March Audio P701 Mono Block Power Amp

[March Audio]

But the 400/700/1200W of the NC1200 seems to be very amazing. In fact, they are at extremely high distortion output power. If it becomes 0.01% distortion output power, it may only be half of the original. . 200/500/700W???

The manufacturer clearly states the power handling capability of the speakers. They simply can't handle what the nc2k can output.

Recommended amplifier power: 80 – 600 [W/Channel]
Suitable for amplifier rated between: 4-8 Ω
Rated power (Continuous): 400 [W]
Rated power (Dynamic): 600 [W]

 

[AnLaoJin]

The manufacturer clearly states the power handling capability of the speakers. They simply can't handle what the nc2k can output.

Recommended amplifier power: 80 – 600 [W/Channel]
Suitable for amplifier rated between: 4-8 Ω
Rated power (Continuous): 400 [W]
Rated power (Dynamic): 600 [W]

The key to the problem is that the nominal power of the HYPEX Class D amplifier is 1% THD and the distortion is high. This power distortion is too large and has no reference significance at all. In fact, the high distortion power of my speaker NC1200 is not suitable for me at all, and NC2K seems to have a power greater than 2000W, in fact, the low distortion power still needs to be halved, which is just right for my speaker.

 

[March Audio]

But the 400/700/1200W of the NC1200 seems to be very amazing. In fact, they are at extremely high distortion output power. If it becomes 0.01% distortion output power, it may only be half of the original. . 200/500/700W???

They are not extremely high distortion. It is normal to rate amplifier power output at 1%. Most manufacturers rate power output this way.

Here is the distortion plot for the nc1200 at 4 ohm load.

As you can see they can output about 580 watts at 0.01% distortion. So distortion stays very low until it nears clipping.

 

[DonH56]

But the 400/700/1200W of the NC1200 seems to be very amazing. In fact, they are at extremely high distortion output power. If it becomes 0.01% distortion output power, it may only be half of the original. . 200/500/700W???

Your speakers are probably between 0.1% and 1.0% with a few watts of power. I would bet they are pushing 10's of % by the time you get to several hundred watts. Speakers far, far dominate the distortion of your overall system. Do not worry about the amplifier or buying 2x to 4x the power the speakers will take. Look at the curves Alan (@March Audio ) provided and notice how the distortion is very, very low right up to the clipping point. If you consistently use half or quarter the power you will never notice any reduction in distortion but might notice the higher noise since greater power output from the same maximum input voltage means more gain through the amplifier, increasing noise.

As an engineer I am always seeking the optimum design for the application. Bigger is not always better. To use a gross analogy, since I have actually driven one (though my CDL is long expired), you might want a small pickup truck to pick things up from the hardware store instead of using a small car, but buying a diesel semi-trailer truck is likely overkill...

 

[March Audio]

The key to the problem is that the nominal power of the HYPEX Class D amplifier is 1% THD and the distortion is high. This power distortion is too large and has no reference significance at all. In fact, the high distortion power of my speaker NC1200 is not suitable for me at all, and NC2K seems to have a power greater than 2000W, in fact, the low distortion power still needs to be halved, which is just right for my speaker.

With respect the nc1200 is exactly the right amp to take full advantage of your speakers capabilities. The speakers can only handle peaks of 600 watts and RMS of 400 watts. This falls exactly within the very low distortion range of the nc1200.

Within the power handling capabilities of the speakers the nc2k is no better than the nc1200

As Don rightly mentions above your speakers near their max power input will have distortion measured in percent, maybe 5 to 10%

He also makes a good point about the gain. The nc2k graphs show the module performance. It has a 20 dB gain. It still would require the addition of an input buffer to increase the gain by around 10dB to allow it to reach full output power and work with typical DACs of 2 volt output. This will probably make the sinad graphs show worse performance than the nc1200 within the power range of your speakers.

 

[maverickronin]

The manufacturer clearly states the power handling capability of the speakers. They simply can't handle what the nc2k can output.

Recommended amplifier power: 80 – 600 [W/Channel]
Suitable for amplifier rated between: 4-8 Ω
Rated power (Continuous): 400 [W]
Rated power (Dynamic): 600 [W]

ELAC Concentro，4 subwoofers are connected in parallel, and the impedance is very low. I use a 100W power amplifier to push it, and the sound pressure is very small, and the power amplifier is protected.

(Emphasis mine)

He said he has subwoofers connected in parallel with his speakers (which seems kinda odd but whatever...) so not all of that power is going just to the Concerto.

