Frequency response vs low frequency extension ratings

[theglobalelite]

Explain like I'm 5, the difference between the lowest frequency response and the low frequency extension ratings on a speaker manufacturer's provided specifications page for a speaker model.

Which one is the more accurate rating of how "low" it can go?

Random example from a low-ish cost Paradigm Monitor SE 6000F floorstanding speaker

 

[Blumlein 88]

DIN is a standard. It tries to take into account room gain. Your speaker may respond down to 53 hz if outdoors. Indoors there is some room gain at low frequencies. So it may actually put out useful sound to a lower frequency. DIN tries to take this into account to give a useful frequency your speaker will reach in your home listening environment.

 

[theglobalelite]

So the frequency response is the baseline "guarantee", and the range in between it and the low frequency extension varies due to room conditions with the low frequency extension being the absolute floor in perfect conditions?

 

[Blumlein 88]

So the frequency response is the baseline "guarantee", and the range in between it and the low frequency extension varies due to room conditions with the low frequency extension being the absolute floor in perfect conditions?

Well I wouldn't say absolute or guarantee. You did ask for a simple explanation.

The more complex one is below 100 hz your listening position and the position of the woofers can make for a roller coaster response. You might have rather large peaks and dips there. If a peak happens to coincide with where you speaker is rolling off, you might get lower response than even the DIN rating. This is due to room mode resonances even if the speaker is very flat in response you'll get this result indoors.

You'll see some speakers quote the response like above +/- 3 db and then give a -10 db low end number quite a bit lower in frequency. Again it gives you an idea that with room gain or room resonance you might get close to that low number. Below that the speaker isn't doing much of anything so there want be anything much below that number.

Things are messy with speakers because of the room among other things.

You can move your listening position or you can move the speakers and the peaks and dips will all change to some other frequency.

 

[solderdude]

When they use this DIN45 500 spec then LFE simply means -8dB which would explain why the frequency is lower.
It says something about the steepness in the roll-off.

It may well be another DIN norm or they may reference to something else entirely.