More details for KEF Audio

[Johnson]

One of the more useful piece of information I got out of Cambridge Audio's video, which they didn't mention, is that the OEM subwoofer looks to be a 6x9 oval unit with a 1-inch voice coil…

Yeah, I noticed this too. I’m confused, as the fresh air sub is supposed to be an enclosed system (not infinite baffle), ported to the outside, using the cabin as the enclosure.

https://bluacs.com/technology/freshairspeaker/

We shouldn’t be able to see the front of the cone. What‘s going on?

 

[Nova]

Yeah, I noticed this too. I’m confused, as the fresh air sub is supposed to be an enclosed system (not infinite baffle), ported to the outside, using the cabin as the enclosure.

https://bluacs.com/technology/freshairspeaker/

We shouldn’t be able to see the front of the cone. What‘s going on?

Fresh air sub is infinite baffle. The cabin volume is large enough to be at least an order of magnitude larger than the Vas of a typical subwoofer driver. We see it as enclosed in some other designs but it's acoustically not enclosed. For example the photo shown on Bluacs.com actually shows the screened backside of a subwoofer with a small neodymium magnet. The cone likely uses an inverted design to minimize depth.

 

[Speedy Emira]

After playing about with the setting and linking it to Spotify I didn’t think the sound system was that bad. Ok it could be better but l can live with it. I’ve definitely decided not to change or add anything to try and improve it because it’s going to add more weight and my intention is to reduce the weight and increase the performance.

 

[Nova]

Yea, me too. I will likely just make some EQ adjustments and live with it.

 

[Fasttoys]

I have not heard the system in the Emira. I'm waiting for CARB approval like everyone else in the US for my FE 1.0, which as of now is still in England.

The concerns you indicated for the KEF system in the Emira are absolutely valid. A small vehicle like the Emira provides both pros and cons in terms of challenges. Pros being that the small cabin typically makes it *easier* to get good bass, and cons being the small cabin typically makes it harder to get deep expansive sound stage. I have posted many theoretical critiques of the OEM KEF system and while I'm reserving judgement until I actually hear it, my guess is that KEF was so limited in what they could do with the car that they sort of just became a parts supplier. I don't know who, if anyone, did the system integration beyond setting the crossover points and relative levels. Some simple signal analysis of the amplifier outputs would be very revealing in this regard.

The Eletre is a brand new design, which I guess really allowed KEF a lot more creative/design freedom to act as a proper system integrator.

Interesting so you are jumping all in without even driving it. I have done it before and never regretted my choice. Dallas has a demo that anyone can drive been in it 8 time now and headed to Dallas Lotus in a few days. I finally got the call for my Z06 vette. Dam thing all in will cost me 128k before taxes, it’s hard to believe I am spending that much on a GM product. The Bose system in the vette is okay it’s Bose and we know they are nothing specia, love my B&O in my Audi GT or B&W in the BMW.
My ears are getting older and truly don’t need to listen to loud music anymore. My Lotus is still in the UK guess they won’t ship till approval from Carb. Dallas did not have Lotus when I got on the list in Silicon Valley meaning Board Walk as it’s close to my company.

 

[lynchy73]

Yea, me too. I will likely just make some EQ adjustments and live with it.

The EQ is just bass, mid and treble adjustment. Not going to do much correction with that. No sub control

 

[Nova]

Interesting so you are jumping all in without even driving it. I have done it before and never regretted my choice. Dallas has a demo that anyone can drive been in it 8 time now and headed to Dallas Lotus in a few days. I finally got the call for my Z06 vette. Dam thing all in will cost me 128k before taxes, it’s hard to believe I am spending that much on a GM product. The Bose system in the vette is okay it’s Bose and we know they are nothing specia, love my B&O in my Audi GT or B&W in the BMW.
My ears are getting older and truly don’t need to listen to loud music anymore. My Lotus is still in the UK guess they won’t ship till approval from Carb. Dallas did not have Lotus when I got on the list in Silicon Valley meaning Board Walk as it’s close to my company.

Yep, I figure the Emira's driving feel and dynamics is so far above anything else I would buy that I don't need to drive it to know that I would love it.

 

[Nova]

The EQ is just bass, mid and treble adjustment. Not going to do much correction with that. No sub control

I knew this but reading it again still makes me sad.

 

[Porter]

The KEF Uni-Q is a bit unique because it's one of the few designs that keeps a pretty stable stereo image when toed in so far that the axis crosses well in front of the listener. In fact, some KEF reference systems are set up that way intentionally in listening rooms.

I'm not saying that that solves any of the audible issues with the Emira, I'm just pointing out that the fact that the tweeters aren't up on the A-pillar isn't necessarily a fundamental problem with these particular drivers and their potential for reasonable sound reproduction to the listening position.

