More general amplifier questions.

[TankTop5]

I’ve heard some terms and I’m wondering what’s real and if it’s real is it something to worry about with equipment above a big box store quality?

Stereo separation -

Cross talk -

THD - yes I know this is real but it’s typically listed at max RMS. What’s the distortion at a realistic listening volume?

Warm/bright - yes I know this is also a thing but usually in reference to speakers and sometimes speaker wire?

Anything else I’m not thinking of?



NAD lists most of their amps at .03 THD but states it’s almost unmeasurable, is that marketing hype or do they have something cool they’re doing? Why not make a 150 watt amp and rate it at 120 watts then claim a really low THD number and lots of headroom or dynamic power?


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[lovinthehd]

Try this article, it covers several of your questions (together in the case of crosstalk/separation). https://www.audioholics.com/audio-amplifier/basic-amplifier-measurement-techniques

Warm/bright is something some swear they can keep track of over various amps (often compared very informally with differing equipment and speakers in different rooms, so not much to go on). It's not been a particular characteristic in my use of several ss amps; tube amps with their type of distortion seems to be the type of amp that gets this type of description due certain euphonic distortion. A good amp should simply amplify and not color. That speaker wire has sound qualities like warmth would need one of those idiotic cables with electronics in line to purposely alter the signal, which is something I sure wouldn't want wire to do. Now speakers that might be warm or bright makes a lot more sense....

.03% THD isn't all that remarkable but also keep in mind that THD will vary with power. Look at a typical measurement graph as to that relationship (again, in the article). Some do deliberately rate their amps more conservatively than others (sometimes when rating for 4 ohm compared to their 8 ohm spec, they go very conservative on the 8 ohm spec to make the 4 ohm power rating look better), when I've seen NAD claims vs bench testing I've seen really nothing remarkable except their marketing of such.

 

[PENG]

I’ve heard some terms and I’m wondering what’s real and if it’s real is it something to worry about with equipment above a big box store quality?

Stereo separation -

Cross talk -

THD - yes I know this is real but it’s typically listed at max RMS. What’s the distortion at a realistic listening volume?

Warm/bright - yes I know this is also a thing but usually in reference to speakers and sometimes speaker wire?

Anything else I’m not thinking of?



NAD lists most of their amps at .03 THD but states it’s almost unmeasurable, is that marketing hype or do they have something cool they’re doing? Why not make a 150 watt amp and rate it at 120 watts then claim a really low THD number and lots of headroom or dynamic power?


Sent from my iPhone using Tapatalk

Good question, the answer is, it depend.. Anyway, sometimes pictures are better than word so take a look of the graphs below using an example from NAD, Denon, Marantz and Yamaha. Note that the Marantz and Yamaha examples were their top model for that model year whereas the NAD and Denon were their lower mid to mid range model. Where available, I would rely more on bench test results than specs found on manufacturers website.

Now please look closely and carefully, then tell me which one looks the best/worst.

NAD:
https://www.soundandvision.com/content/nad-t758-v3-av-receiver-review-test-bench

Denon:
https://www.soundandvision.com/content/denon-avr-x3400h-av-receiver-review-test-bench

Marantz:
https://www.soundandvision.com/content/marantz-sr7011-av-receiver-review-test-bench

Yamaha:
https://www.soundandvision.com/content/yamaha-aventage-rx-a3060-av-receiver-review-test-bench

 

[AcuDefTechGuy]

Brands like NAD, Anthem, Audio Control, etc. tend to give you less power for your money compared to D/M/O/P and Yamaha.

In this example, the Yamaha gives you the most power at 0.1% and 1.0% THD.

 

[Grandzoltar]

What’s shocking with the Yamaha is at seven Channels driven it drops to 52 watts. It also has the biggest drop with all channels driven.

 

[lovinthehd]

What’s shocking with the Yamaha is at seven Channels driven it drops to 52 watts. It also has the biggest drop with all channels driven.

More due to their protection scheme it seems, they don't seem to have issues with actual content vs "ACD" demands...

 

[AcuDefTechGuy]

What’s shocking with the Yamaha is at seven Channels driven it drops to 52 watts. It also has the biggest drop with all channels driven.

