Kii THREE Review

[bigjacko]

My listening room is 18' x 30 ' (basement rec room) and my speakers are placed with their front baffles 7 feet from the front (18 foot) wall and 4 feet from the side walls. I sit 12 feet from the speakers. In this type of set up is having cardioid speakers a moot point? Will I derive a massive improvement changing to Cardioid speakers when I have already have the freedom to place speakers far from the front wall? ( I don't want or need to cram my speakers and furniture close to the front wall.)

If you don't want to put any absorbing material or diffusor at the back, cardioid will still work ad radiate less sound to the front wall. The early reflection of 7 feet front wall is maybe 12ms, not too bad if that reflection is there, but breaking that up by diffusion or absorbing might help image too.

 

[hardisj]

I don't do youtube comments so thought I'd mention this here after watching your review of the Kii 3:

You review was one of the most comprehensive, informative and well-articulated I've seen. Bravo! You are just getting better and better!

I really appreciate that.

 

[Absolute]

I agree with earlier replies. Remember also that a cardioid's main goal is to produce big-speaker performance in a smaller box. Look at Erin's reviews, consider resulting Dutch/Kii polars when near the front wall, then ask what the JBL M2 delivers with similar placement.

In the end, it's always about how the speaker & room work as a system.

Here you go, Kii vs M2 placed near a corner, single speaker measured.

Kii is blue.

Keep in mind that the distance from woofer to side-wall and to floor is about the same with M2, so this is a worst-case scenario for M2. I forgot to remove one EQ point at 42 hz with the M2, so ignore that.

I can probably find similar measurements of the left speakers who only have the front wall to deal with for a more like-for-like comparison. That'll have to wait until I'm home from vacation.

 

[abdo123]

Here you go, Kii vs M2 placed near a corner, single speaker measured.

Kii is blue.
View attachment 171051

Keep in mind that the distance from woofer to side-wall and to floor is about the same with M2, so this is a worst-case scenario for M2. I forgot to remove one EQ point at 42 hz with the M2, so ignore that.

I can probably find similar measurements of the left speakers who only have the front wall to deal with for a more like-for-like comparison. That'll have to wait until I'm home from vacation.

Did you place the speakers in the corner simply to accentuate the Kii? Or do you live in a tiny apartment in an urban city where that’s literally the only space you have?

 

[Absolute]

Did you place the speakers in the corner simply to accentuate the Kii? Or do you live in a tiny apartment in an urban city where that’s literally the only space you have?

Apartment, not that small. Could place stuff in the center of the rectangular room if I wanted to, but there's no hope for hifi in these conditions anyways.

The ceiling is 10 cm insulation behind Ecophon Focus plates, the gray stuff behind the couch is 4 inch RPG Absorbors. Room size is 7,65m x 4m.

 

[abdo123]

Could place stuff in the center of the rectangular room if I wanted to, but there's no hope for hifi in these conditions anyways.

It would make a gigantic dramatic difference if you do, right now the setup is rigged for the Kali to shine.

 

[Absolute]

It would make a gigantic dramatic difference if you do, right now the setup is rigged for the Kali to shine.

Nah, it's just the inherent bitchness of physics rearing its head where the distance from woofer to first reflection points on the M2 is unfortunate. Not rigged, the living room was designed and cabins wall-mounted long before either of speakers came into the picture.

A more even comparison is the Devialet Phantom placed exactly on the Kii stand near the same corner.

As we can see there's not that much benefits to be had with cardioide below 200 hz in this situation. Perhaps you need a bit of space to the sides for a proper effect? Also, stupid amounts of bass in the Phantoms.

 

[hardisj]

Kii is blue.

I forgot to remove one EQ point at 42 hz with the M2, so ignore that.

This seems counter to what you've shown. Is the M2 in blue? Because that's the line that has the 42Hz peak. Unless my mind just hasn't woken up yet.

 

[abdo123]

Unless my mind just hasn't woken up yet.

