So... after a lot of fiddling about trying to get the Z4's sound system to sound right I thought I'd take the scientific approach... after all, to measure is to know...
If your car is fitted with the DSP sound system (aka Carver, Logic7 or Top-HiFi) you can use the built-in equalizer to fine-tune the frequency response. But which settings would you use? I've used RightMark AudioAnalyzer to measure the sound system's frequency response. Based on an initial analysis, with the DSP disabled, a best guess as to what the equalizer settings should be was then made. Using these settings a new analysis run was performed, which in turn resulted in tweaks to the settings. After several iterations (enough to drain the battery
) I reached my goal - an as flat as possible frequency response and vastly improved sound.
The resulting equalizer settings are:
80Hz: +1
200Hz: -5 (-9 is too much)
500Hz: -1
1kHz: 0
2kHz: +2
5kHz: 0
12kHz: +2 (+5 is too much)
Edit: after a testdrive I must say that the 12kHz setting sounds a bit harsh and should be a notch or two-three lower at +3 or +2.
Edit2: well, in practice the resonance bump @ 200Hz is indeed huge, but dropping to -9 does't leave enough bass, but -5 sounds about right.
I've got a feeling that while driving along, using higher sound levels than during measuring, the automatic loudness function kicks in. Main thing to take from all this is the huge resonance bump around 200Hz, and whereas you'd usually 'up' the 80Hz slider to compensate for the lack of low-end bass you actually need to lower the 200Hz slider quite significantly.
The blurb, or, how the measurements were taken:
The car used for these measurements is an E86, with M sport seats and extended leather (furniture influences frequency response
). Similar results will be achieved with the Z4M Coupe, but probably not with any of the roadsters, as they not only have another top, but also a very different trunk.
The measurements were made using RightMark AudioAnalyzer 6.2.3 and a Denon DM-S205 microphone. This microphone has an almost flat frequency response, with a 6dB/octave drop above 10kHz. The graphics have not been corrected to this 6dB/octave drop, and therefore show a larger drop off than is actually there.
In car measurements were taken at the left and right shoulder and several inches in front of the face. Three measurements were taken at each location and the (9) results then averaged.
Fader, balance, treble and bass controls were at their center level and the GAL (GeschwindigkeitsAbhängigeLautstärke) at 2.
The results, before and after:
DSP OFF:
DSP ON:
If anyone would like to have their ragtop's sound system calibrated, you're welcome to c'mon over to Eindhoven.
If your car is fitted with the DSP sound system (aka Carver, Logic7 or Top-HiFi) you can use the built-in equalizer to fine-tune the frequency response. But which settings would you use? I've used RightMark AudioAnalyzer to measure the sound system's frequency response. Based on an initial analysis, with the DSP disabled, a best guess as to what the equalizer settings should be was then made. Using these settings a new analysis run was performed, which in turn resulted in tweaks to the settings. After several iterations (enough to drain the battery
) I reached my goal - an as flat as possible frequency response and vastly improved sound.The resulting equalizer settings are:
80Hz: +1
200Hz: -5 (-9 is too much)
500Hz: -1
1kHz: 0
2kHz: +2
5kHz: 0
12kHz: +2 (+5 is too much)
Edit: after a testdrive I must say that the 12kHz setting sounds a bit harsh and should be a notch or two-three lower at +3 or +2.
Edit2: well, in practice the resonance bump @ 200Hz is indeed huge, but dropping to -9 does't leave enough bass, but -5 sounds about right.
I've got a feeling that while driving along, using higher sound levels than during measuring, the automatic loudness function kicks in. Main thing to take from all this is the huge resonance bump around 200Hz, and whereas you'd usually 'up' the 80Hz slider to compensate for the lack of low-end bass you actually need to lower the 200Hz slider quite significantly.
The blurb, or, how the measurements were taken:
The car used for these measurements is an E86, with M sport seats and extended leather (furniture influences frequency response
). Similar results will be achieved with the Z4M Coupe, but probably not with any of the roadsters, as they not only have another top, but also a very different trunk.The measurements were made using RightMark AudioAnalyzer 6.2.3 and a Denon DM-S205 microphone. This microphone has an almost flat frequency response, with a 6dB/octave drop above 10kHz. The graphics have not been corrected to this 6dB/octave drop, and therefore show a larger drop off than is actually there.
In car measurements were taken at the left and right shoulder and several inches in front of the face. Three measurements were taken at each location and the (9) results then averaged.
Fader, balance, treble and bass controls were at their center level and the GAL (GeschwindigkeitsAbhängigeLautstärke) at 2.
The results, before and after:
DSP OFF:
DSP ON:
If anyone would like to have their ragtop's sound system calibrated, you're welcome to c'mon over to Eindhoven.
.