Help me understand "watts" in receivers vs amplifier

[Pankh]

I'm trying to educate myself on how the measurements work.

Why is a 50 watts integrated amp better that a 7channel avr with 85 watts per channel?
I can buy a nice avr 7x85 watts for $300 and an integrated amp with 2x50 from the same company is usually more expensive.
What should I be looking for in a good quality amplifier?
Thanks

 

[solderdude]

Why is a 50 watts integrated amp better that a 7channel avr with 85 watts per channel?

The question perhaps should be: Why is a 50 watts integrated amp sometimes more expensive than a 7channel avr with 85 watts per channel?

There are so many factors involved here such as speaker impedance, efficiency, power supplies in the amplifiers, specifications from manufacturers, the way the specs are obtained. Build quality, used components etc.

So 'better' is not as easy to answer. Nor do specs say much to those who don't know how to interpret all measurements.

 

[restorer-john]

Generally, an AVR is a compromise, one-size-decodes-everything box, whereas a stereo integrated amplifier is a simpler device, designed to do one thing well- play 2 channel music.

Back in the early days of home cinema, 2 channel amplifiers were being obsoleted and the big business was in HT, with ever bigger and more powerful AVRs hitting the market every week it seemed. Some of them were enormous, very expensive and performed very well in 2ch mode as well. Now with the wholesale apathy toward HT, and the resurgence of 2ch, the market has flipped again. Economies of scale mean a less well equipped and less powerful integrated may cost more than an AVR. I see that position will gradually change in time.

Good 2 channel integrated amplifiers will pretty much always outperform AVRs on the bench.

 

[vitalii427]

One more thing. Receivers usually rated only two channels driven. And it is better to choose specific devices for correct comparison.

 

[DonH56]

I'm trying to educate myself on how the measurements work.
Why is a 50 watts integrated amp better that a 7channel avr with 85 watts per channel?
I can buy a nice avr 7x85 watts for $300 and an integrated amp with 2x50 from the same company is usually more expensive.
What should I be looking for in a good quality amplifier?
Thanks

Marketing and sales volume plays a large part in the higher cost of separates IME/IMO. Those who buy separates are perceived as higher-end customers more willing to pay extra for perceived value and there is always the tie to the old "do one thing well instead of many poorly" analogy. Manufacturers can point to separate power supplies, minimal functions in one box so less chance of crosstalk and noise, claimed higher build quality, etc. Whether those claims result in audibly superior products is often debatable. Since separates usually sell in much lower volume (based on old experience but I doubt it has changed) they cost relatively more to produce and that translates to higher cost to the consumer. And of course if you have say an integrated amp plus tuner instead of AVR you must pay for two boxes, additional power supplies and other components, the dealer must pay for the additional shelf space, etc. Since AVRs are most in demand economies of scale matter -- AVRs can be cheaper because so many more of them are made, dropping the per-unit cost to produce.

On the technical side, you'd have to look at the performance of the two components. AVRs tend to have smaller power supplies in terms of power/channel both to save space and for thermal management. Putting seven channels plus all the processing, tuner, switching, etc. in a box the same size or little larger than an integrated means something has to give. One metric often used is to check the two-channel power vs. all channels driven power. A substantial difference means the AVR does not have the power supply and/or cooling (thermal management) to support all channels running at full power all the time. In practice that rarely matters since the surrounds and rears typically require much less power than the from left, right, and center speakers. Other things that might be traded are things like noise (SNR) and crosstalk with the AVR giving up some in noise floor.

Note that, unless you are pushing the power limits of the integrated amp, the difference between 50 W and 85 W is not huge, about 2.3 dB. It takes about a 1 dB change to even notice the difference in volume, and 3 dB is what most people will change if asked to "bring it up just a little" -- and 3 dB takes twice the power. To sound twice as loud in the midrange takes 10 dB and ten times the power (dB power = 10 * log10(power1/power2) ).

I would weigh the features desired, current and future use (and likelihood of upgrading/changing later), etc. If it is to be only a two-channel music system, you don't need a tuner, and don't see needing video and its related audio processing, the the integrated may be a good choice. If you think you might want to use it in an HT later, want a tuner, or want to try multichannel music, then the AVR is the obvious choice. And note the power you need is heavily dependent upon the speakers and your distance from them as well as the room. A simple online calculator can provide a rough idea, such as http://myhometheater.homestead.com/splcalculator.html.

HTH, IME/IMO, etc. - Don

 

[RayDunzl]

Since separates usually sell in much lower volume (based on old experience but I doubt it has changed)

AVRs have tended to obsolete themselves via the addition of new features, which, until more recently, integrated amplifiers had fewer of.

 

[amirm]

Most low to mid-tier AVRs are sold at a loss by major brands. They do that to stay in the channel and hope that they can sell enough of their higher end products to make up for it. This doesn't always work and has lead to demise of some companies in the space.

2-channel products are less competitive and hence can be priced with better margins.

 

[amirm]

Related, I was speaking to a top executive in a major consumer electronics company. He told me their entire TV business was running at a loss. I asked him why they would continue to stay in that market? He said was shameful for a Japanese company to pull out of the market and let other Asian companies "win!" So they kept subsidizing that division with profits from other parts of the company. Reminds me of the Xbox business we had at Microsoft when I was there....

