MCU2 Upgrade Audio EQ Balancing - Coming From MCU1

[Topgun66]

I'm glad to hear this helped. Looking at your settings, I think you hit on what is most important, which is EQ slider 2 and 3. These control the frequencies of the human voice (roughly 100 Hz to 1000 Hz). If that is screwed up, music tends to sound terrible, and the default in my Tesla was boosted 6-8 dB. The decibel scale is logarithmic, so that amount of increase is in the range of nearly doubling the perceived volume for those frequencies.

If you like thumping bass, then, by all means, crank slider one up. Same for the ultra-high treble. Those frequencies are perceived as much less critical to the human ear and become a matter of choice/style in music. Thus the classic "V" EQ settings that have worked for you in the past. The bottom of the "V" typically needs to be at the mid voice frequencies for a baseline. Tesla's baseline was just screwed up. I have rarely had to have such a skewed EQ setting to get a good sound.

The test tracks I have used for decades when setting up any new audio system are still readily available and a cheap investment if you care about sound quality.

https://www.amazon.com/Sheffield-A2TB-Test-Disc-My/dp/B000V93NKY

Thanks I found that these sound samples are available for free if you have Apple music or Pandora.

 

[Ostrichsak]

If this is intentional, I guess it makes sense that they would limit bass or the sub frequencies to just two speakers rather than four. There's a reason people typically have only 1-2 subs and not 4. This allows the penetrating bass to not overwhelm the rest of the frequencies, and maybe is a better distribution of frequency load (not having he same crossover for all four door speakers). I mean I can't say mine sounds bad at all, I just wanted to know if I have an issue. I'll definitely ask them on Thursday how it should be.

For me this is the opposite of what I want. I'm fine with higher frequencies coming from the front for "staging" purposes but I want my lower midrange frequencies and down to be done anywhere it can be done since these frequencies are less directional than the higher ones. We're not talking about subs here (which is a totally different animal since the sounds these create are largely non-directional) we're talking about full-range speakers. I'm pretty limited to the # of them in my car so I'd rather not half of them not being used.

Cars also have more constraints than home systems and the largest of those is real estate. We simply don't have the room to mess with so the fact that I have four door speakers capable of playing midrange frequencies means I want them to be used for this and, as I already stated, if one prefers more of a front stage they can easily fade to the front through the menu. I can't "fade" a rear in for fuller sound if it doesn't exist. This would be the same as someone who only listens to NPR talk radio saying "Well, I only listen to it a volume 2 so since I don't need it any higher I don't understand why someone else is complaining that the volume only goes up to 2" because we all have different wants from our audio. The next consideration that varies larger from home audio versus factory car audio is cost. In a home audio system the user generally has a budget that can account for proper hardware which is generally more flexible. In car manufacturing they tend to skimp on audio because it's low on the priority scale since it's so subjective and, quite honestly, most buyers don't care. They are easily impressed with pretty budget oriented components as long as they're in their shiny new car capable of 3-second 0-60 blasts.

I don't get why Tesla would go to the effort of putting rear door speakers in these UHFS systems and then basically not using them. Our base audio cars distributed the audio much more evenly to the point where I legitimately thought the rear channel on the external amp was smoked. This was made apparent when I had people with me and the one in the back asked me if my audio was faded all of the way to the front since they couldn't hear the sound as well in the back. I also verified by other UHFS vehicles.

I should add that my experiences are all with the MCU1 and I know this thread was more about the audio changes from MCU1 to MCU2. I just wanted to give my personal opinion on the MCU1 UHFS as I feel it could be useful in this conversation since it seems to closely resemble that of the MCU2 replacements. It seems as though some claim MCU2 helps while others claim it hurts. What seems to be the same is that the rear door speakers have little to do with this in any direction. If someone out there has UHFS and does indeed get full power out of their rear doors I'd be curious to hear about this. Part of me wonders if this "loss" of rear audio has nothing to do with the MCU2 upgrades and more to do with how they all work as intended for whatever reason and only those who upgrade to MCU2 are paying close enough attention to finally notice this aspect that appears to be on every UHFS Model S I've been in.

 

[WASD]

... we're talking about full-range speakers. I'm pretty limited to the # of them in my car so I'd rather not half of them not being used.

A typical 6.5" driver (rear door) is not a full range driver unless it is coaxial. We have a mid-woofer in the rear doors, in fact I have one sitting on my desk right now and "midwoofer" is printed on the back sticker.

