Audio thread- to KEF or not to KEF?

Nova

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Taking a step back, I would argue that it's probably unnecessary to use any sort of DAC as a signal *source* into the head unit. The reason I say this is that looking at the design of the headunit (built by LG electronics), the entire signal path from the Bluetooth module to the headunit audio core, to the amplifier, is completely digital. There is *NO* DAC at all in the head unit. The conversion happens *IN* the amplifier after the SigmaDSP ADAU1466 chip. I don't know what DAC chip is being used, but it feeds the Class-C NXP amplifier chips directly. Since the signal chain remains purely digital up to this point, it's not really logical to try and add a DAC anywhere else.

Edit: in earlier/older/other headunits, it was common for the Bluetooth module to be an "afterthought" and implemented as an analog input into the headunit. Depending on the choice of coupling capacitors, poorly implemented Bluetooth modules are prone to noise and poor frequency response. In those cases, sending music in via the AUX input may in fact provide superior audio. But this doesn't appear to be the case for the Emira.
 
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Taking a step back, I would argue that it's probably unnecessary to use any sort of DAC as a signal *source* into the head unit. The reason I say this is that looking at the design of the headunit (built by LG electronics), the entire signal path from the Bluetooth module to the headunit audio core, to the amplifier, is completely digital. There is *NO* DAC at all in the head unit. The conversion happens *IN* the amplifier after the SigmaDSP ADAU1466 chip. I don't know what DAC chip is being used, but it feeds the Class-C NXP amplifier chips directly. Since the signal chain remains purely digital up to this point, it's not really logical to try and add a DAC anywhere else.

Edit: in earlier/older/other headunits, it was common for the Bluetooth module to be an "afterthought" and implemented as an analog input into the headunit. Depending on the choice of coupling capacitors, poorly implemented Bluetooth modules are prone to noise and poor frequency response. In those cases, sending music in via the AUX input may in fact provide superior audio. But this doesn't appear to be the case for the Emira.
Thanks for the thorough explanation- it sounds like DAC isn’t the solution.

Nova, I am curious- have you had a chance to hear the KEF audio in the Emira yet? What are your thoughts?
 

Nova

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Thanks for the thorough explanation- it sounds like DAC isn’t the solution.

Nova, I am curious- have you had a chance to hear the KEF audio in the Emira yet? What are your thoughts?
I have not. I am also not sure if any of the test drive vehicles have the final sound system configuration. It seems that things have improved for other aspects of the car between test-drives and final delivery. I am hopeful that the sound system has also improved.

My expectations are tempered, however. There may be some serious issues with the sound system based on how it's described by others who have taken delivery. The causes may range from individual sample defect, to poor system integration, to poor system design in terms of driver characteristics and install location.
 

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I have not. I am also not sure if any of the test drive vehicles have the final sound system configuration. It seems that things have improved for other aspects of the car between test-drives and final delivery. I am hopeful that the sound system has also improved.

My expectations are tempered, however. There may be some serious issues with the sound system based on how it's described by others who have taken delivery. The causes may range from individual sample defect, to poor system integration, to poor system design in terms of driver characteristics and install location.
Or, to play devil's advocate, it may simply be a well frequency-balanced system (including in the midbass and bass) and most people have never heard that in a car. If it doesn't have a big frequency hump giving a perceived "kick" in the midbass, most people will say the quality is low, even if it's subjectively high quality to a trained ear and also measures well.

It's also possible that the system hasn't been engineered with enough road noise compensation to suit many people's preference. That's a related but slightly different issue.

What I'm driving at is that it might be quite good from an audio science perspective and still not meet some people's particular expectations.
 

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It could also have a lot to do with the type of music people listen to, and the quality of the sound source. The one thing high-end sound systems tend to do, is really show the difference in source quality; sometimes it can be quite stark. Most low to mid-range systems typically color and compensate for deficiencies in their systems, and if you don't know this, you think it's the sound source that's making it sound like that, but it isn't. Play that same sound source through a high-end system and suddenly it can sound terrible. People mistakenly blame the system, without realizing that it's correctly reproducing what the source actually sounds like without the coloring and compensation.

On a high-end system, mediocre on lesser systems sounds bad, ok sounds mediocre, good sounds ok, great sounds good, and truly great sounds epic. It all comes down to how the source was recorded, mixed and mastered. There can be an amazing amount of difference which most people probably don't realize.
 

Nova

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Or, to play devil's advocate, it may simply be a well frequency-balanced system (including in the midbass and bass) and most people have never heard that in a car. If it doesn't have a big frequency hump giving a perceived "kick" in the midbass, most people will say the quality is low, even if it's subjectively high quality to a trained ear and also measures well.

It's also possible that the system hasn't been engineered with enough road noise compensation to suit many people's preference. That's a related but slightly different issue.

What I'm driving at is that it might be quite good from an audio science perspective and still not meet some people's particular expectations.

