My second DIY speaker attempt (after an Overnight Sensations kit) has been causing me some confusion. I've been using a Mark Audio driver that only became available in the past month- the Pluvia 7.2 HD, which is a replacement for the Alpair 7.3. Reasons for selecting these drivers were: Full range to avoid thinking about crossovers Availability of established plans online Mark Audio is located locally (ironically, ordering them was very complicated) Plans are located on https://www.markaudio.com/Plans/itemlist/category/22-Alpair-7-Gold. So far I'm building enclosures out of foam core board, before deciding on a design for wood. Stuffing follows the recommend amount of polyfill plus some additional damping behind the drivers. My chain is RPi + SPDIF HAT -> Modi Mulitbit -> Loki -> Sys (for volume control) -> Akitika GT-102 -> Speakers. Measurements were done with a MiniDSP u-mik and REW, with measurements gated at 4.5ms (so anything under 200Hz should be ignored). 1/12 octave smoothing has been applied. The initial 8L bass reflex box which I tried sounded so anemic that I moved on to the Pensil MLTL design which sounds a lot better, but has too much treble. The treble reminds me of listening to an HD800S, and I can solve it exactly the same way- using a Loki with the treble knob turned down to the 10 o'clock position. The weird thing is, I tried measuring both the normal and the equalised output, and the graphs look practically the same. The same thing happened with the HD800S when I measured on the EARS- the sound is different, but the graphs are virtually indistinguishable. Green line is no EQ, red is EQ. So for starters, I am not quite sure what's going on here. Just to check my own sanity, I did an extreme EQ test with the treble knob turned all the way down, just to confirm that the Loki really was doing something. It's the orange line below: Can anyone suggest what to do about the treble? I'd prefer not to remain dependent on external or software EQ, so I'm wondering if modifications can be made to the enclosure design, to the electronics (perhaps figuring out a notch filter around that massive 13KHz peak?) or whether I have to look at different drivers entirely. Thanks. Edit: Any other advice is also welcome, this has been a a fun learning experience so far.