The UHFS system doesn't use full-range speakers. It has midbass/midwoofers in the doors, mids in the dash and hatch, tweeters in the A pillars, and a sub in the hatch floor. Each speaker has it's own range and they all compliment each other. That's how a typical 2,3,4-way system works. Either using passive crossovers (physical) or active crossovers (digital, done with DSP). Tesla uses DSP built into the MCU. The rear doors are going to play (some) bass, low midrange, and midrange. High midrange and above will be the mids in the dash. This was already verified by another user with a test disc.

I'm getting a full system installed in my S right now, which has front 3-way active, but I'm also adding a center channel and 4 rear speakers. The center and rear speakers will play very specific frequencies to compliment the front stage, but they will not sound good on their own. If you were to play music out of only the center and rears it would sound really really bad. The "fader" if implemented properly should move the sound stage or perceived center, not just the bare signal to the rear drivers.

Again, I'm not saying Tesla didn't break or change something, since I haven't hear before/after of any of your systems. There very well could be issues or changes and those should be brought up to Tesla and hopefully fixed by them. I'm just trying to set expectations for how a fully active sound system should behave. There is a reason why you don't hear sub-bass or mid/highs from the rear doors.

 

[Topgun66]

For me this is the opposite of what I want. I'm fine with higher frequencies coming from the front for "staging" purposes but I want my lower midrange frequencies and down to be done anywhere it can be done since these frequencies are less directional than the higher ones. We're not talking about subs here (which is a totally different animal since the sounds these create are largely non-directional) we're talking about full-range speakers. I'm pretty limited to the # of them in my car so I'd rather not half of them not being used.

Cars also have more constraints than home systems and the largest of those is real estate. We simply don't have the room to mess with so the fact that I have four door speakers capable of playing midrange frequencies means I want them to be used for this and, as I already stated, if one prefers more of a front stage they can easily fade to the front through the menu. I can't "fade" a rear in for fuller sound if it doesn't exist. This would be the same as someone who only listens to NPR talk radio saying "Well, I only listen to it a volume 2 so since I don't need it any higher I don't understand why someone else is complaining that the volume only goes up to 2" because we all have different wants from our audio. The next consideration that varies larger from home audio versus factory car audio is cost. In a home audio system the user generally has a budget that can account for proper hardware which is generally more flexible. In car manufacturing they tend to skimp on audio because it's low on the priority scale since it's so subjective and, quite honestly, most buyers don't care. They are easily impressed with pretty budget oriented components as long as they're in their shiny new car capable of 3-second 0-60 blasts.

I don't get why Tesla would go to the effort of putting rear door speakers in these UHFS systems and then basically not using them. Our base audio cars distributed the audio much more evenly to the point where I legitimately thought the rear channel on the external amp was smoked. This was made apparent when I had people with me and the one in the back asked me if my audio was faded all of the way to the front since they couldn't hear the sound as well in the back. I also verified by other UHFS vehicles.

I should add that my experiences are all with the MCU1 and I know this thread was more about the audio changes from MCU1 to MCU2. I just wanted to give my personal opinion on the MCU1 UHFS as I feel it could be useful in this conversation since it seems to closely resemble that of the MCU2 replacements. It seems as though some claim MCU2 helps while others claim it hurts. What seems to be the same is that the rear door speakers have little to do with this in any direction. If someone out there has UHFS and does indeed get full power out of their rear doors I'd be curious to hear about this. Part of me wonders if this "loss" of rear audio has nothing to do with the MCU2 upgrades and more to do with how they all work as intended for whatever reason and only those who upgrade to MCU2 are paying close enough attention to finally notice this aspect that appears to be on every UHFS Model S I've been in.

I upgraded to MCU2 and rear doors seems to be more wide range but the front speakers in my car are 50-350hz verified from playing note samples at these ranges

 

[Ostrichsak]

A typical 6.5" driver (rear door) is not a full range driver unless it is coaxial. We have a mid-woofer in the rear doors, in fact I have one sitting on my desk right now and "midwoofer" is printed on the back sticker.

The UHFS system doesn't use full-range speakers. It has midbass/midwoofers in the doors, mids in the dash and hatch, tweeters in the A pillars, and a sub in the hatch floor. Each speaker has it's own range and they all compliment each other. That's how a typical 2,3,4-way system works. Either using passive crossovers (physical) or active crossovers (digital, done with DSP). Tesla uses DSP built into the MCU. The rear doors are going to play (some) bass, low midrange, and midrange. High midrange and above will be the mids in the dash. This was already verified by another user with a test disc.

