Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • The final cut of the 8th episode of the Tesla Motors Club Podcast, featuring Balazs Biro, of the prominent Hungarian EV channel Villanyautósok, is now available. You can watch it now on YouTube or listen to it on all major podcast networks.

Quantitative Audio Data

David.85D

Active Member
Oct 29, 2016
1,614
1,390
USA
Got a calibrated microphone and an Android sound analyzer app to play with. Used it to make some measurements of the base audio system (upgraded with light harmonic door speakers, for whatever that is worth - one of the four is dead after 18 months).

This is the spectrum from the front speakers (they get more bass, as you will see), with the equalizer flat. Surprisingly weak above 3 kHz.
Screenshot_2018-05-05-16-03-59 EQ Flat.png




This is the spectrum with the first band (bass) maxed out (+8 dB) and all the other channels at their minimum (-8 dB) to see what that changes. You can see a peak around 80 Hz.

Screenshot_2018-05-05-16-04-30 First Band Maxed out.png



Here is the same idea, with the second band maxed out, others at min. Peak around 250 Hz.

Screenshot_2018-05-05-16-05-07 Second Band Maxed out.png



Same idea, third band of equalizer. Peak around 620 Hz.

Screenshot_2018-05-05-16-06-03 Third Band maxed out.png



Same idea. Fourth Band. Peak around 1600 Hz
Screenshot_2018-05-05-16-07-06 fourth band maxed out.png



Same idea. Fifth Band. Peak around 8k.
Screenshot_2018-05-05-16-07-45 fifth band maxed out.png





So I then did my best to get a flat response. I understand that this doesn't mean it sounds best. Or will sound best to all people, and ignores all sorts of other metrics that can be used to define audio goodness. Just something to play with. To achieve this flatness, I had the bass EQ on 7.0, the second one on 4.0, the Mid on 0, The fourth on 0, and the treble on 8.0. Again, this is the base audio with LH speakers, not stock speakers. I'm going to try to hook up my old stock speakers tomorrow and see what the best/flatest spectrum would look like.

Screenshot_2018-05-05-16-11-03 Front Speakers Optimal Setting.png



And for grins, here is what the rear speakers are doing with the same settings - note the missing bass below 250Hz, and even the very highs seem to be cut out. I'm old enough, I can't hear 16kHz anymore ;-)

Screenshot_2018-05-05-16-12-21 Rear Speakers Optimal Setting.png
 
  • Informative
Reactions: PrGrPa and spottyq

David.85D

Active Member
Oct 29, 2016
1,614
1,390
USA
Heres a comparison of the stock 160mm speaker in the front door compared to the LH speaker in the front door. Flat EQ response, volume set to 5 on both (and not changed at all). These were measured on the car, so door resonance is captured to some degree.


Stock 160mm speaker
Screenshot_2018-05-07-20-01-00 Stock160mm Flat.png



LH door speaker
Screenshot_2018-05-07-20-02-03 LH Flat.png


And something else interesting - an impedance sweep of the two speakers. Green is stock 160mm, Blue is the LH speaker. Note that the data goes all the way down to 2 Hz.

DATS LH and stock Tesla160mm.JPG
 
  • Informative
Reactions: MP3Mike
David.85D,

Thank you for sharing these graphs with us. This just proves my suspicions when I was shopping for speaker upgrades that a full range driver in these sizes can't adequately reproduce the upper frequencies without a lot of manipulation of the equalizer and even with that the results are not that good. What's really disappointing is that the LH speakers have a tougher time with the upper frequencies vs the stock speakers. This could be because the cone is more ridged which would be better for controlled base response but worse for hitting the high notes. A separate tweeter is needed to flatten that curve.

Could you share what brand of microphone and android app that you used? I would be interested in how the Infinity Kappa's that I installed recently compared with what you have measured.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top