• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

"Stand Subwoofers" like the Genelec W371, Kii BXT, etc. Ideally with DSP & Multi-Drivers

ferrellms

Active Member
Joined
Mar 24, 2019
Messages
296
Likes
254
Neumann does with the KH870 for the KH420.

However you should refrain from this idea. The best position in a given room for a sub is very seldom identical to the best position for the sats, so either bass suffers or soundstage.
In the cases of the Kiis and Genelecs, they are not really subwoofers, they are specifically designed to extend the bass and improve the directivity of the system as a whole and are designed to used as shown in the photo. In the case of the Genelecs, the GLM software is used to integrate the bass units, top units, and the room EQ.
 

jhaider

Major Contributor
Forum Donor
Joined
Jun 5, 2016
Messages
2,823
Likes
4,522
In the cases of the Kiis and Genelecs, they are not really subwoofers, they are specifically designed to extend the bass and improve the directivity of the system as a whole and are designed to used as shown in the photo. In the case of the Genelecs, the GLM software is used to integrate the bass units, top units, and the room EQ.

To put it more simply, accurately, and directly, they’re just subwoofers.

To have any impact on “directivity” in a small room they’d need to play up to 500Hz at least.
 

thewas

Master Contributor
Forum Donor
Joined
Jan 15, 2020
Messages
6,763
Likes
16,235
They are bass cardioids, by using rear woofers delayed and in 180° phase to create a bass cardioid, something which is more common than most think in the PA world

1585673645875.png
 

jhaider

Major Contributor
Forum Donor
Joined
Jun 5, 2016
Messages
2,823
Likes
4,522
They are bass cardioids, by using rear woofers delayed and in 180° phase to create a bass cardioid,

While that is true, there isn’t “directivity” to speak of in this bandwidth in a small room. A cardioid or dipole will excite modes slightly differently, with a significant efficiency penalty. Mode excitation could be “better” or “worse.” “Differently” is the only concept one can use for the general case.

Dutch & Dutch takes the objectively most sensible approach to balance directivity and bass efficiency: cardioid midwoofer in front of monopole bass units.
 

Hephaestus

Active Member
Joined
Jun 2, 2019
Messages
233
Likes
495
Location
Rapture
To put it more simply, accurately, and directly, they’re just subwoofers.

To have any impact on “directivity” in a small room they’d need to play up to 500Hz at least.

Genelec W371A does play up to 500Hz.
 

jhaider

Major Contributor
Forum Donor
Joined
Jun 5, 2016
Messages
2,823
Likes
4,522
Genelec W371A does play up to 500Hz.

Thanks, I missed that. In that case, I wonder if there would be any real performance difference aside from minor FR variations due to waveguide loading/cabinet diffraction between the different coaxial monitors used with a pair of these.
 

ferrellms

Active Member
Joined
Mar 24, 2019
Messages
296
Likes
254
To put it more simply, accurately, and directly, they’re just subwoofers.
l
To have any impact on “directivity” in a small room they’d need to play up to 500Hz at least.
Can subwoofers do this? Flat response 25 to 500hz! Directional from 50hz up! Smart software to EQ and time-align the system as a whole! 123 db! How the heck? I want to at least hear them sometime. At 8K each plus another 8K for a pair of the monitors...

Genelec's goal is to approach the performance of their giant soffit- or wall-mounted monitors in a system that does not need a room specifically designed for them.
 

Attachments

  • polar.JPG
    polar.JPG
    96.5 KB · Views: 263
  • Cfr.JPG
    Cfr.JPG
    96.6 KB · Views: 231
Last edited:

Dj7675

Major Contributor
Forum Donor
Joined
Jan 12, 2019
Messages
2,116
Likes
2,782
Ah yes, the ugly duckling version of the Revel Gem2s.
I actually quite like the look. But the spin looks pretty impressive too considering it’s age.
 

