The Low Volume Loudness Dilemma

@wolf_garcia 

The third is a Loki Max remote EQ in my main hifi pile...this thing is brilliant.

I had a Loki Max on order when you wrote this; got it two days ago and have been fiddling with it. I agree completely with your assessment! My initial setup is to use the presets to approximate different equal loudness Fletcher-Munson curves.

The loudest I typically listen is about 80 dB SPL, but I do a lot more listening in the 65-70 dB range. With the Loki Max, I now can dial in the appropriate F-M curve to have a richer, more detailed soundstage at lower volumes. 

I hadn't really thought about it before, but F-M curves lead to the logical conclusion that, if your system is truly linear at all listening volumes, you can optimize the sound for only one listening level. The others really need to be corrected using EQ based on the science of equal loudness perception.

For you Roonies out there right now Roon’s PEQ feature can be used to build an EQ curve based on the Fletcher Munson curve (see Wikipedia) for a specific end point volume level. I used a free app on my phone (Sound Tools) to determine I wanted one for a 60 db volume level. I build an approximation of the curve using Roon’s PEQ features and WOW. It sounded great. I have put in a feature request to the folks at Roon for them to consider offering this in a bit more user friendly fashion where you just enter you desired listening room sound level and it automatically generates the appropriate curve, then you save it as an EQ for use as desired. Hope they do it.

PS- Another solution for anyone with a RME ADI2 dac, there is a built in loudness function.

Frequency loudness sensitivity aside, there are differences in the abilities of different systems to sound rich and full at low volume.  

The combination of robust amplification and higher than usual speaker efficiency gets the job done.  Look for amps that have more power as the impedance is reduced- e.g. amps that double down.  

At one extreme HE and Horn Speakers tend to do the best job at producing bass at low volume levels, something like JBL or Klipsch Heritage, Volti Audio etc.  Larger more sensitive woofers e.g. 12 to 15 inch / 90+ db efficiency for example. 

I had a really modest system with PSB tower speakers and a NAD 150 watt amp and the woofers seemed to be connected mechanically to the amp- every punch and note was felt despite very low listening levels.  

It can be done. 

+1 @bruce19

Would love to see more standard filter settings like those to deal with loudness delivered with Roon. Anything to make the tremendous power of Roon DSP easier for the masses to apply properly.

Also with Roon for lower volumes I find turning on headroom management to be a useful option.

I am of the opinion that speaker efficiency need not matter as long as the amp is up to the task of driving the speakers to maximum performance. Granted that is an easier job for many amps with speakers that present an easy load to drive (Fritz speakers are an example of easy to drive yet not particularly efficient) as opposed to being more efficient, which is different. More efficient just means louder overall with fewer watts which is a non issue for low volume listening.