How important is doubling down power to 2 ohm or 1ohm on Hi Fi Speakers on high dynamic range music?

[MasterApex]

I experimented with Levinson 333 300W@8ohm , doubling down to 1200W @2ohm , Krell KSA 200s 200W @8ohm that double down to 1600W @ 1ohm vs a few highly rated class D 200W - 400W @8 ohm amplifiers.

On my B&W N801 speaker, the sound quality is comparable below 75dB....do show different "brightness" and "bass punch" which can be subjective in term of preference.

But when playing high dynamic classical music like 1812 overture at peak (not sustained) volume above 94dB, the Class D amplifier sounds compressed relative to Levinson or Krell.

Why is that?

 

[Spkrdctr]

Playing music at 94db is running some very high peaks when the booming starts. So, the signal in the amp may be clipping, or the speakers can't handle that kind of blast or both. With the proper electronic test equipment it is very easy to see what is going on. But the average consumer will not know. So, in the end, everyone just turns the music down a bit till it sounds normal. Sorry for no precise answer. As "It all depends"

 

[ahofer]

I experimented with Levinson 333 300W@8ohm , doubling down to 1200W @2ohm , Krell KSA 200s 200W @8ohm that double down to 1600W @ 1ohm vs a few highly rated class D 200W - 400W @8 ohm amplifiers.

On my B&W N801 speaker, the soun How important is doubling down power to 2 ohm or 1ohm on Hi Fi Speakers on high dynamic range music?d quality is comparable below 75dB....do show different "brightness" and "bass punch" which can be subjective in term of preference.

But when playing high dynamic classical music like 1812 overture at peak volume above 94dB, the Class D amplifier sounds compressed relative to Levinson or Krell.

Why is that?

It could be insufficient power, but it doesn’t necessarily have anything to do specifically with the rated power doubling at half the resistance (that sounds suspiciously like “millercarbon” from Audiogon, who was absolutely dogmatic about that spec, if I remember). What counts is the peak power available vs the demands of the speaker at the time.

These things can be answered with the same measurements that I linked in your prior post. The B&W D3 presents a difficult load in the 80-1000hz range, right where most of your dynamics are being delivered. You might well have insufficient power for high SPLs with your (unspecified) class D amps vs. your (specifically named) high end space heaters. 3 ohms and a steepening phase angle right in the range with all the musical action (and the opposite in the range where it has a measurable emphasis). I would tentatively view this chart as another strike against the B&Ws.

Here’s a speaker that’s much easier to drive, although still 86db sensitivity, so far from the most efficient:

 

[MasterApex]

Thanks...that explains why high-end speakers tend to be a difficult load and needs more powerful amp to showcase its strength.
I read interview with Revel engineer that explained they improve efficiency on the new model F338Be over the Salon 2 but at the expense of less bass quality and among other thing.

 

[ahofer]

Thanks...that explains why high-end speakers tend to be a difficult load and needs more powerful amp to showcase its strength.

Is that really what you took from this discussion? Let me be clearer: being difficult to drive, all else equal, is a vice, not a virtue in a speaker. There is nothing intrinsically “high end” in presenting a difficult load - just the opposite.

 

[MasterApex]

I agree with what you said.
Since all else are not equal between high-end and low-end speakers, I am observing that high end speaker tend to present itself as more difficult load.

So, do we think the sound compression on Class D Amp is because of the load or lack of double down?
Even though these class D amp have the same power or higher power rating at 8 ohm (and is spec to be stable at 2ohm) than the Levinson or Krell?

 

[ahofer]

Since all else are not equal between high-end and low-end speakers, I am observing that high end speaker tend to present itself as more difficult load.

You are implicitly assuming, then, that there is some high end quality that necessitates a difficult load, rather than it simply being a design flaw. Not sure I agree with that.

Or perhaps question-begging: the D3 is high-end, therefore anything that it demands must therefore be necessary for high end.

There are many speakers with superior frequency response and directivity (i.e. very high end, in my book) that do not inhibit their dynamic range with a difficult amplifier load. It does not appear to be a necessary trade-off.

And the best measuring speakers here are active, with compact, often class D, amps built into them, and much of the load difficulty removed by way of an active crossover.

There’s a weird cult thing around hard-to-drive speakers-it reached its...apogee...with the old Apogee Scintilla. It seems to prime subjectivists to believe the speakers must be truly great if they require such beefy hardware.

 

[MakeMineVinyl]

You are implicitly assuming, then, that there is some high end quality that necessitates a difficult load, rather than it simply being a design flaw.

If only the audio world had embraced active crossovers from day one instead of the wasteful, imprecise, and the difficult load presented by passive crossovers, we could have avoided all this demanding speaker load shit.

 

[Katji]

The usual B&W problem.

 

[MasterApex]

I am still puzzled why the sound is more compressed on Class D Amp in mu aforementioned experiment.
The measurement review showed stable down to 2ohm despite no double down.
The speakers impedance never drop below 3 ohm.

So , is doubling down an important criteria for good dynamic sounding amp driving a more complex crossover/speaker?