I'm pretty sure he meant that he EQed the 42Hz peak in the M2 and he forgot to remove it.

 

[Absolute]

This seems counter to what you've shown. Is the M2 in blue? Because that's the line that has the 42Hz peak. Unless my mind just hasn't woken up yet.

The M2 in red. I just forgot to remove the last EQ point in the M2, which is why it doesn't have that peak that Kii does.
Good morning!

 

[hardisj]

Good morning!

Indeed!

Yes, you said "remove".... see, I called it... my mind has woken up yet. Sorry about that.

 

[Absolute]

No worries, Erin. I wish I knew about MMM back when I had the Kiis.

That would make for better comparisons in-room.

 

[HammerSandwich]

Thanks for the info, @Absolute.

I wish I knew about MMM back when I had the Kiis.

So is there any spatial averaging in these measurements?

My initial point was that the M2's baffle step is around 200-250Hz, so the Kii/8c add only an extra octave or so of control. On the NFS, of course. With EQ, M2 against the front wall should be able to match the cardioids very closely above 300Hz or so, though the 3 patterns aren't exactly the same width.

One thing I did ignore is the M2's depth, which probably caused the ~110Hz hole in your measurement. That would be much harder to fix.

(And I'd love to understand why the Kii peaks at 1.5kHz.)

 

[Absolute]

Thanks for the info, @Absolute.


So is there any spatial averaging in these measurements?

My initial point was that the M2's baffle step is around 200-250Hz, so the Kii/8c add only an extra octave or so of control. On the NFS, of course. With EQ, M2 against the front wall should be able to match the cardioids very closely above 300Hz or so, though the 3 patterns aren't exactly the same width.

One thing I did ignore is the M2's depth, which probably caused the ~110Hz hole in your measurement. That would be much harder to fix.

(And I'd love to understand why the Kii peaks at 1.5kHz.)

There's no spatial average in those measurements. For the M2 you end up with pretty much exact Harman curve with a spatial average, allowing for some peaks and dips in the bass of course.

Kii have really wide dispersion in the lower end, and with the claimed 4,6 dB cardioide effect I'm not sure we can say that it significantly removes the room below a few hundred hz, which I believe my measurement against the Phantom shows.

I reckon cardioide has two selling points of real merit; you can minimize/eliminate front wall cancellation and you create a virtual much wider baffle allowing for a controlled dispersion all the way down even with small speakers.

Oh, the peak around 1khz is likely just interference from the microphone stand or pillow in the couch. Don't pay attention to single-point measurements above a few hundred hz.

 

[richard12511]

Erin, if you still have the D&D 8C, I'd be super curious to hear your side by side impressions with it and the Kii. Both of these are 2 of the speakers I'm considering for my main entertainment room. I don't want subs in that room, and the BXT is more than I want to spend(I'd rather go another set of 8351b + W371 at that price).

 

[Kvalsvoll]

As we can see there's not that much benefits to be had with cardioide below 200 hz in this situation.

We really can not see anything useful form this graph, because it does not show the difference - if there is a difference.

You need to look at what happens in time - look at decay and spectrogram, then you may be able to see differences, but it may still not be obvious and easy to analyze.

There will still be deviations from flat on the freq resp, because all sound is not attenuated to the sides and backwards, and there will be early reflections close to the listening position from the back wall, and floor-ceiling is not affected much, since the angle is too shallow at less than 40 degrees for the cardioid to have any effect.

You may end up with a freq graph with more deviations when some reflections are removed, while others are still present. With more reflections, they tend to fill each other out over some time, so you measure something that looks like it is flat - but it is not.

The information of interest here is what happens in time - how the sound initially starts, and then decays. A better directivity will show up as better attenuation of very early sound.

But what matters is what this means for the sound. When you listened to this, did you notice a difference? How was this difference perceived? Now, this is quite complicated, because the speakers are different also in other ways than the cardioid. So it may be difficult to say for sure that any difference in sound is caused by the improved directivity alone.