Attachments

  • 26D3D533-E3A4-40F1-9E97-11E6A87F859A.png
    26D3D533-E3A4-40F1-9E97-11E6A87F859A.png
    442.7 KB · Views: 171

hvbias

Addicted to Fun and Learning
Joined
Apr 28, 2016
Messages
574
Likes
411
Location
US
I've heard the Kii Three without BXT and I was quite impressed with the sound. My understanding is this- the BXT essentially let you play louder without the speaker protection kicking in (as well as offering some additional extension, more on this later), from what I am reading Kii have made this level fairly high with a firmware update that came out a while back. I can't recall what the SPLs were off the top of my head but I seem to recall thinking it was at the limit where no one would realistically want to listen at those levels, and I do listen to primarily classical so lots of music with wide dynamic range.

My reasoning was either way for my average size room that I intend them for I am going to need to do something to smooth out the bass. The BXT does not fix this issue, it will extend the bass essentially turns it into a truly full range speaker. This does nothing for the room modes and where I think Geddes or Welti multi-sub is still the most high fidelity way to do it. So either way I'll be buying high quality subwoofers to fix these issues, these will also offer the additional extension and relieve some of the low bass duty that would presumably normally kick in the protection without the BXT. Bringing me back to my point that at least for my use (anyone's use if they want truly flat bass?) I can't see the advantage of the BXT.
 

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
I'm a fan of saying unpopular things, so here goes; Cardioide dispersion below the room transition frequency means diddly squat. The room resonates and becomes one with the speakers below 2-300 hz and no amount of directivity will change that. If you happen to excite certain modes differently in a better way because of directivity, you're lucky.
In a normal room the BXT will be just another subwoofer with high crossover-capability and the benefit of reduced effect of floor dip in the upper bass.
 

firedog

Senior Member
Joined
Jun 19, 2016
Messages
378
Likes
642
I'm a fan of saying unpopular things, so here goes; Cardioide dispersion below the room transition frequency means diddly squat. The room resonates and becomes one with the speakers below 2-300 hz and no amount of directivity will change that. If you happen to excite certain modes differently in a better way because of directivity, you're lucky.
In a normal room the BXT will be just another subwoofer with high crossover-capability and the benefit of reduced effect of floor dip in the upper bass.

Unpopular or untrue?
Cardoid dispersion clearly removes lots of room effects - when you hear Kii's or 8c's in your room the difference is obvious. Neither Kii nor D&D claim their speakers eliminate room effects.
Yes you can still have a room node with such a speaker. So what? Easily taken care of with DRC. And then they sound even better.
 

Matias

Master Contributor
Forum Donor
Joined
Jan 1, 2019
Messages
5,031
Likes
10,806
Location
São Paulo, Brazil

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
Unpopular or untrue?
Cardoid dispersion clearly removes lots of room effects - when you hear Kii's or 8c's in your room the difference is obvious. Neither Kii nor D&D claim their speakers eliminate room effects.
Yes you can still have a room node with such a speaker. So what? Easily taken care of with DRC. And then they sound even better.
Unfortunately, cardioide dispersion does not help you much in the room's resonating area. Standing waves will build up energy while bouncing around and will ignore the dispersion characteristics because there's no longer any controlled directivity to stop it once the initial wave hits the walls and reflects. In the resonating area the steady-state response is the best metric to use as a visual aid to see what we hear, and in the same steady-state response even Kii and the like will suffer from the same room-behavior as other speakers. Here's a few examples with the Kii;

917Kii3fig4.jpg

https://www.stereophile.com/content/kii-audio-three-loudspeaker-measurements


Kii THREE Comparison.jpg

https://www.gearslutz.com/board/high-end/1048540-kii-three-have-you-heard-them-23.html#post12588247


I have a ton of measurements demonstrating the same thing in my own room with Kii and other speakers. Differences can of course be seen, but they are completely dwarfed by the evilness of the room and could mostly be explained by small differences in placements.
Above about 200 hz the effects will begin to show.

Don't take this as criticism of Kii or any other cardioide speakers because it isn't.
 

Sprint

Senior Member
Forum Donor
Joined
Sep 19, 2019
Messages
455
Likes
304
HEDD Audio has one here
 
Top Bottom