Preface: if you want to try out the following you'll need to know how to use NCS Expert and have the appropriate D-CAN cable (see the stickies in the Electrical forum).

Background: I had previously upgraded my HiFi audio system by replacing all of the audio drivers with JL Audio speakers. I also added a 10" JL sub (with 250 watt JL amp). I did not replace the factory amp. In the end I still found the audio to be muddy in the low-end and, when cranked, the shrillness of the mid-range would make my ears bleed.

To that end, this weekend I tried changing some of the filter settings that are coded in the HAMP (HiFi amp module) using NCS Expert. My initial results have dramatically improved the sound:

• Better soundstage (moves the sound up forward)
• Less muddiness in low-end (gets rid of the awful bass boost added by MINI to compensate for the tiny door "woofers")
• Flatter overall frequency response

You'll probably have to have a subwoofer (and better than factory speakers) to get the full benefit from this mod.

How-to:
If you look in the FSW_PSW.TRC file for the HAMP you'll find settings that look like "FILTER_FZG_BLOCK_AMP_xx" where xx ranges from 00 to 21. Currently they are all set to the "R56" option.

All you have to do is change the settings for blocks 00 to 0F from "R56" to "E83" (5-series coupe). Then write the new coding to the amp. It will quickly reboot and will instantly sound different (and hopefully better!).

If you're not sure what settings I'm referring to, here is what the FSW_PSW.MAN file that I'm using looks like:
Don't like the new sound?
No worries - just change all the settings back to "R56" and recode. You'll be back to where you started.

I know this still doesn't get the truly flat response (and higher power per channel) that I'd get from replacing the amp, but changing the settings is free.

I'd love to try playing around with the actual parameters in each of the filter blocks to further tweak the frequency response, but that would be very time-consuming - and I'm not sure I want to take that on right now.

Enjoy!

 

This is very interesting.. So by doing this your saying your bass is better? What about the highs? They clearer too?

 

Yes, the TL;DR version is that actually reduces the bass a bit (makes it less boomy by decreasing the hump in the 80-120 Hz range) and makes the highs brighter.