I can tell you that if you test this with the same speaker - with and without directivity control - there will be a measurable difference, and there will also be a difference in sound. How do I know this - becuase I am looking at such measurements right now, taken from 2 different rooms with different acoustic properties, and I have listened to both systems in both rooms and compared.

The cardioid is just one property of such a speaker. It may even not be the most important. But it sure makes a difference - one that you can hear, and if you turn up the volume you can feel the difference, and it can be measured.

 

[Soniclife]

I can tell you that if you test this with the same speaker - with and without directivity control - there will be a measurable difference, and there will also be a difference in sound. How do I know this - becuase I am looking at such measurements right now, taken from 2 different rooms with different acoustic properties, and I have listened to both systems in both rooms and compared.

Can you share some of these graphs please, what you are saying makes intuitive sense to me, it would great to see evidence from the real world.

 

[BrokenEnglishGuy]

Here you go, Kii vs M2 placed near a corner, single speaker measured.

Kii is blue.
View attachment 171051

Keep in mind that the distance from woofer to side-wall and to floor is about the same with M2, so this is a worst-case scenario for M2. I forgot to remove one EQ point at 42 hz with the M2, so ignore that.

I can probably find similar measurements of the left speakers who only have the front wall to deal with for a more like-for-like comparison. That'll have to wait until I'm home from vacation.

wow that's a ugly cancelation, traditional design are very problematic, i wonder if you could fix that moving a lot the speakers and finding the best placement

 

[Absolute]

We really can not see anything useful form this graph, because it does not show the difference - if there is a difference.

You need to look at what happens in time - look at decay and spectrogram, then you may be able to see differences, but it may still not be obvious and easy to analyze.

I think it's useful information to see whether or not dispersion control affects steady-state frequency response below the Schroeder in the worst likely scenario (speaker close to corner).

You are completely on point, though, I should also look at the time-domain to see if there's any major differences there. If that's to contain valuable information we need to limit the frequency response to below a certain frequency, match the level and then take a look. I can access the measurements I have when I get home from vacation. Those impulse-plots I have on my phone is full-range and thus skewed for this purpose since the Kiis have both lower bass output and less energi above 200 hz or so.

If you have measured this with the same speaker with and without dispersion control and calibrated to the same frequency response, it would be very interesting to see the effects below 2-300 hz.

The information of interest here is what happens in time - how the sound initially starts, and then decays. A better directivity will show up as better attenuation of very early sound.

But what matters is what this means for the sound. When you listened to this, did you notice a difference? How was this difference perceived? Now, this is quite complicated, because the speakers are different also in other ways than the cardioid. So it may be difficult to say for sure that any difference in sound is caused by the improved directivity alone.

Bandwidth-limited to below 200 hz? Nothing. The greatest benefit I ever experienced in the low frequencies was achieved by placing two subwoofers on the floor crossed to Kii at 200 hz, effectively reducing floor bounce cancellation and increasing the capacity.

Full-range the benefit was very clear with more clarity and impact from the upper bass/lower mids compared to Phantom silver.

wow that's a ugly cancelation, traditional design are very problematic, i wonder if you could fix that moving a lot the speakers and finding the best placement?

Indeed you can. Proper placement should always be number 1 priority if possible. If not then one should consider speakers more suitable for your situation or proper acoustic treatment to help out.

 

[Cadguy]

Nah, it's just the inherent bitchness of physics rearing its head where the distance from woofer to first reflection points on the M2 is unfortunate. Not rigged, the living room was designed and cabins wall-mounted long before either of speakers came into the picture.

A more even comparison is the Devialet Phantom placed exactly on the Kii stand near the same corner.

View attachment 171073

As we can see there's not that much benefits to be had with cardioide below 200 hz in this situation. Perhaps you need a bit of space to the sides for a proper effect? Also, stupid amounts of bass in the Phantoms.

Do you have the Phantom 103 or 108? Do they sound "big" like a floor standing speaker?