I'm getting a full system installed in my S right now, which has front 3-way active, but I'm also adding a center channel and 4 rear speakers. The center and rear speakers will play very specific frequencies to compliment the front stage, but they will not sound good on their own. If you were to play music out of only the center and rears it would sound really really bad. The "fader" if implemented properly should move the sound stage or perceived center, not just the bare signal to the rear drivers.

Again, I'm not saying Tesla didn't break or change something, since I haven't hear before/after of any of your systems. There very well could be issues or changes and those should be brought up to Tesla and hopefully fixed by them. I'm just trying to set expectations for how a fully active sound system should behave. There is a reason why you don't hear sub-bass or mid/highs from the rear doors.

I understand the difference between a full-range speaker and a midwoofer, technically speaking. I was only using that as a laymen term for purposes of this discussion where I've got speakers behind me capable of more than just LFE (like the sub in the back) and yet I have basically nothing coming from them. What a midwoofer is capable of is exactly the sound I want coming out of my rear door speakers and it's not. That's the primary point I'm trying to make w/o getting caught up in semantics.

 

[WASD]

I understand the difference between a full-range speaker and a midwoofer, technically speaking. I was only using that as a laymen term for purposes of this discussion where I've got speakers behind me capable of more than just LFE (like the sub in the back) and yet I have basically nothing coming from them. What a midwoofer is capable of is exactly the sound I want coming out of my rear door speakers and it's not. That's the primary point I'm trying to make w/o getting caught up in semantics.

It's not going to have the same volume as the front -ever- in a properly tuned system. Like I said before, if you remove the front audio and only leave the rear speakers, it will sound like garbage and at a very low volume. The fader will move the perceived sound stage center to the rear using timing and some volume, but the sound is largely still being produced by the front speakers. Just use the correct terms, people have google, if they don't know a word they can look it up. "Laymen's terms" will just confuse people who do know, and spread misinformation to those who don't. Saying our cars have full range speakers is just false, though if you want to get technical, the "mids" in our cars are the closest thing to a full range speaker. Not the mid woofer in the doors.

Topgun66 already verified the rear doors are playing from around 125hz and up, exactly what they should be doing.

 

[oldpueblo]

If we standardize on the same audio files (easily done thanks to posters) then we can start gathering more data regardless of how it should or should not be. Since I have base audio with MCU1, and MCU2 soon, I'll go ahead and see what frequency "falloffs" I have on all the doors. Let me know if there's anything else you'd like me to test for more data points. I'm no audio engineer, but I know enough conceptually about crossovers and frequencies to be dangerous.

 

[SucreTease]

If we standardize on the same audio files (easily done thanks to posters) then we can start gathering more data regardless of how it should or should not be. Since I have base audio with MCU1, and MCU2 soon, I'll go ahead and see what frequency "falloffs" I have on all the doors. Let me know if there's anything else you'd like me to test for more data points. I'm no audio engineer, but I know enough conceptually about crossovers and frequencies to be dangerous.

It would be great if you could measure the frequency spectrum before and after (with the equalizer settings flat).

 

[WASD]

Might be hard to isolate each driver without disconnecting the others, but a good baseline would be to do octave sweeps on each driver to confirm which frequencies each one is playing before and after the MCU install to see if there are any differences. Also doing a full sweep to measure the overall response before and after (with all EQ settings at defaults of course).

That would show us individual driver changes and the overall sound signature between the two MCU.

I would offer to do this as well, but my whole stock system has been ripped out and my new system is almost complete. I'm interested in the differences between MCU1 and MCU2 since I will be doing the upgrade when it's available, and I don't want to have to retune the input section of the DSP.

 

[CraigE1965]

@WASD , What you are saying is completely ridiculous for the standard 5 speaker system. And I can tell you for a fact that I have had over 25 cars with both stock, premium, and aftermarket systems, and what is going on in my car now is NOT right. With MCU1 the 2 rear door speakers worked properly, they had the same level of volume as the front door speakers (not 1/2), and more importantly they had bass, for 2 years I put the balance towards the back for my teenagers to feel the thump of the bass, and when they weren't in the car I moved the balance to the middle, and still heard volume and bass from the rear speakers. I always listened to it at 4 or 5 volume max. Once MCU2 was upgraded, 7 or 8 is the equivalent volume, there is no bass at all coming out of the 2 rear speakers, and all other audio from them is 1/2 volume and muffled, the 2 rear door speakers are now completely useless. And it seems the center dash speaker is now doing the majority of the bass (along with the 2 front door speakers to a lesser degree). There is no scenario in this universe where you can say my good sounding system where all speakers worked properly with MCU1 is now ok or better or should be that way after the MCU2 install. It simply broke the stereo system, and will get fixed one way or the other.

