Axiom Home Page Forums General Discussion Home Theater Overstating AV Receiver Power -

WOW. I woke up this morning and checked our stats logs and noticed high Axiom Audio hits which is usually uncommon. I came here and found people in disarray regarding my comments on power rating of the RXV-2400 review and thought I should comment.

First I would like to say the whole concept of power is one of the most widely misunderstood topics in consumer audio. In reality, most people doing home theater use high efficient speakers (>90dB SPL @ 1 meter) and place their multi channel speaker packages in medium sized, usually lively living rooms. This being the case, the receiver/power amp spends most of its time at the low end of the spectrum in terms of power delivery. Usual power draw is between 4-5 watts rms/channel to achieve 80-85dB SPL at the listening position. Which is quite loud! Also, consider that most people doing home theater have actively powered subwoofers (this is where power is needed most!) the headroom of their receivers is greatly improved since it is not taxed to deliver all of that raw bass power to the speakers. That being the case, it is critical for an amp to be very clean, and noise free to preserve low level details. In that regard, the Yamaha does an impeccable job.

When you consider the $1000 price point, what do you expect? As a processor alone, this receiver outguns most costlier dedicated processors. IF you feel you need more power down the road, add another amp and preamp out the receiver!

I certainly don't hope people look at my power estimates and start bring their receivers back because they feel as if they have been robbed!

The RXV-2400 has a 640VA Xformer, one of the biggest in its price class! I don't know of any other 7CH receiver for $1000 retail that will deliver more power (>10wpc or so) than this one does, so please don't feel as if you are being ripped off.

It is funny how people never question cable vendor claims of cables that cost more than this receiver, and how they don't even require cable metrics to measure or compare their performance.

I know I am new to this forum and don't want to solicite links to Audioholics, but I encourage you to read some of our articles on these topics. We even have an SPL calculator that talks about how much power you need in your room based on room dimensions, #of speakers, liveliness, etc.

On a closing note, consider that average power of your receiver is about 1 watt /channel (to reach 75dB SPL at listening position with moderately sensitive speaker system), if you consider 20dB of dynamic headroom required for music as a good rule of thumb (THX recommendation as well) then to reach 95dB peaks, would require 100wpc which the Yamaha WILL deliver to each channel for short periods of time. Music is peaky in nature, not continuous with all channels driven. Also note that most receivers and amps use unregulated power supplies and most audio reviewers hold the line voltage constant (another unrealistic condition) when making power measurements. This helps to inflate the power numbers to make products look better. Stay tuned as we are currently working on building a 5CH power test load and we will be making accurate power measurements (without holding the line voltage constant.


Now if you plan on using low efficient ESL's or wish to blast your neighbors out with 100dB SPL levels continuosly, for example, an external amp would be advised.

Off topic: Have you ever measured a 2x4 or a 2x6? :-)

Well said Gene. Thanks for clearing that up for some of us here. I've had my 2400 for about two month and have never felt like I needed more power even with the Magnepan MG12s as mains. As far as features go, I'm just delighted with the 2400. It's a great machine at a great price.

That's a great clarification Gene and certainly it needs to be reiterated constantly.
However, i'm still annoyed at the marketing propaganda that is very misleading for consumers in this regard.

truth in advertising is hard to come by these days.

The truth is, numbers sell. Many consumers believe more is better, thus in a sense, the industry is advertising what consumers believe they need. There is one particular company which I will not name that is the King of boasting unrealistic power #'s and claims, yet very few people have beef with them. Yamaha is playing the game everyone else is, but IMO at least they are providing a value product that will satisfy a majority of their target customer base.

On that note, I personally feel this receiver is a great match for Axiom Audio speakers which is why we included a whole Yamaha/Axiom Audio package in our HT Recommended Systems Guide.

Hi Gene,

Thanks for your thoughtful and informative contribution here. I do find many of the ads misleading, kind of reminiscent of what used to go on with car stereo amps, where power output would be spec'd to 10% distortion levels (it may still be happening), especially with in-dash head units with self-contained power amps.

Regards,

In reply to:

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I personally feel this receiver is a great match for Axiom Audio speakers

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System matching is one thing that has always been a little confusing to me. I know you don't mean decor wise, so is it generally a matter of impedence/sensitivity? Because some experts say that it is ok to use 4ohm speakers with an 8/6 ohm rated receiver .

BTW, I noticed that the review for the 2400 has made it to the front page www.audioholics.com. I'm so glad someone finally came out with an indepth review of the RX-V2400 and I'm glad its Audioholics! I like how you guys think over there...no BS(or at least very little). BTW, I know I speak for many of us here when I say we appreciate that you take the time to post here.

I tried the "Adventure and Spectacle" DSP modes and you're right, it does "enhance the movie watching experience". I wouldn't even have thought of using it if you hadn't suggested it because I've always thought DSPs were just a mass market gimick(me being an uppity stereophile who knows what the the absolute sound should sound like and all). But it sure sounded better than the THX mode(at least it did to me watching Bad BoysII last night).

I afraid that your "(hint hint)" concerning the front effects went over my head. Would you be kind enough to elaborate?. BTW, I do use the front effects and I do like it. I'd love to know the procedure for using the front effects and rear channels.

I don't mean to monopolize your time....but I will if you let me.

I'm sure that the clarifying comments of Alan, Gene and Clint are much appreciated. A convenient summary of current amp rating standards of various groups(in particular the EIA/CEA standard mentioned by Alan) can be found in the table in this paper. These days clean amp power is cheap and plentiful and shouldn't be a cause of concern. It would be nice if more of the manufacturers clearly stated the standard used to rate their amps, but it's somewhat ironic to note that when Sony told S&V that they used the EIA/CEA standard that they were subjected to considerable criticism.

MWC;

No problem, seems like I am getting no real work done todays anyway and my review made it on a few other websites and people are asking the same questions.

My hint hint, probably needs to be deleted at this point since apparantly you can set the receiver up in 9.1. Based on my FAQ interview with Yamaha, I was lead to believe it couldn't, not a fault on their part, but in my interpretation of their response.

OK, sorry guys, but I have to post a self promoting link to my site so you know what I am talking about:

Yamaha RXV-2400 FAQ Part I


I promise not to post any more audioholics links, at least today

Anyways, I was under the impression you could not do 9.1, even with an external amp, thus I didn't test it in my review.

Upon consulting with Yamaha Engineering yesterday, they informed me that if you enable "Surround Back", the "Surround/Back/Presence" preamp outs reroute to the actual "Presence" channels. Then you can connect an external two channel amp to power those channels and have a full 9.1 set-up featuring their propietary DSP.

I would have preferred rerouting the main channels to the "Presence" channels, and used a dedicated amp for the main channels where it would be needed most. But you can't always have your cake and eat it too, especially for $1000!

The very fact that you can do Yamaha 9.1 in a sub $1000 receiver IMO is awesome! I believe this holds true for the RX-V1400 as well?

If any owners here have this unit, and and an extra amp and speakers, please confirm. I already disconnected this receiver from my set-up and it would involve considerable work to set-up again.

I am waiting on feedback from Yamaha on my review, and would love to add some of this to the addendum. Thanks all!