Amplifier distortions - what, and how much are audible

[sterling shoote]

I was able to find the SM and OM of the TA-N55ES and it seemed like an excellent amp for its time. You simply pushed it too hard trying to get the best of a big passive subwoofer!! Every time you pushed it pass the 500 W (8 ohms) mark it's only to clip, no doubt about that.. The amp is really only rated 300 W into an 8 ohm load bridged to mono.

The 600 W rating could only be reached (or exceed, for short durations) without clipping if the impedance of the subwoofer happened to be at 4 ohms at that moment. It would be great if you have the impedance/phase angle curve of that JBL B380.

Yeah, I liked the 55 ES amps. As I recall, I had 5 of them and two 80ES amps. Now I have just one 80ES, still powering my sub, and a 5 ch. 9000ES powering my mains, center, and surrounds. At any rate, I am managing the sub for a 5.1 system, as well as two 2.1 systems. For awhile it was a juggling act; but, I think I've finally got a handle on it. The 80ES will be put back into service powering my mains soon and I will be getting a Crown amp to power my sub , as I go from a 5.1 to a 7.1 configuration.

 

[PENG]

Yeah, I liked the 55 ES amps. As I recall, I had 5 of them and two 80ES amps. Now I have just one 80ES, still powering my sub, and a 5 ch. 9000ES powering my mains, center, and surrounds. At any rate, I am managing the sub for a 5.1 system, as well as two 2.1 systems. For awhile it was a juggling act; but, I think I've finally got a handle on it. The 80ES will be put back into service powering my mains soon and I will be getting a Crown amp to power my sub , as I go from a 5.1 to a 7.1 configuration.

For subs, the Crown amps are great. Just thought the very fine Sony power amps can be used for the most demanding speakers if "sound quality" related specs on paper are important.

Take a look:

THD:
0.008% 10 W 4 ohms, 0.004% 8 ohms
0.01% from 20-20,000 Hz from 250 mW to rated output (150 W minimum), both channels driven into 4 ohms
0.05%, 110 W minimum from 250 W to rated output.

IMD:
0.008% at rated output, 4 ohms
0.004% at rated output, 8 ohms

Slew rate:
120 V/usec

These amps were clearly designed to perform a little better with 4 ohm loads. Fantastic slew rate spec whether that makes a difference or not.

 

[PaulBe]

How Loud is the Distortion and Noise from Your Amplifier?

 

[lovinthehd]

How Loud is the Distortion and Noise from Your Amplifier?

What's with the silly capitalization of letters? What's a summary of the video? Or do you not really understand this like so many other things?

 

[PaulBe]

What's with the silly capitalization of letters? What's a summary of the video? Or do you not really understand this like so many other things?

The capitalization is just the copied and pasted title. What is so silly about this? Isn't this thread the "Amplifier distortions - what, and how much are audible" thread? Summary: 'Amplifier distortions - what, and how much are audible', is what Gene and John are talking about. Do you not understand this from the title itself? This is a new video from 4 days ago. Did I add this video interview to the wrong thread?

 

[TankTop5]

What about dynamic range? Obviously it’s irrelevant for most media sources beyond maybe 16 bits

 

[PENG]

What about dynamic range? Obviously it’s irrelevant for most media sources beyond maybe 16 bits

That's practically irrelevant too if your amp has excellent SNR, or as described in this video, very quiet amplifier. Yes 16 bits (such as the CD spec) should be transparent enough for all intense and purposes.

 

[PENG]

John Siau's video, and I watched quite a few, are typically very good for people with basic EE principles related to this hobby but they also could mislead (of course unintentionally) a lot of people if they don't watch the whole thing, preferably at least twice.

As @lovinthehd alluded to..., one has to understand........ For example, one of the take aways for me is that people who might focus on power amps, could almost do better by focussing on the room and speakers more, based on audible sound quality benefits. In terms of objective measurements, in absolute term, class D amps such as Hypex, Purifi, and some ICE based amps such as Marantz Amp 10, 20, and other well measured ones, along with Benchmark's class AB amp, namely the AHB2 are going to be among the top picks that mostly have noise/distortions below the audible threshold when used at well below their rated limits, but not something like the Parasound Halo models regardless of the fact that even Gene and John may not likely hear a difference in a DBT AB comparison between the worst and best power amps mentioned in this video.

Also for example, the high level of noise/distortions for the worst amp at 100 W output level would not likely be of concerns for most people if we keep in mind that for speakers with sensitivity above 85 dB, at say 12 ft, will produce 79 dB SPL with just 1 W, that's not that great for people who listen to reference level for sure, but in that scenario, "masking" will save the day anyway, rendering such a concern practically unnecessary, no wonder I spent so much time in room correction/eq and always keep an eye or known media contents that has excellent recording/mastering quality.

 

[PENG]

How Loud is the Distortion and Noise from Your Amplifier?

That's an excellent video to add to the links posted on this thread, totally relevant, thank you very much. I wish I could add it to the first page.

