Audio terms BS and not BS

[AcuDefTechGuy]

If this is in question, I'd say music is very dynamic hence the short time periods for measuring dynamic power.

Why measure this "Dynamic Power" at all for amp reviews?

Is it because on Average, most amps are only putting out 1-10 watts; but then there are "Dynamic Moments" that would require a lot more power (headroom) for a fraction of a second?

For example, an amp may be able to output an Average Power of 70W x 2 Ch into 8 ohms 20Hz-20kHz, but it has a Headroom of 180W into 2 ohms for those "short burst of Dynamic moments"?

Some people may believe that amps are putting out 100-200 watts on Average.

 

[mtrycrafts]

Why measure this "Dynamic Power" at all for amp reviews?

Is it because on Average, most amps are only putting out 1-10 watts; but then there are "Dynamic Moments" that would require a lot more power (headroom) for a fraction of a second?

For example, an amp may be able to output an Average Power of 70W x 2 Ch into 8 ohms 20Hz-20kHz, but it has a Headroom of 180W into 2 ohms for those "short burst of Dynamic moments"?

Some people may believe that amps are putting out 100-200 watts on Average.

Good question. But 180 looks much more than 70. Looks matters no matter what.
And that 2 Ohms? Very few speakers have such low impedance here and there. Dynamic into 8 and 4 would be more realistic.

 

[AcuDefTechGuy]

Good question. But 180 looks much more than 70. Looks matters no matter what.
And that 2 Ohms? Very few speakers have such low impedance here and there. Dynamic into 8 and 4 would be more realistic.

Well, Dynamic Power or Headroom at 2 ohms looks a lot more IMPRESSIVE than 8 ohms!

 

[GrimSurfer]

If this is in question, I'd say music is very dynamic hence the short time periods for measuring dynamic power.

1/50th of a second dynamic... and I'm not talking about the spaces between notes...

 

[ski2xblack]

If this is in question, I'd say music is very dynamic hence the short time periods for measuring dynamic power.

I feel there is value to IHF ratings, as long as the potential buyer realizes that they overestimate real world capabilities.

If, say, the Yamaha in our example touts RMS power of x and IHF power of x + 2db (at 1 khz and for but a few milliseconds), the amps real world power using music lies somewhere in between, probably much, much closer to the lower RMS power.

Only a few amps can provide genuinely useful (wide band, longer duration) dynamic power well above their RMS rated power, and they employ things like dual rail or adaptive supplies (class g/h).

Gene's adoption of the more challenging method from the auto zone is a step in the right direction, where the numbers arrived at are more conservative/realistic.

 

[mtrycrafts]

Well, Dynamic Power or Headroom at 2 ohms looks a lot more IMPRESSIVE than 8 ohms!

Yes, looks matters, reinforced.

 

[Ponzio]

The "10 biggest lies" is gone.. domain for sale
1. The Cable Lie
2. The Vacuum-Tube Lie
3. The Antidigital Lie
4. The Listening-Test Lie
5. The Feedback Lie
6. The Burn-In Lie
7. The Biwiring Lie
8. The Power Conditioner Lie
9. The CD Treatment Lie
10. The Golden-Ear Lie

Attached is the link to the article I believe you speak of in PDF format.
https://1drv.ms/b/s!AuzzS1BGAuKtiPNDsSv1LkexbGlGDg

This is why I download/rip my cd's/whatever. Everything on the intergoogle is transient and I like to have the original whenever possible before it's vaporized.

 

[mtrycrafts]

1/50th of a second dynamic... and I'm not talking about the spaces between notes...

Now we are getting somewhere.
That is like 60 frames per second in video

 

[JerryLove]

Another good response; hey brother, looks like you’re trying to learn about hi fi. Unfortunately there aren’t any short cuts, if you really want to learn, here are some good places to start... please come back when you have questions about what you’re learning.

There is (or at least was) a site called lmgtfy.com. Stood for "let me google that for you". I used it terribly often in response to questions that were easily googled; so I can understand the frustration.

On the other hand: your question could have been asked "hey: can anyone recommend a location where I can find a list of [I forget your phrasing, but you get the point]".

So errors were made on both sides. Like I said. I am not interested in voting "A was right and B was wrong". I'm not interested in attacking nor defending your question nor his response. I have opinions, though they may be different than you think they are, but I don't want to derail the derail.

On the other hand when someone I have never met calls me lazy, someone like myself, new to a forum could get the idea that that people here are snobs.

I think he accused your question of being an example of laziness.

A couple people have mentioned the the forum has been slow lately, anyone ask themselves if there’s a correlation?

I don't think so. At least, not as you've expressed it.

There's of course the simple issue of "people are where they are"; but the other problem (from a per-person post volume) is that we generally either agree, or we agree that the thing we disagree on is subjective.

If we had, like audio-circle, tons of people asserting that cable risers improved sound or the like; the disagreements would spawn more active discussion (which, in turn, would pull in more people); but AH would also risk becoming irrelevant given that other places already do so.

So as to offer something on topic.
http://www.roger-russell.com/wire/wire.htm

 

[JerryLove]

You should have asked him what he means, how he defines efficiency.

