Tech Article Title Author Date
Bose Stereo System Testing Don Pavlik 2000

Frequency response curve

This testing was done on my A4.  I measured with a digital sound meter using the Stereophile Test CD2 1/3 octave warble tones (tracks 16,17,18).  This is hardly a scientifically accurate measurement but it does give a "ball park" idea of what's happening.  For the volume, I chose 76dB @ 250Hz as it's a comfortable volume for "normal" listening. I did not touch the volume until finished with all measurments.  I did this to satisfy my own curiousity... and maybe yours. 

The stock system has a definite hump in the frequency response around 50Hz that was very obvious before I even started measuring.  The system is surprisingly smooth (for a car) except for the dip in response at 400Hz which tends to make male voices sound a bit lean.  It drops off quickly after 10kHz.  Don't let the bass curve fool ya... road noise masks a lot of it. 

The sub reproduces the dynamics and transient response that the stock system is missing.  Don't be deceived by what appears to be a small gain in the graph... it makes a BIG difference.  Remember that it takes double the power to realize a 3dB increase in sound pressure level and 6dB is a doubling of the sound pressure level.   Most people perceive something as being "twice as loud" when the volume is increased by 10dB.  The frequency curve only tells a small part of the story.   If I had the means to plot "energy vs. time" you'd see what I'm talking about.  The factory system has "slow" bass meaning it does not faithfully reproduce bass that has a sharp attack (like a drum kick).  This is pretty common... it takes a lot of power and good drivers to reproduce bass correctly.

Frequency
(Hz)

w/ sub
(dB)

Stock
(dB)

Change
(dB)

20

77

70

7

25

83

75

8

31.5

89.5

81

8.5

40

94

88.5

5.5

50

96

92

4

63

94.5

89

5.5

80

80.5

78

2.5

100

76

76

0

125

76.5

75

1.5

160

76

75

1

200

73

73

0

250

76

76

315

71

71

400

67

67

500

70.5

70.5

630

76

76

800

75

75

1000

73

73

1250

73

73

1600

71.5

71.5

2000

72

72

2500

70

70

3150

70

70

4000

73

73

5000

72

72

6300

73

73

8000

71

71

10000

69

69

12500

65.5

65.5

16000

58

58

20000

50

50




Terms of Use Privacy Policy| Copyright © 1996-2012 by AudiWorld. All rights reserved.