hypex power ratings

[davidr3032]

I own a pair of magnepan 3.5's which are being powered by a quad 909. The word online is that these speakers sound much better with higher powered amps than what I'm currently using. I would like to try this out just to see and it looks like the hypex based amps from companies like Nord are the best value for money for high powered amps at the moment. However I'm getting very frustrated trying to work out how powerful these amps actually are.

Most amplifier specs ive seen give the power rating as RMS 20Hz-20kHz
And my amp is rated at 140 watts

The hypex specs are considerably higher but they are not RMS and are with a 1Kz signal rather than with the full frequency spectrum

The problem with this is it makes it hard to compare with other amps that are measured differently. And I have no idea if an nc400 is more powerful than my quad 909. The good thing with a standardised system of measurement is you can easily compare specs and if you want to try a more powerful amp its easy to source one

On looking through various forums its seems that the actual rms power of the nc400 is around 100 to 150 watts. So that would make it around the same wattage as my quad. Anyone know if this is correct? If so i would need to look elsewhere. And does anyone know what the rms power of the nc500 and the nc1200 are?

If I was to buy a more traditional amplifier design that had a RMS power rating of 250 watts or so, would it be more powerful than any of the hypex based amplifiers?

Its frustrating that its difficult to compare amps by their specs. And it seems unfair that hypex give power ratings which give the impression that they are more powerful than they actually are. Or do they?

 

[mdsimon2]

Hypex gives substantially more performance information than most other manufacturers including Quad.

For example as far as I can tell from the manual the Quad 909 has the following power ratings.

140W into 8 ohm (0.05% THD)
250W into 4 ohm (0.05% THD)
100W into 8 ohm (0.01% THD, 20Hz-20 kHz)

OK, how does the THD change with power level? Is it higher at lower power levels? How does it change with frequency? We do not know because they give us limited information.

Compare this to Hypex which gives you plots of THD+N vs power level for 3 frequencies (100Hz, 1 kHz, 6 kHz).

All power levels discussed so far are AVERAGE power which is calculated using RMS voltage, RMS power is an often misused term and has no meaning. I will agree that the Hypex data sheet tables are not the greatest in terms of how they summarize performance but it is all there for you to see in the plots. Also because Hypex sells modules (not completed amps) you have the additional variables of how will the module be heatsinked and what power supply will be used (not an issue with the Hypex MP amps). However, given all this Hypex still gives you tons more information to evaluate performance.

Looking at the NC400 datasheet at I would put the NC400 power ratings as follows.

300 W into 4 ohm (0.05% THD+N)
150 W into 8 ohm (0.05% THD+N) - datasheet does not show power in to 8 ohm but halving power in to 4 ohm should be close

For the NC1200.

500 W into 4 ohm (0.05% THD+N)
290 W into 8 ohm (0.05% THD+N)

So the NC1200 would provide double the power compared to what you currently have and NC400 would be about the same.

Michael

 

[EdW]

I own a pair of magnepan 3.5's which are being powered by a quad 909. The word online is that these speakers sound much better with higher powered amps than what I'm currently using. I would like to try this out just to see and it looks like the hypex based amps from companies like Nord are the best value for money for high powered amps at the moment. However I'm getting very frustrated trying to work out how powerful these amps actually are.

Most amplifier specs ive seen give the power rating as RMS 20Hz-20kHz
And my amp is rated at 140 watts

The hypex specs are considerably higher but they are not RMS and are with a 1Kz signal rather than with the full frequency spectrum

The problem with this is it makes it hard to compare with other amps that are measured differently. And I have no idea if an nc400 is more powerful than my quad 909. The good thing with a standardised system of measurement is you can easily compare specs and if you want to try a more powerful amp its easy to source one

On looking through various forums its seems that the actual rms power of the nc400 is around 100 to 150 watts. So that would make it around the same wattage as my quad. Anyone know if this is correct? If so i would need to look elsewhere. And does anyone know what the rms power of the nc500 and the nc1200 are?

If I was to buy a more traditional amplifier design that had a RMS power rating of 250 watts or so, would it be more powerful than any of the hypex based amplifiers?

Its frustrating that its difficult to compare amps by their specs. And it seems unfair that hypex give power ratings which give the impression that they are more powerful than they actually are. Or do they?

The QUAD amp isn’t bad. I’m not sure that you would notice any significant improvement even with the NC1200 high power amp - it is only a few dB more powerful. Often most improvements can be obtained by speaker placement and listening position optimisation combined with room damping and maybe room equalisation. If more bass is what you desire have you considered subs?