Yet another “All Channels Driven” post.

Here, read the ACD fallacy article by Audioholics.

https://www.audioholics.com/audio-amplifier/the-all-channels-driven-acd-amplifier-test

If you don’t feel like reading, the take-home message is that in the real world, you are not going to see more than 5CH Driven simultaneously, probably not even more than 3Ch (Front 3 Channels) driven simultaneously.

That’s why you don’t read about a bunch of Yamaha AVR blowing up speakers and why you do read about Yamaha being arguably the most reliable brand. And Yamaha AVR, Pre-pro, and amps being arguably the most cool-operating and least-heat-generating brand.

 

[Grandzoltar]

The link you provided is where I got that 52 watt information from. It came directly from a sound and vision bench test. I assumed those are pretty accurate.

 

[Grandzoltar]

Out of those four links the Yamaha was the highest from 2ch and also the lowest all channel . Which I found interesting. That’s all I’m saying. Regardless of real world usage. The measurement was not something I’d expect from the higher watt less thd receiver. You are a Yamaha fan I take it.

 

[lovinthehd]

The link you provided is where I got that 52 watt information from. It came directly from a sound and vision bench test. I assumed those are pretty accurate.

Out of those four links the Yamaha was the highest from 2ch and also the lowest all channel . Which I found interesting. That’s all I’m saying. Regardless of real world usage. The measurement was not something I’d expect from the higher watt less thd receiver. You are a Yamaha fan I take it.

I think you're starting to get it

Real world usage does mean a lot, and, depending on speakers can vary quite a bit....

 

[Verdinut]

What’s shocking with the Yamaha is at seven Channels driven it drops to 52 watts. It also has the biggest drop with all channels driven.

That 52 watts is irrelevant. The possibility that a sound track will require as much power from all channels simultaneously doesn't exist. That will only happen when you use the "All channel stereo" option.
For example, in an action movie with a space ship or other object moving from the front channels to the surround back channels, the bigger power need will switch to the surround back channels with reduced power need in the front.

You have to take into account that the reduced power represents only about 6dB less than the 2 channel power rating.

 

[AcuDefTechGuy]

I found interesting. That’s all I’m saying. Regardless of real world

It’s not about whether someone is a fan of Yamaha or Denon or Anthem, etc.

I hope that all of us are a fan of components that sound great to us, have the features we desire, and are the most reliable and compatible to us. And that may be different for all of us.

Since we don’t live on the test bench and inside an anechoic chamber, the salient point is to take what we see in the lab and extrapolate that to the real world.

It’s about learning that the ACD test is only a test tool on the test bench to guide us.

Once we understand what ACD is, it no longer becomes THAT interesting to us.

Well, maybe it is still interesting to us.

 

[AcuDefTechGuy]

The measurement was not something I’d expect from the higher watt less thd receiver.

As consumers, I think we have the right to question the professinal electrical engineers who designed and built these AVRs, particular the YAMAHA AVRs and amp ($2900 MX-A5200 amp).

Why did these very experienced professional engineers (who graduated from their Engineering colleges, not from the university of Google) make even their flagship amp (MX-A5200) go into protection mode with ACD (~ 50 watts x 7Ch)?

It's like a $3,000 amp for crying out loud!

Why build an 11-Channel Amp if it goes into protection mode when 7CH is driven?

RIGHT?

But at the same time, have we seen reports of these Yamaha AVR and Amps NOT being able to power 7, 9, or 11 speakers hooked up to them? I mean actually not being able to power the speakers, not anecdotal reports of "not having enough power because I have to turn up the volume knob".

I have the Yamaha MX-A5000 amp powering Nine (9) RBH speakers in a room size of 22' W x 26' L x 14' H. Five of the RBH speakers are the SX-T1R, which are 4-ohm speakers. The other four RBH speakers are 8-ohm speakers. I sit 18' away. The volume knob on my Yamaha CX-A5100 is often never more than -30.0. The volume is very loud.

So the question is, do these Yamaha professional electrical engineers know something most of us NON-professional electrical engineers don't know?

Is it because it helps make their components operate at a cooler temperature and improve reliability?

