Monitor Audio PL100-3G 'nominal impedance' vs 'minimum impedance'

[RayDunzl]

There are no musical recordings with 30 dB musical peaks!

I have a Rite of Spring that doesn't comply with your edict.

-40dB during the 5 minute segment marked, with some headbanging by the bass drum(s) elsewhere.

Redwood Symphony:

Drumbling example:

 

[Vladimir Filevski]

I have a Rite of Spring that doesn't comply with your edict.

I have this versions of Rite of Spring, with max DR=21, which comply to my edict:

 

[Vladimir Filevski]

We don’t disagree on this but you have to use peak dynamics to account for the peak power needed from the amplifier:
How Much Amplifier Power Do I Need?
This is why using DR numbers from the loudness database is not useful as those numbers are not peak numbers.

Quote from your link: "For example, if you need 100 watts continuous power to achieve the desired average SPL, you need 1,000 watts continuous to handle 10 dB peaks, 3,162 watts to handle 15 dB peaks,..."
So, for 15 dB peaks over average SPL we need 31,62 times more power. OK.
Now quote from my post #18:

Average loud SPL at the listening position is about 80-86 dB. For the calculation let choose 83 dB value. If listener is at 3m distance from the loudspeaker, than loudspeaker must deliver SPL=92.5 dB/1m (83+9.5). Two loudspeakers (as in stereo) in the room can deliver more, but let keep calculation simple. Sensitivity of PL100 is 85 dB/2.83/1m (82dB/1W/1m), so to achieve average SPL=92.5dB/3m it needs 11.2 W of amplifier power.
Maximum 400 W power from M23 allows clean 15.5 dB peaks from the average 11.2 W.

For average SPL = 92.5 dB/1m it needs average 11.2 W.
11.2W x 31.62 = 354 W needed for clean 15 dB peaks. Or as I wrote: "400 W allows clean 15.5 dB peaks".
Q.E.D.

Edit:
Another quote from your link:
"The recommended power allows for signal peaks of 10 dB for folk, jazz and pop music. Actually the peaks might be as high as 25 dB, but we're allowing for some inaudible short-term clipping.

In compiling this list, we made the following assumptions:

• Typical loudspeaker sensitivity is 85 dB SPL/W/m for home stereos,

​

Total amplifier power required in various applications​

• Nearfield monitoring: 25 W for 85 dB SPL average (with 15 dB peaks), 250 W for 95 dB SPL average (with 15 dB peaks)
• Home stereo: 150 W for 85 dB SPL average (with 15 dB peaks), 1,500 W for 95 dB SPL average (with 15 dB peaks)"

 

[MatrixS2000]

"The recommended power allows for signal peaks of 10 dB for folk, jazz and pop music. Actually the peaks might be as high as 25 dB, but we're allowing for some inaudible short-term clipping.

Which is what I said, that your amp will be clipping if you don’t account for the peaks! If you chose to allow clipping, that is your choice.

• Nearfield monitoring: 25 W for 85 dB SPL average (with 15 dB peaks), 250 W for 95 dB SPL average (with 15 dB peaks)

Right, we agree on this. I already said this. You are still confused because you stated this:

I have this versions of Rite of Spring, with max DR=21, which comply to my edict:
View attachment 452115

Max DR is not peak. It is telling you which track as the highest average DR on the album. The DR value then averages out over all the tracks. The loudness database does not give you peak DR information.

Over and out….

 

[Vladimir Filevski]

Which is what I said, that your amp will be clipping if you don’t account for the peaks! If you chose to allow clipping, that is your choice.

It will not clip, even with 15.5 dB peaks:

Quote from your link: "For example, if you need 100 watts continuous power to achieve the desired average SPL, you need 1,000 watts continuous to handle 10 dB peaks, 3,162 watts to handle 15 dB peaks,..."
So, for 15 dB peaks over average SPL we need 31,62 times more power. OK.
Now quote from my post #18:
For average SPL = 92.5 dB/1m it needs average 11.2 W.
11.2W x 31.62 = 354 W needed for clean 15 dB peaks. Or as I wrote: "400 W allows clean 15.5 dB peaks".
Q.E.D.

Another quote from your link:
Total amplifier power required in various applications

• Nearfield monitoring: 25 W for 85 dB SPL average (with 15 dB peaks), 250 W for 95 dB SPL average (with 15 dB peaks)
• Home stereo: 150 W for 85 dB SPL average (with 15 dB peaks), 1,500 W for 95 dB SPL average (with 15 dB peaks)"

I am tired of repeating this simple calculation. If Crown is satisfied with 15 dB peaks for nearfield monitoring and home use, then it is good enough for all others.
The DR value is in use in broadcasting, to prevent clipping in the whole audio chain, including preventing clipping of amplifiers.
Over and out.

 

[epping4est]

c.f. A Beginner's Guide to Dynamic Range in Audio Production

As shown, the Dynamic Range (DR) is the difference between quietest and loudest audio signal levels [e.g. measured in dB] -- regardless of how much amplification one ultimately applies to that audio signal.

Every 10 dB increase of DR draws 10x the amplifier power. If the recording has a DR of 30 dB and one is listening to the quietest audio signal at a modest 0.7W, then that recording's loudest audio signal will require 0.7W x (10 x 10 x 10) = 700W.

 

[mhardy6647]

Every 10 dB increase of DR draws 10x the amplifier power. If the recording has a DR of 30 dB and one is listening to the quietest audio signal at a modest 0.7W, then that recording's loudest audio signal will require 0.7W x (10 x 10 x 10) = 700W.

Yes, but for how long?
So much vim, vigor, and vitriol goes into "discussions" of this topic.
I'll -- ahem -- just note (yet again), that the power arithmetic becomes much less frightening if one simply makes one's loudspeakers, say, 20 dB more sensitive than the current crop -- which hover, distressingly, in the low to mid 80s (and are sometimes also hard to drive, besides).
That's the way we roll at my house.
In the neighborhood of 102 dB per watt at 1 meter.

EDIT: For a bit of historical context, I'll add that the acoustic suspension craze of the 1960s and 70s, begun by Villchur & colleagues in the late 1950s, was greatly enabled by (and certainly "democratized" by) the availability of cheap, high-powered (by the standards of the day) solid state amplification.
Whether that was a good thing or a bad thing is a matter of debate.

 

[epping4est]

In the neighborhood of 102 dB per watt at 1 meter.

Nice. Even nicer if that were the norm!

 

[MatrixS2000]

As shown, the Dynamic Range (DR) is the difference between quietest and loudest audio signal levels [e.g. measured in dB] -- regardless of how much amplification one ultimately applies to that audio signal.

Which is not what is measured at sites like the loudness database. Depending on the tool, those measurements will either be based on PLR or PSR. The site tells you which algorithm is being used for each album - none of which are the above.

 

[epping4est]

Which is not what is measured at sites like the loudness database. Depending on the tool, those measurements will either be based on PLR or PSR. The site tells you which algorithm is being used for each album - none of which are the above.

Agreed, but neither PLR nor PSR algorithms would measure more than the delta of the recording's (raw) quietest and loudest audio signal levels.