 

[davidr3032]

Thanks Michael. I think its interesting that you started of saying that hypex provide more performance information than most other manufacturers then later on you have to estimate the nc400s power into 8ohm. For me that's pretty crucial information

Yes it looks like my suspicions were correct in that the nc400 isn't a particularly powerful amp. It seems the internet is full of people who are unaware of this. I've read many a forum post where people are considering swapping their various 150 watt or so amps for a hypex nc400 based amp because of its extra power. And all the manufacturers I've seen that use hypex modules just mention the inflated power specs on their websites. There's no mention that they aren't RMS and using a standard measurement method that most other amp makers use. From what I've heard they are great sounding amps. I'm sure they would sell just as well with less misleading specs.

It looks like the nc1200 is the way to go for my needs. Or perhaps the nc500. Do you happen to know it's power- Watts into 8 ohm (0.05% THD+N)? Perhaps it has enough power to do the trick

People say the purifi modules sound better than the hypex ones. But they seem to be less powerful. Or are they just less misleading with their power specifications?

 

[davidr3032]

The QUAD amp isn’t bad. I’m not sure that you would notice any significant improvement even with the NC1200 high power amp - it is only a few dB more powerful. Often most improvements can be obtained by speaker placement and listening position optimisation combined with room damping and maybe room equalisation. If more bass is what you desire have you considered subs?

I bought the quad years ago for some quad electrostatic speakers and it sounded wonderful with them. I'm not enjoying the magnepans as much. So I think it makes sense to try some other amps with them first. Rather than sell them on after just trying them with an amp I already had. Its interesting you think an nc1200 amp wouldn't sound better than the quad 909. There's quite a price difference as well as a few decades between them. As well as the big power difference and all the great hypex user reviews. Have you tried some hypex based amps and were disappointed?

I do use a Rel sub with the Maggies and it works great. So I've no craving for sub bass particularly. What people tend to say is that you need at least 250 watts to make magnepans sing. I've no idea what that means. Bit I can see the logic in them liking more power due to the sheer size of them as well as being 4ohm. It makes sense that possibly some more power would get those big panels moving more easily. But if I don't hear any improvement I will stick to the 909. Or perhaps try some valve amps. As far as room treatment and positioning I've done enough of that to drive myself slightly mad. Plus a better sounding amp is going to sound better even after you get the room and positioning right

One thing I've always wondered is if there's a price point were amps don't really improve that much beyond. I guess I'm going to find that out. There certainly does seem to be a lot of folks online that think their hypex or purifi sounds better than their previous x5 or x10 priced amp

 

[EdW]

An NC500 amp is reviewed by @amirm here
https://www.audiosciencereview.com/...-and-measurements-of-nord-one-nc500-amp.7704/
and a IET400 Amp here
https://www.audiosciencereview.com/...-se-1et400a-dual-mono-stereo-amp-review.9938/
both made by Nord
they both have low levels of distortion with the Purifi being slightly cleaner but less powerful.
I’d concentrate on the power delivery into 3-4 Ohm speakers not 8 Ohm since I suspect your speakers may be significantly below 8 under measurement for much of the spectrum where power matters.

 

[davidr3032]

An NC500 amp is reviewed by @amirm here
https://www.audiosciencereview.com/...-and-measurements-of-nord-one-nc500-amp.7704/
and a IET400 Amp here
https://www.audiosciencereview.com/...-se-1et400a-dual-mono-stereo-amp-review.9938/
both made by Nord
they both have low levels of distortion with the Purifi being slightly cleaner but less powerful.
I’d concentrate on the power delivery into 3-4 Ohm speakers not 8 Ohm since I suspect your speakers may be significantly below 8 under measurement for much of the spectrum where power matters.

Yes I have read the review of the nc500 already. And I was still confused as to what its power rating was. The only reason I mention 8ohm is thats the standard way hifi amps power is measured. So if an amp says its 200 watts or whatever, that's what it means. It means 200w rms into 8hm 20Hz to 20kHz. It doesn't mean its 200 watts with the measurement methods changed. Like using 1kz rather than the full frequency spectrum etc. If manufacturers start messing around with specs like this then no one will know where they are. You've got an amp and you want to try a more powerful one and you have to go through data sheets and graphs then have to ask people on a forum to try to work out if an amp is more powerful than the one you already have. And no one is quite sure anyway. Its a bit of a pain. That's why they should have standardised measurement methods. You can include all the graphs and extra info if you like as well. But use standardised methods for the basic amp info.