You're right. For many people, it does appear strange or interesting or even alarming to see the power drop with ACD test. But maybe these professional electrical engineers do know something we don't know.

 

[M Code]

IMHO...
The basic answer is real-world design experience..
Yamaha has been designing amplifiers & loudspeakers for many, many years for both consumer, industrial and pro-audio applications. This has provided them a wealth of knowledge, what works and what doesn't...
Their approach early on for HDMI & HDCP where they invested heavily in having their own in-house testing lab for inter-operability delivers positive results. Also by managing their own design, procurement & production processes they have minimized field returns & defectives, all boosting their bottom line....

Just my $0.02...

 

[PENG]

As consumers, I think we have the right to question the professinal electrical engineers who designed and built these AVRs, particular the YAMAHA AVRs and amp ($2900 MX-A5200 amp).

Why did these very experienced professional engineers (who graduated from their Engineering colleges, not from the university of Google) make even their flagship amp (MX-A5200) go into protection mode with ACD (~ 50 watts x 7Ch)?

It's like a $3,000 amp for crying out loud!

Why build an 11-Channel Amp if it goes into protection mode when 7CH is driven?

RIGHT?

But at the same time, have we seen reports of these Yamaha AVR and Amps NOT being able to power 7, 9, or 11 speakers hooked up to them? I mean actually not being able to power the speakers, not anecdotal reports of "not having enough power because I have to turn up the volume knob".

I have the Yamaha MX-A5000 amp powering Nine (9) RBH speakers in a room size of 22' W x 26' L x 14' H. Five of the RBH speakers are the SX-T1R, which are 4-ohm speakers. The other four RBH speakers are 8-ohm speakers. I sit 18' away. The volume knob on my Yamaha CX-A5100 is often never more than -30.0. The volume is very loud.

So the question is, do these Yamaha professional electrical engineers know something most of us NON-professional electrical engineers don't know?

Is it because it helps make their components operate at a cooler temperature and improve reliability?

You're right. For many people, it does appear strange or interesting or even alarming to see the power drop with ACD test. But maybe these professional electrical engineers do know something we don't know.

First of all, it may be just semantics, but there are no requirements for audio amps to be designed by "Professional engineers" in North America and I highly doubt it is required anywhere in the world. I don't doubt that many such engineers do hold degrees in physics, and/or EE, but it is not a requirements so many good designers could have been self taught or are college graduates in EE. So you can ask them your questions, but you can't get them disciplined by their licensing bodies.

Secondly, you have already answered your own questions.

 

[Grandzoltar]

I agree with you Yamaha, Denon, Marantz are the leaders of AVR’s and separates. If I were to go the route of separates Yamaha would be at the top of my list. In my opinion. Each maker has its own team that works on their product and produces a product that best fits the vision of their company. There is no industry standard. Each company does what will and has worked for their company and their tests. It’s not to say Yamaha is absolute. It’s not to say toroidal transformer is right and EI core is wrong as an example. That’s what makes the industry so good is each company brings something to the market that performs to the best of the design teams ability. I’m simply the target buyer of these companies and that’s it. If a third party publishes numbers even though achieved in a “perfect listening” environment they are still numbers and numbers don’t lie.

Enough of that. That’s a really sweet system you have. I’ve been reading about rbh they are pretty cool. A lot of people seem to enjoy them. What do you think about the ceo stepping down. I didn’t look up those exact models but are the the modular ones that sit on top the dual subs. That’s a pretty large room those speakers must fill out the room very well.

 

[AcuDefTechGuy]

That’s a really sweet system you have. I’ve been reading about rbh they are pretty cool. A lot of people seem to enjoy them. What do you think about the ceo stepping down. I didn’t look up those exact models but are the the modular ones that sit on top the dual subs. That’s a pretty large room those speakers must fill out the room very well.

Mr. RBH (Roger B Hassing) has been at it for 43 years and has decided to retire. The new president/owner (Todd A Stewart) seems to also be an audio enthusiast (hopefully like many of us).

Yeah, the RBH Modular Towers-of-Power is definitely my style.

I have five SX-T2/R modular towers (dual 10" woofers) in my HT room and two SVT towers (dual 12" woofers) in my living room. Love them.