watts per channel

[Rick22]

I am looking at the harmon kardon avr645 receiver. First I want to know if this is a decent receiver. My sceond question is why is the watts per channel so small on the harmon kardon receiver. When I look at other receivers in the same price range such as denon, marantz and yamaha, there watts per channel range from 100w to 140w, and the harmon kardon is only rated at 75w per channel.




Thanks

 

[racquetman]

I am looking at the harmon kardon avr645 receiver. First I want to know if this is a decent receiver. My sceond question is why is the watts per channel so small on the harmon kardon receiver. When I look at other receivers in the same price range such as denon, marantz and yamaha, there watts per channel range from 100w to 140w, and the harmon kardon is only rated at 75w per channel.




Thanks

Read this (taken from Wikipedia):

"While it is tempting to try to get a bit more power out of an amplifier, or to criticise certain amplifiers for not being able to sustain their rated power out when, for example, all channels are driven simultaneously, these details are really just academic in terms of what really matters — loudness. Because our ears respond logarithmically to intensity, we normally measure this in dB (decibels). A change of 1 dB corresponds to a 25.9% change in power level, and yet is considered the very smallest change in level that anyone can detect even under test conditions. 3 dB corresponds to a doubling of power, and yet represents a change in level that is just-noticeable. So anything less than a doubling of power is hardly worth bothering about! The sensitivity of loudspeakers is much more important. Many high quality domestic speakers have a sensitivity of 84 dB for 1 W at 1 metre, but professional speakers can have a figure of 90 dB for 1 W or even 100 dB (especially for some large-coned woofers). 6 dB represents four times the power, so it would take a 400-watt amplifier driving the '84 dB' speaker (assuming it didn't burn out) to produce the same loudness as a 100-watt amplifier driving a '90 dB' speaker. A '100 dB' speaker could produce the same loudness with just 10 watts (though in practice modern sub-woofers are often driven with high power amps to overcome the restriction of a small enclosure through the use of equalisation)."

You can find this info in a million different places. I just posted the 1st one I saw. Focus on the efficiency of your speakers and whether or not the amp has enough power to drive them in real world conditions. That is all that matters.

Once you understand that doubling the power only gains you 3 dB, then you understand that the difference between 140 watts and 75 watts is really very small.

 

[Mr. Lamb Fries]

The amount of energy delivered or used by a device or system, expressed in Watts. In audio, power ratings of amplifiers and loudspeakers are subject to a lot of variation and uncertainty because of the very large difference in the long-term, steady-state, power rating, and the transient, or momentary, power rating, which can be several times larger. Further confusion is added when ratings at a single frequency (say, 1 kHz) are compared with the more realistic 20 - 20 kHz rating. In multichannel amplifiers, there is the further variable of ratings done with a single channel operating vs. ratings with all channels operating. The result, for consumers, is that advertised power ratings are often almost meaningless.

Harmon Kardon does not use the tradtional ??? watts/channel as their main marketing tool to sell their products so they are not inflated or adjusted to deceive the consumer (reletively speaking).

 

[MDS]

Harmon Kardon does not use the tradtional ??? watts/channel as their main marketing tool to sell their products so they are not inflated or adjusted to deceive the consumer (reletively speaking).

I agree with everything said prior to this statement. HK DOES use their power rating as a marketing tool because many people are still under the misguided impression that an 'all channels driven' rating means the receiver is more powerful.

Their power ratings are lower simply because they rate it when all channels are driven simultaneously whereas all of the other manufacturers rate their receivers when 2 channels are driven simultaneously. Given that no real world music source will ever peak all channels at the same time it really is 'academic' as the link provided by alandamp said.

Music is constantly varying and the different channels peak at different times. The receivers that are rated into 2 channels simultaneously often have more dynamic power as the power is allocated to each channel on an as needed basis instead of always the same power to each channel regardless of need. Gene and the crew have written many articles explaining power ratings and they are a very good read.

 

[wire]

I am looking at the harmon kardon avr645 receiver. First I want to know if this is a decent receiver. My sceond question is why is the watts per channel so small on the harmon kardon receiver. When I look at other receivers in the same price range such as denon, marantz and yamaha, there watts per channel range from 100w to 140w, and the harmon kardon is only rated at 75w per channel.




