• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Is the LXmini by Siegfried Linkwitz the answer for home audio?

abdo123

Major Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
2,667
Likes
2,291
Location
Brussels, Belgium
#1
So just to get it out there, i'm not an expert or anything close to that. so take whatever I say here with a grain of salt, I'm just discussing what I understood from different speaker building/purchasing trends and processing it all together.

This discussion is also for home audio, and i also mean typical everyday person home audio. So the 1% here with giant mansions this discussion doesn't apply to you.

Also, this discussion is also for people who want to share their audio experience with other people. It does not apply to people with audio rooms with one chair in the 'perfect spot', this is a discussion to have a very wide 'perfect spot' (thus the 'home audio' in the title) so more than person can enjoy the 'perfect spot'.

Part 1: Tonal Balance VS Stereo image.

This is the main compromise for people that want to have a wide sweet spot, most people purchase a wide directivity speaker that radiates equally over a wide surface so that tonal balance is maintained for everyone (flat off and on-axis response).

While this is a very interesting proposition, the stereo image suffers dramatically. the moment someone is not sitting at the center between the two speakers, the stereo image instantly collapses towards the speaker you're closer to.

1611570126672.png


While both volumes are somewhat equal, the time it takes for the sound to reach our ears is not the same. sound arrives quicker from the speaker you're closer to. this causes a shift in our perception of the sound and the image collapses to the speaker we're sitting nearest to. The SPL from the pic above represents perceived loudness.

Well how about speakers with narrow directivity (flat on-axis response)? Well this is the other side of the compromise. When you sit off center, the volume from the speakers decrease. and the farther off-axis that you sit, the worse the tonal balance become.

However, just like wide directivity, the sound from the speaker you're sitting closer to arrives before the speaker that you're sitting far away from.

Under optimal conditions, one can trade time of the sound for the intensity of the sound so that the stereo image doesn't collapse to one speaker when someone sits closer to one speaker over the other.

Basically, the center position would be just 15° off axis to both speakers (or whatever the speaker can handle without severely affecting the tonal balance). so a person sitting left center would be on axis to the speaker on the right, and 30° off-axis to the speaker on the left. This way both speakers are perceived as equally loud and center image is maintained.

1611573435041.png


With a narrow directivity speaker, if the path to the further away speaker is the most on-axis path, then center image is maintained for all people sitting equally on the horizontal plane (the sofa).

However, this is all hypothetical and many people find time intensity trading too complicated and not very practical to do in their own room and with their own speakers. Not to mention that tonal balance is not perfectly maintained to people sitting off center.

Part 2: The LXmini by Siegfried Linkwitz, is it the answer for proper stereo image and tonal balance to a wide audience?

The LXmini is a DIY speaker with a very very wide directivity that promises flat on-axis and off-axis response. the LXmini also prevents the sound image from severly collapsing (some collapse ofcourse still happens) to the speaker you're sitting closest to.

1611574509627.png


Briefly, the LXmini uses an upward firing woofer, which is omni-directional. and right above it is a dipole (a bare full range driver) that radiates to the front, and also to the back (in the opposite polarity). the Full range driver is basically an oscillating plate with the baffle removed.

When you cross an omnidirectional driver with a dipole driver, the negative phase of the dipole (radiation behind the fullrange driver) cancels the radiation to the back produced by the omnidirectional driver. The resulting response is a carotid frequency response, which is wider than a dipole, but less wider than an omni.



1611575611724.png


So basically the LXmini is an omnidirectional speaker at the low frequencies, a cardioid at the middle and a dipole at the high-end.

the pole behind the full-range also works to scatter the sound towards the listener at the high (dipole) end.

The result is (Acording to Linkwitz) a very wide dispersion speaker that radiates the entire room (except the wall behind the speakers), and the recipient percieves a stereo image that is not hard bounded by the speakers, the stereo image spreads smoothly between the speakers and extends well beyond the edges of the two speakers. Also the auditory scene is not very crunched to one speaker when you sit off-axis on the horizontal plane.


What are your thoughts on this? Do you agree that the LXmini seems like a good solution to achieve a good stereo image and tonal balance?
 

Attachments

mdsimon2

Active Member
Joined
Oct 20, 2020
Messages
297
Likes
309
Location
Detroit, MI
#2
Why not build a pair and find out? Part of the attraction of the LXminis is that they are very easy to build and low cost. I recently built a pair that I had planned to use in my office but they ended up staying in my living room because I enjoyed the sound so much.

I am not sure how much of my enjoyment is related to the omni -> cardoid -> dipole radiation pattern but I can say they seem exceptionally well engineered. The sound stage is a bit more diffuse than other box speakers I have used but overall they sound much more natural, especially with acoustic instruments.

They are definitely limited in output although adding a pair of subs and removing the woofer bass boost certainly adds a bit of headroom. As you alluded to I think they are a very good match for small listening spaces.

Michael
 
Joined
Apr 26, 2020
Messages
30
Likes
87
#3
I built the LX Mini a couple of years ago and found them a bit bright for me. It’s certainly possible it was the room they were in...I always meant to try them elsewhere but never got around to it. They are incredibly easy to build, though, and reasonably priced.
 

Shazb0t

Senior Member
Joined
May 1, 2018
Messages
416
Likes
686
Location
NJ
#4
I'm curious to see how these, or the other LInkwitz designs, measure on the Klippel. Someone send a pair to Amir!
 

buz

Active Member
Forum Donor
Joined
Dec 17, 2020
Messages
129
Likes
91
#5
The speakers may be affordable, but the electronics they need are non trivial (tho I wonder if a bunch of TPA3255 would do for amping), especially when adding subs.
 
