ROOSKIE
Major Contributor
2db over a less than 50hrz wide zone is not even remotely an insane bass peak and has little effect on the drivers excursion there.Yes, this is part of the problem... The driver's Fs is around 120hz, so that is useless because lacking any bass. But the cabinet is a Bass Reflex design using the sub tuning trick in order to boost somewhat the bass. In this case the cabinet is tuned around 80hz (the minimum between impedance peaks), and the result is an insane peak above 100hz ( which also interacts with the passive Eq netwoork...). This insane BR tuning is what causes distortion because cone movement cannot be under control as a sane BR design would allow. But this would also mean sacrifice bass, tuning the BR at 120Hz or above.
The issue is that the driver is small and it takes a lot of movement to generate anything under 125hrz and substantial displacement to get something like 70-80hrz kick drums or electronica beats. The port is tuned to 80hrz and as such the unit is subjected to a significant and a constant quantity of content below the tuning frequency. There is a ton of stuff in music at 60-80hrz.
Content below the port tune is bad for most every ported design but often at 30-40-50hrz or even 60hrz tunings there is little content below to cause extreme distortions and usually it happens fast enough one thinks it is just the way it sounds on the recording (until you hear it without all that sub port junk and overexcusion IMD/doplar) and some designs are crafted to roll off faster below fb or smartly use DSP to either alter a myriad of things keeping the driver in check longer (often at the expense of something else though).
This driver should be High Passed at 100-120hrz and used for quite farfield or perhaps pretty lively nearfield. I would still keep the ported enclosure to allow for a better blending with the sub. A sealed version of this speaker would be possible but have absolutely no bass and need to be crossed more like 150-180hrz.
Total waste of speaker based on price.
Now maybe a need to test these just to see...
$159 pair no filter https://www.madisoundspeakerstore.com/full-range-speaker-kits/markaudio-tozzi-one-kit-pair/
$120 pair includes 2 filter options https://www.parts-express.com/Copperhead-Desktop-Full-Range-Speaker-Kit-Pair-300-7180