Of course I should be concentrating on how an amp performs into 4ohms as well as below that. That's the most important specs for my speakers. I'm just annoyed at hypex and companies like Nord that give misleading specs. I'm sure most people who see 200w beside an amp on a website assume its more powerful than an amp on another website that says 140w beside it. Turns out that's not always the case

I'm guessing the nc500 is around 250 watts using standard measurement methods. But I'm just guessing. So that sounds like it might be the way to go to drive the Maggies nicely

 

[Matias]

Magnepans are usually around 4 ohms impedance reasonably flat. So if I were you I would compare amp power in that impedance, as it relates better to your use.

 

[davidr3032]

OK I've just read through the data sheet for the nc500. Its states continuous output power as 100 watts. So now I'm more confused. The main power ratings stated are for peak power at 1% thd. Does this mean an nc500 amp would be really just be a 100 watt amp?

 

[mdsimon2]

OK I've just read through the data sheet for the nc500. Its states continuous output power as 100 watts. So now I'm more confused. The main power ratings stated are for peak power at 1% thd. Does this mean an nc500 amp would be really just be a 100 watt amp?

Probably best to move on, doesn't sound like Hypex is a good fit for you.

Michael

 

[AdamG]

Mangepan MG3.5/R specs:

Sensitivity 86dB
Bass——-4 Ohms
Mid/Tweeter——3.5 Ohms

Recommend power: 100 Watts RMS (8 Ohm rated
Maximum power 200 Watts RMS (8 Ohm rated)

I don’t know why they recommend power spec using 8 Ohm load when these speakers are clearly 4 Ohm and 3.5 Ohms? Makes it convoluted. But, if using the standard expectations that good Amps will double Watts at half Ohm loads you could surmise they are recommending 4 Ohm Amp @ 200 Watts with Maximum power handling of 400 Watts @ 4 Ohm output. Therefore you should focus on the 4 Ohm rated power specs for that Amp.

This is making the assumption that the above doubling is accepted. I would contact Mangepan CS and confirm with them.

 

[EdW]

Before spending any money I would try to get a loan of a more powerful amplifier to see if it makes any difference. (perhaps express an interest in purchasing a new amp at a local dealer )
I too noticed that some websites are saying that your speakers need a lot of drive power. I haven’t seen the impedance curve for your speaker but I suspect that it has an impedance of ~3 Ohms over much of its range. Speaker sensitivity is rated with 2.83V rms and with a 3 ohm impedance that’s 2.66X more power than a true 8 Ohm speaker. It is possible that reviewers had to go to more powerful amps to get the current delivery into a low impedance insensitive speaker.
I’m surprised the data sheet shows the nc500 as only 100W - @amirm measurements clearly show more

 

[Matias]

OK I've just read through the data sheet for the nc500. Its states continuous output power as 100 watts. So now I'm more confused. The main power ratings stated are for peak power at 1% thd. Does this mean an nc500 amp would be really just be a 100 watt amp?

This is like the No. 1 FAQ for class D amplifiers, discussed at length here over countless topics.

These are continuous power rating of full scale sine waves during several minutes continuously. In this extreme situation the modules overheat and lower their power output as a protection. One can add heatsinks or even fans to prevent this, but frankly, this is just a hypothetical test situation and no real world music is going to push this much for so long. Real world music one can consider the normal power rating.

 

[AdamG]

Update to above post about Maggie’s view of power amps and ratings. The below quote is copy pasted from their web site FAQ section:

“Everyone understands they need plenty of power, but the role of power supply is not understood. There is one important concept you need to understand when shopping for an amplifier or receiver: and it is somewhat like understanding "good" and "bad" cholesterol. The ratio is very important. An Gold Standard for an amplifier would be to double the power at 4 ohms. This concept is important even if you are buying an 8 ohm speaker. If the amplifier is rated at 80 watts at 8 ohms, it should (ideally) produce 160 watts at 4 ohms (or close to it). None of the receivers will do that. However, this is the benchmark of a good amplifier design. A 10 watt amplifier that produces 20 watts at 4 ohms "speaks volumes" about the PHILOSOPHY of the designer. (But, of course, it does not tell you if a 10 watt amplifier is enough for your room.) In the final analysis, buy an amplifier that comes as close to doubling the power at 4 ohms as your budget will allow.”

https://www.magnepan.com/faq#power

The above guidance from Maggie seems to confirm my above assumption about doubling of Watts when halving Ohms. So you should be shopping for Amps rated @ 4 Ohms at between 200 Watts to 400 Watts.