OP
A

abdo123

Major Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
2,667
Likes
2,291
Location
Brussels, Belgium
Thread Starter #7
The speakers may be affordable, but the electronics they need are non trivial (tho I wonder if a bunch of TPA3255 would do for amping), especially when adding subs.
Yeah i have been thinking of getting two Hypex FusionAmps (FA122) which should be everything someone needs to run them (transparently) and that costs around 700$ without proper enclosures for the units.
 

mdsimon2

Active Member
Joined
Oct 20, 2020
Messages
297
Likes
309
Location
Detroit, MI
#8
At the base level the electronics are very simple, $95 miniDSP 2X4 and 4 channels of amplification. Adding subs can be as simple as adding another miniDSP 2X4 and 2 more channels of amplification. Of course if you want more input options the 2X4HD or the 4X10HD are great choices.

The nice thing to me is that the DSP and amplifiers can be repurposed for something else down the line. When I built these I already had DSP and amplifiers from past projects so it was literally just the cost of the speakers themselves.

Michael
 
Last edited:
Joined
Nov 22, 2020
Messages
25
Likes
24
#9
Thanks for the writeup. I've always found these speakers fascinating in their unique approach to directivity. It's likely an approach that works, given how universally acclaimed these are.

I wonder if one might design a similar pair with ribbons or other such wide directivity drivers as the dipole?

Unfortunately, I live very far away from the States, and shipping a kit here would be prohibitive, let alone a finished pair. Would otherwise have built a pair myself by now.
 
Joined
Jan 2, 2021
Messages
22
Likes
19
#10
The Linkwitz LX Mini, is one of the most cleverly designed speakers, ever. People may think that's an overstatement, but it's not. I think Linkwitz himself was even surprised by how it eventually turned out, with the LX Mini being described as coming "uncomfortably close" to its bigger brother Linkwitz open-baffles. Essentially a hybrid omni & open baffle because the front-facing driver has no backing. Some may fight that description tooth and nail......because they don't understand the design. Very clever, remarkable actually, and with the added benefit of having all that space behind the bass driver to control the rear wave. For my purposes I need a speaker with some more "oomph" to fill my living space, but that's not a detraction from that speaker's design.
 

AudioJester

Senior Member
Forum Donor
Joined
Jan 7, 2020
Messages
333
Likes
328
#13
LXmini's are amazing. Wonder how they would measure on the klippel?
Subjectively I only bettered them with the Lx521
 

dreite

Addicted to Fun and Learning
Joined
Aug 10, 2018
Messages
676
Likes
845
Location
Bremerton, WA
#15
Would an ASR test of these make them more viable for your consideration??
These speakers were not designed with any sort of CEA 2034 objective in mind. You fellas understand that, right?

I live really close and considered taking my spare LXmini pair to Amir for NFS testing, but based on the speaker reviews from Amir I've seen so far, I don't see any point in it. These speakers are outside his understanding of what a speaker radiation pattern objective might be.

There are hundreds of LXmini's (kits and commercial) that have been constructed and are in the field providing enjoyment to their owners. A number of them have been augmented by the inexpensive subwoofer setup I designed for them.

Objective testing is fine and dandy, but the large number of folks enjoying the sound of these speakers is a far better (ultimate) indicator of the design success Mr. Linkwitz achieved here.

Dave.
 
Last edited:
Joined
Dec 22, 2016
Messages
407
Likes
544
Location
Co. Durham, UK
#16
My LXMinis are in the living room where they are used for TV, movies and music via a Squeezebox. They are driven by a MiniDSP 2x4HD and a Audiolab 8000x7 which cost me all of £250. They are not in an ideal position, but everyone on the sofa and even those in chairs each side of that still get excellent sound and movie dialogue. The image does not collapse into the nearest speaker. The sofa is about 4.5 meters from the speakers. They don't have the weight and SPL of the LX521 but their imaging is quite exceptional.
lxmini.jpg
 
OP
A

abdo123

Major Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
2,667
Likes
2,291
Location
Brussels, Belgium
Thread Starter #17
I live really close and considered taking my spare LXmini pair to Amir for NFS testing, but based on the speaker reviews from Amir I've seen so far, I don't see any point in it. These speakers are outside his understanding of what a speaker radiation pattern objective might be.
I see a lot of 'point' in validating this speaker design.

The most effective EQ is the EQ that is designed from anechoic measurements. Siegfried designed and measured these speakers in his backyard.

You would be doing everyone who owns these speakers a really big service.
 
OP
A

abdo123

Major Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
2,667
Likes
2,291
Location
Brussels, Belgium
Thread Starter #19
'You think Amir is an appropriate/qualified person to 'validate' a speaker design from Siegfried Linkwitz??? :)

Dave.
don't you want specialized anechoic measurments of your own speakers that will allow you to further fine tune them to get the best sound possible?

you will be getting measurments. and the rest of the internet as well. we can make our own judgements if you're not satisified with Amir's judgements.
 

maverickronin

Major Contributor
Forum Donor
Joined
Jul 19, 2018
Messages
1,849
Likes
2,190
Location
Midwest, USA
#20
'You think Amir is an appropriate/qualified person to 'validate' a speaker design from Siegfried Linkwitz??? :)
Myabe the question should be, "Is Wolfgang Klippel an appropriate/qualified person to 'validate' a speaker design from Siegfried Linkwitz?" ;)
 
Top Bottom