I suspect a good multi-band EQ and some time with an RTA would produce a reasonable outcome. Rather than trying to do that through the head unit, it's probably possible to tune or EQ the Harman DSP amp directly using their control software. That's the route that I would take rather than trying to do something completely custom in the aftermarket and try to resolve all the technical challenges around that.

 

[Nova]

The KEF Uni-Q is a bit unique because it's one of the few designs that keeps a pretty stable stereo image when toed in so far that the axis crosses well in front of the listener. In fact, some KEF reference systems are set up that way intentionally in listening rooms.

I'm not saying that that solves any of the audible issues with the Emira, I'm just pointing out that the fact that the tweeters aren't up on the A-pillar isn't necessarily a fundamental problem with these particular drivers and their potential for reasonable sound reproduction to the listening position.

I suspect a good multi-band EQ and some time with an RTA would produce a reasonable outcome. Rather than trying to do that through the head unit, it's probably possible to tune or EQ the Harman DSP amp directly using their control software. That's the route that I would take rather than trying to do something completely custom in the aftermarket and try to resolve all the technical challenges around that.

The Harman amp has a SigmaDSP chip, but there is no way to adjust it except with specialized connection (USBi?), power mode, and software. It's the job of the onboard micro controller to load the DSP profile on power up. So any changes you manage to make will be overwritten.

I am very curious how the Audison processor gets a full range signal out of the Harman Amp. It would be amazing if it did some kind of signal splicing - measure the impulse response of each amp channel and then used the sum of those signals to reconstruct a flat full range signal.

 

[Speedy Emira]

The Harman amp has a SigmaDSP chip, but there is no way to adjust it except with specialized connection (USBi?), power mode, and software. It's the job of the onboard micro controller to load the DSP profile on power up. So any changes you manage to make will be overwritten.

I am very curious how the Audison processor gets a full range signal out of the Harman Amp. It would be amazing if it did some kind of signal splicing - measure the impulse response of each amp channel and then used the sum of those signals to reconstruct a flat full range signal.

Blimey you guys are on a different planet with your knowledge compared to me. This makes me realise I know nothing about car audio systems.

 

[digilotus]

What I haven't quite worked out with the factory KEF setup is how the speakers can be driven by 8 amplification channels. By my count, the KEF setup requires 9 amplification channels as follows:

* Centre dash - KEF UniQ: tweeter + midrange (2x amp channels).
* Left and right door cards - 2x KEF UniQ: tweeter + midrange (4x amp channels).
* Left and right B pillars behind driver/passenger - (2x amp channels).
* Subwoofer - (1x amp channel).

Can anyone who has undertaken some audio modifications in the Emira explain how the amp channels are all wired up?

 

[Porter]

The Harman amp has a SigmaDSP chip, but there is no way to adjust it except with specialized connection (USBi?), power mode, and software. It's the job of the onboard micro controller to load the DSP profile on power up. So any changes you manage to make will be overwritten.

I am very curious how the Audison processor gets a full range signal out of the Harman Amp. It would be amazing if it did some kind of signal splicing - measure the impulse response of each amp channel and then used the sum of those signals to reconstruct a flat full range signal.

I doubt the Harman amp is customized to the point of full lockout, the control software I believe is available to hobbyists since they do sell more than one version of the hardware on the open market under both the Harman and JBL brands. Could be a fun experiment.

 

[Time2Fly]

I doubt the Harman amp is customized to the point of full lockout, the control software I believe is available to hobbyists since they do sell more than one version of the hardware on the open market under both the Harman and JBL brands. Could be a fun experiment.

Let's hope!

 

[Nova]

What I haven't quite worked out with the factory KEF setup is how the speakers can be driven by 8 amplification channels. By my count, the KEF setup requires 9 amplification channels as follows:

* Centre dash - KEF UniQ: tweeter + midrange (2x amp channels).
* Left and right door cards - 2x KEF UniQ: tweeter + midrange (4x amp channels).
* Left and right B pillars behind driver/passenger - (2x amp channels).
* Subwoofer - (1x amp channel).

Can anyone who has undertaken some audio modifications in the Emira explain how the amp channels are all wired up?

I thought of this exact question and have a couple of theories about this…

One is that the rear fill is mono - which is possible.

Another possibility is that the 8 channel Harman amp is not a one to one map on top of the CX11 amp. They could be working in parallel, or one channel from the CX11 could map to two channels on the Harman amp.

 

[Eagle7]

I doubt the Harman amp is customized to the point of full lockout, the control software I believe is available to hobbyists since they do sell more than one version of the hardware on the open market under both the Harman and JBL brands. Could be a fun experiment.

A software EQ with the ability to choose crossover filters would be ideal, although for a car like the Emira, I don't know how much you're going to be able to do because of the noise the car itself generates.