I have to agree with HD though, that people (surely not you and him) might not understand enough to interpret the whole contents/messages they might try to convey, without a more clearly worded conclusions (even if certain points made might be necessarily inconclusive).

 

[Speedskater]

What's with the silly capitalization of letters? What's a summary of the video? Or do you not really understand this like so many other things?

From AI:
In title case, you typically capitalize the first and last words, and all other major words in a title. This includes nouns, pronouns, verbs, adjectives, and adverbs. Minor words like articles (a, an, the), prepositions (in, on, at), and conjunctions (and, but, or) are usually lowercase unless they are the first or last word of the title, or if they follow a colon.

 

[PaulBe]

That's an excellent video to add to the links posted on this thread, totally relevant, thank you very much. I wish I could add it to the first page.

I have to agree with HD though, that people (surely not you and him) might not understand enough to interpret the whole contents/messages they might try to convey, without a more clearly worded conclusions (even if certain points made might be necessarily inconclusive).

Answering both of your latest posts:

John Siau offers his take on priority focus starting at about 12:20 in the video. His order of importance is 1. Room, 2. Speakers, 3. Amplifiers…

I think John is trying to speak to people who are not EE’s. Example – trying to relate distortion to the sound level of a home utility appliance. Perhaps the video needs two views. I do think he is honestly trying share difficult concepts with an audience susceptible to audiophoolery, while also trying to sell his products. BTW – I know EE’s who succumb to audiophoolery – audiophoolery like using majik power cables to their audio components. The industry has been very good at snow jobs.

Residual noise and distortion will be differently perceived with differences in system sensitivity. And, not all amps have equally low distortion up to clipping. Masking may save the day for some systems and listeners. Masking won't save anyone with a higher sensitivity system. Mine is 95dB at 1 meter and 89dB at MLP, with 2.83V to the DSP crossover inputs - about 1W to the 8ohm woofers. We could pick nits here, but my example is functional for the thread discussion.

Gain matching is important, but little attention is paid to gain matching outside of pro applications. John’s Benchmark AHB2 amp offers 3 different sensitivity/gain settings. Benchmark’s preamp offers switchable (with a jumper) gain. My DSP crossovers offer several separately adjustable input and output sensitivity settings. A lot of so-called differences in sound would be minimized with better system gain matching. The Benchmark products offer both gain matching, and SINAD’s well below accepted audibility thresholds on the residual side and the full use range side.

Disclosure - I use all of Benchmark's current components.

 

[AcuDefTechGuy]

Here's my take-away: If you use a washing machine in the forest and there is no one around to hear it, does it still make a sound?

If an amp makes a 35dB snake-hissing noise at 100W producing 100dB of music, can you still hear the 35dB snake-hissing noise in the background?

Well, like anything else, it doesn't matter because you can do whatever you want with your money.

If you want to spend thousands of dollars on amps to get -10dB sound, you can do that.

If you would rather spend that extra money on other things, you can do that.

We all have different priorities.

 

[PENG]

Here's my take-away: If you use a washing machine in the forest and there is no one around to hear it, does it still make a sound?

If an amp makes a 35dB snake-hissing noise at 100W producing 100dB of music, can you still hear the 35dB snake-hissing noise in the background?

Well, like anything else, it doesn't matter because you can do whatever you want with your money.

If you want to spend thousands of dollars on amps to get -10dB sound, you can do that.

If you would rather spend that extra money on other things, you can do that.

We all have different priorities.

Well said, you could have helped Gene and John do a "better" job in terms of summary and conclusions. I assume John was trying hard to make his point, but in doing so, like the louder than washing machine thing, was one example of what I suspected as potentially a reason why some people might be mislead.

He did list some good reasons why people would still go for amps that have specs that put them in the well below threshold of audibility in terms of SINAD, but again, some people would have to watch the whole thing till the end, and have some basic technical knowledge.

I would agree with PaulBe that EE degree is not a prerequisite, but just some basic EE principles and hobby related technical knowledge would help in interpreting things they explained, without ending up misunderstanding some of the concepts.

 

[AcuDefTechGuy]

Another thing that is misleading is the actual noise levels of appliances since there is no measurement STANDARD. So these companies could just say whatever they want within the "ballpark".

Just because a washer is spec at "40dB" doesn't mean it is truly "40dB from 1 meter away". In reality, it could be 80dB from 1 meter away, but 40dB from 4 meters away.

So when an amp is making the hissing sound through the speaker, is it at 1 meter away?

The other issue is the pitch (frequency of the noise). Washers are not making "hissing" noises like speakers/amps. Washers are making really loud annoying noises that could be a lot higher in pitch.

IOW, are we really comparing apples to apples?

 

[Verdinut]

The other issue is the pitch (frequency of the noise). Washers are not making "hissing" noises like speakers/amps. Washers are making really loud annoying noises that could be a lot higher in pitch.

They are making a lot of annoying noises, We are actually missing the low noise of 1970-80's Maytag machines.