How to do speaker correction on a MacBook Pro Retina On a MacBook Pro 15inch Retina I find the sound output from the internal speakers to be quite 'strange'. It is like there is too much bass from where the spectrum starts and then as if there are some kind of gaps in the spectrum where middles and highs are somehow absent or underdeveloped. 

These are small speakers and they are usually judged as quite good for their size. Yet they seem to me part of the wrong side in the loudness war.

On older machines I previously used a complicated setup involving SoundFlower and AULabs equalizer settings to correct for some of the perceived deficiencies. 

Besides the cumbersome setup of this surely outdated solution: On these newer machines I cannot arrive at a satisfactory result.

But I remembered a few "audio optimizers" offered some speaker correction presets for these machines. (Examples would be Boom3D, Hear, eqMac2, Bongiovi DPS…) With the smallest settings I found Boom quite smooth. But that piece of software is unreliable in operation, costs money, and offers a range of other features I do not want or need, and it is even accused of possibly damaging your audio hardware if misused. On top of it the results on this machine are not in that way 'better' as I remember it (and re-tested with an older version just now) from older machines.

Since I am lacking even the right terminology for this kind of task: 

How do I approach speaker correction for this machine properly? Are there equalizer presets to start from? Settings perhaps to download somewhere or to copy along the sliders of the band?
Can these speakers or their response curve really be calibrated (as the setup from one of the software titles seem to suggest) Other software solutions to consider altogether?



Note that I am aware of "perceived sound quality" as pretty much opinion based, therefore I am not asking about "the best setting" but about the proper approach to this problem in general. The huge difference between the so called "optimized for this machine" settings offered by Boom and Bongiovi DPS is testament to the "opinions differ" thing as well.
Late edit:
Since writing this, Rogue Amoeba have released a simpler &amp; cheaper app specifically to tailor output rather than provide full internal audio routing &amp; recording - SoundSource. You can set up your EQ or whatever as a global or on a per-app basis, making it very flexible.

I wrote this before checking all the proposed apps in the OP; my issue with these kind of things usually is that I tend to avoid the &quot;we can do it all for you&quot; apps, like Boom &amp; Bongiovi; because I always think, &quot;How can you do all that for me? You can't hear my speakers!&quot;.
eqMac2 does look like a simpler version of what I'm already doing on the first machine example below... for free. You still need ears, or an analyser, but the investment could become 'merely time' rather than actual cost.

Potentially what you could do if you have access to a smart phone is download a free Spectrum Analyser &amp; find a white noise sample or generator online* then use the EQ to flatten the perceived EQ curve as the phone hears it.
You could do this with Soundflower &amp; a graphic EQ too, or potentially with eqMac2 - for free.
There's a slicker solution than Soundflower, but it's far from free - Audio Hijack - which I use to tame the audio on several machines here, for slightly different purposes.
I get the feeling it won't be what you're looking for, but it's quick enough to throw in here &amp; see if any future Googlers might like it. I do seem to come across as a one-man campaign for this app, but it's just that it's the best I've found for many similar purposes. I have no affiliation whatsoever.
If someone can find a free equivalent, I'm all ears - quite literally ;)
One cool thing, though is you can set timers for it - so to get it to be 'always on' I set it for 23h 59m of every day &amp; let that spare minute be when I'm bound to be asleep.

On one machine, I use it to compensate for cheap external speakers with an odd EQ curve. I simply send all audio through it to flatten the perceived EQ curve.

On the other machine, I use it to compensate for the very high dynamic range whilst watching movies - which are piped through to my powerful 5.1 system, capable of offending the most tolerant neighbour. I use it to simply keep things within a more acceptable range to suit me &amp; my neighbours...

Both these setups just use Apple's built-in AU plugins.
Unfortunately, there is no automatic setting for either of these setups. I do it by ear - but I'm a pro sound engineer &amp; I trust my ears to get it at least close enough to be acceptable to any listener.
*No affiliation, just one I've used before.