I might have read him the riot act instead.

 

[mtrycrafts]

Attached is the link to the article I believe you speak of in PDF format.
https://1drv.ms/b/s!AuzzS1BGAuKtiPNDsSv1LkexbGlGDg

This is why I download/rip my cd's/whatever. Everything on the intergoogle is transient and I like to have the original whenever possible before it's vaporized.

Or, you can get all or most of those mags here:
http://www.biline.ca/

 

[mtrycrafts]

I might have read him the riot act instead.

Oh, that would have followed his answer.

 

[GrimSurfer]

Now we are getting somewhere.
That is like 60 frames per second in video

Or 60, 120 or 240 Hz in TVs.

 

[TankTop5]

Or 60, 120 or 240 Hz in TVs.

Plasma or LCD?


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[VonMagnum]

Wow. The thread is out of control in a day....

Dynamic usually corresponds to peak. Continuous to RMS (not average). Dynamic can also possibly have extra current reserves (big old electrolytic caps are popular for dealing with thumps in the car sub market).

Power always looks more impressive into lower impedances, but OHM's Law states it must. The problem is that a 100 Watt into 8Ohm amp should ideally put out 200 Watts into 4 Ohms and 400 into 2 Ohms and 800 into 1 Ohm. That almost never happens (save Sunfire/Lightstar ; go Bob Carver!) but it gives you an idea what you SHOULD be getting for those loads in an ideal world.

 

[davidscott]

The "10 biggest lies" is gone.. domain for sale
1. The Cable Lie
2. The Vacuum-Tube Lie
3. The Antidigital Lie
4. The Listening-Test Lie
5. The Feedback Lie
6. The Burn-In Lie
7. The Biwiring Lie
8. The Power Conditioner Lie
9. The CD Treatment Lie
10. The Golden-Ear Lie

I love the CD treatment lie. I remember when you were supposed to use some sort of magic marker to color the edge of the cd. Oh and I'll add one more - the magic clock which when plugged in improved the sound of every component in your system. Not mentioning the name but it rhymed with mice.

 

[TankTop5]

I was looking to see if my receiver will power speakers and send a pre-out signal at the same time. That’s still unanswered even after emailing NAD but it did find this article on its power output rating. Best $20 I’ve spent in awhile.

hifi-review.com


“The amplifier's power delivery fully lived up to NAD's claims. At a constant 0.1 percent distortion into 8-ohm loads (with both channels driven), the power output was between 48 and 52 watts per channel from 20 Hz to 20 kHz. Under the same conditions into 4 ohms (for which the Model 705 is not specifically rated), the power ranged between 53 and 55 watts from 20 to 800 Hz, reached 61 watts at 1.2 kHz, dropped to 53 watts from 3 to 8 kHz, and climbed back to 61 watts at 20 kHz. The 1-kHz distortion into 8 ohms at the receiver's rated 40 watts was 0.03 percent in one channel and 0.04 percent in the other.
But where the Model 705 really showed its mettle was in our dynamic power measurements, which use a 20-millisecond 1-kHz tone burst repeated at half-second intervals. Into loads of 8, 4, and 2 ohms, the output clipped at 95, 144, and 263 watts, respectively, easily surpassing NAD's specifications. Very impressive for a "40-watt" amplifier!”


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[lovinthehd]

I was looking to see if my receiver will power speakers and send a pre-out signal at the same time. That’s still unanswered even after emailing NAD but it did find this article on its power output rating. Best $20 I’ve spent in awhile.

hifi-review.com


“The amplifier's power delivery fully lived up to NAD's claims. At a constant 0.1 percent distortion into 8-ohm loads (with both channels driven), the power output was between 48 and 52 watts per channel from 20 Hz to 20 kHz. Under the same conditions into 4 ohms (for which the Model 705 is not specifically rated), the power ranged between 53 and 55 watts from 20 to 800 Hz, reached 61 watts at 1.2 kHz, dropped to 53 watts from 3 to 8 kHz, and climbed back to 61 watts at 20 kHz. The 1-kHz distortion into 8 ohms at the receiver's rated 40 watts was 0.03 percent in one channel and 0.04 percent in the other.
But where the Model 705 really showed its mettle was in our dynamic power measurements, which use a 20-millisecond 1-kHz tone burst repeated at half-second intervals. Into loads of 8, 4, and 2 ohms, the output clipped at 95, 144, and 263 watts, respectively, easily surpassing NAD's specifications. Very impressive for a "40-watt" amplifier!”


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Most avrs have live pre-outs at all times....can't you test it for yours?

 

[TankTop5]

Most avrs have live pre-outs at all times....can't you test it for yours?

I don’t currently have equipment to test it with but I think I found the answer. If I’m reading this correctly I cannot use the pre outs for a sub while using speaker A/B and the system is designed as a loop to add an external processor.

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[lovinthehd]

I don’t currently have equipment to test it with but I think I found the answer. If I’m reading this correctly I cannot use the pre outs for a sub while using speaker A/B and the system is designed as a loop to add an external processor.

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You could use a splitter on the pre-out main-in to get signal for a sub...