 

[ahofer]

Again, forget the doubling down or worries about stability at low impedance, that's relevant but not central.The important thing is the total power required on the peaks. An insensitive speaker (esp. in the range where impedance is low and phase angle is material), will pull huge wattage. Consider the peaks reached in this video, with a somewhat less sensitive speaker/easier load than yours (specs below):

With heavy dynamic peaks the amp is putting out 400+ watts. Your perception may well be a bias (and you should blind test to verify), but it also may be that you are demanding wattage above the rated spec for the (unspecified) amps you are using and hearing a real difference. I believe I have heard the same with small class D and AB amps.

https://www.stereophile.com/content/harbeth-m401-loudspeaker-measurements

 

[MasterApex]

Thank You for the link,
That explains certain music does requires a LOT more peak power to get the full dynamic even at moderate volume level.
This is explains the "compressed" sound on the Class D amp I observed.

 

[MusicNBeer]

As stated, a good designer makes a well behaved impedance one of the important tradeoffs. It's far easier to make a crossover with proper filters when the impedance isn't considered. Seems some "high end" designers to exactly this.

 

[Sir Sanders Zingmore]

I experimented with Levinson 333 300W@8ohm , doubling down to 1200W @2ohm , Krell KSA 200s 200W @8ohm that double down to 1600W @ 1ohm vs a few highly rated class D 200W - 400W @8 ohm amplifiers.

perhaps not relevant but take “doubling down” specs with a grain of salt. Manufacturers often understate the 8ohm power to give the appearance of doubling.

Stereophile measures the Levinson at 400w into 8 ohms and 1250w into two ohms.

They have the Krell at 280w into 8 ohms and about 850w into two

 

[ahofer]

perhaps not relevant but take “doubling down” specs with a grain of salt. Manufacturers often understate the 8ohm power to give the appearance of doubling.

Stereophile measures the Levinson at 400w into 8 ohms and 1250w into two ohms.

They have the Krell at 280w into 8 ohms and about 850w into two

Yes, I think this has sort of become a misleading tradition - a long time ago. I have an old Bryston 3B I bought in 1987 that claimed 100/200 at 8/4 ohms, but came with an individual test reading of 135 watts into 8 ohms (4 unstated).

 

[MasterApex]

There are many Levinson model.
For my current Amp, Stereophile measurement says
"Finally, the No.333 outperformed its power specification in a big way. As can be seen from fig.6, it clipped (defined as 1% THD+N) at 400W into 8 ohms (26dBW) with both channels driven and a wall voltage of 117V. This almost doubled to 700Wpc into 4 ohms (25.4dBW) with both channels driven, and almost doubled again at 1250W into 2 ohms (25dBW), one channel driven. Note that the AC line voltage drooped to 114V for these last two measurements, implying that with a "stiff" AC supply (as Madrigal recommends), the No.333 will pump out even more watts.—John Atkinson "
https://www.stereophile.com/content/mark-levinson-no333-power-amplifier-measurements

Anyway, back to the need for "peak" power to be able to reproduce certain music recording at its full dynamic as the video stated.
How does one know whether the Amp has good peak or how high of peak is needed?
Does the doubling down infer higher ability of peak power than non-doubling down amp?

 

[Rip City Dave]

Macintosh rates many of their SS amps with the same advertised wattage @ 2, 4 or 8ohms.

IMO, it is not important how much more power an amplifier puts out as impedance lowers, but that it CAN deliver power into low impedance without vaporlocking.

 

[DonH56]

Macintosh rates many of their SS amps with the same advertised wattage @ 2, 4 or 8ohms.

IMO, it is not important how much more power an amplifier puts out as impedance lowers, but that it CAN deliver power into low impedance without vaporlocking.

Mac is special case as they use an output transformer (balun, autoformer) in their SS designs.

 

[pjug]

Again, forget the doubling down or worries about stability at low impedance, that's relevant but not central.The important thing is the total power required on the peaks. An insensitive speaker (esp. in the range where impedance is low and phase angle is material), will pull huge wattage. Consider the peaks reached in this video, with a somewhat less sensitive speaker/easier load than yours (specs below):

With heavy dynamic peaks the amp is putting out 400+ watts. Your perception may well be a bias (and you should blind test to verify), but it also may be that you are demanding wattage above the rated spec for the (unspecified) amps you are using and hearing a real difference. I believe I have heard the same with small class D and AB amps.

View attachment 128058
https://www.stereophile.com/content/harbeth-m401-loudspeaker-measurements

That video seems strange. The track that was used (Laptevinmeri by Pan Sonic) isn't even extremely dynamic. But it has a strange spectrum with a couple peaks and a lot of energy concentrated around 50Hz (spectrum below). So maybe this is why they could play at very high volume without being blown out of the room. It would be more interesting to me to see what the same equipment showed on a very dynamic recording of real instruments. But that probably wouldn't do for getting the display to consistently flash close to 600 watts.

 

[ahofer]

That video seems strange. The track that was used (Laptevinmeri by Pan Sonic) isn't even extremely dynamic. But it has a strange spectrum with a couple peaks and a lot of energy concentrated around 50Hz (spectrum below). So maybe this is why they could play at very high volume without being blown out of the room. It would be more interesting to me to see what the same equipment showed on a very dynamic recording of real instruments. But that probably wouldn't do for getting the display to consistently flash close to 600 watts.
View attachment 128342

50Hz is right at the phase angle extreme. I'm not expert in these things, but I think past +/-45 degrees will draw a ton of current?