Non-Bose frequency response

[sillyxone]

As ColtX-5 posted the response curve for Bose, I thought I should do the same for non-Bose for completeness.

The setup:

• closed garage, closed CX-5 doors and windows, engine not running
• 6-speaker system in 2016 Touring
• two AKG P170 mics to the front-left seat (right channel) and back-right seat (left channel)
• mics hooked to Tascam DR-40 recording a linear frequency-sweep generated in Audacity (computer to AUX)
• input level of DR-40 was low enough to minimize background noise
• frequency response data extracted out of the recorded WAV files using Plot Spectrum in Audacity
• data syntax: "b0_t3_f20-15k" means bass=0, treble=+3, frequency=20Hz-15KHz
• the frequency if omitted is 20Hz-20KHz (the shorter ranges just to show that the mics/speakers do work between 15K-20K)

All audios, pics, and charts can be downloaded from this GDrive folder:
https://drive.google.com/open?id=0B1wdJ3PpKsLGV1VrTF9TMkloN3M

To keep the post short, I'm inserting just a few pics below. This is by no mean scientific, just a rough idea of the quality of the sound system. You can get more details by downloading the WAV files in the GDrive folder and analyze them yourself (for the audio, left channel maps to back-right seat, right channel maps to front-left seat).

 

[fvansan]

For those of us who never worked in a sound lab, what does all this research mean?

 

[sillyxone]

For those of us who never worked in a sound lab, what does all this research mean?

I've never stepped into a sound lab, so I'll leave the analysis to the experts. Practically for me the charts show:
- quality of non-Bose system is not too bad
- comparing to front seat, back seat doesn't get the deep bass and consistency is not as good
- a good EQ setting is bass +1, treble +2 or +3 would make the sound more balanced (I prefer b1_t3, but I'm used to Grado clear high)

I'm hoping somebody with the DB351 in the dash would measure the response on their system (just looking for incentive to upgrade

 

[ColtX-5]

For those of us who never worked in a sound lab, what does all this research mean?

It means the non-Blose system is nearly optimal for audio in a car environment and I got screwed with the Blose system.

I think the system would be pretty close to flat +/- 5 dB from about 40 to 17k Hz, if you cut the bass control about 5 dB (-5 clicks?). Flat means voices and instruments sound real and do not sound artificial by over boosted bass or treble.

Most music is between 80 and 1000 Hz. The low E on a bass guitar is 41 Hz, Heavy Metal. Lead guitar solos are 1k to 3k Hz. The very, very delicate shimmer from cymbals (aka "air") is 12k to 19k. Young women and pre-teen males can hear from 20 to 20k Hz, normally.

 

[sillyxone]

While waiting for them to fix the fuel filler line recall, the saleswoman was nice enough to let me test the 9-speaker Bose system. Note that the dealer lot was noisier than my garage, and there's a loud speaker playing music about 15 feet behind the car, although the mics didn't pick up much.

Google Drive folder with audio files and charts (left channel is front-left seat):
https://drive.google.com/open?id=0B1wdJ3PpKsLGUU1Kb3NSSVZ0TWs

For the non-Bose, I have to set fading all the way to front, turn bass to lowest and treble to highest in order to tell that the dash speakers are working. For Bose, the dash speakers are a lot more obvious, but I feel the mid and high are too busy/muddy. I have to admit that I do like the non-Bose more.