 

[Fasttoys]

I tested the Kef system again in a dealer-owned car tested for a long time around 35 minutes. This car is a Dealer car as they bought it and are waiting for Carb is approval. I was able to sit and at least spend some time in the car to listen and test the Nav/audi systems. I was able to set up Apple Car Play & use some other sources from my phone with higher-end source material. What is interesting is the sound was better than the Demo cars I was able to drive during test drives & sit in them afterward. The SUB was better than the other Demo Emira's I was able to listen to. The highs were okay I changed them in the settings which helped during certain music listening. What was strange was the volume control needed to be at 85% to get enough volume out of the speakers. If I had done this in my Audi B&O system my ears would have been bleeding and the speakers would have been distorted and damaged (Max I put that system is at half volume most listening is at 35 to 40%. The Emira system felt like it has a limiter of some sort maybe it's protecting the amp not sure. I was told in the KEF Lotus SUV that you can't control the base because the built-in EQ systems control that sub-system volume.

I know in my home I have 4 Sonos amps & in the APP you can control the max volume limit so if you're having a party the system will only go to a % volume of your choice. I have mine st at 65% MAX to protect the system/speakers. I need to do this when the wife has friends over during her crazy parties to protect the system & stop calls from the HOA. You would think that 4 Sonus Amps & 8 total (8-inch Monitor Audio C380-IDC ceiling speakers with the largest Sonus sub (Gen-3) would be enough, no not for her and her friends. ( I won't allow them in the home theater, way too complex & too much power)

Anyway back to the Emira I played all types of music and if I had to rate it on a scale from 10 being the best and 0 being the worst I rated it to be a middle 5. The Demo cars I was able to drive and listen to in the past were considered a solid 2 max in my ratings. I am not sure what happened but at least I can say it was not horrible like I mentioned in the past post. I wonder if the AMP or the volume is limited because on 99% of any cars I ever listened to in my time if you put the volume at 65% or higher the speakers and the system would have distortion and major issues would arise (Damage to the drivers). Anyway after today's experience, I bet there will be new Emira USA owners that will be okay with the system and with some that are not as picky being happy. Anyway felt I would post it and I also drove a Demo car this week the Emira is a very nice car, with interior and fit and finish light years better than its predecessor, yes the shifter is notchy similar to my old Evora & it is not butter smooth like my previous Porsches. What was funny after I drove the Emira this week, I was able to drive a friend's new C8 Z06, that car is just stupidly loud & way too fast for the streets ( Feels very Lambo Aventador not like Hurcan). I still want one I have about 6 weeks to decide as my allocation came up but I am not sure where I will be able to drive that thing, It feels much larger than the Emira in every way but the power is on another level of crazy town.

Anyway at least in this Emira, it's not that bad as I said in my previous post. This was a production vehicle that could be sold, not a pre-production/demo car. But let me be clear this is not a customer's car, I would never do that, this is a dealer-owned car that they will be keeping for the near future.

 

[Liquid Hot Magma]

Kef tested again today in a VIN dealer-owned car tested for a long time around 35 minutes. This car is a Dealer car as they bought it but it can't be driven till Carb is approved. I was able to sit and at least spent some time in the car to listen and test the Nav/systems & stuff. I was able to set up Apple Car Play & use some other sources from my phone with higher-end source material. What is interesting is the sound was better than the Demo cars I was able to drive during test drives & sit in them afterward. The SUB was better than the other Demo Emira's I was able to listen to. The highs were okay I changed them in the settings which helped during certain music listening. What was strange was the volume control needed to be at 85% to get enough volume out of the speakers. If I had done this in my Audi B&O system my ears would have been bleeding and the speakers would have been distorted and damaged (Max I put that system is at half volume most listening is at 35 to 40%. The Emira system felt like it has a limiter of some sort maybe it's protecting the amp not sure. I was told in the KEF Lotus SUV that you can't control the base because the built-in EQ systems control that sub-system volume.

I know in my home I have 4 Sonos amps & in the APP you can control the max volume limit so if you're having a party the system will only go to a % volume of your choice. I have mine st at 65% MAX to protect the system/speakers. I need to do this when the wife has friends over during her crazy parties to protect the system & stop calls from the HOA. You would think that 4 Sonus Amps & 8 total (8-inch Monitor Audio C380-IDC ceiling speakers with the largest Sonus sub (Gen-3) would be enough, no not for her and her friends. ( I won't allow them in the home theater, way too complex & too much power)