 

[March Audio]

(Emphasis mine)

He said he has subwoofers connected in parallel with his speakers (which seems kinda odd but whatever...) so not all of that power is going just to the Concerto.

Passive subs? If this is the case it's an inappropriate set up, the impedance would be too low for any amp to sensibly drive.

 

[Matias]

I think he meant the woofers on his speakers..

 

[March Audio]

I think he meant the woofers on his speakers..

That was my interpretation.

 

[maverickronin]

Passive subs?

That's how I read it at least...

If this is the case it's an inappropriate set up, the impedance would be too low for any amp to sensibly drive.

Don't disagree there.

I think he meant the woofers on his speakers..

That reading makes even less sense to me, but I guess we'll wait for @AnLaoJin to clarify.

 

[Soniclife]

That's how I read it at least...



Don't disagree there.



That reading makes even less sense to me, but I guess we'll wait for @AnLaoJin to clarify.

https://www.elac.com/series/concentro/concentro/
Standard passive speaker it looks like.

 

[AnLaoJin]

I think he meant the woofers on his speakers..

Yes, the 4 subwoofers are in parallel + series, and the impedance is very low

 

[March Audio]

Yes, the 4 subwoofers are in parallel + series, and the impedance is very low

What is the impedance of the subs?

Can you clarify the wiring set up as I am a little confused?

Is it 2 subs on each channel left and right?

Are the 2 subs wired in series and then this wired in parallel to the main speaker?

 

[AnLaoJin]

What is the impedance of the subs?

Can you clarify the wiring set up as I am a little confused?

Is it 2 subs on each channel left and right?

Are the 2 subs wired in series and then this wired in parallel to the main speaker?

Left and right channels, each channel has 1 super treble, 1 midrange, 1 bass, and 4 super bass. . There are two pairs of binding posts, the DC impedance of the binding posts for 1X bass (220mm) and 4X subwoofer (250mm) is 3.2Ω

 

[AnLaoJin]

Subwoofer, impedance is too low. The stroke is too long. . So I need a super high damping coefficient + high current power amplifier

 

[AnLaoJin]

My avatar is the perspective view of my speakers

 

[March Audio]

Left and right channels, each channel has 1 super treble, 1 midrange, 1 bass, and 4 super bass. . There are two pairs of binding posts, the DC impedance of the binding posts for 1X bass (220mm) and 4X subwoofer (250mm) is 3.2Ω

So if I understand correctly you have 4 x 3.5 ohm impedance (the AC impedance will be a bit higher than the dc resistance) subs in parallell. It's as you stated originally but I didn't believe it could be correct.

The subs on their own present an impedance of 0.8 ohm. Add the main speaker and it drops again to about 0.7 ohms.

I'm afraid this is a completely inappropriate configuration. It's virtually a short circuit. It is of no surprise that your current amp was quiet and went into protection. So will most others.

You do not require higher power, you require higher impedance. Alternatively powered subs.

 

[AudioJester]

Mr March, I think he is confused. The 4x "subwoofers" are part of the speaker design and not seperate passive subs?

 

[March Audio]

@AnLaoJin just to expand upon this with a bit more explanation. It's a bit simplistic but makes the point

Your main speakers can handle 600 watts peak. They are a 4 ohm load. To drive this the amp needs to output a 49 volt signal and deliver 12.25 amps of current.
49volts / 4ohms = 12.25 amps
12.25 amps x 49 volts = 600watts

If you add the 4 subs the impedance drops to 0.7 ohms. The main speakers still require 49 volts to reach 600 watts.

However if you apply 49 volts to the subs they will demand enormous amounts of current.
49 volts / 0.8 ohms = 61.25 amps

Add the subs and the mains together and the amp needs to deliver 73.5 amps. This is 3.6 kW.

This is way beyond the capability of even the nc2k which maxes out at 49 amps.

So you need an amp that is capable of delivering 73 amps and 3.6 kW into a 0.7 ohm load. This ignores the issues of load phase angle which will increase the power dissipation requirements of the amp.

I wouldn't go so far as to say impossible, but nothing (hifi amp) I'm aware can do this.

 

[March Audio]

Mr March, I think he is confused. The 4x "subwoofers" are part of the speaker design and not seperate passive subs?

Well that's what I originally thought. I dismissed the additional 4 external passive sub concept as it is completely unworkable. Can't offer any further comments until we have a clear understanding of what he is using.

Perhaps some pictures @AnLaoJin ?