Power amplifier tests with respect to FTC: 16 CFR Part 432 (July 5, 2024) requirements on output power claims

[pma]

Any seriously designed amplifier will fulfil the requirements. Only compromised designs (for the reason of cost effectivity and size) will not. Then, derate the specs, as was said many times here. Otherwise the competition is dishonest when claiming something and the amp fails at the fraction of the claimed power.

 

[mdsimon2]

Just throwing it out there, I purchased two Behringer A800 amplifiers based on the ASR review. It was my first purchase based on ASR.

When I tested them, I found that they would only put out ~250 W @ 4 ohms for a few seconds and then power would drop significantly. I would have liked to have known that they would do this prior to purchasing.

Michael

 

[amirm]

But how will they know they've found an amp that can fullfill their needs if the power spec are unclear, that's the point of discussion I believe?

Through my measurements and that of others sites who also measure. Further, power is cheap these days so people need to get a lot more than they think they need. If we insist on massive cooling to play at those max levels, then the cost will go up, reducing this advantage.

 

[amirm]

Any seriously designed amplifier will fulfil the requirements.

Only if you live in a fantasy land where cost doesn't matter.

The market cares about most value. And most value is not going to come from an ad-hoc government edict on what that "requirement" is.

Go ahead and build a version of AIYIMA with that fulfills that requirement and let's see how many you sell.

 

[amirm]

When I tested them, I found that they would only put out ~250 W @ 4 ohms for a few seconds and then power would drop significantly. I would have liked to have known that they would do this prior to purchasing.

This happened when playing music??? If so, how did you determine that?

FYI power limiting routinely shows up in my measurements: https://www.audiosciencereview.com/.../onkyo-tx-rz50-review-home-theater-avr.30842/

If you read the thread, you see a number of people saying that has not impacted them at all in actual use.

 

[amirm]

Otherwise the competition is dishonest when claiming something and the amp fails at the fraction of the claimed power.

The entire industry is dishonest currently with hardly any specs provided. The veil of dishonesty is pulled back through my measurements and others. Asking for more power over time has not been shown to have marketable value for customers. Again, if that were not the case, we would have amps with massive heatsinks instead of the diminutive ones that are gaining massive popularity. People are buying that "300 watt" amp and are happy using it.

Let me say again: there is no tooth behind FTC regulation. There is a reason they thought of abandoning it altogether. I can test for it and bring that forcing function but you have failed to convince me that it solves any real problem and won't cause a regression in the market.

 

[danadam]

Just throwing it out there, I purchased two Behringer A800 amplifiers based on the ASR review. It was my first purchase based on ASR.

When I tested them, I found that they would only put out ~250 W @ 4 ohms for a few seconds and then power would drop significantly. I would have liked to have known that they would do this prior to purchasing.

Hm... the review has this:

Using 1% threshold for THD+N, we get more power naturally than my graphs above indicate:

Left hand is short-term burst power, right side is long term.

So it seems that what you asking for was tested, "long term" and 258W. Or are you saying that you suspect "long term" was less than a few seconds? Or what different test you would like to have there?

 

[amirm]

Let's just start reporting each and every product ASR reviews (or any other remotely competent reviewer/tester) that DOES NOT reach its advertised, compliant power output to the FTC.

Go ahead. No one would care one bit.

A parallel story. Someone stole a new $2000 "Kicker" motor from my boat. I immediately see it on sale in Craigslist. I call the police and tell them about it. I ask if they are going to go and get it. Answer: no. He said even if you had a $5,000 car stolen, the DA likely would do nothing about it. He told me I could go and meet the seller and try to get my engine back! And that I should do it in an open space in case they guy tries to do something to me. I said no thanks and filed for insurance.

Given that, you think there are people running around in the government to enforce FTC ratings? How would you prove your case as an individual anyway?

And what if those products did get stopped. How are you/we are better off now? All of a sudden no Fosi or AIYIMA amps. We are happier for it???

 

[amirm]

Adding to my last post, these enforcements work when a competitor professionally tests your products and reports it to the government through their lawyers and resources. In the old days when most companies followed FTC rules, this could happen. Today, they all sell non-compliant products so as heck not going to go and report someone, lest the arrow point back at them....

 

[kyuu]

Some AVR manufacturers do list FTC ratings:

JBL MA7100HP

Onkyo TX-RZ30

I wasn't able to find anything from Denon, Yamaha, or Sony that stated an FTC rating, however. At least with my brief lookover of product listings, spec sheets, and owner's manuals for a limited number of models. So enforcement must be lax as Amir states given that not everyone is bothering.

 

[mdsimon2]

This happened when playing music??? If so, how did you determine that?

FYI power limiting routinely shows up in my measurements: https://www.audiosciencereview.com/.../onkyo-tx-rz50-review-home-theater-avr.30842/

If you read the thread, you see a number of people saying that has not impacted them at all in actual use.

