I dont think its available to DIY. You can buy just the crossover as a finished unit from Frank.
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Linkwitz LX521.4 - new build and impressions
- Thread starter suttondesign
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- Jan 7, 2020
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Wow, just looked up the price of the Rockports!
I had AE 15 inch drivers in a previous setup in large sealed boxes. Yes, the multiple 10 inch seas drivers are no match. You would need to add multiple subs under 80Hz, but still wont match a 15 or 18 inch AE driver going upto 300-350Hz. Best bass I ever had.
I still dont get why people are not in favour of dsp - it really can sound better as there is no one perfect solution for every driver and every build, there will always be variations with sound consequences. All you need is the new Topping multichannel dac - I have been using an okto for a few years. If you use a computer source the Topping is cheaper than the ASP and then add a custom Buckeye multichannel amp with mix of modules.
The advantage is having different profiles which you can switch on the fly - flat, Harman curve, BBC dip, B&W treble lift etc. You really can make the Lx521 sound like whatever you want within reason. I could never get it to sound like a point source horn system though.
Yeah my longer term plan is to build the sub ".4" with AE drivers, make a custom amp for all 8-10 channels, and tune everything myself with a DSP. I have yet to see a home audio DSP that is as good as a car audio DSP though, such as the Helix DSP Ultra. If I can't find one, then I may just use a car audio DSP for the system. The downside is it only has unbalanced RCA outputs. I haven't looked closely at all the MiniDSP products yet though. Maybe they have good options for 8-10 channels of output.
And yes I completely agree with you on the DSP. They are game changers for any system! I think Mr. Linkwitz developed the 521.4 in an era where the DSP wasn't as developed, so he came up with the ASP.
What do you like about car audio DSP? Amir has measured some of the minidsp stuff and it performs pretty well.
I think that a minidsp 4x8 going into rack mount amps and then to the speakers via 8 conductor speakon cables is probably the cleanest way of executing the LX521 or any other 4 way speaker.
I'm not aware of any 4-way dsp amps, but Hypex does make a 3-way fusion amp. If you take out the bass module, these amps could power a dipole mid-treble unit quite well.
You are planning to use the AE-woofers as dipoles? As you are probably aware, SL designed the closed box Thor subwoofers to complement the Orion. He noted that the subs could be used up to 50 Hz without detrimental effects. Since dipoles are hysterically inefficcient in the 20-30 Hz range, you might find even four 15- or 18-inchers lacking...
Should also be much easier to integrate with the LX521's since you wouldn't have to redesign the original crossover...Love this design! I too was looking to recess the cables and add some sort of grill to hide the sub drivers (for WAF). How did you go on about recessing the cables? I've been working through a few ideas but not quite sure how to execute.View attachment 126564
I painted my panels black and wrapped everything else in black velvet. They look pretty fantastic. The room they are in is also black velvet. Gives new meaning to speakers disappearing
Dipole bass is nice but it is not a magic bullet. Dirac helps a lot. I am crossing over to a pair of subs built with Eminence NSW6021 drivers. For music I don't think that subs are necessary but for home theater they are valuable.
I noticed that Archimago came across the LX521 at the Pacific Audio Show - https://archimago.blogspot.com/2022/07/pacific-audio-fest-2022-paf-2022-day-1.html
''Duke Ellington's "Take The 'A' Train" and Christian McBride & Gina Gershon's "Chitlins and Gefiltefish" (Conversations With Christian) showed off the remarkable soundstaging ability and just the "cleanliness" of the amp and speaker combo. No doubt certainly one of the best (if not the best) sound I heard all day.''
''Duke Ellington's "Take The 'A' Train" and Christian McBride & Gina Gershon's "Chitlins and Gefiltefish" (Conversations With Christian) showed off the remarkable soundstaging ability and just the "cleanliness" of the amp and speaker combo. No doubt certainly one of the best (if not the best) sound I heard all day.''
phoenixdogfan
Major Contributor
MiniDSP Flex 8 seems like it would be just the ticket for this kind of build.
Yep awesome to see it, would jump on an 8ch shd version
phoenixdogfan
Major Contributor
Flex is pretty much the same thing less the volumio streamer.
I have been thinking about building these speakers for a while now. It seems like most of the peoples concern is about the output in the sub region. My concern is about the midbass. I could always use a closed sub below 50 Hz for HT or party is my thinking here.
Isn't an 8" (and without to much baffle support) a little to weak for midbass in the 120 - 200 Hz region??
Someone mention you could choose a higher crossover for the bass units, but I guess there is a reason for this "low" crossover point. Cavity resonances??
What do you guys think was Mr. Linkwitz choice of this midbass solution?
Someone here that has experimented with a 10 or 12"?
Isn't an 8" (and without to much baffle support) a little to weak for midbass in the 120 - 200 Hz region??
Someone mention you could choose a higher crossover for the bass units, but I guess there is a reason for this "low" crossover point. Cavity resonances??
What do you guys think was Mr. Linkwitz choice of this midbass solution?
Someone here that has experimented with a 10 or 12"?
The baffle isn't really affecting a driver at those wavelengths. Mr. Linkwitz worked with Seas to design that driver (which is quite efficient and has a generous xmax and a huge mechanical limit beyond xmax) and I'm quite confident that if that driver weren't the perfect solution for him, he would have used something different. He designed these for his own personal use and just happens to sell them.
From my experience, I can get well over 100dB from pink noise in room from them and when listening to music, my ears give out before the speakers do. It is uncomfortable and painful to be in the room with everything at full tilt. ...and after trying it once, I just won't do that again.
