Fletcher Munson Curve

A

a5150guy

Member
Ok this question or task is for Leon Todd or any other pro out there. We all suffer from the fletcher Munson effect when we crank up our frfr speakers. I personally use the QSC 8.2, 10.2 and 12.2 series speakers. Pretty good speakers, but like all speakers, get brighter the louder you push them.

I have been trying to set up my volume pedal to address this. Now I know it is possible to set my hardware master volume and frfr levels to peel paint. I have been tweaking my volume pedal to control my output volume IN TANDEM with a multi band compressor level to compensate for this. That is, the higher the loudness volume, the higher the level of multi band compression to reign in the offending mid and high frequencies our ears are magnifying. I have been trying to balance the control percentages of the level of the compressor to work seamlessly with the overall loudness. Starting at 50% and going to say 80% something like that for level. It is a finesse game. Notching the frequencies seems like the easiest part.

I know Cliff, Leon, Cooper etc will probably be able to work this out much better than little old me. My brain already hurts. This is such an issue that I would think it deserves its own block eventually. However, given my limited knowledge of super deep diving with the insane capabilities, I feel I am close to achieving what I want but am suffering feedback issues. Maybe it's not there yet? Whoever solves this, would be up for a Nobel prize, as this is tantamount to solving fission IMHO. The task is basically keeping the perceived frequency responses linear as you raise the overall loudness. I know all speakers are different, but something basic would work for most situations with a tiny bit of tweaking. And please, for the love of the community, this is too important to charge for it if you solve the issue. Do it for the good of all humanity. With the collective brain power on this forum, I know this can be solved. OK.... Go!!!

ps: Leon I will buy 10 copies of every CD if you solve this lol...

imageproxy.php.gif
 
I know it's going to be the least satisfying answer of all time, but I personally just dial tones in for the context they're going to be used in. I'll get ballpark by cranking my Adam A7X monitors at home and then include a PEQ after the cab so I can make on the fly adjustments at shows when needed.

Funny timing as I have a video scheduled to come out today that touches on a few of these points.
 
The other day, I went from using two QSC K12's in stereo at home, dialed in presets. Went to rehearsal with one RCF NX 12 SMA. That was a huge mistake! Never again! Dial in at gig volumes!
 
What’s the new fangled “Fletcher Munson” concept you speak of ;)

perhaps the work of some up and coming grad students looking to make a name for themselves in the field of psychoacoustics ?
 
Your best bet really is to use separate presets for home / recording and live. In a sadistic way, I kind of enjoy seeing how terrible my preset sounds at home after I tweak it live and loud.
 
Over time I have just gotten used to having my home sound sounding like a cocked wah.... gig life.
 
Well it just seems like a solvable theory. When we all take the easy way out, we lose progress. I will continue to fumble with it and in the meantime dial in the patch at gig volumes. Maybe simpler is better hehe... Thanks for the "feedback" :)

I will sleep better at night knowing that Cliff will instill a post hardware volume block in the Axe IV that addresses this phenomena lol....
 
Home hi fI gear has had this feature for many years. The loudness control is intended to compensate for the FM effect. However, the correct compensation depends on many things, including exactly which notes you’re playing, so it would be quite difficult to precisely solve the problem. If you’re just looking for a rough compensation, yes, that’s been done.
 
Last edited:
Fission was mastered a long time ago, ‘tis fusion which future Nobel ‘endless, clean energy’ prizes will be awarded for :cool:;)

good luck with your hunt for the volume-linked EQ solution - sounds cool!
 
GlennO said:
Home hi fI gear has had this feature for many years. The loudness control is intended to compensate for the FM effect. However, the correct compensation depends on many things, including exactly which notes you’re playing, so it would be quite difficult to precisely solve the problem. If you’re just looking for a rough compensation, yes, that’s been done.
Click to expand...
The loudness control on home hi-fi gear is grossly inaccurate. Most people just leave it turned on all the time because “I like bass.”
 
What is IME a far bigger issue than the Fletcher-Munson description of the perception of loudness: Is the room reflections, which have a far more significant impact on the frequency response at any given SPL. This varies so substantially from one space to another that it is not possible to predict, but can only be empirically evaluated, and corrected for. It can be done fast and loose: by ear, or by using an RTA and a measurement mic and "wring out the room" in advance. Many venue type spaces will exhibit significant dampening up to a certain SPL: and then at some point they become saturated with standing waves and become a reflective hash of resonances, so a room needs to be tested at working volume. Notably, an empty room will sound different than when its full of sound dampening dancing people, and this may be the only treatment that can somewhat mitigate against a poor sounding space.