On the bench. I talked to you about this a few years ago -> https://www.audiosciencereview.com/...lifier-with-sinad-over-120.31305/post-1151158. That was when I first learned about the short duration of the ASR power sweeps.

My preference is to test to the FTC standard, but without that I would at least like to see the test conditions specified in the power sweep so folks can know what it is based on.

Michael

 

[mdsimon2]

So it seems that what you asking for was tested, "long term" and 258W. Or are you saying that you suspect "long term" was less than a few seconds? Or what different test you would like to have there?

Duration of “long term” is unspecified in that review. I saw power throttling after 5-10 seconds at full power so I assume it was shorter than that.

Michael

 

[amirm]

Duration of “long term” is unspecified in that review. I saw power throttling after 5-10 seconds at full power so I assume it was shorter than that.

The duration is variable. The analyzer will hunt for the stated 1% THD by varying the input level. It goes too high, then too low and iterates. In that regards, it pushes the amplifier well into clipping. With some amps, it arrives at the final results in 2 to 4 seconds, others take longer. Inefficient amplifiers are quite hot at the end of my testing as a result. Note also the sweep vs frequency. That test lasts minutes with the amp going into clipping multiple times.

 

[amirm]

Went to look for something else and landed on this article from Audioholics point out why they disagree with the new ruling: https://www.audioholics.com/audio-a...he new FTC Rule does,power must NOT exceed 1%.

 

[IvoDiy]

Imagine if you have two amps side by side, both 100W max. One can sustain 20W continuous, other full 100W. Most of the time you can't play as loud as you want, wife complains, kids are asleep, amps sound identical to you. One day, you are finally home alone. You decide to really crank up the volume. First amp shuts down after a few seconds, other one start clipping heavily. First one costs 300usd, other one 1000usd. Which one do you keep?

 

[amirm]

Imagine if you have two amps side by side, both 100W max. One can sustain 20W continuous, other full 100W. Most of the time you can't play as loud as you want, wife complains, kids are asleep, amps sound identical to you. One day, you are finally home alone. You decide to really crank up the volume. First amp shuts down after a few seconds, other one start clipping heavily. First one costs 300usd, other one 1000usd. Which one do you keep?

Continuous on test tones is not the same as continuous with music. Test tones have lower cress factor than music so stress the amplifier a lot more. I would say the $300 can easily produce the 100 watt you want with music or else, it will fail in my tests. Or spend $1000 on a much more powerful amplifier that can only sustain 100 watts for few seconds on test tones. Both would be better choices.

 

[kyuu]

Imagine if you have two amps side by side, both 100W max. One can sustain 20W continuous, other full 100W. Most of the time you can't play as loud as you want, wife complains, kids are asleep, amps sound identical to you. One day, you are finally home alone. You decide to really crank up the volume. First amp shuts down after a few seconds, other one start clipping heavily. First one costs 300usd, other one 1000usd. Which one do you keep?

Neither? False dichotomy anyways.

I'm not convinced of the view that we need all amplifiers to be able to play full-bandwidth sweeps for 5 minutes straight. As Gene points out in the above linked Audioholics article, that's simply not representative of actual loads on audio amplifiers. I like his suggestion:

I would like to see a power rating use a simultaneous broad-band stimulus that has equal power per octave (in practice this means pink noise or multi-tone, but not a sweep). This is representative of real-world use, which I believe is most likely the intention of the FTC by specifying a 20Hz-20KHz bandwidth, but unfortunately, they miss the mark by use of a linear amplitude sweep.

If Amir is going to do anything on this front, I think following this idea and using pink noise or a multi-tone test rather than a sweep would be more meaningful rather than simply blindly following the FTC standard.

 

[restorer-john]

Adding to my last post, these enforcements work when a competitor professionally tests your products and reports it to the government through their lawyers and resources. In the old days when most companies followed FTC rules, this could happen. Today, they all sell non-compliant products so as heck not going to go and report someone, lest the arrow point back at them....

Anyone can make reports to the FTC. You should know that. Even people in other countries can submit reports.

They track trends and initiate action where there is a pattern or scams, deception, bad business practices, false advertising, etc.

You can't be testing achievable power output in an inconsistent manner going forward. It diminishes the valuable work you do. As of right now, all the power output tests you have done to date are meaningless as not one of them has a specified duration. You've been told about this for years and years.

Continuing to double down, deflect and spread FUD doesn't work either.

 

[amirm]

Anyone can make reports to the FTC. You should know that. Even people in other countries can submit reports.

Which will immediately go to the dust bin as you all call it. No way, no how they can take these reports seriously or even bother to read them.

 

[amirm]

They track trends and initiate action where there is a pattern or scams, deception, bad business practices, false advertising, etc.

Bots and false reports will overwhelm such systems, resulting in nothing meaningful. We saw this in FCC's net neutrality comments.

As I said, the only way such things are taken serious if at all, is if you have an attorney with personal connection in the department. And solid documentation from a trusted lab/authority for them to even bother to do anything.

This is on top of hardly anyone knowing what these things mean and what to complain about.