THD vs. Amperage?

[alexmoreira]

Hi Folks, I am new to the audiophile world and have a VERY basic question. I am buying my first receiver and am torn between a Denon 1609 and the Yamaha 463. The former has a power rating of 75W per channel with 0.08 % THD; the latter seems more powerful at 105W per channel, but with THD at 0.9%.

The speaker set up will be: a pair of Polk Monitor 50 tower speakers and a pair of legacy bookshelf speakers for a start.

Between the two receivers, which is a better choice for a beginner? I heard that in other to power tower speakers you needed at least 90W per channel, reason why I am currently testing the Yamaha (even though the Denon seems to be a more sophisticated option).

Any advice would be much appreciated. Thank you.

 

[TLS Guy]

Hi Folks, I am new to the audiophile world and have a VERY basic question. I am buying my first receiver and am torn between a Denon 1609 and the Yamaha 463. The former has a power rating of 75W per channel with 0.08 % THD; the latter seems more powerful at 105W per channel, but with THD at 0.9%.

The speaker set up will be: a pair of Polk Monitor 50 tower speakers and a pair of legacy bookshelf speakers for a start.

Between the two receivers, which is a better choice for a beginner? I heard that in other to power tower speakers you needed at least 90W per channel, reason why I am currently testing the Yamaha (even though the Denon seems to be a more sophisticated option).

Any advice would be much appreciated. Thank you.

I think you mean power output in watts not amperage. Now you have to consider power output at the same THD to compare amps. Also the THD will vary with load, so the amps have to have the same THD under identical conditions of load. A reasonable level of THD to compare amps is a THD of 0.1%.

You have basically asked a question that is continuously asked on these forums, probably more often than any other. So I'm keeping my response handy.

 

[no. 5]

I heard that in other to power tower speakers you needed at least 90W per channel...

Cabinet size has nothing to do with power requirements. Preferred volume, loudspeaker sensitivity, reactiveness and impedance curve, do. knowing those things will tell you how much power you will need.

 

[audio ninja]

Either will work

I went to Polk Audio's website, got your speakers specs, hope this gives you some relief...

Recommended Amplifier Power = 20 - 150 w/channel
Efficiency = 89 dB

Is your issue the only deciding factor between the 2 receivers? I can't easily find if the Yamaha is compatible with a HDMI version 1.3 video signal, whereas the Denon is. That's a make or brake deal for me, so I'd start with the Denon. Unless you're buying online, most stores allow you to buy and return it within a specified period of time if it doesn't work out. That way, you can try out the equipment. I don't agree you NEED to have at least 90 watts per channel. The mfg. specs for your speakers prove that.

 

[no. 5]

I can't easily find if the Yamaha is compatible with a HDMI version 1.3 video signal, whereas the Denon is.

The Yamaha's HDMI connections are repeating v1.2a, and the Denon's are switching v1.3.

For what it's worth, I don't see the HDMI v1.3 as a compelling reason to go with the Denon, for one thing, its HDMI connection does not process audio, but the Yamaha's does.

 

[audio ninja]

I still think Denon

The Yamaha's HDMI connections are repeating v1.2a, and the Denon's are switching v1.3.

For what it's worth, I don't see the HDMI v1.3 as a compelling reason to go with the Denon, for one thing, its HDMI connection does not process audio, but the Yamaha's does.

Yes, you're right:
http://www.usa.denon.com/AVR_4_Digit_HDMI_Capabilities_xx09_v0708.pdf

Neither the Yamaha or Denon models process the new 7.1 formats but alexmoreira can defeat this by using the 8 channel input on the Denon that the Yamaha does not have. Or, if running 5.1, he'll just need to run a coax or optical cable for the audio & a HDMI to benefit from Denon's video 1.3a capabilities. Whereas on the Yamaha, he'll be limited only to 5.1 audio, whether by HDMI or Coax/Optical and have no 1.3a video support. (This is all assuming alexmoreira ends up with a blu-ray player and HDTV w/ HDMI 1.3 inputs where he'll benefit from the Denon's capabilities)

 

[no. 5]

No skin off my nose if the OP goes Denon, but what exactly are "1.3a video capabilities"? Higher bit rate? Deep Color?

 

[alexmoreira]

Thank you everyone for the research and advice. I will follow one of the suggestions and try both receivers once the Polk speakers arrive on Tuesday. I did buy the receiver in Best Buy, which means I can return.

From what I have read so far:

1) You don't necessarily need >90 watts per channel to power the Polk Monitor 50 tower speakers that I am about to receive (though more power at comparable THD is more likely to yield higher quality sound)
2) The Denon 1609 may indeed be a higher grade equipment than the Yamaha 463 given it supports 7.1, higher version HDMI, has lower THD, etc, even though lower powered to the non-expert eye.

Any additional insights will be of course appreciated. Achieving good audio seems far from obvious, but I shall get there one day!

 

[rnatalli]

I would add the Pioneer 918 to the mix. Although, in terms of straight power, Denon has a history of meeting its specs when tested on the bench so it'll likely outpower the Yamaha and Pioneer. That said, your speakers are efficient enough so it wouldn't matter.

 

[alexmoreira]

I would add the Pioneer 918 to the mix. Although, in terms of straight power, Denon has a history of meeting its specs when tested on the bench so it'll likely outpower the Yamaha and Pioneer. That said, your speakers are efficient enough so it wouldn't matter.

Thanks rnatalli. One question: I saw the Pioneer 918 has a power rating of 120 w/channel. How can the Denon 1609 with 75 w/channel outpower the Pioneer? That is mainly the question I have been struggling with...

 

[no. 5]

Thanks rnatalli. One question: I saw the Pioneer 918 has a power rating of 120 w/channel. How can the Denon 1609 with 75 w/channel outpower the Pioneer? That is mainly the question I have been struggling with...

For one thing, don't trust manufacturers ratings. If you want to know how much power to actually expect, look for bench tests of the products you are interested in, but those are very hard to find for less expensive models, so take the advertised ratings with some salt.

The other thing is know what to expect with differences in Wattage. Watts in and of themselves usually have little to do with sound quality, and a fairly small increase in loudness requires a doubling of power.

 

[audio ninja]

but what exactly are "1.3a video capabilities"? Higher bit rate? Deep Color?

Yes and Yes and then some. See link below and click on Orange question labeled: "Q. What’s new in the HDMI 1.3 Specification"

http://www.hdmi.org/learningcenter/faq.aspx#15

 

[no. 5]

Yes and Yes and then some. See link below and click on Orange question labeled: "Q. What’s new in the HDMI 1.3 Specification"

http://www.hdmi.org/learningcenter/faq.aspx#15

But even v1.0 supports any current video format you care to put through it, and as far as I know, there are no plans in the near future to implement things like Deep Color, higher frame rates or higher resolutions in consumer video.

"Future proofing" isn't a bad idea though, but that has it's limitations; component video was future proof in '99.