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Linkwitz LX521.4 - new build and impressions

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
 

Joecarrow

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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

It's both. I've experimented moving them separately, and there are different deleterious effects for each. Moving the bottom section closer quickly reduces the bass output. As it gets within a foot or so of the wall it's a very noticeable reduction in bass. I found that three feet is really the bare minimum, though more is recommended. For the top section you start to get some significant timbral effects, I found it started to sound sort of boxy and indistinct. It's somewhat better if the surface is really diffusive and not a flat blank wall. I have mine in front of a pair of book shelves right now and the bookshelf fronts approach a little closer to the speakers than three feet, but they are open front and full of stuff.

If space is tight then I strongly recommend the LXmini. I've heard them both back to back in the same room and it's quite surprising how similar they sound despite being such different designs. Yes the LX521 does a lot of things better, but it does need the space and in a small enough room the mini wins.
 

JimB

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It's both. I've experimented moving them separately, and there are different deleterious effects for each. Moving the bottom section closer quickly reduces the bass output. As it gets within a foot or so of the wall it's a very noticeable reduction in bass. I found that three feet is really the bare minimum, though more is recommended. For the top section you start to get some significant timbral effects, I found it started to sound sort of boxy and indistinct. It's somewhat better if the surface is really diffusive and not a flat blank wall. I have mine in front of a pair of book shelves right now and the bookshelf fronts approach a little closer to the speakers than three feet, but they are open front and full of stuff.

If space is tight then I strongly recommend the LXmini. I've heard them both back to back in the same room and it's quite surprising how similar they sound despite being such different designs. Yes the LX521 does a lot of things better, but it does need the space and in a small enough room the mini wins.
The top and bottom sections need to remain close together.
 

jeffbook

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Linkwitz covered woofer and midrange separation distances on his website. See this link:

http://www.linkwitzlab.com/frontiers_5.htm

It shows the effect of separation distance on crossover behavior for various crossovers at different frequencies. However, speaker placement within the listening room with regard to distance from side and front walls is still a paramount concern with both the LXmini and the LX521. Suggested minimum distances to walls, speaker separation and room size for the LX521 need to to be heeded for best performance.
 

JimB

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Linkwitz covered woofer and midrange separation distances on his website. See this link:

http://www.linkwitzlab.com/frontiers_5.htm

It shows the effect of separation distance on crossover behavior for various crossovers at different frequencies. However, speaker placement within the listening room with regard to distance from side and front walls is still a paramount concern with both the LXmini and the LX521. Suggested minimum distances to walls, speaker separation and room size for the LX521 need to to be heeded for best performance.
With that, one wants to consider the crossover frequency of the upper panel and the woofers (~120 Hz?). The speaker is not intended to be treated as a satellite with subwoofer.
 

Joecarrow

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I’m sorry if I’ve created some confusion with my description of experimentation- yes, the system needs to be built and used as designed. No, it’s not condoned or a good idea to separate them, but you can’t hand me a speaker like this with a DSP that allows easy digital delay and expect me not to screw around with it and measure the results. I’m just reporting that two separately observable issues arise from approaching the wall to closely, and they could just as easily be shown by moving the whole speaker and turning sections off to isolate the problems. Sometimes in order to find the best performance it’s useful to probe the glaring issues and see how quickly they get worse.
 

jeffbook

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With that, one wants to consider the crossover frequency of the upper panel and the woofers (~120 Hz?). The speaker is not intended to be treated as a satellite with subwoofer.
Correct. The LX521 is a full spectrum integrated 4 way speaker system crossing over at 120 Hz..

However, There are instances where a separate dipole bass module can be used in the Linkwitz speaker universe that require proper integration. My current speaker system consists of the LXmini integrated with separate dipole bass modules from my original Linkwitz system, the Orion. Since the dipole modules are freestanding, the integration techniques discussed in the link posted come into play.

I am currently considering building a hybrid system that would consist of the Orion bass modules currently in use with the LXmini along with the LX521 upper baffle with the Seas MU10B upper midrange as used in the LX521 system along with Seas W22EX001 8" speakers (used in the original Orion system....) as the lower midrange drivers instead of the U22REX drivers specified in the LX521 design. A similar hybrid system has been designed and built and is discussed on the Linkwitz user group. In this case, the integration techniques from the link in my prior post once again comes in handy to assist in DIY design.

Siegfried never discouraged such experimentation with his designs. His website and availability of his designs and construction plans can inspire and encourage DIY experimentation under the guise of learning and simply having fun as well as creating a great sound system for music enjoyment.
 

capslock

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How much do the L26 woofers actually move when listening to real music (i.e. not home theater or synthetic stuff) at high but not concert volume (90 - 95 dB at listening position)?

My dealer stood me up on my order of four L26, and there are cheaper and more efficient drivers with nearly the same fs and Qts but lower excursion.
 

