Ten Percent Distortion?


I have a little Panasonic SA-XR25 digital receiver for my TV rig (I can't really call it HT). Driving some good speakers it sounds great, and cost me all of $287. Tonight I was killing some time wandering around the Best Buy shop looking at similar electronics from Panasonic, and others, and I noticed that output power was quoted at 10 percent distortion! At first I thought this was a missprint, surely they meant 1 percent or even 0.1 percent. However several units, from several manufacturers, were described this way. Back home I quickly checked the SA-XR25 spec and was reassured to find a reasonable 0.3 percent stated.

What the heck is going on? Wouldn't 100 watts at 0.3 percent sell better than 140 watts at 10 percent?
eldartford
Why would you think that? Even "audiophools" do not know how to read and interpret specifications. How would a Best Buy shopper know anything more than "watts"?
Hey, bigger is better in this country. I once read the specs for a sony receiver that was rated at 100wpc. In reality, it was 100wpc peak into 4ohms at 1Khz 10% distortion. When you read the fine print, it was actually 20 wpc into 8 ohms 20-20000hz no distortion figure given. Now, you know some fool is going to crank it up, to impress his friends, and fry his speakers
My personal favorite is the Marantz PM-17 integrated amp that is "only" 60 watts. At sixty watts,into 8 ohms,Marantz lists its total harmonic distortion at less than one one hundredth of one percentage point. Imagine what its watts rating would be at,say,one percent total harmonic distortion?
Actually, I think that "10 percent distortion" would turn off even the most nonaudiophillic people. Everyone knows what "distortion" means, but plenty of audiophiles don't understand watts.
If it sounds good to you, what difference does it make what the specs say? Do you like it less now?

Seriously, you certainly know why they do it.
Simply to claim higher wattage.
You've been around long enough to know.
Twl....Maybe it's because I've been around so long that distortion is of interest to me. When I started out, harmonic and IM distortion in even the best amps were both over one percent. Technical improvements have made numbers on the order of a few tenths commonplace, and this is the big advance that I see in audio amps. Sure, distortion specs are not the whole story, but (IMHO) an amp that starts out with more than 1 percent distortion has two strikes against it.

Pragmatist...Most amps exhibit an abrupt increase in distortion at some power level (a "knee" in the curve), and you don't gain much more power by citing a higher distortion level.
The sales people at BestBuy seem to know what distortion is, as that seemed to be the only selling point this chump was using to get some poor guy to buy the most expensive Yamaha receiver they had. I tried to convince him that 140 wpc was way more than his 6ohm 91db Yamaha speakers needed to sound loud.
Personally, while you can find a decent sounding component as BestBuy once in a blue moon, the stuff they carry is the antithesis of what almost all of us here are searching for.

Distortion, watts, whatever. I found out a long time ago, these specs mean little in the grand scheme of things. Show me a 250 wpc Panasonic, Sony, or what have you, and I will show you a 50 wpc high end amp that walks all over it when it comes to power. Remember, there are lies, damn lies, and then there are statistics. Power is speced through an 8 ohm RESISTIVE load, playing a 1 KHz sine wave. But, almost all speakers are reactive(not a flat load), and many are highly so. Further, we listen to MUSIC(not a flat signal), not test tones - at least, most of us do(I do see far too many audiophiles who care more about how their system measures than they do about music) .

So, what do these specs reaallly tell you???

But, yes, for the massfi buyer, I would think that 100 wpc at 0.3% sounds better than 140 wpc at 10%.
These Panys(I have two 45's) are actually around 80 watts rms into an 8ohm load.
Need more power, then daisy chain two of then through the digital out and bi-amp like I have done.
This provides 200 watts rms into each of my 6 ohm speakers and is a dramatic improvement in every area.

So much so, that I sent both 45's off for new binding posts, solid silver hookup wire direct to the posts, along whith Jensen 4 pole and Blackgate caps in the power supply and signal path.

All 6 channels will be bi amped, and I am going to compare to some hi end gear after mods for 2 channel playback.

The Kenwood,Jvc,Yamaha ect digital amped receivers also play the numbers game whith quoted specs.
Actually, the 100wpc at .3% distortion amp sounds the same as the 140wpc at 10%, since it is the same amp.! But which spec is more attractive? The 140wpc one, of course, so it is the one used. The % distortion is rarely quoted in big letters.

Bob P.
A distortion spec at the onset of clipping is pretty much worthless. A more useful number is the THD at 1W. This corresponds to a level you are more likely to listen to. Most amps are well under .1% at 1W. However, that simple number still tells you very little about how the amp sounds. You need to know more about the spectral content of the distortion to infer anything about the sonics.
It is useful to know how much power an amp is good for, bcause your speakers or type of listening may require a certain amount of power. Of course it doesn't tell you how the amp will sound, but it does help select amps for further consideration.

I am truly surprised that the stated distortion level is of such little interest. For the appropriate application I would buy an amp with relatively low power (20 watts used to serve me well in my tube days), but I would never even consider one with a distortion spec of 10 percent. How do I know that this represents the onset of clipping?
Of course true audiophiles aren't interested in the distortion figure! It is probably that 10% distortion that makes that amplifier sound better to that audiophile's ears, who naturally says that the sound of an amplifier is all that counts. That goes for power also. In fact, the lower power amps probably sound better due to the distortion!
Meanwhile, the non-audiophile, is oblivious to the "sounds better" issue and only sees watts and that is what he buys and that is the market which those products are aimed at.

Bob P.
who naturally says that the sound of an amplifier is all that counts.

What a silly idea! Everyone knows all that counts is the amount of coal it can carry.

KP
When I look for speakers on ebay or craigslist, I love when the seller lists how many watts they are.
The law allows you to print any power ratings as long as you print how you got there.... Would you rather print it was a 100 watt amplifier or 20 watt amplifier. Most people wouldn't know the difference.
Funny, back in the 50's it was normal to quote power ratings at 10%, for table radios, tv's etc. A tube amp is generally not unpleasant with 10% of mostly 2nd or 3rd harmonic content (it's not high fidelity either). But an inexpensive transistor amp at 10% is painful.