How to get true audiophile Sound Quality in a Tesla S

How to get true audiophile Sound Quality in a Tesla S

TLDR: Easy to do audio upgrades for a Tesla S that give results. Build log for Tesla S being taken to MECA world finals in Stock class.

Obtaining audiophile level sound in a car is a difficult task due to odd speaker placements, glass, plastic, standing waves, cabin gain, off axis reflections, etc. As an IASCA and MECA promoter, trainer, and competitor, I have spent the last 30 years building “Sound Quality” competition cars. These cars are judged on tonality, staging, and realism using a variety of reference material. For the sake of having a scale, I will use MECA scoring criteria to explain the level at which a car reproduces the source material.

Put it in terms of MECA SQ scoring:
• Most new cars stock would score: 45 to 55
• A quality stereo installation: 55 to 60
• The best cars in the world:
o Stock class- minimal modifications 72 to 74
o Master/Extreme class 85 to 87
• Tesla S Premium with no upgrades 66 to 67

The Tesla S sound system is an amazing starting point for modification because of the research and time that went into its design. There are many issues to deal with in the car, but the foundation is solid. I read a funny article, where the designers of the Tesla audio system were being interviewed. They said something to the effect of, “We didn’t tune it for audiophile taste, we tuned it for American taste and they seem to like that heavy muddy bass.” Let’s identify the positives and negatives of this specific vehicle.

Tweeters recessed to avoid off axis reflections
Center channel built in
8” speakers in doors stock
Subwoofer enclosure in rear quarter
200+ Amp DC converter for power
Already plays relatively flat from 35 Hz to 15,000 Hz
Can stream music at 96k
Full wiring diagrams available online from Tesla
Most of the audio problems are from how it was tuned by the engineers

Sub diameter is only 8”
Mid range bounces off glass
Not a lot of deadening in this car
Getting almost any car to sound good can take years of research, trial, error, work, and money. I was surprised how good the Tesla S premium system was right out of the box, with just a bit of tweaking on the balance and fade and the addition of an EQ app. I will be doing the mods in steps as much as possible while taking measurements and scoring the car.

Equipment Upgrade Options:
• Speakers- For competition we will only use the front 8 speakers and sub. I really only need to change out two tweeters in the A-pillars, three 4 “ mid-range in the dash, and two 8” mid-bass in the doors.
• Subwoofer – The 8” is anemic under 30 Hz. It will get swapped out to the largest sub I can conveniently fit in the driver’s side rear quarter panel area.
• Amplifier – An 8 channel DSP amplifier will handle the front stage. Once I upgrade the sub, I plan on adding a monoblock amplifier, which allows me to use a center channel on the DSP amp.
• Signal processing
o Equalization- Because I am competing in stock class, I am limited to 16 bands of EQ. There are processors with 32 stereo bands per speaker, but I will not be using them for this car. You can get much better results with something like the Helix processor.
o Time correction- The only way to get a car to image correctly is by using time correction. It delays the signal from speakers that are closer so that the sound from each hits you at the same time. This is imperative to getting a good and accurate stage
o Crossovers- This is where you decide what information goes to which speaker. Often times speakers have a range that they don’t do well in, its your job to make sure they don’t play in that range. Crossovers can also be used for phasing adjustment, but at a cost.
o Phasing adjustment- When speakers are placed facing different directions it causes phasing problems. In a car this happens all the time. In a home system it does not. This helps untangle the mess. My processor does not have phasing adjustment, but a higher end processor does.
• Dampening and deadening
o Deaden doors/roof/quarter panels- This will take care of the nasty mid-bass resonance and cut down on your door panel acting like a speaker. (put your ear against the plastic and you can actually hear the plastic playing music)
o Put sun visors down and parallel to glass – This helps reduce the mid-high frequency resonance, which seems to be coming off the dash and windows. Unfortunately in stock class, I can’t use a dash pad.
• Seating position – The best imaging I can find so far is obtained if you can line your left ear up with the bottom right corner of the plastic seat belt holder on the driver’s side B-pillar.

The installation I am doing consists of 6 Stages. At each step I will take measurements, score the car according to MECA guidelines, describe the improvements, post videos of work, do simple blog posts. Some forums do not let me post pictures, so they will not include the frequency response, waterfall graphs, pictures of settings, pics of install etc. I am happy to email word documents out to anyone who is interested. The car will be at 5 shows in Southern California and possibly CES for demos.

• Stage 1: Stock no mods – January 2018 - 0 hours invested total – Scores 60
• Stage2: Just head unit adjustments – 1 hour invested total - February 2018 - Scores 65
• Stage 3 Add 16 band EQ app for Ipad – 6 hours invested total - March 2018 – Scores 68
• Stage 4: Change speakers – 14 hours invested total - April 2018
• Stage 5: Add amplifier with digital signal processing – 22 hours invested total – May 2018
• Stage 6: Upgrade subwoofer – June 2018 – 30 hours invested total – June 2018

You can find pictures and frequency response graphs here: | March 15, 2019

Great work, I'm impressed. Can you provide a better link - the one above just dumps you into a general Tesla Facebook group.

reed_lewis | March 17, 2019

...And post links to some other place for the people like me who would never put anything on or go anywhere near Facebook.

fkhera | March 17, 2019

Reus audio

hafidortega | March 20, 2019

Wasn’t there a guy that would fly out to your house for $5k and complete some tweaks to your model S in a day and make the thing incredible? I seem to remember this a few years back. Any joe, anyone upgraded there stereo? Opininions?

avesraggiana | March 20, 2019

I'm most interested in your use of sound deadening material. For the purposes of suppressing road noise, would putting sound deadener on the floorpan help appreciably?

Also, do you recommend keeping the optional sun screen for the all-glass roof in place at all times, to improve audio quality? Does THAT make a difference?

Thanks for your detailed report. | March 20, 2019

I don't see how adding sound deadening in the floor will help. Remember you have a 4" stack of cells under the car, with lots of structure. Then there is carpet on top of that. The firewall is a 1" sandwich of aluminum-foam-aluminum, and carpet on part of it as well. I suspect most exterior sound that can be controlled is from the insides of the doors. Others may have additional ideas.

Of course glass lets some exterior noise in too, but not too much can be done with the windshield. Tinting films may help a tiny bit on other glass, but nothing compared with the doors. Metal roofs are the best, as Tesla also adds quite a bit of insulations/sound deadening material. It's disappointing that they dropped metal roof option (I have it on my S).