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  • LX521 revisited

    Got to visit the LX521 on their “native turf” for a couple hours Sunday (my first visit to their “place of birth"), and to listen on them to some very familiar (and somewhat flawed) recordings that I heard up close and personal both in rehearsal and in performance. Since I was primarily interested in further evaluating the new midrange I took a soprano aria (Christina Major singing Ruhe Sanft, Midsummer Mozart Festival) and the Serenade #10 for winds (Gran Partita, also Midsummer Mozart). SL then played a couple “studio mixed” recordings that highlighted issues of “phantom image” formation (more about that later).

    First, about the lower midrange bump (I previously described it as “forward sounding”) that I noted at BurningAmp. It is entirely absent in SL’s listening room, and as I speculated before it is now clearly an artifact of the space at Ft. Mason. No speaker can be completely immune to the room. In SL’s room (which is itself relatively “live” and reflective) overall balance and “timbre” are as good as it gets. There was simply nothing wrong with the reproduction of the various winds in the Partita.

    Second, regarding issues of the midrange crossover and driver integration . . . I had heard no problem with that at BurningAmp, but it has been suggested that there might be some, and that, more than anything else, is what I went to listen for. Put it to rest, there is no “problem”. The lower and upper mids sound like one driver, and there is not the slightest hint otherwise. And, to answer your next question, it’s one very good driver indeed . . . every bit the match for ORION’s W22 in the lower midrange and Millennium in the upper, but without the oft discussed issues those two have around crossover. The higher order crossover that is simply a necessity with the drivers in ORION is not needed with the LX521 drivers . . . whether the increased phase shift of a higher order crossover can be heard or influences “image formation” is here moot, since it is not necessary. This makes putting the passive (first order) crossover between the two midrange drivers the obvious, and correct, choice with these drivers.

    But back to “imaging” and the “auditory scene” . . . that’s more a “mixed bag”, not because of any LX521 problem but because they ruthlessly expose problems in the recording. When it’s there it’s there, when it’s not it’s not. These are rightly called “monitors”, and they will embarrass many a recording engineer who might listen to his previous work product on them (even though it might not be entirely his fault . . . there are unavoidable “issues” with two-channel stereo). The female vocalist in one of the clearly mixed-and-pan-potted recordings SL played was “present” as a near perfect phantom when I listened centered on axis, but fled into the speakers when I move more than a few degrees to either side. Christi (singing the Ruhe) was less precisely located in her actual left-of-center position, but she stayed there as I moved around the room (that recording was straight through from a ORTF pair). We’ve still got a lot to learn about creating stable “auditory scenes”, and I expect the LX521 (or something like it) will play a significant role in learning and demonstrating what it is.

    I much preferred listening from the back seat (you can find pictures of SL’s listening room at the linkwitzlab site). I don’t know exactly what that means, or how it will translate to my room (where I generally prefer a somewhat “further back” position with ORION as well). For the “average listener” they (the LX521) may be almost too ruthless in the way they “expose” a recording. For someone in the trade, on the other hand, they should be regarded as indispensable . . . it just doesn’t “do” to have a client demonstrate to you on their own speakers flaws in your work that you cannot hear on your own “studio monitors”.
    "It suggests that there is something that is happening in the real system that is not quite captured in the models."

  • #2
    Re: LX521 revisited

    Thank you Mr. Hastings for you impressions and putting your ears where mouth is. I am not suprised at your obsevations about room difference since dipole work better with diffuse relective sufaces and the Burning Amp room picture looked like any thing but a diffuse room. As I believe you were member of the Berkely free speech movement I will respect your right to express your opinions in the future. Especially against the status quo.....
    Fred


    I don't who tacobandit is but.......

    http://www.youtube.com/watch?v=3cUY9MaZQ4Y&feature=plcp

    Exactly duplicate post here and at Diyaudio are in questionable taste, but I defend your right to do so.
    Last edited by fdieck; 11-19-2012, 07:36 PM.

    Comment


    • #3
      Re: LX521 revisited

      Originally posted by Deward Hastings View Post
      We’ve still got a lot to learn about creating stable “auditory scenes”, and I expect the LX521 (or something like it) will play a significant role in learning and demonstrating what it is.
      Hi Deward,

      I am glad, that spatial issues in loudspeakers are finally being considered as important.

      http://www.bodziosoftware.com.au/Att...udspeakers.pdf

      Best Regards,
      Bohdan

      Comment


      • #4
        Re: LX521 revisited

        Originally posted by bohdan View Post
        Hi Deward,

        I am glad, that spatial issues in loudspeakers are finally being considered as important.

        http://www.bodziosoftware.com.au/Att...udspeakers.pdf

        Best Regards,
        Bohdan
        Finally..........?