Thanks

Take a look at the link from mtrycrafts

http://www.geocities.com/Area51/Hollow/3401/ratevsac.htm
Maybe this will help you .

 

[HiJon89]

I'd take a 50W/ch H/K receiver over a Yamaha/Denon/Pioneer/Onkyo 100W/ch receiver any day. It's almost laughable when some of these companies release 110Wx7 receivers that weigh 20 lbs. (*cough*VSX816*cough*).

H/K builds quality products that perform as well, if not better, than advertised. Example: The H/K Signature 2.1 amp is rated at 100Wx5 and it weighs 47 lbs. You know you're getting 100Wx5

 

[Tod]

Also, think about what you actually will use in terms of that available power. 90 db at 1 watt at 1 meter is a pretty common speaker sensitivity. 90 db is plenty loud enough for casual listening. You're only using 1 watt. At full power, you'd be producing 109 db at 1 meter. Fairly loud.

 

[PENG]

I am looking at the harmon kardon avr645 receiver. First I want to know if this is a decent receiver. My sceond question is why is the watts per channel so small on the harmon kardon receiver. When I look at other receivers in the same price range such as denon, marantz and yamaha, there watts per channel range from 100w to 140w, and the harmon kardon is only rated at 75w per channel.




Thanks

Questions like yours have been asked a few times before and you will be getting all kinds of answers. Some will tell you that 75 HK watts mean more than 110 Sony/Yamaha/Pioneer watts. That could be true depending on which Sony/Yamaha/Pioneer model they are talking about. I mean you can always pick an apple and compare to an orange. Others, like MDS already has, will explain why their numbers are lower. I suggest you read as many reviews that include bench/lab test results and then judge them by yourself.

At the end of the day you will find that HK receivers (except the 7000 series) will get you less watts per dollar, though not by as much as they seem on paper. This gets much worse if you are in Canada because their Canadian prices anywhere from 25 to over 100% higher depend on which model.

 

[highfihoney]

Take a look at the link from mtrycrafts

http://www.geocities.com/Area51/Hollow/3401/ratevsac.htm
Maybe this will help you .

Man i just looked at that link,alot of the recievers in the link are over rated in wattage,i wonder what these companys explainations would be if asked why their products dont meet or exceed their advertised capabilities.

 

[mtrycrafts]

I'd take a 50W/ch H/K receiver over a Yamaha/Denon/Pioneer/Onkyo 100W/ch receiver any day. It's almost laughable when some of these companies release 110Wx7 receivers that weigh 20 lbs. (*cough*VSX816*cough*).

H/K builds quality products that perform as well, if not better, than advertised. Example: The H/K Signature 2.1 amp is rated at 100Wx5 and it weighs 47 lbs. You know you're getting 100Wx5

You mean those receivers cannot meet their RMS power rating? Are you sure?

You think that 50watt HK will deliver 100 RMS to any one or two of it's channels? You think you will ever see a music or movie passage that demands full power at the same instant in all channels?

 

[MDS]

That GeoCities link is so old and fundamentally flawed; eg 'output at clipping' - how did they define clipping? Also same old B.S. of testing at 1 kHz, holding the line voltage constant, etc. Gene has debunked that crap so many times it's not worth repeating.

I don't mind one bit if people prefer HK receivers for any reason under the sun, but the notion that '55 HK watts are like 100 Onkyo/Denon/Yamaha watts' is entirely ridiculous - watts are watts.

 

[Buckle-meister]

I am looking at the harmon kardon avr645 receiver...

from Wikipedia...The sensitivity of loudspeakers is much more important [than power]....

Yes, and even sensitivity itself must become almost irrelevant in a bass-managed setup.

 

[Buckeyefan 1]

AVR watt ratings are for one or two channels only, and root mean square (rms). Many of the budget 100 watt AVR's drop significantly when adding more channels.

If volume is what you're after, something as or more improtant than a watt rating would be the spl/impedance rating on the speaker. A Klipsch speaker rated at 98dB compared to a Polk speaker rated at 89dB - both 8 ohms, are worlds apart. This doesn't take into consideration sound quality, so make sure you demo. Just keep in mind those little numbers called dB/ohm.