Very true. I'm concerned that this is the issue, that the subwoofer design doesn't generate enough output to deliver the approximately +6dB bass output relative to 1kHz that people find "pleasing". Normal listeners also tend to prefer a bit more treble output and associate that with "detail". Audiophiles prefer a "boring" sound signature.
 

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Taking a step back, I would argue that it's probably unnecessary to use any sort of DAC as a signal *source* into the head unit. The reason I say this is that looking at the design of the headunit (built by LG electronics), the entire signal path from the Bluetooth module to the headunit audio core, to the amplifier, is completely digital. There is *NO* DAC at all in the head unit. The conversion happens *IN* the amplifier after the SigmaDSP ADAU1466 chip. I don't know what DAC chip is being used, but it feeds the Class-C NXP amplifier chips directly. Since the signal chain remains purely digital up to this point, it's not really logical to try and add a DAC anywhere else.

Edit: in earlier/older/other headunits, it was common for the Bluetooth module to be an "afterthought" and implemented as an analog input into the headunit. Depending on the choice of coupling capacitors, poorly implemented Bluetooth modules are prone to noise and poor frequency response. In those cases, sending music in via the AUX input may in fact provide superior audio. But this doesn't appear to be the case for the Emira.
I have a Firefly LDAC in my M100 so I can stream from my phone to the head unit which is basically a radio with a CD player. Makes a big difference.
 

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I have a Firefly LDAC in my M100 so I can stream from my phone to the head unit which is basically a radio with a CD player. Makes a big difference.

LDAC is as good as hard-wired, especially in a car environment. Even good old SBC is actually pretty good. It's just that earlier implementations made poor configuration choices in the name of better range and lower latency. That or they were unoptimized designs, especially for an automotive environment. Modern Bluetooth modules used in car audio systems are much better optimized and specialized, even if most of them are still just using SBC.
 
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Very true. I'm concerned that this is the issue, that the subwoofer design doesn't generate enough output to deliver the approximately +6dB bass output relative to 1kHz that people find "pleasing". Normal listeners also tend to prefer a bit more treble output and associate that with "detail". Audiophiles prefer a "boring" sound signature.
Thanks for confirming what I already suspected: I'm not an audiophile!!
 

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One interesting finding that I think is strange: When you turn the "seating position tuning" (balance) all the way left or right you not just turn the mid / hi frequency range more to the left or right speaker. You actually kill all other channels completely once going far left or far right. You don't just lower their output, you completely switch them off.

Means that they must have attached the sub to a center channel that gets killed when going left or right. A strange design idea in my opinion to remove their frequency range output completely when tweaking the driver focus of the audio balance.

You end up with -just- the speaker in the door playing when you turn the balance all the way to one side.

None of the other cars I have ever had did this and in my opinion shows that there are some strange design decision when it comes to chaining crossovers and amps etc.

Regarding the volume: It may also just be a hidden software setting that has a too low input -db for the preamp (if there is any as per @Nova s statement) or power amp stage. Something that could give the system more power with a software update. Also the volume knob is software based and can probably have it's max setting adjusted via an update. The system does not sound as if it couldn't handle a higher output when turned up to the max.
 

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Yesterday I was just sitting in the garage and listened to the sound of the KEF system, engine was turned off.

And I really like the sound quality of the system. It has one of the best cohesive quality when it comes to speech intelligibility, it's like listening with good headphones, you start hearing all the details that are normally not present with other brands. Also instruments sound very naturally.

But sometimes it's also too much for my tasting, depending on the records you play.

My equalizer setup I now use is:

trebble: -2
mids: -1
bass: +1
 

Nova

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Yesterday I was just sitting in the garage and listened to the sound of the KEF system, engine was turned off.

And I really like the sound quality of the system. It has one of the best cohesive quality when it comes to speech intelligibility, it's like listening with good headphones, you start hearing all the details that are normally not present with other brands. Also instruments sound very naturally.

But sometimes it's also too much for my tasting, depending on the records you play.

My equalizer setup I now use is:

trebble: -2
mids: -1
bass: +1
Thanks for the feedback. I am guessing the biggest "sin" of this system is a lack of bass. Can't wait to listen to it myself.
 

Eagle7

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Thanks for the feedback. I am guessing the biggest "sin" of this system is a lack of bass. Can't wait to listen to it myself.
These types of speakers are designed to reproduce what's actually there, not add to it. This is why the quality of source material becomes so much more important. As they break in, a high end speaker will warm up in the bass and mid-range, but it will not add bass. Cheaper systems add bass because their manufacturers know that's the wow factor people like, so even mediocre source material sounds punchy. Put that same source on a high end system, and suddenly it sounds thin and tinny, lacking in bass, so people assume it's the system, but it's not. That's actually how the original was recorded and mastered.

