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Linkwitz LX521.4 - new build and impressions

Pultzar

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I don't know, but I doubt that it does in a meaningful way. The woofers have a speaker grill material for the front and back.

Oh to clarify, I don't think the velvet on the speakers does anything sonically. The velvet in the room probably does, but it is worth it for the visual quality. I'm running a 6' x 14.4' ST100 screen.
 

Jim Matthews

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Oh to clarify, I don't think the velvet on the speakers does anything sonically. The velvet in the room probably does, but it is worth it for the visual quality. I'm running a 6' x 14.4' ST100 screen.
This is one of the best looking DIY speakers I have seen, certainly the nicest example of the LX521.

Kudos
 

Pultzar

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This is one of the best looking DIY speakers I have seen, certainly the nicest example of the LX521.

Kudos

Thanks! It wasn't all me though as I started from the plywood kit from magicLX521. Then I:

-Built the speakers according to spec
-Sanded/painted/edge banded the panels
-Fabricated the speaker grills by cutting frames from 1/4" Baltic birch plywood
-Attached the panels to the speakers with rare earth magnets so they are easily removed
-Routed wires within the bass cabinet so that I can have a single 8-pole plug at the rear of the speaker
-Wrapped/stapled velvet to the speakers as well as used velvet tape in certain areas. This was *very* tedious

The black base is made from plywood. I have some very heavy steel bases that were water-jet cut to replace the plywood and screw into the bridge for added stability. Haven't gotten around to doing that yet. I need the base because I have to move my speakers to the sides some when watching 2.40:1 movies as otherwise they get in the way. If I didn't need to move them, I would have cut a hole in my floor to route the cables up into the bottom of the speaker so that they aren't visible on the ground.
 

Jim Matthews

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Do I understand correctly that the upper housing is not connected to the base?
 

Pultzar

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The baffles are Panzerholz which I find to be an incredible material. Too bad it doesn't seem available in the USA.
 

Pultzar

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Do I understand correctly that the upper housing is not connected to the base?

Right now the speakers are just sitting on the base like they would be sitting on the floor. The base has furniture sliders under it and I can slide them around with ease. My plan is to screw the base into the bridge section.
 

kjb

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Right now the speakers are just sitting on the base like they would be sitting on the floor. The base has furniture sliders under it and I can slide them around with ease. My plan is to screw the base into the bridge section.
Don't screw them together, the vibrations from the dipole bass section will make the bridge and the top baffle vibrate as well and distort the sound. There's a good reason why the bridge is there in the first place. When playing loud one can feel the bass section vibrate. The top baffle vibrates a lot less thanks to the bridge.
 

Pultzar

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Don't screw them together, the vibrations from the dipole bass section will make the bridge and the top baffle vibrate as well and distort the sound. There's a good reason why the bridge is there in the first place. When playing loud one can feel the bass section vibrate. The top baffle vibrates a lot less thanks to the bridge.

Ya I was considering this and curious if putting the woofers on some vibration dampening material would help or not, along with the fact that my new bases weigh like 50-60 pounds each. Honestly the only reason to screw them together is in case somebody bumps into them. Right now I'm not feeling vibrations making their way to the top panel.
 

Pultzar

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Not to get off topic but I have also considered experimenting by replacing the dipole woofers with force cancelling sealed drivers. To many hobbies and not enough time though :)
 

Everett T

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Not to get off topic but I have also considered experimenting by replacing the dipole woofers with force cancelling sealed drivers. To many hobbies and not enough time though :)
That would take a strong crossover redesign, not that I wouldn't like someone to attempt it
 

kjb

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Don't screw them together, the vibrations from the dipole bass section will make the bridge and the top baffle vibrate as well and distort the sound. There's a good reason why the bridge is there in the first place. When playing loud one can feel the bass section vibrate. The top baffle vibrates a lot less thanks to the bridge.
Sorry!Just realized that you weren't talking about the bass section ☺️ That is a better idea. Just make sure you can angle the top baffle horizontally. This is how I did it. The top can rotate to adjust the angle.
Polish_20210427_203353832.jpg
 

Pultzar

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That would take a strong crossover redesign, not that I wouldn't like someone to attempt it

Ya and that probably won't be me anytime soon! Dirac multi-sub optimization has done way more magic for the bass response in my room compared to various subwoofer alignments.
 

