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KEF System Casual Analysis

Nova

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Picking up the Emira, I didn't listen to the sound system much on the 300 mile drive home. What little I did listen, it sounded thin and I wasn't sure if the subwoofer was working. It's been a few days and I was able to spend a bit of time listening to it. Again the system sounded thin, and I checked the equalizer settings were all flat. So I did a "Audio Settings Reset" and all of a sudden, there was bass. I am not sure what happened. The following are my listening impressions, all done through Android Auto playing Spotify. I'll take some measurements when I have time.

Volume: Overall volume is good. It got about as loud as I would be comfortable listening to without hearing damage. In fact, I had to lower it a 2-3 clicks from max just to be safe. The car is very loud when it is being driven, so the audio system will sound "quieter" since there is reduced dynamic range due to the high noise floor. However, keeping in mind the potential for hearing damage, it doesn't really need to be louder than it already is. It certainly is powerful enough to enjoy to over the engine/road noise. If anyone feels some type of way about the volume being set to near max, that's purely a psychological consideration from the days of analog audio when system sensitivity had to be high enough to work with a wide range of input sources. In the modern days of digital audio, we know with absolute certainty what the full input signal level is going to be, so the system only needs to be as sensitive as the level for numerical saturation, no more.

Bass: Bass quality is mediocre, better than some of the Mercedes Burmester systems I've listened to but not as good as many other premium audio systems I've enjoyed. The main issue is lack of low end extension. It feels like the subwoofer output falls off fairly quickly after about 40Hz. There is ample midbass output, especially upper midbass, giving percussion instruments good impact and "punch". If the low bass extension was better, it would significantly improve the overall quality of the sound. One good thing is that I didn't hear a lot of distortion in the bass, everything stayed under the 10% THD threshold that I'd consider problematic. I don't listen to a lot of bass heavy HipHop/R&B so those that do may have a different experience.

Midrange: Lower midrange seem a bit shy. Male vocals don't have the warm presence that I prefer. It's not a huge shortfall, maybe 2dB in the 200-400Hz region? I'd love to see what the measurements look like in this regard. If I could dial in just a bit more output in this region, it'd be golden. Clarity is great and the sound is very dynamic. Overall I'd say the midrange is pretty good, but not great.

Treble: As is, the treble sounded a little bright. It sounded "detailed" with good "air", but it was a bit too artificial. I dialed the treble equalizer setting to -2 and it sounded more balanced. Aside from that, the extension was good and I had no other complaints. Overall the treble was great after the EQ adjustment.

Overall Tonal Balance: Adding the bass, midrange, and treble together, you get the picture that the system sounds a tad bright overall, and the bass is boosted significantly in the midbass region. While parked and with the engine off, the bass is just too much by about 3-4dB and distracts from the music. With the engine on and While driving, the background noise drowns out the bass and it sounds more balanced.

Stage and Separation: Pretty darned good. The sound stage was at eye level and just slightly listener-side biased. Stereo imaging effect was very strong with distinct, convincing, and stable sound source placement. The stage width is very spacious, spanning perhaps 120 degrees in front of the listener. It's definitely one of the better car systems I've heard in this regard. Many OEM systems rely on a large number of drivers to produce a neutral tonal balance, sacrificing imaging in the process, but this KEF system was able to avoid this common pitfall.

Clarity, Noise, and Vibrations: Clarity was very good even at high volume. There was no noticeable onset of additional strain or distortion even at max volume - which while being an excellent trait, can be especially dangerous for hearing damage because you feel like you can keep turning it up. Knock on wood, my car had no audible rattles, buzzing, or vibrations. Everything seems to be fairly well buttoned down.

Summary: Overall, it's a decently good system and about par for what I'd expect from a premium OEM car audio system. I would be shocked if a base sound system was this good. Except for the bass extension, which is its key weakness, everything else works well as a package together. I really enjoy listening to it and look forward to spending more time with it during longer stretches of driving when there isn't much shifting to do.
 
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On to the measurements. Let me state clearly that I am not an expert at measuring car audio environments. I don't know all of the potential pitfalls that could happen, and I certainly don't have the right equipment for this. I am guessing that the proper measurement rig would consist of a dummy with calibrated binaural microphones. Plus, multiple measurements would need to be taken at different seat positions and the average calculated from all measurements.

What I did was sitting in the driver seat at my driving position and holding my UMIK-1 microphone to about my left ear, and rotating/moving my head around within the normal range of head movement and rotation while driving to perform a moving-mic measurement. I then repeated this with my right ear. I then averaged the two measurements and applied 1/6 octave smoothing and below is what I got:

Emira-Driver-Measurement.png


The green trace is left ear, and red trace is right ear, they are remarkably similar. The thick blue curve is the average of the two. The thin blue line is the target "house curve" that is typically the one used by home audio people. You generally want to have a sound system response that is "close" to this curve as it represents that *most* average people regard as a good sounding system. One warning about moving mic measurements is that the treble response is typically lower than fixed point measurements due to the averaging effect of off-axis movements. So the system is actually a bit brighter than what the measurements show.