Anyway back to the Emira I played all types of music and if I had to rate it on a scale from 10 being the best and 0 being the worst I rated it to be a middle 5. The Demo cars I was able to drive and listen to in the past were considered a solid 2 max in my ratings. I am not sure what happened but at least I can say it was not horrible like I mentioned in the past post. I wonder if the AMP or the volume is limited because on 99% of any cars I ever listened to in my time if you put the volume at 65% or higher the speakers and the system would have distortion and major issues would arise (Damage to the drivers). Anyway after today's experience, I bet there will be new Emira USA owners that will be okay with the system and with some that are not as picky being happy. Anyway felt I would post it and I also drove a Demo car this week the Emira is a very nice car, with interior and fit and finish light years better than its predecessor, yes the shifter is notchy similar to my old Evora & it is not butter smooth like my previous Porsches. What was funny after I drove the Emira this week, I was able to drive a friend's new C8 Z06, that car is just stupidly loud & way too fast for the streets ( Feels very Lambo Aventador not like Hurcan). I still want one I have about 6 weeks to decide as my allocation came up but I am not sure where I will be able to drive that thing, It feels much larger than the Emira in every way but the power is on another level of crazy town.

Anyway at least in this Emira, it's not that bad as I said in my previous post. This was a production vehicle that could be sold, not a pre-production/demo car. But let me be clear this is not a customer's car, I would never do that, this is a dealer-owned car that they will be keeping for the near future.

Thanks for the report and sharing your thoughts. Were you able to A/B compare the same music through wireless vs. wired CarPlay? Wireless is limited in bandwidth compared to wired. Could you detect a noticeable difference in audio quality?

 

[Fasttoys]

Thanks for the report and sharing your thoughts. Were you able to A/B compare the same music through wireless vs. wired CarPlay? Wireless is limited in bandwidth compared to wired. Could you detect a noticeable difference in audio quality?

Could not plug it in, no cable so this was all done through Wireless CP.

 

[Eagle7]

Kef tested again today in a VIN dealer-owned car tested for a long time around 35 minutes. This car is a Dealer car as they bought it but it can't be driven till Carb is approved. I was able to sit and at least spent some time in the car to listen and test the Nav/systems & stuff. I was able to set up Apple Car Play & use some other sources from my phone with higher-end source material. What is interesting is the sound was better than the Demo cars I was able to drive during test drives & sit in them afterward. The SUB was better than the other Demo Emira's I was able to listen to. The highs were okay I changed them in the settings which helped during certain music listening. What was strange was the volume control needed to be at 85% to get enough volume out of the speakers. If I had done this in my Audi B&O system my ears would have been bleeding and the speakers would have been distorted and damaged (Max I put that system is at half volume most listening is at 35 to 40%. The Emira system felt like it has a limiter of some sort maybe it's protecting the amp not sure. I was told in the KEF Lotus SUV that you can't control the base because the built-in EQ systems control that sub-system volume.

I know in my home I have 4 Sonos amps & in the APP you can control the max volume limit so if you're having a party the system will only go to a % volume of your choice. I have mine st at 65% MAX to protect the system/speakers. I need to do this when the wife has friends over during her crazy parties to protect the system & stop calls from the HOA. You would think that 4 Sonus Amps & 8 total (8-inch Monitor Audio C380-IDC ceiling speakers with the largest Sonus sub (Gen-3) would be enough, no not for her and her friends. ( I won't allow them in the home theater, way too complex & too much power)

Anyway back to the Emira I played all types of music and if I had to rate it on a scale from 10 being the best and 0 being the worst I rated it to be a middle 5. The Demo cars I was able to drive and listen to in the past were considered a solid 2 max in my ratings. I am not sure what happened but at least I can say it was not horrible like I mentioned in the past post. I wonder if the AMP or the volume is limited because on 99% of any cars I ever listened to in my time if you put the volume at 65% or higher the speakers and the system would have distortion and major issues would arise (Damage to the drivers). Anyway after today's experience, I bet there will be new Emira USA owners that will be okay with the system and with some that are not as picky being happy. Anyway felt I would post it and I also drove a Demo car this week the Emira is a very nice car, with interior and fit and finish light years better than its predecessor, yes the shifter is notchy similar to my old Evora & it is not butter smooth like my previous Porsches. What was funny after I drove the Emira this week, I was able to drive a friend's new C8 Z06, that car is just stupidly loud & way too fast for the streets ( Feels very Lambo Aventador not like Hurcan). I still want one I have about 6 weeks to decide as my allocation came up but I am not sure where I will be able to drive that thing, It feels much larger than the Emira in every way but the power is on another level of crazy town.

Anyway at least in this Emira, it's not that bad as I said in my previous post. This was a production vehicle that could be sold, not a pre-production/demo car. But let me be clear this is not a customer's car, I would never do that, this is a dealer-owned car that they will be keeping for the near future.

This sounds about right for a new system that hasn't been broken-in yet. Give it about 25+ hours of listening, and the sound should warm up with a little more volume and sound richer. High-end speakers need this, and they may very well have a volume limiter on it until listening hours have reached a certain number.

I'm definitely going to have my system on while I drive around for the 1,000 mile break-in period. It will be interesting to see what happens.

Nice write-up!