 

[HiJon89]

You mean those receivers cannot meet their RMS power rating? Are you sure?

Yes that is what I am saying and yes I am sure.

You think that 50watt HK will deliver 100 RMS to any one or two of it's channels?

Not sure, and I really am not too concerned with whether or not it can since it is rated at 50W.

You think you will ever see a music or movie passage that demands full power at the same instant in all channels?

I don't think so, but that doesn't mean manufacturers should feel free to fabricate power ratings.

 

[no. 5]

but that doesn't mean manufacturers should feel free to fabricate power ratings.

I agree, but I don't think manufacturers just make up numbers, thay just test there products in a way that gives the best number (i.e. at 6 ohms at 1 kHz ect...).

bench tests are the only way to go, personly I like to see 1, 2 and ACD tests.
as far as Yamaha vs. H/K, well, go with what you like. but, below is a example of why bench tests are better to have than the numbers the manufacturers say:

Harman/Kardon AVR 330 $799
55 watts X 7
30.5 pounds

Yamaha RX-V750 $650
100 watts X 7
27.5 pounds

sound and vison bench tests of both:
Harman/Kardon
one channel 8 ohms: 95 watts, five channels: 66 watts
Yamaha
one channel 8 ohms: 159 watts, five channels: 61 watts

 

[MDS]

You mean those receivers cannot meet their RMS power rating? Are you sure?

Yes that is what I am saying and yes I am sure.

What's that famous quote? 'It's not what people think they know, it's what they think they know that just isn't so'.

 

[furrycute]

In terms of evaluating the power of the amp section, I would pay more attention to the actual weight of the receiver. The heavier the receiver, the beefier its power supplies, and hence the more power it can crank out. I don't really feel comfortable using 20lb receivers. It's just not heavy enough.

But this rough benchmarking no longer holds true when you are talking about the newer generation of digital amps.

 

[mtrycrafts]

That GeoCities link is so old and fundamentally flawed; eg 'output at clipping' - how did they define clipping?

At the bottom of the page, .3% THD+ N is where clipping is measured. Nothing wrong with that number.

Also same old B.S. of testing at 1 kHz, holding the line voltage constant, etc. Gene has debunked that crap so many times it's not worth repeating.

Yes, he has. 1kH and 20-20kHz seems to be about 10%-15% difference. And, these test method is applied to all those amps equally, right? So, you can see how well they performed with this testing protocol.
You lower THD at clipping, all amps will deliver less. You measure 20-20k will reduce all amps proportionally, right? Also, when it clips, most likely you don't have music covering the audio band fully, 20-20k, nor is it at one frequency only but somewhere in-between. So, I would say, there might be a 7% difference with half band?
It is not the same as if one amp is measure one way and another another way.

I don't mind one bit if people prefer HK receivers for any reason under the sun, but the notion that '55 HK watts are like 100 Onkyo/Denon/Yamaha watts' is entirely ridiculous - watts are watts.

Precisely

 

[mtrycrafts]

Yes that is what I am saying and yes I am sure.

Which ones?

Not sure, and I really am not too concerned with whether or not it can since it is rated at 50W.

Precisely. It won't. A 100 amp will.

I don't think so, but that doesn't mean manufacturers should feel free to fabricate power ratings.

What are manufacturers fabricating? Please specify. Don't confuse all channels driven and two channels driven as mandated by FTC, that makers are fabrication specs. Perhaps you just don't understand what specs mean on the printed spec sheet of amps?

 

[mtrycrafts]

In terms of evaluating the power of the amp section, I would pay more attention to the actual weight of the receiver. The heavier the receiver, the beefier its power supplies, and hence the more power it can crank out. I don't really feel comfortable using 20lb receivers. It's just not heavy enough.

But this rough benchmarking no longer holds true when you are talking about the newer generation of digital amps.

You mean that 30lb HK above puts out more power than the 27lb Yam?
Are you sure the extra weight is in the power supply and not in the extra weight of the faceplate or chassis, or knobs, or some other irrelevant part?