What's an acceptable THD % for a home theatre reciever?

[yllus]

I'm doing some shopping for a home theatre receiver. All I really want is a bunch of optical inputs (3 or more) and that the unit be less than 6 inches tall (I know, weird criteria but I don't really have a choice).

Right now I'm looking at the Onkyo 7.1 Channel TXSR573S Home Theater Receiver, but I'm pretty open as to what to buy as long as it fits the bill as described above. The main sticking point I have with this unit is that the THD on the Onkyo is 0.08%. Isn't that a little on the high side? Is that number important?

 

[wyvrn]

Would you hear .08% THD? Chances are no, so why worry about it? Same argument for why would you want 192 FPS from your video card, you can only see 60FPS.

 

[yllus]

Okay, did some research on my own. According to TechLore.com:

Watch out for distortion ratings. Within limits, lower numbers are more desirable, but usually anything under 1% is inaudible.

 

[NanoStuff]

There's more to a receiver than THD. Various other factors such as step response, phase distortion, IMD and resolution (a consequence of other factors) are rarely mentioned but have a very serious impact on sound. Same thing goes for speakers. I've heard some rather bad amplifiers rated well below 1%.

THD could however be used as a rough guideline to approximate other factors if they're unknown. So while you may not hear a difference for anything below 0.1%THD, and amplifier at 0.001 THD could nonetheless sound plenty better.

 

[spidey07]

1st off, don't pay attention to any of those specs. They're most likely made up.

Best to just go and listen and make sure it has all the features and inputs you need.

 

[StormRider]

Onkyo has a pretty good reputation. That unit you're looking at looks pretty good. The THD figure looks good to me. Like you said, anything under 1% is probably good. I have a Yamaha 5750 I bought a few years ago and I now wish I had features like upconversion from composite/s-video to component analog (to reduce cable clutter). An HDMI switch (for my future HDTV). A dialog enhancing mode (for some reason I'm having trouble hearing dialogs)

Like Spidey07 says, I would look more into the features I want rather than the specs (within limits -- I wouldn't want an awful sounding unit --- but I would think most of the major brands to be good sounding).

 

[AgaBoogaBoo]

You could probably get a nice Harmon Kardon for that price if you wanted one

I picked up the AVR 335 on sale for $400 last thanksgiving weekend.

 

[b0mbrman]

Originally posted by: spidey07
1st off, don't pay attention to any of those specs. They're most likely made up.

Best to just go and listen and make sure it has all the features and inputs you need.

That was to be my answer. Figure out which features and inputs you need, then buy the most inexpensive unit of a reputable brand with those features and inputs.

And I'd add that nearly all modern receivers have THD ratings well under what's audible to humans.

 

[Tiamat]

0.08% THD at what frequnecy and loudness? Since you dont have the complete information, ignore it. Buy receivers based on features, customer reviews, and customer support and the numbers will turn out fine.

 

[b0mbrman]

Originally posted by: NanoStuff
THD could however be used as a rough guideline to approximate other factors if they're unknown. So while you may not hear a difference for anything below 0.1%THD, and amplifier at 0.001 THD could nonetheless sound plenty better.

All else equal, "plenty better" would be stretching it. I imagine someone who paid for the .001% THD receiver would convince himself it sounded much better and use phrases like "earthier tones" or "more dynamic" to justify the higher price, but would not be able to tell them apart in a blind A-B test.

 

[spidey07]

bombarman, all receivers sound different to me. Almost to where I can tell what it is without knowing or seeing it.

I was over at a buddies house as he showed off his new home theater. I couldn't see the receiver or the remote. After about 5 minutes I said "you have a denon, don't you? Probably the 2800 series?"

sure enough.

Each receiver seems to have a distintive sound. Yamahas are easy to pick out as are denons.

Anyway, here's some important features.
1) Can't have too many inputs, ever
2) good video scaling and digital video switching
3) a "direct" mode that bypasses all digital circuitry
4) strong amps, big power supply

 

[YOyoYOhowsDAjello]

Originally posted by: spidey07
1st off, don't pay attention to any of those specs. They're most likely made up.

Best to just go and listen and make sure it has all the features and inputs you need.

:thumbsup:

 

[b0mbrman]

Originally posted by: spidey07
bombarman, all receivers sound different to me. Almost to where I can tell what it is without knowing or seeing it.

I was over at a buddies house as he showed off his new home theater. I couldn't see the receiver or the remote. After about 5 minutes I said "you have a denon, don't you? Probably the 2800 series?"

sure enough.

Each receiver seems to have a distintive sound. Yamahas are easy to pick out as are denons.

A receiver's individual "sound" has more to do with any inherent signal processing rather than differences in THD.

Why spend as many as 4 figures more to get that individual sound when any number of inexpensive equalizers can recreate it for much less?

 

[RaynorWolfcastle]

Originally posted by: spidey07
bombarman, all receivers sound different to me. Almost to where I can tell what it is without knowing or seeing it.

I was over at a buddies house as he showed off his new home theater. I couldn't see the receiver or the remote. After about 5 minutes I said "you have a denon, don't you? Probably the 2800 series?"

sure enough.

Each receiver seems to have a distintive sound. Yamahas are easy to pick out as are denons.

Anyway, here's some important features.
1) Can't have too many inputs, ever
2) good video scaling and digital video switching
3) a "direct" mode that bypasses all digital circuitry
4) strong amps, big power supply

Good video scaling in a receiver is useless. Either have a good source, or a TV that has a good scaler built-in. If you've got enough money for it, pop for a standalone scaler.

Most receivers are audio-centric in that they offer tons of audio features with a video switch and maybe basic video capabilities. Let the audio people do what they do best and leave the scaling to the video people.

 

[StormRider]

What about the situation where our TV has component inputs and we use that to hook up to our receiver. And into the receiver, we hook up various devices like VCR (composite), DVD player (component), Tivo (S-Video), etc. and we want the receiver to switch between devices.

When the receiver switches to the VCR or Tivo, the receiver will "up-convert" it to component to feed to the TV. Does that use any video scaling to do that? I would want that to be as high a quality as possible.

The reason why I would want to do this is to reduce cable clutter.

 

[NanoStuff]

Originally posted by: b0mbrman

Originally posted by: NanoStuff
THD could however be used as a rough guideline to approximate other factors if they're unknown. So while you may not hear a difference for anything below 0.1%THD, and amplifier at 0.001 THD could nonetheless sound plenty better.

All else equal, "plenty better" would be stretching it. I imagine someone who paid for the .001% THD receiver would convince himself it sounded much better and use phrases like "earthier tones" or "more dynamic" to justify the higher price, but would not be able to tell them apart in a blind A-B test.

I've compared a few integrated amplifiers with a THD rating well below 1% to a component amplifier with an unspecified THD rating on passive monitors. While I had blind switches performed, I certainly didn't need those; there was no mistaking. Of course the active model with a relatively inexpensive integrated amp spanked even the best external component amplifiers

 

[Oblivionaire]

I like my Panny xr-50 digital amplifier receiver, IIRC 0.09%THD but nevermind that....it sounds excellent to me. And that's all that matters.

 

[Howard]

THD% is meaningless without any qualifiers. Two amps at the same power with 0.1% THD could sound completely different (distortion-wise).