 

[davidr3032]

Before spending any money I would try to get a loan of a more powerful amplifier to see if it makes any difference. (perhaps express an interest in purchasing a new amp at a local dealer )
I too noticed that some websites are saying that your speakers need a lot of drive power. I haven’t seen the impedance curve for your speaker but I suspect that it has an impedance of ~3 Ohms over much of its range. Speaker sensitivity is rated with 2.83V rms and with a 3 ohm impedance that’s 2.66X more power than a true 8 Ohm speaker. It is possible that reviewers had to go to more powerful amps to get the current delivery into a low impedance insensitive speaker.
I’m surprised the data sheet shows the nc500 as only 100W - @amirm measurements clearly show more

Yes that surprised me too. I thought it about 270 watts rms with amirms measurements

 

[davidr3032]

This is like the No. 1 FAQ for class D amplifiers, discussed at length here over countless topics.

These are continuous power rating of full scale sine waves during several minutes continuously. In this extreme situation the modules overheat and lower their power output as a protection. One can add heatsinks or even fans to prevent this, but frankly, this is just a hypothetical test situation and no real world music is going to push this much for so long. Real world music one can consider the normal power rating.

OK I see. So class d amps don't perform well in continuous output power tests but that doesn't necessarily mean they aren't powerful? That explains a lot. I guess that makes it hard to compare their specs with class a / ab amps. Can you direct me to a thread where this has been discussed and explained?

 

[Willem]

The Quad 909 delivers 140 watt ch rms into 8 Ohm and 225 watts rms into 4 Ohm, which is a pretty decent score in my book. The manual should give a graph of output for a range of impedance loads.
I use a virtually identical (refurbished) Quad 606-2 driving Quad 2805s (plus sub). I think the 606-2 (and by implication the 909) is an excellent amplifier without any sonic signature. It has been impossible to identify far lesser amplifiers in double blind tests. If you think you may not have enough power you could, if you have not already done so, use a high pass filter on the main amplifier and speakers to take some of the heavy lifting away from the 909 and the Maggies and make your sub do a bit more of that hard work.
Since much of the power is needed for the lowest frequencies, relieving the main amp and speakers of that job really works. So you may even consider adding a second active subwoofer for more bass power, and of course also a smoother in-room response. Adding some kind of dsp room eq will also give a much tighter and realistic bass - I have been very pleased with a simple Antimode 8033 dsp unit for the sub(s).

 

[davidr3032]

Update to above post about Maggie’s view of power amps and ratings. The below quote is copy pasted from their web site FAQ section:

“Everyone understands they need plenty of power, but the role of power supply is not understood. There is one important concept you need to understand when shopping for an amplifier or receiver: and it is somewhat like understanding "good" and "bad" cholesterol. The ratio is very important. An Gold Standard for an amplifier would be to double the power at 4 ohms. This concept is important even if you are buying an 8 ohm speaker. If the amplifier is rated at 80 watts at 8 ohms, it should (ideally) produce 160 watts at 4 ohms (or close to it). None of the receivers will do that. However, this is the benchmark of a good amplifier design. A 10 watt amplifier that produces 20 watts at 4 ohms "speaks volumes" about the PHILOSOPHY of the designer. (But, of course, it does not tell you if a 10 watt amplifier is enough for your room.) In the final analysis, buy an amplifier that comes as close to doubling the power at 4 ohms as your budget will allow.”

https://www.magnepan.com/faq#power

The above guidance from Maggie seems to confirm my above assumption about doubling of Watts when halving Ohms. So you should be shopping for Amps rated @ 4 Ohms at between 200 Watts to 400 Watts.

Yes I've read this before and thats one of the things that drew me initially to the hypex nc400. It looked like the perfect specs for my speakers. But that seems to be not the case upon many hours of investigation. People often say krell amps work great for maggies for this very reason. They double all the way down to 1ohm

 

[Matias]

OK I see. So class d amps don't perform well in continuous output power tests but that doesn't necessarily mean they aren't powerful? That explains a lot. I guess that makes it hard to compare their specs with class a / ab amps. Can you direct me to a thread where this has been discussed and explained?

https://www.audiosciencereview.com/...ments-of-hypex-nc400-diy-amp.5907/post-313562

https://www.audiosciencereview.com/forum/index.php?threads/on-class-d-amplifiers-measurements.9940/

 

[AdamG]

Yes I've read this before and thats one of the things that drew me initially to the hypex nc400. It looked like the perfect specs for my speakers. But that seems to be not the case upon many hours of investigation. People often say krell amps work great for maggies for this very reason. They double all the way down to 1ohm

‘Take a look at Buckeye Amps. I ordered a 6ch 502 series to drive my ML Electrostatic panels. I think they are similar in regards to being 4 Ohm loads. More damage is done to speakers by driving them with underpowered amp then overpowered.