Bass output rolls off after about 40Hz, and the bass response peak is at about 60Hz. Factoring in the 12dB/Octave cabin gain of car environments, this subwoofer is simply giving up below 40Hz. Ideally, you want the bass response to be just about a flat line down to about 25Hz or so.

The dip at 200Hz may correlate with the "a bit shy" comment I had. Although instead of a mild overall dip, this is a narrower dip of a more significant magnitude - about a -8dB dip if we reference the target Harman curve. Psychoacoustics theory indicates that humans hear relative loudness in "bands" of frequencies rather than fixed frequencies.

The midrange response from about 300-2kHz is nice and even.

There is a slight dip between 3-5kHz, but it's really not that severe. Female vocals may be lacking some of their natural sibilance, and some instruments may sound slightly muted, but it's not bad - I didn't hear these issues.

Relatively speaking, there is a peak at 6kHz and 10kHz, with generally elevated response in between. This may be the slight brightness that I heard? The human ear is more sensitive to peaks versus valleys in sound. Our ears are trained to notice additional information versus information that's missing.

Overall, the response curve looks decent in that it follows a general downward slope from bass towards treble. This system has obviously been tuned by someone who knows what they are doing. You don't get this type of a frequency response slope by just slapping drivers together and connecting them to an amplifier. Other than the valley at 200Hz, there are no serious issues. I'm interested in finding out if the 200Hz null is a production error: the subwoofer may be wired out of phase. I'm going to do some wire swapping when I have the time to see if the null is resolved once the subwoofer phase is reversed. Of course, it could also just be that 200Hz is the frequency that this car's cabin develops some nasty nulls near the listener's head position. If so, there is nothing that can help alleviate this, unfortunately.

In the future, I may do some sweeps so that I can check the distortion levels. That takes more work to set up, but I'll see if I can find the time.
 
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ManOfSteel

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Picking up the Emira, I didn't listen to the sound system much on the 300 mile drive home. What little I did listen, it sounded thin and I wasn't sure if the subwoofer was working. It's been a few days and I was able to spend a bit of time listening to it. Again the system sounded thin, and I checked the equalizer settings were all flat. So I did a "Audio Settings Reset" and all of a sudden, there was bass. I am not sure what happened. The following are my listening impressions, all done through Android Auto playing Spotify. I'll take some measurements when I have time.

Volume: Overall volume is good. It got about as loud as I would be comfortable listening to without hearing damage. In fact, I had to lower it a 2-3 clicks from max just to be safe. The car is very loud when it is being driven, so the audio system will sound "quieter" since there is reduced dynamic range due to the high noise floor. However, keeping in mind the potential for hearing damage, it doesn't really need to be louder than it already is. It certainly is powerful enough to enjoy to over the engine/road noise. If anyone feels some type of way about the volume being set to near max, that's purely a psychological consideration from the days of analog audio when system sensitivity had to be high enough to work with a wide range of input sources. In the modern days of digital audio, we know with absolute certainty what the full input signal level is going to be, so the system only needs to be as sensitive as the level for numerical saturation, no more.

Bass: Bass quality is mediocre, better than some of the Mercedes Burmester systems I've listened to but not as good as many other premium audio systems I've enjoyed. The main issue is lack of low end extension. It feels like the subwoofer output falls off fairly quickly after about 40Hz. There is ample midbass output, especially upper midbass, giving percussion instruments good impact and "punch". If the low bass extension was better, it would significantly improve the overall quality of the sound. One good thing is that I didn't hear a lot of distortion in the bass, everything stayed under the 10% THD threshold that I'd consider problematic. I don't listen to a lot of bass heavy HipHop/R&B so those that do may have a different experience.

Midrange: Lower midrange seem a bit shy. Male vocals don't have the warm presence that I prefer. It's not a huge shortfall, maybe 2dB in the 200-400Hz region? I'd love to see what the measurements look like in this regard. If I could dial in just a bit more output in this region, it'd be golden. Clarity is great and the sound is very dynamic. Overall I'd say the midrange is pretty good, but not great.

Treble: As is, the treble sounded a little bright. It sounded "detailed" with good "air", but it was a bit too artificial. I dialed the treble equalizer setting to -2 and it sounded more balanced. Aside from that, the extension was good and I had no other complaints. Overall the treble was great after the EQ adjustment.