        Baffle diffraction: Jon Dahlquist, Jim Theil, Richard Vandersteen and many others
        Low order crossovers: Jim Theil, Richard Vandersteen, John Dunlavy, and many others.

        The LX 521 maybe called First order, but I bet if you measure it it looks like a Second order LR. Linkwitz himself has stated it is 6 dB down at 1kHz and the drivers phase inverted....

        Comment


        • #5
          Re: LX521 revisited

          When I set up the Note II with 1st order with phase tracking through the crossover the LP and HP poles had to be shifted considerably, with upper mid connected with reversed polarity. The phase response looks pretty much LR4 though, not LR2.



          The version with the best looking impulse has an LR2 crossover for the coupler. After some extended listening with 1st, 2nd and 4th order crossovers I really can not say there is any big difference in the sound of my system, but the 10F is certainly working harder with the 1st order whcih is very obvious from toughing the cone, and in that regard alone I would still suggest that higher order is a better choice, though I see some things in the CSD plots on my system that suggest 2nd order may be the superior configuration over 4th order. I have yet to measure the polar response with the 1st and 2nd order configurations. Probably do that tomorrow.

          CSD plots are presented at the bottom of my News page.
          John k.... Music and Design NaO dsp Dipole Loudspeakers.

          Comment


          • #6
            Re: LX521 revisited

            Originally posted by Deward Hastings View Post
            Second, regarding issues of the midrange crossover and driver integration . . . I had heard no problem with that at BurningAmp, but it has been suggested that there might be some, and that, more than anything else, is what I went to listen for. Put it to rest, there is no “problem”. The lower and upper mids sound like one driver, and there is not the slightest hint otherwise. And, to answer your next question, it’s one very good driver indeed . . . every bit the match for ORION’s W22 in the lower midrange and Millennium in the upper, but without the oft discussed issues those two have around crossover. The higher order crossover that is simply a necessity with the drivers in ORION is not needed with the LX521 drivers . . . whether the increased phase shift of a higher order crossover can be heard or influences “image formation” is here moot, since it is not necessary. This makes putting the passive (first order) crossover between the two midrange drivers the obvious, and correct, choice with these drivers.
            See my response to fdierk about the phase of the 1st order.


            But back to “imaging” and the “auditory scene” . . . that’s more a “mixed bag”, not because of any LX521 problem but because they ruthlessly expose problems in the recording. When it’s there it’s there, when it’s not it’s not. These are rightly called “monitors”, and they will embarrass many a recording engineer who might listen to his previous work product on them (even though it might not be entirely his fault . . . there are unavoidable “issues” with two-channel stereo). The female vocalist in one of the clearly mixed-and-pan-potted recordings SL played was “present” as a near perfect phantom when I listened centered on axis, but fled into the speakers when I move more than a few degrees to either side. Christi (singing the Ruhe) was less precisely located in her actual left-of-center position, but she stayed there as I moved around the room (that recording was straight through from a ORTF pair).
            I like that, "they ruthlessly expose problems", spoken like a typical reviewer. Why would you expect anything else from stereo? There is only one optimum position for creation of a phantom image and that is centered between the speakers. Sit anywhere else and there is necessarily degradation in the image.

            By the way, is classical music all you guys listen to? How about some Jazz or contempory or some good old Rock and Roll How does the LX521 sound with Little Feat at 95 to 100dB?
            John k.... Music and Design NaO dsp Dipole Loudspeakers.

            Comment


            • #7
              Re: LX521 revisited

              Deward gave us his subjective opinion on the LX521's, and although I doubt I'll ever have the money to use them, I value his input. The crossover order may be more dependent on the driver you're crossing from than the LX's characteristics. It's not "the perfect tweeter" because that hasn't be created yet. ;)

              Comment


              • #8
                Re: LX521 revisited

                Originally posted by johnk... View Post
                See my response to fdierk about the phase of the 1st order.



                I like that, "they ruthlessly expose problems", spoken like a typical reviewer. Why would you expect anything else from stereo? There is only one optimum position for creation of a phantom image and that is centered between the speakers. Sit anywhere else and there is necessarily degradation in the image.

                By the way, is classical music all you guys listen to? How about some Jazz or contempory or some good old Rock and Roll How does the LX521 sound with Little Feat at 95 to 100dB?
                Ah... you are making me miss my design review days (as long as I was not the designer in the hot seat) . I really don't see how one can call a design with out of phase driver connections and -6dB at crossover point, anything but a (quasi) 2nd order LR response. When you factor in baffle roll off (or defraction), driver roll off, and driver directionality; call something First Order is more semantics than reality. Second order sounds like good compromise to me.

