Is lower THD % the better the sound for a receiver?

[mugupo]

It seems to be more pricey receiver the THD % is lower. Does that mean is better sound?

[Drew664]

I think it means better, distortion free sounds at higher volumes.

Someone else can chime in and tell you for sure though.

[mugupo]

Originally Posted by Drew664

I think it means better, distortion free sounds at higher volumes.

Someone else can chime in and tell you for sure though.

so if low volume it won't be a difference?

[Rob J in WNY]

Originally Posted by mugupo

It seems to be more pricey receiver the THD % is lower. Does that mean is better sound?

Generally, yes.

THD (Total Harmonic Distortion) increases exponentially once an amplifer reaches its theoretical output limit. It is of little concern among the bulk of consumer home theater receivers running at volumes lower than "reference" (maximum, or sometimes referred as "0dB") levels.

If you can, read reviews where the technical aspects of the receiver in question are measured - especially its "real world" power output, and where THD begins to spike. You will be surprised at how many manufacturers "pad" their output claims - often by large margins. Remember that an amplifer can often comfortably put out a 1KHz tone burst with less THD than a full-spectrum burst from 20Hz to 20KHz.

Hope that helps!

[Drew664]

http://en.wikipedia.org/wiki/Total_harmonic_distortion

Lesser THD allows the components in a loudspeaker, amplifier or microphone or other equipment to produce a more accurate reproduction by reducing harmonics added by electronics and audio media.

That is a very cold answer. What you are looking for, I can't answer 100%. I think at higher volume levels the shortfalls or gains of having either a high or low THD% become more apparent. However the benefits should be there throughout all volume levels.

Again, I'm no expert. Wait for someone with a deeper knowledge of speaker terms to come along.

[CasualKiller]

THD is just another marketing number. They list these numbers to try and impress you but the reality is there's not a human on the planet that can detect the difference at less than 1% THD. A signal with 10% THD would be pure distortion bearing no resemblance to an audio signal.

[JasonR]

Usually whenever wattage is increased, so does THD. So, technically whenever a manufacturer says well, we increased the ouput of the receiver and it measured 110w @ .08% THD...So, our receiver is a 110w receiver. They could have just as easily said well we increased output and we measured it at 150w @ .1% THD....So, our receiver is a 150w receiver.

So, when looking at a receiver, don't just look at wattage...look at it in accordance with THD.

It would be best to find a third party source though and see what they measure the wattage at the manufacturers stated cap THD...those are usually more accurate.

I hope that made sense.

[jibucha]

Hello

These two factors are fundamental and extremely important to audio sound quality; always!

This does not mean that many pay the proper attention to them, however, they are very important to sound quality; no exceptions!

To be clear; these are not marketing numbers; they really do matter.

It's up to anyone to ignore them, but this would be irresponsible.

Thank You

[JasonR]

It should just be stated when a manufacturer states the wattage produced by their receiver, it is done at a certain THD. They are directly related in manufacturer wattage specs.

I could say my receiver produces 400w, but does it at 100% THD for instance. (This is not accurate, purely done as an example)

[richteer]

Originally Posted by mugupo

It seems to be more pricey receiver the THD % is lower. Does that mean is better sound?

Within reason, no. Once the THD is below, say, 0.1%, anything lower is academic and/or marketing bullshit. You should be chosing your audio equipment based on how it sounds, not its measurements.

[Yeha-Noha]

Originally Posted by richteer

Within reason, no. Once the THD is below, say, 0.1%, anything lower is academic and/or marketing bullshit. You should be chosing your audio equipment based on how it sounds, not its measurements.

Richteer, that's excellent sound advice!

[Yeha-Noha]

Originally Posted by Rob J in WNY

Generally, yes.

THD (Total Harmonic Distortion) increases exponentially once an amplifer reaches its theoretical output limit. It is of little concern among the bulk of consumer home theater receivers running at volumes lower than "reference" (maximum, or sometimes referred as "0dB") levels.

If you can, read reviews where the technical aspects of the receiver in question are measured - especially its "real world" power output, and where THD begins to spike. You will be surprised at how many manufacturers "pad" their output claims - often by large margins. Remember that an amplifer can often comfortably put out a 1KHz tone burst with less THD than a full-spectrum burst from 20Hz to 20KHz.

Hope that helps!

Here's a real world bench test for an early model (2003) of the AudioSource Amp 5.3 150 Watt Monoblock Power Amplifier. I have the newer 5.3 A model but it's pretty much the same. Check out this link. Secrets of Home Theater provided o-scope signal traces along with a description of how they tested it.

AudioSource spec'd it out as having 150 Watts RMS at 8 Ohms; 250 Watts RMS at 4 Ohms in the FR: 20 Hz - 20 kHz ± 1 dB; THD: < 0.1%.

Secrets of Home Theater found that it actually delivered a clean 133 Watts RMS into 8 Ohms and 248 Watts RMS into 4 Ohms; 0.1% THD + N.

Where THD + N = [Sigma {harmonic powers} + noise power]/total output power.

AudioSource was thus honest with their power output rating. I bought one and I wasn't disappointed with its performance.