 

[WASD]

@WASD , What you are saying is completely ridiculous for the standard 5 speaker system. And I can tell you for a fact that I have had over 25 cars with both stock, premium, and aftermarket systems, and what is going on in my car now is NOT right. With MCU1 the 2 rear door speakers worked properly, they had the same level of volume as the front door speakers (not 1/2), and more importantly they had bass, for 2 years I put the balance towards the back for my teenagers to feel the thump of the bass, and when they weren't in the car I moved the balance to the middle, and still heard volume and bass from the rear speakers. I always listened to it at 4 or 5 volume max. Once MCU2 was upgraded, 7 or 8 is the equivalent volume, there is no bass at all coming out of the 2 rear speakers, and all other audio from them is 1/2 volume and muffled, the 2 rear door speakers are now completely useless. And it seems the center dash speaker is now doing the majority of the bass (along with the 2 front door speakers to a lesser degree). There is no scenario in this universe where you can say my good sounding system where all speakers worked properly with MCU1 is now ok or better or should be that way after the MCU2 install. It simply broke the stereo system, and will get fixed one way or the other.

I was mainly referring to the UHFS which is what I have and the original OP has. I know for a fact that Tesla did extensive tuning to the DSP for the UHFS system and they have stated such.

I don't know how the stock 5 speaker system is tuned, but I imagine that it doesn't have the same type of tuning as the UHFS.

So if you take what I said about the UHFS system and apply it to your stock system, then you would likely experience the lack of sound/bass coming from the rear. Maybe Tesla accidentally loaded the UHFS tuning in your stock system car. Just because you have had a certain type of audio system in your cars doesn't mean that others do not exist. I have had 8 cars, this Tesla being my 9th. Quantity of cars doesn't matter. I have had systems that you describe, basic passive systems that have high quality components (headunits, amps, drivers, etc.) and they sounded fine. I've also had full active systems like I've been describing (and what the UHFS is) and the sound quality is on a whole different level. Just because something doesn't make sense to you doesn't mean it's not real. Yes, if Tesla loaded the UHFS tuning into your car that does not have the extra amp, bigger front door speakers, and subwoofer, it would indeed sound terrible.

Again, as I said before, I'm not arguing that you should be happy with how your car sounds or just accept it and move on. You should most definitely bring this up to Tesla and find a way to rectify it if you can, or at minimum get an explanation from them as to why it is happening. Maybe you can tell them you think that the UHFS tuning got flashed in to your MCU by mistake? Tesla doesn't make the basic/standard audio system anymore, so it would make sense that they may have forgotten to put that software in the new MCUs. I'm not trying to debate or argue with you, I'm trying to add (hopefully) valuable information to this thread.

 

[agtdDelirium]

Out of curiosity, I looked up some dates. MCU2 was launched in March 2018. I couldn't find the exact date but only references made to the fact that all Model S and X were produced with only UHFS by "mid-2018." That is pretty close timing.

Were there any MCU2 cars originally produced with standard audio? And if not, maybe MCU2 only has audio tuning written for UHFS? That would really screw a 5 speaker system. I hope that's not the case or Tesla really does need to change it fast.

BTW, Tesla Tap has a good description of the different audio systems and speaker sizes in the various configurations.

Audio Systems for the Tesla Model S and Model X | TeslaTap

 

[sonofagunn]

Maybe this info will help...

I recently bought an early 2014 Model S with Premium Audio and still an original MCU1. I have been extremely impressed with the clarity of the audio. Sometimes I hear songs and they sound almost alien because I hear things in the songs I've never noticed before.

As a quick test after reading this thread, I changed the balance from front to back and immediately noticed that the rear speakers were much softer with less bass. I then turned off Dolby Audio and changed the balance. With Dolby Audio off, there is volume and bass balance between the front and rear. To me, it sounds like Dolby Audio turns the system into a home theatre style system where the rears are surround sound speakers and the majority of the sound is carried by the fronts. But if you turn Dolby off, it turns into a more traditional car stereo system.

Maybe the difference people are noticing between MCU1 and MCU2 is because the setting of Dolby Audio has been changed from off to on?

I'm not saying for sure this is the case, just something else to explore. The reports of poor audio with MCU2 have me cautious to upgrade so I just want to help find out what is going on.