As far as predictive planning: The sonic meat and potatoes of the guitar/amp/cab or FRFR is roughly between 100hz and 2.5khz: If you look a bit more closely at those Fletcher-Munson curves: one thing that stands out is that if you overlay the curves: the mids vary substantially - and as the mids are where the ear is most sensitive: this must be regarded as the most important factor. The mind may interpret it as more bass or treble: but its the perception of the mids that is driving this interpretation. Within the range of the instrument, if you high pass/low cut at 200 hz, that will take care of over-amplifying the bass (which is exactly what an SM57 does: thus accounting for its enduring popularity as a cabinet mic. Also, the 57’s 5 khz peak won’t boost it enough to be sibilant).

A PEQ adjusted to mid-range adjustment on a per guitar basis for Loud or Normal can be useful. Its really in the 1khz-3khz mid range where the ear is the most sensitive and the perception goes from pleasant to harsh as the volume increases (combining with room resonance reinforcement). Since the high end is largely harmonic overtones generated from the midrange, adjustment of the mids will automatically provide some high end correction. Similarly, if excess lower frequencies are over energizing the mids, rolling off bass and low mids allows more dynamics in the midrange. Even if a inverted F-M curve were calculated and applied as an EQ: it would not solve the problem of room resonances, and would not inherently respond accurately in representing the harmonic interactions of tone generation. Not playing as loudly to minimize room resonance is also an option seldom explored. But there is no plug and play solution. The quick and sure guide is to listen carefully and adjust until its the best you can do at that time and place. Venue specific adjustments are generally accomplished in the Global EQ.

As Lee Van Cleef memorably proclaimed (In a rather more problematic context) in The Good, the Bad, and the Ugly: "I wish you luck"
 
Last edited:
What I see as a problem is that each person hears different "Fletcher/Munson curves".
I once read an interesting article: During the development of these curves, different tones (different frequencies) have been played to several people who had to judge which tone is louder. The resulting curves are mean values across several peoples hearing which do not necessarily match your hearing or the hearing of the audience. And additionally there is the problem with the frequency dependent room reflections... (already mentioned in @artzeal 's post above)
 
Yamaha has had this "variable loudness" feature for years on its receivers. I had one back in the 70's and you set the volume to what you would consider "max volume" and used the loudness knob to raise or lower the volume. Lowering the loudness knob lowered the volume but boosted the highs and lows. Raising it increased the volume but decreased the highs and lows. At all volume levels you had the same perception of highs and lows. Why it hasn't become ubiquitous in audio gear is a bit of a mystery to me. It's common sense and can't involve too much voodoo.

Here is Yamaha's description:

https://hub.yamaha.com/ypao-volume-guarantees-fantastic-audio-at-all-volumes/
 
B-Rad said:
Yamaha has had this "variable loudness" feature for years on its receivers. I had one back in the 70's and you set the volume to what you would consider "max volume" and used the loudness knob to raise or lower the volume. Lowering the loudness knob lowered the volume but boosted the highs and lows. Raising it increased the volume but decreased the highs and lows. At all volume levels you had the same perception of highs and lows. Why it hasn't become ubiquitous in audio gear is a bit of a mystery to me. It's common sense and can't involve too much voodoo.

Here is Yamaha's description:

https://hub.yamaha.com/ypao-volume-guarantees-fantastic-audio-at-all-volumes/
Click to expand...

Because not everybody's hearing is the same. The way I hear highs at low volume may be totally different from what you hear. So a simple single slider doesn't suffice.
 
Multi-band compression works great for this exact scenario but only takes you so far. As others have stated, setting up sounds for specific venue types is the best approach.
 
yek said:
Because not everybody's hearing is the same. The way I hear highs at low volume may be totally different from what you hear. So a simple single slider doesn't suffice.
Click to expand...
Agreed, and very true. But that is what treble and bass adjustments are for. I believe that Yamaha's approach uses how you setup the EQ as the "base loudness", and then applies the Fletcher Munson adjustments as you change the volume. It may not be the same for everyone, but the overall approach is superior to a standard volume knob because of how drastically Fletcher Munson effects our hearing. That effect is far more dramatic than individuals perception differences.
 
You must log in or register to reply here.
Back
Top Bottom