Overall Tonal Balance: Adding the bass, midrange, and treble together, you get the picture that the system sounds a tad bright overall, and the bass is boosted significantly in the midbass region. While parked and with the engine off, the bass is just too much by about 3-4dB and distracts from the music. With the engine on and While driving, the background noise drowns out the bass and it sounds more balanced.

Stage and Separation: Pretty darned good. The sound stage was at eye level and just slightly listener-side biased. Stereo imaging effect was very strong with distinct, convincing, and stable sound source placement. The stage width is very spacious, spanning perhaps 120 degrees in front of the listener. It's definitely one of the better car systems I've heard in this regard. Many OEM systems rely on a large number of drivers to produce a neutral tonal balance, sacrificing imaging in the process, but this KEF system was able to avoid this common pitfall.

Clarity, Noise, and Vibrations: Clarity was very good even at high volume. There was no noticeable onset of additional strain or distortion even at max volume - which while being an excellent trait, can be especially dangerous for hearing damage because you feel like you can keep turning it up. Knock on wood, my car had no audible rattles, buzzing, or vibrations. Everything seems to be fairly well buttoned down.

Summary: Overall, it's a decently good system and about par for what I'd expect from a premium OEM car audio system. I would be shocked if a base sound system was this good. Except for the bass extension, which is its key weakness, everything else works well as a package together. I really enjoy listening to it and look forward to spending more time with it during longer stretches of driving when there isn't much shifting to do.
If that's your "casual" analysis I doubt I'm educated enough to understand your "thorough" analysis. ;)(y)

Thank you for your insight, I'm looking forward to listening to mine for the first time in a few days!
 

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Picking up the Emira, I didn't listen to the sound system much on the 300 mile drive home. What little I did listen, it sounded thin and I wasn't sure if the subwoofer was working. It's been a few days and I was able to spend a bit of time listening to it. Again the system sounded thin, and I checked the equalizer settings were all flat. So I did a "Audio Settings Reset" and all of a sudden, there was bass. I am not sure what happened. The following are my listening impressions, all done through Android Auto playing Spotify. I'll take some measurements when I have time.

Volume: Overall volume is good. It got about as loud as I would be comfortable listening to without hearing damage. In fact, I had to lower it a 2-3 clicks from max just to be safe. The car is very loud when it is being driven, so the audio system will sound "quieter" since there is reduced dynamic range due to the high noise floor. However, keeping in mind the potential for hearing damage, it doesn't really need to be louder than it already is. It certainly is powerful enough to enjoy to over the engine/road noise. If anyone feels some type of way about the volume being set to near max, that's purely a psychological consideration from the days of analog audio when system sensitivity had to be high enough to work with a wide range of input sources. In the modern days of digital audio, we know with absolute certainty what the full input signal level is going to be, so the system only needs to be as sensitive as the level for numerical saturation, no more.

Bass: Bass quality is mediocre, better than some of the Mercedes Burmester systems I've listened to but not as good as many other premium audio systems I've enjoyed. The main issue is lack of low end extension. It feels like the subwoofer output falls off fairly quickly after about 40Hz. There is ample midbass output, especially upper midbass, giving percussion instruments good impact and "punch". If the low bass extension was better, it would significantly improve the overall quality of the sound. One good thing is that I didn't hear a lot of distortion in the bass, everything stayed under the 10% THD threshold that I'd consider problematic. I don't listen to a lot of bass heavy HipHop/R&B so those that do may have a different experience.

Midrange: Lower midrange seem a bit shy. Male vocals don't have the warm presence that I prefer. It's not a huge shortfall, maybe 2dB in the 200-400Hz region? I'd love to see what the measurements look like in this regard. If I could dial in just a bit more output in this region, it'd be golden. Clarity is great and the sound is very dynamic. Overall I'd say the midrange is pretty good, but not great.

Treble: As is, the treble sounded a little bright. It sounded "detailed" with good "air", but it was a bit too artificial. I dialed the treble equalizer setting to -2 and it sounded more balanced. Aside from that, the extension was good and I had no other complaints. Overall the treble was great after the EQ adjustment.

Overall Tonal Balance: Adding the bass, midrange, and treble together, you get the picture that the system sounds a tad bright overall, and the bass is boosted significantly in the midbass region. While parked and with the engine off, the bass is just too much by about 3-4dB and distracts from the music. With the engine on and While driving, the background noise drowns out the bass and it sounds more balanced.

Stage and Separation: Pretty darned good. The sound stage was at eye level and just slightly listener-side biased. Stereo imaging effect was very strong with distinct, convincing, and stable sound source placement. The stage width is very spacious, spanning perhaps 120 degrees in front of the listener. It's definitely one of the better car systems I've heard in this regard. Many OEM systems rely on a large number of drivers to produce a neutral tonal balance, sacrificing imaging in the process, but this KEF system was able to avoid this common pitfall.