Joecarrow

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They can move quite a bit, like I see them moving from my seat. What's remarkable about them is how much they can move without making extraneous noises. I do think that you can have success with other woofers, especially if you highpass them and also use a conventional subwoofer for the lowest notes. The trouble is that you'll need to be able to measure and iterate to get the crossover just right.
 

mamsterla

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They barely move at all. It takes something like heavy synth music to see them move at all. They are really amazing drivers so I urge you to use them in your final build, but if you need to do some substitution, just try to match the parameters. If you want me to play something, I can video it close up. I want to saw that I cross-over my LX-521.4 at 60Hz to my dual Rythmik subs.
 
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capslock

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They barely move at all. It takes something like heavy synth music to see them move at all. They are really amazing drivers so I urge you to use them in your final build, but if you need to do some substitution, just try to match the parameters. If you want me to play something, I can video it close up. I want to saw that I cross-over my LX-521.4 at 60Hz to my dual Rythmik subs.

So this is essentially a 60 Hz LR2 or LR4 lowcut? This would make a lot of difference to a 1st order 30 Hz low cut as proposed by SL in the plans.
 
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Adam_M

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In my experience, they move quite a bit. Many mm. I'd be afraid to use a driver less robust than SL specified.

More efficient may be a problem, but will certainly require a filter modification. You will also want to make sure the frequency response matches. Running drivers with no enclosure puts a ton more stress on them (through movement) than in a sealed box or even a ported box above the tuning frequency. You also need to consider the physical design. While not terribly critical for the woofers, a relatively open basket may be helpful.

I'd suggest you consider if you have the experience with open baffle speakers and DIY speakers in general before modifying this design. While it isn't rocket science, it's more difficult (at least to me) than a conventional box speaker. I've designed dozens of speakers, and built dozens more from kits. The LX521 is the only one in the lot I wouldn't mess with.

This probably sounds more negative than I intend it to be. Experimentation is at the heart of DIY speakers. You should run the experiment, but don't rule out the need to buy the L26's if the experiment doesn't work. I've had more failed (initial) designs than successes. I learn something from every one.
 

capslock

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Ok, how about XXLS12 then?, either in Peerless or Scan Speak incarnation? They should just about fit without making the V-baffle any wider, they have about 1.5x surface while having 0.83x excursion so a net higher air volumen they can move. Max excursion is given as +/- 28 mm (so the same as L26).

Another option may be to use the two layer L26ROY which higher sensitivity and seems to be overall a better driver than the RO4Y.

These are my options (I either have the drivers or can actually buy four of them - unlike the RO4Y).

Peerless XXLS12 Nomex 830845 (27 Hz / Qts 0.52 / mms 98 g / Vas 119.5 l / 87.5 dB at 2.83V) - this is an 8 Ohm driver
Scan Speak 30W4558T (17 Hz / 0.31 / 135 g / 197 l / 89 dB)
Peerless SLS12 (31.5 Hz / 0.54 / 74 g / 132 l / 90 dB) - again an 8 Ohm driver, max excursion unknown
L26ROY-new (25 Hz / 0.42 / 118 g / 56 l / 87 dB)

as compared to
L26RO4Y-old (24 Hz / 0.27 / 173 g / 46 l / 85.5 dB)
L26RO4Y-new (26 Hz / 0.27 / 160 g / 40 l / 86 dB)

It is worth noting that while the new RO4Y has gained +/- 1 mm of linear excursion and half a dB of sensitity, its already high mechanical resistance has gone up to, from 5.4 to 6.53 Ns/m.

The L26ROY is actually pretty close in parameters but more efficient, has half the mechnical resistance and much lower inductance.

The 30W is way more efficient (especially considering it has an 8 Ohms coil) and also has a pretty heavy cone. I suspect differences in LF extension (fs, Q) will only play out below 30 Hz, which is low cut or room gain territory anyway. Not sure how the soft suspension will play out, but then this is a V baffle, so no heavy air loading.

The 830845 has considerably higher Q and lower mass. Is this going to be a concern?
 

Adam_M

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It all depends on how much fussing with the filters and measurements you are willing to do. There is more than the t/s parameters and physical fit to make this work. You will have to alter the filters to achieve the correct on axis freqency response and it would also be highly beneficial to keep the same off axis radiation pattern. SL says somewhere on his website that flat on axis is required but it isnt all that is required (I'm paraphrasing here). I'd look at other ob designs - like John K.'s no longer available NaO series as well as SL's previous products to find suitable woofers.
 

Emphyrio

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Hello All,

I reside in NW Houston and currently have the LX521 speaker system with the Mg midrange and ASP PowerBoxes set up in my listening room.
Drop me a line if you are interested in hearing this world-class speaker system.

Regards,
Fernando
 
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