• 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.

Linkwitz LX521.4 - new build and impressions

suttondesign

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
520
Likes
879
Location
Austin, TX
Hi all,

One of my COVID projects was to build the Linkwitz LX521.4 to replace my first LXmini. I finished them last week and hooked them up to Nord-built Hypex 4-channel amps and a MiniDSP 4x10HD. And Yes, I know these things are ugly. I had put off building them for some time for several reasons: (1) cost; (2) uncertainty about whether they would be too visually obtrusive; and (3) ugly. But COVID made me say, What the heck, just do something already. So I did. I don't think building them out of pretty wood makes them appreciably nicer looking, so I just ordered the Madisound Baltic-birch kit.

I've had the weekend to listen, and I just want to report that these are, hands-down, my favorite speakers ever, including the Dutch & Dutch 8C, which I sell as a dealer and think are awesome. Of course, by the time you've built the LX521.4 and obtained the 8- or 10-channel amp(s), 4x10HD, and decent cabling (copper speaker wire, a bunch of XLR's, 6 or 8 male and female Neutriks, etc.), you'll have spent about $6,000, give or take, so it's not like you're getting off cheap, but what a payoff.

If anyone knows why, I found I couldn't use unbalanced RCA connections from MiniDSP 4x10HD to the Nord amps without ungodly ground loop noise. But once I switched over to balanced connectors using the Phoenix pigtails supplied with the MiniDSP, the noise went away entirely. I've got two separate Nord amps, one a year old, one new, and the older one had no problems running unbalanced to my prior LXmini. I can't figure how this new build created a ground loop.
 

Attachments

  • IMG_1080 copy.jpg
    IMG_1080 copy.jpg
    186.2 KB · Views: 1,428
  • IMG_1081 copy.jpg
    IMG_1081 copy.jpg
    150.8 KB · Views: 1,631

Juhazi

Major Contributor
Joined
Sep 15, 2018
Messages
1,551
Likes
2,492
Location
Finland
Nice to hear that! I've never heard LX521 myself.

I got rid of noise with 4x10HD by using shielded subwoofer RCA cables. My amps can't take balanced.
 

jhaider

Major Contributor
Forum Donor
Joined
Jun 5, 2016
Messages
1,546
Likes
1,991
I would love to hear this design, as well as the NaO Note, which is broadly similar in design and uses drivers I like better (because I have midbasses and midranges on hand!)

I heard the ORION set up by Linkwitz at Axpona, and except for the upper bass wasn’t particularly wowed. But this one has a lot of design improvements.
 

FrantzM

Major Contributor
Forum Donor
Joined
Mar 12, 2016
Messages
2,567
Likes
3,783
Considered building them but my room is too small ... :(
 
OP
S

suttondesign

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
520
Likes
879
Location
Austin, TX
I got rid of noise with 4x10HD by using shielded subwoofer RCA cables. My amps can't take balanced.

I was wondering about that. When I was doing the test hookup, I pulled out some ancient RCA cables from a bin in the attic. With the LXmini, I was using some new, high-quality RCA cables, but I needed four additional ones in a pinch to get the LX521.4 going. When the hum started up, I had an inkling it might be the crummy old cables, but it was late in the evening and I was tearing out my hair to get them hooked up. Since I had the pigtails with the XLR connectors, I tested out one side, and it was clear the problem was gone. It just made sense to go fully balanced, at that point.

Can anyone enlighten me about shielded vs. unshielded RCA cables? I assumed they were all shielded and basically good enough, but it sounds like that's wrong.
 
OP
S

suttondesign

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
520
Likes
879
Location
Austin, TX
Considered building them but my room is too small ... :(

Agreed, they just aren't workable in a small room in the sense that they won't image properly. I've got almost exactly the minimum dimension specified by Siegfried. My main problem is that I don't have a lot of room behind my listening sofa. However, there is the equipment closet there with doors on two different planes communicating with the room. There's also the main entry room into the adjoining open living area. Since none of the gear has fans except the Mac Mini, which is virtually inaudible, what I do is open the equipment closet doors, and sometimes the main entry door, and that helps tame standing waves and break up reflections off the area behind me. Not perfect, but the sound is glorious if I don't crank the volume way up.
 
OP
S

suttondesign

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
520
Likes
879
Location
Austin, TX
Very cool. More pics please!
Here's the original room as designed back in 2007. I think it tells the story. I built Linkwitz Orions for this very room. And BTW, I was in design for a long time, don't you love the shadow showing the shape of the Linkwitz Orion baffle?
acousticiandrawing1.jpg
 
OP
S

suttondesign

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
520
Likes
879
Location
Austin, TX
Hey, great pic! You appear to have 10' long legs.

My Waterlox resin-modified tung oil finish (true) smooths out the impudence curve, imparts a velveeta midrange, and mellifluates the midranges (very true). I'm sure you'll find a lot of improvement if you slather a clearcoat over those things.
 

JP

Senior Member
Joined
Jul 4, 2018
Messages
441
Likes
539
Location
Brookfield, CT
Plan was black paint on the lowers, veneer on the uppers, and I never settled on what to do on the bridges. So I listen while I contemplate.
 

JimB

Addicted to Fun and Learning
Forum Donor
Joined
Sep 19, 2019
Messages
717
Likes
460
Location
California
Hi all,

One of my COVID projects was to build the Linkwitz LX521.4 to replace my first LXmini. I finished them last week and hooked them up to Nord-built Hypex 4-channel amps and a MiniDSP 4x10HD. And Yes, I know these things are ugly. I had put off building them for some time for several reasons: (1) cost; (2) uncertainty about whether they would be too visually obtrusive; and (3) ugly. But COVID made me say, What the heck, just do something already. So I did. I don't think building them out of pretty wood makes them appreciably nicer looking, so I just ordered the Madisound Baltic-birch kit. ...
Nice! Glad you like them. Mine are 'only' the Orion 3.3, which I built in 2008, but I like them a lot. I did them from "brown oak", with just clear coat. I have the ASP (slightly upgraded). Originally, I had 10 independent channels of Emotiva amps. These days, I drive the paralleled woofers with mono-bloc Hypex NC400's (with reduced gain), and the mid and paralleled tweeters of each side with an AHB2. Originally, I had more noise than I liked, but now I run the AHB2s at mid gain and the signal into the ASP much higher. That works for me. In my case, the outputs of the ASP are single ended, but the amps are all balanced, so I use star-quad adapter cables. I try to keep about 4 feet free around them. Room still matters. I had bad slap echo in the early days which took all the magic out of them. Once I got that under control, and a minimal amount of bass management in the room, I was a happy camper.
IMG_2911r 25p.jpg
IMG_2913r 25p.jpg
 

MrPeabody

Addicted to Fun and Learning
Joined
Dec 19, 2020
Messages
657
Likes
856
Location
USA
Nice. For the people who have these speakers, what is the consensus for the need for subwoofer augmentation? Don't need them? Could use them but not essential? Definitely needs them?
 

bb8

Member
Joined
Feb 16, 2021
Messages
19
Likes
22
As always the answer is it depends. They don't need subwoofers in general, but it's dependent on the size and placement of your room. A very large room would definitely benefit but an average room they can really dig down deep. They can also get pretty loud. Congrats on your build sutton, the LX521's are such an amazing speaker. Wish I had the room for these, maybe one day. Little bit jealous :)
 
Top Bottom