THD .04% vs .08% .. Noticeable?

[Catdaddy]

THD .04% vs .08% .. is it noticeable?

 

[WmAx]

THD .04% vs .08% .. is it noticeable?

No, it's not, unless you are using steady-state sine waves as your listening material. For music, [1]>1% THD must be present to be detected by the most sensative listeners, in normal circumstances.

-Chris

Footnotes
[1]
Just Detectable Distortion Levels
James Moire, F.I.E.E.
Wireless World, Feb. 1981, Pages 32-34 and 38

 

[warnerwh]

That is so little of a difference as to be ridiculous. No way could you ever notice that. There's alot more to worry about. Speakers commonly have hundreds of times those specs, add the room acoustics to the equation and it's really a non issue.

 

[tbewick]

What confuses me is that these amplifier distortion ratings are typically given at 8 ohms, and most speakers operate over a range of impedances. For example, my B&W speakers hit a low of 4.2 ohms (probably in the higher frequency area) with a nominal impedance of 8 ohms.

warnerwh, I've read that speakers normally distort at low frequencies, and such distortion is described as being less unpleasant. I think I've experienced this myself with a pair of Tannoy HPD-315A Lancaster speakers. With the tweeter turned down, there is a considerable amount of low frequency distortion audible, but this distortion is not audible with the tweeter in the flat setting.

For amplifiers, they are supposed to distort mostly in the high frequency area, which apparently sounds more disagreeable. 40 to 90 watt stereo amplifiers that I've used, having distortion ratings less than 0.5% (8 ohms), all sound the same.

 

[Catdaddy]

I use the system mostly for movie viewing in a media room, that is almost a perfect rectangle.

Reason why I ask is that I feel like I am getting inferior sound with my SR8500 than I was with my Yamaha 5590. Not really looking forward to unwiring the SR8500 and rewirinig the 5590 to do a comparison, but it looks like I might have to go down that road.

My speakers have gone through a couple of disconcerting events in the last two days .. a battery test (the installer of my screen ran a 1.5v AA battery on the ends of my speaker wire to ID which speakers the wires were for) and I knocked in/inverted (wince) the silk cone dome tweeter of my center RBH sound 661 speaker with my knee as I was rewiring it (having unpopped the dome back out when I noticed it 16 hours after I knocked it in - although it does have some unsightly wrinkles/and dimples slight larger than the size of those on golf balls)

I am trying to rule out me imagining the sound disparity so am ruling out the THD differences between my Yamaha and Marantz receivers.

I also tested out a lot of material at high volume levels this morning.

"Excalibur" sounds like crap on it, period.
"MI 2" and "Star Wars Episodes 2 and 4" sounded respectable, but I could hear some hissing through some conversations that I am not certain were there before Friday with my Yamaha and my 2 speaker incidents.

I imagine the installer/tech knows what he is doing .. but I cant help but wonder if the battery thing is a shortcut that could degrade my speaker's performance, even if just a smidge. I should expect contractors to treat my gear as I would but in reality ...

I already have threads up in the receiver and speaker forums but I would appreciate any input you guys can give regarding the above.

 

[Catdaddy]

I rewired my HTR-5590 and surprisingly it sounds much better than the SR8500. Dont know why, but the 5590 rolls through areas where the SR8500 hisses and the 5590 sounds so much fuller.

 

[mtrycrafts]

I use the system mostly for movie viewing in a media room, that is almost a perfect rectangle.

Reason why I ask is that I feel like I am getting inferior sound with my SR8500 than I was with my Yamaha 5590. Not really looking forward to unwiring the SR8500 and rewirinig the 5590 to do a comparison, but it looks like I might have to go down that road.

My speakers have gone through a couple of disconcerting events in the last two days .. a battery test (the installer of my screen ran a 1.5v AA battery on the ends of my speaker wire to ID which speakers the wires were for) and I knocked in/inverted (wince) the silk cone dome tweeter of my center RBH sound 661 speaker with my knee as I was rewiring it (having unpopped the dome back out when I noticed it 16 hours after I knocked it in - although it does have some unsightly wrinkles/and dimples slight larger than the size of those on golf balls)

I am trying to rule out me imagining the sound disparity so am ruling out the THD differences between my Yamaha and Marantz receivers.

I also tested out a lot of material at high volume levels this morning.

"Excalibur" sounds like crap on it, period.
"MI 2" and "Star Wars Episodes 2 and 4" sounded respectable, but I could hear some hissing through some conversations that I am not certain were there before Friday with my Yamaha and my 2 speaker incidents.

I imagine the installer/tech knows what he is doing .. but I cant help but wonder if the battery thing is a shortcut that could degrade my speaker's performance, even if just a smidge. I should expect contractors to treat my gear as I would but in reality ...

I already have threads up in the receiver and speaker forums but I would appreciate any input you guys can give regarding the above.

Well, rule out the receiver

How long was the battery connected? Fraction of a second? Speakers don't like DC, even 1.5V.
Maybe you did damage the speaker beyond the dimple?
You may need to do a frequency test with a test CD on both speakers?

 

[Catdaddy]

Speakers work like before now, when hooked up to the 5590. Checked with Home Theater guys today too, and they tell me that installers use devices that operate on the same principle as the battery test and that the dimpleing was inconsequential.

The SR8500 just doesnt compare to the Yamaha, to me at least, and when I was listening to it .. it just fell short. Maybe its because ive gotten so used to the Yamahas .. using the 5280 and 5590 going on several years now (maybe 8.)