OEM audio "detuning"

So it looks like Toyota really "detuned" head unit output to match crappy OEM speakers. Even good aftermarket speakers which gave near perfect flat curve in other car, are not flat at all when hooked up to Prius C OEM head unit. Despite being much better speakers, their spectral output looks even worse than it was with OEMs. But at least sound clarity and dynamic range are there, so they sound better nevertheless.

After playing with perceptual frequency sweeps and limited adjustments, the best setting appears to be Bass +2, Treble +1, Balance R1. Yes since there are no OEM tweeters in back, Toyota pushed sound to the front. And the higher range is cut back on rears to reduce distortion.There are a few deeps in 90 to 200 range, as well as bump from 9 to 14kHz. Haven't hooked up speakers to aftermarket unit, but 90% sure this is not issue with them.

I suppose the easiest fix would be to replace head unit.

Nobody expects the Spanish Inquisition.

 

Yeah I've looked at those alone with Taco Tunes Recurve EZQ. But it is hard to justify it when new $260 Pioneer head unit comes with HD radio, cameras support and mic-based AutoEQ, which in addition to 13 band EQ also does time delays. Plus coax outputs to feed clean signal into amp.

I ran frequency sweeps this morning and with adjustments it is not as horrid as it looked first. Need to take door skins off and fix buzzing but signal is audible at 20Hz, and relatively flat from ~30-40Hz up, with small bumps at 50Hz and 130Hz, and deeps at 110Hz and 170Hz. Top is relatively flat after burn in/adjustment, and I can't hear past 15.5kHz anyways.

Not bad since all we did just replaced speakers.

The right way would be to get new head, amp and sub but not feeling like sinking more money into commuter at the moment.

Will fix buzz and probably soundproof floors/wheel wells too much noise is coming through.