• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

hypex power ratings

Status
Not open for further replies.

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,584
Likes
38,283
Location
Gold Coast, Queensland, Australia
I hope I am not beating a dead horse but I noticed that NAD also gives the FTC rating on some of their Class D amps. For example, from the manual of the M22 (nCore):

Continuous output power into 8 ohms and 4 ohms (Stereo mode) 300 W (20 Hz-20 kHz at 0.1% THD, both channels driven)
Continuous output power into 8 ohms (Bridge mode) 900 W (20 Hz – 20 kHz at 0.1% THD)
THD+N (20 Hz – 20 kHz, CCIF IMD, SMPTE IMD, DIM 100) <0.005 % (250 mW to 290W, 8 ohms and 4 ohms) Note: Measured with Audio Precision AUX-0025 or Prism dS-LPF passive low pass filter


So maybe the hypex amps can deliver a lot of power at 20KHz?

The NAD M-22 uses two OEM NC-400 modules which are de-rated from Hypex's numbers to be FTC compliant specifications. It also uses a considerably more advanced SMPS than the standalone Hypex PSUs.

When Stereophile tested the NAD M-22, they only tested it at 100W (consider it is rated at 250W/ch) and this is the result (THD vs Freq).

Graph courtesy Stereophile, John Atkinson.
https://www.stereophile.com/content/nad-masters-series-m22-power-amplifier
1611097823750.png


We are seeing skyrocketing THD at high frequencies, and at only 40% of its rated power. That is with the AUX-0025 filter up front of the AP, so he is directly looking at harmonics (and other non-linearities) hopefully above 20Khz but below 200kHz.

The IMD plots at 200W/4R show plenty of in band products and again, this is well below its rated power.

1611098825727.png
 
Last edited:

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,584
Likes
38,283
Location
Gold Coast, Queensland, Australia
Why mention "special-needs tests" and 200kHz Class AB amp bandwidth if bandwidth is not the point?

Let me put it this way.

Do you think a full power bandwidth of only 5kHz for power output compliance purposes is acceptable?
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,804
Location
São Paulo, Brazil
Harmonics after the main 6.67 kHz tone fall out of the hearing range. This was a conscious engineering decision to minimize distortion only in band.
 

pjug

Major Contributor
Forum Donor
Joined
Feb 2, 2019
Messages
1,775
Likes
1,561
The NAD M-22 uses two OEM NC-400 modules which are de-rated from Hypex's numbers to be FTC compliant specifications. It also uses a considerably more advanced SMPS than the standalone Hypex PSUs.
Thanks for that, and in general I am not wanting to come down for or against meeting FTC, that's up to the consumer as others have said. But the part I quoted above does not sound right. I think the M22 uses their own tweaking of the Hypex design not OEM NC-400. See here:
https://darko.audio/2014/09/nad-masters-series-m22-hypex-ncore-for-the-rest-of-us/

It doesn't invalidate your point since they could still be derating the design as you say. I thought they might be using a more robust output filter compared to the standard hypex. So the output filter limitation (maybe) can be overcome.
 

March Audio

Master Contributor
Audio Company
Joined
Mar 1, 2016
Messages
6,378
Likes
9,317
Location
Albany Western Australia
Harmonics after the main 6.67 kHz tone fall out of the hearing range. This was a conscious engineering decision to minimize distortion only in band.

Indeed, and they still perform just fine distortion wise above the audible band (-3dB point Hypex is 50kHz and 60kHz Purifi).

Johns assessment above is wrong. The Hypex designs have excellent IMD performance. he needs to take a look at some A/B amps performance in this area to get a frame of reference. Not to mention of course that any particular implementation of a Hypex module may not take full advantage of its inherent performance.
 
Last edited:

March Audio

Master Contributor
Audio Company
Joined
Mar 1, 2016
Messages
6,378
Likes
9,317
Location
Albany Western Australia
Let me put it this way.

Do you think a full power bandwidth of only 5kHz for power output compliance purposes is acceptable?

I made the mistake of taking you off ignore to see if you have calmed down or accepted any of the clear technical points made. Obviously not. I will reply and put you back on ignore.

Firstly there is no compliance standard. There is just the FTC advertising rule which is applicable to a products advertising literature in the US *ONLY*. It is *not* some kind of world wide agreed technical standard by which all amplifiers should be judged by. This thread covers in detail the technical reasons why it shouldnt be taken as such, and why the testing is technically inept. In fact I would say the FTC test is potentially misleading. You have clearly been misled by it.