Pultzar

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Sorry!Just realized that you weren't talking about the bass section ☺️ That is a better idea. Just make sure you can angle the top baffle horizontally. This is how I did it. The top can rotate to adjust the angle.
View attachment 126686

I am considering screwing the bridge to the base under the speakers. The bass box would still be free floating on some dampeners.

Yours look nice! If I were building from scratch instead of a kit, I'd also like to do the cleaner section above the bridge that you have done.
 

kjb

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I am considering screwing the bridge to the base under the speakers. The bass box would still be free floating on some dampeners.

Yours look nice! If I were building from scratch instead of a kit, I'd also like to do the cleaner section above the bridge that you have done.
Thanks. I borrowed some ideas from linkwitz.store, and also stripped away the pieces on the lowest part of the bridge. And all cables are hidden inside the baffles and bridges all the way down to the speakon connectors at the bottom of the bridge.

Ah, "screwing the bridge to the base under the speakers" might actually be a very good idea.

About the sound. Some aspects of lx521.4 is better than any other speakers that I heard. Comparing to some of the more expensive speakers I listened to, Focal Grande Utopia:s, and Focals bass reproduction appeared boxy. Then again there are some nice qualities about the focals for sure but the cost of that system where about €200K compared to my ~€45K 8ch ncore/najda dsp/lx521.4 system.
 

pokerbarlo

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you can order an motorized acoustically transparent screen from xy screens from alibaba they manufacture elite screens so pretty good quality and still have the lx521 far from the wall and just pull the screen up for 2.1 music listening. that's what I am planning on doing.

Do you think surround and atmos matching matter that much? Was planning on using some old cheesy polk rtis for surround and just upgrade in the future or maybe not at all lol.

I don't have any pictures now but might take some. It's tricky to represent because the room is all black velvet over custom made diffusers, absorbers, etc.

So the LX521 are left and right with a phantom center. I'm using Pluto's for the surrounds. . I haven't completed Atmos but planning on some coax speakers for that. I'm also considering replacing the Plutos with the JBL CBT speakers that were recently reviewed here.

I have considered them for LCR behind a transparent screen, but I'm concerned about the listening distance.

Just when my theater got more or less finished, my wife and I purchased property and we are building a new home which will include a much larger theater space. I might retire the LX521 from theater duty and instead pull them out for music listening. They sound excellent but I want speakers behind the screen so something that doesn't need to be out from the wall would be ideal.
 

pokerbarlo

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Was planning on DIY kits from GSG and building either 4 21 inch full marties or 4 21 inch devastators.

Also for people considering subs for HT use, don't waste your time with Thor like I did. Go for something with much higher output capabilities.
 

dualazmak

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Is there a way to build the crossover and eq filters on a pc based crossover system like Ekio and then use a high quality 8 channel DAC like the Octo Dac 8 Pro? Seems to me using something like 4 Purifi Eigentact amps is going to waste if you're also using the miniDSP 4 X 10.

Just for your info and reference,,,

In my multichannel multi-driver multi-amplifier project, I recently provisionally completed the system with three integrated amps plus L&R active subwoofers using software crossover EKIO and OKTO DAC8PRO:
WS001402.JPG


All the details can be found in the thread.
 

pokerbarlo

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dualazmak

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What is the best way to apply dirac live somewhere in this path and how clme the resolution from the PC is low is there a way to make that better?

At present, I know little about and have no idea to apply "dirac live" in the system like my project, sorry about this.

Software crossover EKIO works just fine up to 192 kHz 24 bit. And ASIO4ALL (together with "BV Audio Hi-Fi Virtual Cable") efficiently and flexibly routes all the digital signal from JRiver MC (or Roon) into EKIO and, then EKIO to DAC8PRO via the dedicated DIYINHK ASIO in 192 kHz 24 bit.

As for the specs of completely silent audio dedicated PCs in my project, please refer to the specific post in my project.

Consequently, I use JRiver's (or Roon's) up-sampling/down-sampling features to feed all the signal in 192 kHz 24 bit into EKIO via ASIO4ALL. At least for the digital crossover (and delay, phase), I could establish with EKIO on Windows PC just like the extraordinary expensive TRINNOV ALTITUDE32.
 
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jdubs

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Hey all, is the necessary room behind the speakers due to the bass section or the top section (holding the midrange through tweeters)? I'm sure its for both (probably) but was wondering if you could get away placing the top sections a little closer to the back wall (separate from the bass).

Thanks,
Jim
 
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