 

[rwortman]

If you look at the specs for the low end AVR you will usually find much less than state of the art distortion numbers. Whether you can hear that or not is subject to debate. Higher priced AVR's have better numbers but still not as good as medium priced two channel amps. There is an audiophile disdain for the AVR just like DD turntables and plain wires. My experience is that there is little if any difference in sound between a midrange or higher AVR and an integrated stereo amp. However, I have stereo receivers and integrateds in rooms with two channel systems. No sense packing all that other stuff in a box to never be used. Also many AVR's are almost impossible to use unless they are connected to a display Most decent AVR's are rated with two channels driven so the power should be equivalent to a similarly rated stereo amp. It should also be stated that many brands of lower powered integrateds are more expensive because magazine led audiophiles believe that price correlates to quality. You don't have to actually add performance to your products. Adding price is often enough.

 

[Willem]

What you should be looking for in a good but modestly priced stereo amplifier:
1 A beefy power supply. So look for large power supply capacitors for good peak performance and as long as the power supply is traditional: weight.
2 A high output power at realistic distortion levels. More power is always better. 2x100 watt is a nice target unless your room is very large and/or your speakers are very insensitive. But look out for how power is measured (both channels driven into 8 Ohm and at low distortion over the entire frequency range).
3 Digital inputs, and enough of them (three) for a streamer like the now discontinued Chromecast Audio, plus a disc player, plus a television. This is far more economical than buying a separate DAC.

My personal favourites in the EU market are the Yamaha AS 501 and the Yamaha AS 701. They measure well and have a high damping factor for a flat frequency response under realistic speaker loads. And they are from a very reputable brand.

 

[Wayne A. Pflughaupt]

Related, I was speaking to a top executive in a major consumer electronics company. He told me their entire TV business was running at a loss. I asked him why they would continue to stay in that market? He said was shameful for a Japanese company to pull out of the market and let other Asian companies "win!" So they kept subsidizing that division with profits from other parts of the company. Reminds me of the Xbox business we had at Microsoft when I was there....

Well, that certainly dashes my hopes of Pioneer bringing back their fine plasma TVs.

Regards,
Wayne

 

[FrantzM]

Hi
A bit of perspective ...
The level of distortion of those AVR is still pretty low, virtually inaudible.from what I am gathering more and more, We are a bunch of perfectionist and 0.1% of THD is "bad" ... On the other side people pay over $100,000 for things that can't drive a 3 ohms load and barely achieve 20 watts in an 8 ohm load with a level of THD >3%!!! Of course those distortion-producing apparatus are more "musical" and "organic" than those essentially transparent AVR we look down at ... A very strange world that of High Fidelity and audiophilia
It is true that some of these AVR when confronted with difficult loads , especially those on the low side (<4 ohms) can become less transparent. Yet One shouldn't assume that the integrated would be automatically more stable when confronted with same loads ... it depends ...

AVRs represent tremendous values.. You get so much for so little ... One can build a great system around those with the appropriate speakers and be happy for years .

 

[JJB70]

AV receivers must have been hit hard by the huge growth of soundbars and wireless speakers. These days AV receivers and traditional speaker packages seem to be very much a niche, over here the department stores and high street TV shops I visit rarely seem to sell that stuff any more, it's all soundbars and wireless speakers. Mind you, the "hi-fi" sections of these shops is now seemingly all BT speakers with no traditional components.

 

[chebum]

Does anybody know why do we need more than 8W amps?

Most of the loudspeakers have 83dB/W sensitivity at 1 meter or better. To get reference level of 85dB at the listening position in 2m from the speakers we need a bit less than 4W, 4m from the speakers we need 2 times more power: e.g. just 8W. (Why 8 Watts: According to Toole every distance doubling reduces volume by about 3dB. And the same time we need to feed twice more power to increase volume by 3dB). So we need just 8W to get really loud even with less sensitive speakers. With more sensitive speakers like Klipsch or JBL we will need less than 8W.

85dB isn't a concert level by it's loud. Prolonged listening to music at levels higher than 85dB can damage hearing. So why do we need 50W, 75W and even 500W amplifiers?

 

[RayDunzl]

To get reference level of 85dB at the listening position in 2m from the speakers we need a bit less than 4W, 4m from the speakers we need 2 times more power: e.g. just 8W.

85dB reference SPL is the -20dB average (so to speak).

If that level requires 4W, to get the implied 105dB peaks would require 4 x 10 x 10 = 400W.

I'm watching TV. The continuous level is about 70dB SPL. The peak value is currently 86.5dB SPL, or 16.5dB higher, not far from the quoted 20dB allocated for "headroom".

Showing 200ms of the material sampled above, adjusted and cherry picked to represent the discussion:

 

[chebum]

85dB reference SPL is the -20dB average (so to speak).

good point. Thank you!

 

[amirm]

85dB isn't a concert level by it's loud. Prolonged listening to music at levels higher than 85dB can damage hearing. So why do we need 50W, 75W and even 500W amplifiers?

Besides the explanation that Ray gave, peaks in music last milliseconds. There are no studies indicating hearing loss for such short intervals. OSHA safety standards are for noise which is quite a bit more annoying and at any rate, has to last quite a while to cause damage, not the few milliseconds.

 

[DonH56]

One caution on OSHA standards: They are NOT meant for audiophiles, musicians, or similar folk. The standard is basically to ensure some old fart at retirement can still hear conversations without shouting.