...and since this is ASR, yes, I measured the distortion (using the DATS, so we aren't talking Klippel) and there was no smoke in that range. I did check it ungated, so there was definitely room involved. It was still just fine.
Proceed with no fear.
Yes, I'm sure this is a well thought construction. Still, every speaker has some compromises. And I think maybe this 8" is the "weakest" link here. I could be wrong of course, but I can't remember seeing such small driver down to 120 Hz in an OB before.
Yes, the driver has pretty good 10 mm max travel, but 4 mm linear coil travel.
For instance, if I remember correctly, Juhazis diy speaker Aino Gradient use a 12 incher (nude) midbass down to 180 - 200 Hz. And commented that he wasn't comfortable going lower.
And of course, if you choose another/bigger alternative than the 8, you're one your own regarding to filters etc. So it's absolutely not certain that the outcome will be better.
Anyone tried the newer miniDSP SHD vs the 4x10HD? Is it a hearable difference? Or to ask differently, why is someone "unhappy" with the 4x10?
Yes, the driver has pretty good 10 mm max travel, but 4 mm linear coil travel.
For instance, if I remember correctly, Juhazis diy speaker Aino Gradient use a 12 incher (nude) midbass down to 180 - 200 Hz. And commented that he wasn't comfortable going lower.
And of course, if you choose another/bigger alternative than the 8, you're one your own regarding to filters etc. So it's absolutely not certain that the outcome will be better.
Anyone tried the newer miniDSP SHD vs the 4x10HD? Is it a hearable difference? Or to ask differently, why is someone "unhappy" with the 4x10?
SL was heavily analog guy yes, but LX521.4 was sold with Minidsp 4x10HD and preset settings in 2016. Sadly the unit is no longer in production and second hand units are prone to die (my unit died after 9 years)
Minidsp Flex 8 accepts only digital input (2). So it is difficult to get intergated in a multichannel system that has one common volume pot. I have replaced my 4x10HD with two 2x4HDs, but I had to redo settings. Minidsp has also a unit for car audio C-DSP 8x12 that can be used, it has SHARC processor like 2x4HD. I don't like the idea of using four 2-ch dacs at all, but that is possible too, as well as using a pc as dsp if it is your only source and you are the only user. To me it is very important that the AVR connected to TV with HDMI-eARC are only "visible" units. Vinyl and CD-player are connected to AVR too.
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Have you tried the auditions thread on OPLUG?
ctrl
Major Contributor
Since I always find such questions exciting, I have simulated it for you - but only with simple means via VCAD (which is sufficiently accurate) and not via a BEM-LEM simulation.
1. Sketch of the baffle and determine baffle diffraction (BD)
I made a rough sketch of the baffle and exported the OB baffle diffraction frequency response.
2. Enclosure simulation, import BD, target curve
Next, the Enclosure tool was used to simulate the behavior of the woofer. The BD FR was imported and adjusted to match our target curve with HP-LR4@120Hz.
The target curve in orange, the frequency response of the driver in the baffle in brown and the driver in the infinite baffle in black.
With this, we have finished creating our target frequency response for the woofer of the LX521 in the open baffle with HP-LR4@120Hz XO.
3. Evaluation of the driver excursion
So now we can take a look at the driver excursion at 90dB@1m, 100dB@1m and 105dB@1m in the free field.
The Seas woofer is provided with a LR4@120Hz high pass. Shown is the 4pi frequency response with crossover as brown curve and in orange the LR4@120Hz high pass target function.
The Seas woofer U22REX has two distortion peaks - at 100Hz (3% HD2@90dB-2pi) and 700Hz (2% HD2@90dB-2pi)***. However, both consist mainly of HD2, so should hardly be audible directly due to masking, but could still provide some increased IMD with multitone excitation.
Because of the 100Hz distortion peak, the woofer should, for best results, in no case be crossed lower than 120Hz.
At 105dB@1m the woofer comes to its Xmax limit.
At the latest at 112dB@1m is the end, because the woofer with 9.6mm excursion comes dangerously close to the maximum 10mm voice coil excursion - so that there is a danger that the voice coil hits the back plate of the motor system, which is not a pleasant noise. At this sound pressure the woofer is loaded with over 600W, which the voice coil is not likely to survive.
***Source: Hobby HiFi 2013-4
Update: By mistake, I subtracted an additional 6dB for the simulation in the free field. I have corrected this and my statements.
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OP
- Thread Starter
- #158
I've run 2 separate Linkwitz systems using the 4x10HD. One runs LXmini's and never seems to hiccup. The other, however, is fritzy. It runs the LX521.4. It will occasionally spew noise. Sometimes all the settings disappear. It's finicky as far as downstream group loops, so everything in the chain has to use balanced connections. That's a problem because I had a downstream sub which had to use unbalanced connections. So, possibly just a unit issue.
After a move to another state, I plan to set up the LX521.4 again using the 4x10HD that formerly ran the LXmini's, which I may not have use for any more. The one advantage of the older 4x10HD over the new Flex 8 is that the 4x10HD has a digital pass-through output. I can send the signal to another MiniDSP unit, such as the 2x4HD, to EQ and run subwoofers.
That’s pretty cool! I don’t know how it translates to other speaker designs, but I can say that in the size of rooms I get to use it in the 8” woofer does not have large visible excursions, and seems to have plenty of clean output for music.
OP
- Thread Starter
- #160
I personally would not deviate from something which Siegfried, after decades of experience and design iterations, designed and specified. He is someone who was dissatisfied with the Orions, which were by far the best speakers I ever heard or owned, and was willing to design something as godawful ugly as the 521.4 in pursuit of improvement. He knew that these designs could never be a mass-market product, or even a small-market product. They are ugly, confusing, finicky, and quite demanding on the user.
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