Bass frequencies are very strong and powerful, so they can easily overwhelm microphones and recording equipment. To prevent clipping and distortion, recording engineers will EQ down bass freqs, and/or lower the volume in that range to prevent that. Since people like volume, they think loud is better, engineers will raise the volume level of the entire recording to make it louder, even though they've lowered the bass frequencies. They'll compress the dynamic range of the entire recording, and move it up to the top of the dynamic range just to make it louder overall. Sound system and speaker companies know this, so they add punch to the bass frequencies to make up for what was done by the recording engineers. This results in lots of bass and punch, but in reality very little dynamic range between loud and quiet.

Some recordings are done so they can capture a much wider dynamic range. Classical music, string quartets, piano, etc. are instruments that benefit greatly from dynamic range. They're recorded in such a way as to not filter down the bass, but allow the full range of the instruments to be recorded. In order to do this, they have to lower the overall volume to avoid clipping and distortion when things get loud. A good system will reproduce all that accurately without coloring or adding anything to it. You'll hear bass, but it won't over-power. You'll hear richness, depth, fullness along with all kinds of detail and sound space imaging. This is something you really notice on a high end pair of headphones, because there's no environment issues to interfere with what you're listening to. A car is a terrible listening environment, so that's not the best place to evaluate high end speakers. Depending on whether your interior is leather or Alcantara, you'll probably have to play around with the EQ somewhat to get the best results. It's also going to depend on what you listen to and how well it was recorded, but if you choose high quality source material, the KEF system should deliver without muddying it up.
 

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Just made an observation today that on the Lotus website, for FE cars, it states that the KEF system is 560W. Are they upgrading the current 340W systems that are being delivered?
 

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That was the original spec but they were uprated during validation and all production cars are the higher output.
 

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Hi EyeFour Eemeerah!
Your “analogy” between high quality waxes that gives a deep, wet lustre with playing vinyl albums on a high quality turntable and cartridge was noted and appreciated. I also appreciated your mentioning that «analog is palpable and you become part of the music. Warm and with depth.» I am a staunch analog supporter, and I am behind one of the leading boutique pickup (phono cartridge) brands available around the world that is said to deliver “absolute sound”.

I am a little unsure how you went from flat hollow, lifeless, shiny, shrill mp3 like ceramic to personally doing PPF and ceramic for protection and longevity? Maybe the latter is more like high-bit, high-over sampling (aka quadruple 11.2MHz DSD) that an audiophile may be willing to live with as a supplement to his/her vinyl collection?

I think we speak the same language, and I may also consider PPF with the addition of some ceramic whenever my ordered Emira FE shows up in my driveway.
Apologies as this is unrelated but seeing you are an audiophile, have you heard the KEF system in the car and if so, what's your opinion on it? I have yet to hear it in person and to be honest, I have yet to try out any products from KEF.
 

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Apologies as this is unrelated but seeing you are an audiophile, have you heard the KEF system in the car and if so, what's your opinion on it? I have yet to hear it in person and to be honest, I have yet to try out any products from KEF.
I am familiar with the KEF brand and their audiophile speakers over 40 -50 years. I am thrilled by the fact that the Emira will be he first car model to feature this brand’s coaxial speakers in a car stereo system.

However, except for a brief demo of the Emira’s car stereo system at my Lotus dealer with preset music material (not of my choice, and of unknown bitrate and quality level), it did not enthuse me at all. I far prefer the Harman Kardon car stereos in my 2008 and 2013 BMW 3-series cars).

Anyhow, except for the KEF speakers, the rest of the system (the electronics) come from a more “generic” source, and it is unknown who did the overall “design coordination” of this audio system. The power amp is said to be branded Harman Kardon (DCY11), but the Harman Kardon brand itself has been sold off a few times, and the design of new products are farmed out to subcontractors, so there is no guarantee of a particular sound or quality, and possibly little consistency between individual products.

The subwoofer in the Emira is an Australian design called The Fresh Air Speaker, and the characteristic is that it does not have a dedicated enclosure to itself, but it is mounted internally into the Emira in a way that it uses the cavity of the Emira itself as the enclosure. This will definitely mean that it will sound and work differently depending on whether the side windows are open or closed. I would definitely prefer a subwoofer with a clearly defined enclosure, even though it has to be a small one, and that the bass frequencies will be limited by the size of the enclosure.

Soon a few friends in Japan will take delivery of their Emira V6 FE, and I may have more chance to listen and test. However, so far my overall impression from reading others impressions on this forum is that the sound quality of the Emira’s KEF audio is “so-so”, and that you have better focus on listening to the exhaust and supercharger (In the V6 FE), and that the Emira as sportscar has other attractions than audio quality.

After I get my own car, this is obviously an area that I will explore and work on. I may for example switch to another subwoofer. I have a particular German brand in mind. I do believe the KEF speakers themselves will work well, and I will look for ways to enhance the core of the audio system and the power supply to the system.
 

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