Hello all,
For a loooong while, I have been unsatisfied with the online postings of EQ and Treble/Base settings in the HiFi system for our E70 X5's. Something just does not sound right to me (self proclaimed enthusiast audiophile LOL). The base seems muddled and over done on some places, and wrongly emphasized mids, and overbearing high frequencies. But I was too lazy to self correct it.
Today, I took my time to sample the frequency response of my 2007 E70 X5 4.8, and I present you the optimal settings modeled after the Harman House Curve (if you do not know what it is, I suggest you look it up).
TLDR:
Treble: 0
Bass: -4
100hz: -3 (-2 if you want a bit more bass)
200hz: +3
500hz: +1
1000hz: +5
2000hz: +3
5000hz: 0
10,000hz: -3
Surround: Stereo
Sunroof cover: Closed
Methodologies:
I used an individually factory calibrated microphone (UMIK-1) with Room EQ Wizard (REW) to preform my frequency response samples. Total of 8 samples with many adjustments in between to get the final audio settings. Each sample consists of 3 slightly varying measurements from the front two seats, rear 3 seats, and center console area.
Above, the original sampled frequency response (average) curve. I took three slightly varying measurements from each location at ear height. The locations being: drivers seat, front passenger, front center console, and rear left-center-right seats. As you can see, there are basically two lines. The higher curves are from the front, and the lower curves at around 50hz is from the rear seats. I think this has to do with the balance/fader settings (which I did not touch). I just averaged the two in my settings.
You can see that for the original frequency response curve, REW suggests reducing the heavy, heavy bass in the factory tuning, and the higher frequencies. We can conclude from this original graph that we need to reduce the bass either in the EQ or in the treble/bass settings, and mildly reduce the higher frequencies.
Above is the 8th iteration of the frequency curve with treble, bass, and the equalizer edited. I think this is the closest I can get the frequency response to be a clone of the Harman House Curve. Setting the settings to my settings, the sound is very balanced. If some extra lower down bass is required, you can set the 100hz to -1.
If you look at the final frequency response curve, you can see that there is a peak at 40-50hz. This seems to be a characteristic that cannot be rid of. Maybe this is due to limitations of the 'room'.
The overall sound with the above settings is very clear, I tested this with various CD's, and Apple Music's High Res-Lossless Audio. The bass is balanced with the high frequencies.
Let me know if you have any questions, I am open ears. I hope this helps. I am not sure if later LCI models and x5M with the top speakers use the same set up. Also, it should also be noted that all speakers from the factory may have some variations.
Misc Pics:
View post on imgur.com
*testing done with pink noise at ~75.0dB*