 

[WASD]

... maybe MCU2 only has audio tuning written for UHFS? That would really screw a 5 speaker system. I hope that's not the case or Tesla really does need to change it fast.

Yeah, that's what I'm thinking as well and basically what I was alluding to in my previous post.

Also, I'm thinking they re-tuned the UHFS in MCU2. I know they took out "Dolby" and introduced "Immersive" sound, maybe that was not just a branding change but a retuning of the system.

So that would explain the two issues that are happening. Old UHFS users getting new UHFS tuning (altering the sound), and standard users getting UHFS tuning on non-UHFS speakers producing terrible audio across the board with little to no rear output.

Sounds like a major oversight, but par for the course with Tesla....

 

[smilepak]

Maybe this info will help...

I recently bought an early 2014 Model S with Premium Audio and still an original MCU1. I have been extremely impressed with the clarity of the audio. Sometimes I hear songs and they sound almost alien because I hear things in the songs I've never noticed before.

As a quick test after reading this thread, I changed the balance from front to back and immediately noticed that the rear speakers were much softer with less bass. I then turned off Dolby Audio and changed the balance. With Dolby Audio off, there is volume and bass balance between the front and rear. To me, it sounds like Dolby Audio turns the system into a home theatre style system where the rears are surround sound speakers and the majority of the sound is carried by the fronts. But if you turn Dolby off, it turns into a more traditional car stereo system.

Maybe the difference people are noticing between MCU1 and MCU2 is because the setting of Dolby Audio has been changed from off to on?

I'm not saying for sure this is the case, just something else to explore. The reports of poor audio with MCU2 have me cautious to upgrade so I just want to help find out what is going on.

The dolby is only available to those with Premium Audio. I have the MCU1 and now MCU2 on 2015 w/o Premium. No dolby setting

 

[oldpueblo]

Good and bad news. The bad news is they bumped my appointment because they didn't have the MCU2 parts in. I had them stick to the appointment though because I had a roof leak I wanted fixed. So knowing I had more time I didn't get to the speaker testing. But when I dropped it off they said good news they did have the parts, so I authorized it. While previously driving I did spend some time fading the audio back and forth, and honestly on MCU1/Base audio for me I feel it's intentional that the bass is just mainly from the front doors. As I faded to back I could hear the mid/higher frequencies coming from the rear doors (the only speakers in back), then fading back to front the mid/higher frequencies seem to shift to the upper speakers while the bass emanates from below. As I'm sure we all know, speakers do best when they have dedicated frequencies/crossovers, so you don't end up with a jack-of-all-trades-master-of-none scenario. I can't complain about how it sounds either, so it makes me think there's something else at play here. Like maybe a different sound source. Something simple but forgettable, for example I stream Spotify from my phone with the music downloaded at the highest quality. If others are using different sources, I could see that accounting for the variations in how it sounds. It's also something that could have unknowingly changed over time. I'll report back how MCU2 sounds, we'll see what happens.

 

[oldpueblo]

Doh I can't edit. Just to be clear I think the DSP retuning thing is probably accurate as well, I think it's probably a couple different factors.

 

[CraigE1965]

I never used my phone, only the tune in and streaming stations built into the car. MCU1 rear door speakers sounded great with bass and full volume when set to rear. MCU2 has 1/2 the volume and NO bass at all in the rear door speakers now. It sounds like complete crap, not to mention you have to listen to it on 7 or 8 volume now instead of 4, to get the same level.

 

[oldpueblo]

I never used my phone, only the tune in and streaming stations built into the car. MCU1 rear door speakers sounded great with bass and full volume when set to rear. MCU2 has 1/2 the volume and NO bass at all in the rear door speakers now. It sounds like complete crap, not to mention you have to listen to it on 7 or 8 volume now instead of 4, to get the same level.

See this is what I mean. I listen on 7-8 already (with phone volume set to full), 4 would be way too quiet for me. There's so many variables involved, so it makes it harder to nail this down. Maybe some of those streaming/tunein stations have changed their bitrate over time, maybe they dynamically adjust the quality depending on the strength of the signal. Could there be a different amp or speaker brands somewhere in the supply line? We need to be able to replicate results with the same variables. The good news is I was just told that they were misinformed and the parts are not actually in stock. So I'll be getting a MCU1 car back and can try to establish a baseline of details for MCU1/Base audio at least.

 

[Cheburashka]

I looked in the service manual for a diagram of the audio system. The rear door channels are driven separately off the MCU. It's very likely that the lower rear door speaker volume is in fact a DSP implementation.