                PS Any speaker that permits one to sit still while listening to Lowell George sing "Fatman in the Bathtub" is fatally flawed.

                Comment


                • #9
                  Re: LX521 revisited

                  Originally posted by johnk... View Post
                  ...Little Feat at 95 to 100dB?
                  +1
                  Charlie's Audio Pages: http://audio.claub.net

                  Comment


                  • #10
                    Re: LX521 revisited

                    Originally posted by johnk... View Post
                    By the way, is classical music all you guys listen to? How about some Jazz or contempory
                    The selections SL played were. I cannot evaluate speakers (at this level of quality) without reference to an "original source" that I am familiar with. Otherwise the evaluation is entirely "subjective" . . . whether I "like" the particular sound coloration (or lack of) or not. Back when I was working rock and bluegrass I could have told you whether a recording sounded like "house sound" (hopefully not :eek but could not in any case say whether a studio mix sounded "real". What was played certainly sounded pleasant enough . . .

                    I seriously considered bringing my "Accordion Babes" CD, but that wasn't what I went to listen for . . . :D
                    http://accordionpinupcalendar.com/2011_gallery.html
                    Last edited by Deward Hastings; 11-20-2012, 12:00 AM. Reason: plug for Accordion Babes
                    "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                    Comment


                    • #11
                      Re: LX521 revisited

                      Originally posted by johnk... View Post
                      After some extended listening with 1st, 2nd and 4th order crossovers I really can not say there is any big difference in the sound of my system, but the 10F is certainly working harder with the 1st order whcih is very obvious from toughing the cone
                      As I replied over at DIYaudio, I don't know what you are doing that is different from what SL is doing, but "excessive excursion" is simply not an issue with the LX521. The cones on the drivers in LX521 are well behaved far enough out from crossover that the benefit of higher out-of-band suppression (necessary, for example, with the W22) just isn't there. With many drivers I'd expect higher order to sound better for that reason (stop-band suppression) alone. Imaging is possibly helped by the lower phase shift of the lower order filter . . . at very least it's one less confounding variable to worry about. What we perceive, even how we perceive, in the critical midband is still an open area of study. The motors and suspension of both drivers are obviously quite good, and seem well matched and balanced for the application. There may be some room for improvement, but I'd expect it to be modest.

                      Initial shipment of the custom "SL" drivers is promised RSN, although until there is sufficient supply they may be reserved for licensed builders. Once they are available you might want to get a set . . . the baffle dimensions can be easily figured from a photograph (especially if you think like an engineer ;)) . . . and then repeat your crossover experiment with them.
                      "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                      Comment


                      • #12
                        Re: LX521 revisited

                        Originally posted by fdieck View Post
                        I really don't see how one can call a design with out of phase driver connections and -6dB at crossover point, anything but a (quasi) 2nd order LR response.
                        I suppose you can call it anything you want . . . especially if you chose to include "baffle effects", but the actual physical crossover is one cap and one inductor, and the drivers are both admirably flat at least a couple octaves either side of the crossover point. If you call it "quasi second order" then I suppose that SL's design matches John's determination that "2nd order sounds best".
                        "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                        Comment


                        • #13
                          Re: LX521 revisited

                          Deward, do you have any information on what the cross-over frequency (or range) on the LX is suggested? I'm just curious.

                          Comment


                          • #14
                            Re: LX521 revisited

                            Originally posted by Whitneyville1 View Post
                            Deward, do you have any information on what the cross-over frequency (or range) on the LX is suggested?
                            "Actual" depends on what you measure because of equalization and acoustic effects, but nominally it's 120 Hz for the W/M, 1000 Hz. for the M/M, and 7000 Hz. for the M/T. The dual mids obviously cover a substantial range. There's more information at http://www.linkwitzlab.com/LX521/Description.htm but for more detail, like ASP circuits and response curves, you'd have to buy the plans.
                            "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                            Comment


                            • #15
                              Re: LX521 revisited

                              Somewhat "flies in the face" of conventional speaker design, doesn't it? Does take a little power too. Makes me wonder wat' Mick an' th' lads wud soun' lak' on 'em doin' "Honky Tonk Women" tho'. You really need to sneak a CD like that into one of those auditions, just to raise some eyebrows and heart-rates. I made a reservation at SON, our snob audio store here, and brought some LP's with me, and I slipped my Hank Williams Sr. on the Pink Triangle after my UHQR of DSOTM, and I thought the "host" was going to die! A $95,000 stereo system with Hank Sr. on it, yodeling no less!:p

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