in sound is debatable to say the least. A good receiver will not have any issue with this and the guy should have said so. Do not worry about 5 or 7 channels driven stats. It is a non factor

hyfynut's picture

How many people will go to seperates over/in addition to receiver after reading this? Hopefully a few. Non factor? Remember that one of the jobs of this magazine is to inform readers if the BEST way of doing things. That is where the recommendations from readers are also headed. Your statements put you in the "good enougher" group. Your groups opinions are invalid as they do not attempt to practice this fantastic hobby of ours from a best practices scenario. The closer one receiver stays to its 2channel power rating when driving multiple channels the more robust(and better built) it's amplifier section. A separate power amp performs closer to this ideal and so YES it is an improvement over the receiver. Keep your good enougher opinions to your self, they're a non feature.

Goodfellow's picture

You are laughable jack ass. I would put my gear up against yours any day. You sound like a know nothing blow hard that can't take the truth. Bet you just love the curved screen TV's too don't you. We just have to upgrade to one of those too right? Keep your opinions to yourself loser and we all will be better for it.

mnc's picture

I use an old Parasound HCA-1200ii two-channel amp for my fronts and it makes a Huge improvement over my Yamaha receiver. Much more dynamic even at medium volume!

joeg3kc's picture

Just always remember in good to top of the hill receiver or amp power enables the ability to reproduce very large contrast a must have for stereo or multichannel music, loud is what you don't want.

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