In answer to your question:

KEF LS50 Wireless
Frequency response 45 – 47,000 Hz ±3 dB (depending on settings)


Power output
200 W low frequencies,
30 W high frequencies

Maximum SPL106 dB


Crossover is at 2.2kHz

So above 2.2kHz the Active LS50 only has 30 watts of power compared to 200 watts below 2.2kHz

Do you think this and all active speakers are crap as a result?
 
Last edited:

Killingbeans

Major Contributor
Joined
Oct 23, 2018
Messages
4,089
Likes
7,550
Location
Bjerringbro, Denmark.
What drew me to this forum was I wanted to avoid a lot of the audiophile mumbo jumbo you get elsewhere. But instead I've got specification mumbo jumbo :)

And it's no use telling people to go looking though the specs and graphs from hypex instead. As the average consumer shouldn't be expected to understand these anyway. And they aren't the specs specifically for your finished amps

Then there would be no need for further debate. Thats the great thing about science. Accurate specific scentific data removes the need

If you want to be really scientific, you quickly realize that the relations between power, frequency and THD+N aren't neat and linear. When you set the target at 1% THD or something else, it's an attempt at getting a "dumb" number that lets you compare products while ignoring most of the important factors. It doesn't really tell you much about the performance of the product.

IMO, when you get a number for Watts RMS, it's describing a worst-case scenario. As in; if you expected to draw less power than this, but exceeded it anyway, you are probably doing something horribly wrong. It's a precautionary number. Not something that should fit in a formula.
 
Last edited:

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
I know this won't help anything between two protagonists here. Both groups I've plenty of respect for. They seem to come at this from different directions from what I can see.

I've some large Soundlab ESL's. They are a difficult speaker for amplifiers, and very inefficient. I've had several different high power conventional amps on them. I use them currently with some Icepower based amps (which isn't even part of the Hypex and Purifi group of course). That amplifier just takes these speakers and plays them with a calm aplomb as loud as I want it to in a way I've only seen equaled once. That was when I heard a pair of Classe 25's bridged with one on each channel. Bridged those are 1000 wpc into 8 ohm amps.

I don't know the Soundlabs are the worst load, I'd probably say the Apogee Ribbons were more difficult though for different reasons than an ESL. And everyone knew with Apogees you wanted the large Classe amps on them. The IcePower amps have even more issues at higher frequencies. But when playing music whatever power they have is entirely sufficient in a way even big iron AB amps struggle. The Hypex and Purifi amps should be better than the Icepower class D amps, if I get another amp it will be one of those. Also when I took a chance and tried the class D amp on my speakers I knew a couple people with Soundlabs and with Acoustats. I took it over and let them hear it. All just immediately went and got some variation of class D for themselves. It was dead plain obvious the advantage.

All anecdotal and subjective. Sometimes a fit thing even on ASR.
 

tmtomh

Major Contributor
Forum Donor
Joined
Aug 14, 2018
Messages
2,636
Likes
7,497
Let me put it this way.

Do you think a full power bandwidth of only 5kHz for power output compliance purposes is acceptable?

I'll be happy to answer your question as soon as you answer mine.
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,584
Likes
38,283
Location
Gold Coast, Queensland, Australia
I made the mistake of taking you off ignore to see if you have calmed down or accepted any of the clear technical points made. Obviously not. I will reply and put you back on ignore.

There is no compliance standard. There is just the FTC advertising rule which is only applicable to products advertised in the US. It isnt some kind of world wide agreed technical standard by which all amplifiers should be judge by. This thread covers the technical reasons why it shouldnt be taken as such.

You make me laugh, Alan.

Whatever you do, don't try and rewrite/cancel history. Amplifiers have been tested to equivalent FTC regulations the world over, by every HiFi magazine and reviewer for many decades. Don't pretend otherwise. Right across Europe, the UK, Australia, Japan and of course the US (where adherence is compulsory). I have thousands of reviews, electronics magazines, and tests, from the present back many decades.

Here's a wonderful example of a company (current model product) that takes its obligations seriously:

1611103614505.png


1611103658133.png



This thread, like so many before, is another example where you climb up on your Hypex high horse to drive your single minded, self-serving narrative without addressing any specific points at all, and all the while, shouting down dissent with puerile ad-hominem attacks.

It's so disappointing.
 
Status
Not open for further replies.
Top Bottom