Clarity, Noise, and Vibrations: Clarity was very good even at high volume. There was no noticeable onset of additional strain or distortion even at max volume - which while being an excellent trait, can be especially dangerous for hearing damage because you feel like you can keep turning it up. Knock on wood, my car had no audible rattles, buzzing, or vibrations. Everything seems to be fairly well buttoned down.

Summary: Overall, it's a decently good system and about par for what I'd expect from a premium OEM car audio system. I would be shocked if a base sound system was this good. Except for the bass extension, which is its key weakness, everything else works well as a package together. I really enjoy listening to it and look forward to spending more time with it during longer stretches of driving when there isn't much shifting to do.

I'll have to try your Audio reset but I'm now running treble -2 and bass +2. If the KEF Uni-Q are anything like the one in their home system. It'll take about 50 hours at moderate volume for them to break-in. The highs will smooth out and the mid and bass will improve as the rubber/foam ring on the speaker loosen up.
 

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I've yet to listen to mine because I've only been able to drive it for a few hours on the one day since I received it that it hasn't been raining. Rain is forecast through Tuesday, so hopefully by Wednesday I can take mine out again.

Just from your description, that sounds exactly like what a brand new higher end speaker system sounds like right out of the box. Typically it sounds somewhat wooden and lacks warmth. Just use it normally with whatever type of music you listen to, and it will warm up. From my experience, it takes about 25 hours of usage at least before you start to notice an improvement.
 
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Update: Posted measurements in the 2nd post of the thread: Link
 

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My biggest issue is how much the bass changes with the windows down -- not sure this is able to be rectified due to the open-air design. I'm wondering if a more traditional sub can be fitted and possibly sound better.
 
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My biggest issue is how much the bass changes with the windows down -- not sure this is able to be rectified due to the open-air design. I'm wondering if a more traditional sub can be fitted and possibly sound better.
All car subwoofers will change in performance with the windows open. I have to try it with the Emirates and see what happens.
 

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Well done on the measurements! I also have a Umik-1, I'll have to pull it out and do some experimentation myself.

The 200hz dip may explain the complaints that some have with bass lacking on certain music. If it is a null issue, you'd think they would have solved that in the DSP on the amp by doing some phase shifting in that frequency range.
 

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I have not yet tried the reset but I agree the bass is almost none existent, hopefully that makes a difference
 
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Well done on the measurements! I also have a Umik-1, I'll have to pull it out and do some experimentation myself.

The 200hz dip may explain the complaints that some have with bass lacking on certain music. If it is a null issue, you'd think they would have solved that in the DSP on the amp by doing some phase shifting in that frequency range.
Yea, fingers crossed that they just wired the sub in reverse phase. I measured the same null in both driver and passenger seat.
 

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My sub sounds like it is broken if I turn the volume up a bit. It "pops" instead of producing nice bass. Sounds like a cheap speaker being overdriven. Hopefully this is a break-in thing.

On another note, I'd like to add some sound insulation in the rear of the car behind/under the rear shelf. Does anyone have product recommendation, or better yet want to put together a kit? I'd just like to reduce some of the driveline noise a bit.
 
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My sub sounds like it is broken if I turn the volume up a bit. It "pops" instead of producing nice bass. Sounds like a cheap speaker being overdriven. Hopefully this is a break-in thing.

On another note, I'd like to add some sound insulation in the rear of the car behind/under the rear shelf. Does anyone have product recommendation, or better yet want to put together a kit? I'd just like to reduce some of the driveline noise a bit.
That doesn't sound normal. The sub should not pop. I would get that checked out.
 

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Nova, thanks very much for your detailed analysis on the KEF system.
Do you care to share your EQ settings?
Thanks!
 

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Yea, fingers crossed that they just wired the sub in reverse phase. I measured the same null in both driver and passenger seat.
In that range it could also be the midbass drivers behind the seats. If the door speakers and sub are in phase but the midbass units are reversed it could do some really weird stuff.
 
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In that range it could also be the midbass drivers behind the seats. If the door speakers and sub are in phase but the midbass units are reversed it could do some really weird stuff.
True, there are some different possibilities here.
 
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Nova, thanks very much for your detailed analysis on the KEF system.
Do you care to share your EQ settings?
Thanks!
The measurement I took are with everything flat. By ear, I preferred a -2 on the treble. Bass and midrange at 0.

Try doing an audio setting reset first.
 

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Update: Posted measurements in the 2nd post of the thread: Link
Excellent effort, and perfectly acceptable considering the environment you're testing. That dramatic drop at 150-250 hz is very unusual. I can't imagine they saw that when setting up the system and just decided to ignore it.

I don't recall if you said what type of interior you have. Is it leather or Alcantara?
 

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