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profsbg

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Posts posted by profsbg

  1. If you have a single listening location, it seems one should do all the filtering at the listening point. Breaking it up into two components (1 meter and listening point) cannot do better in theory,  and in general would be expected to do worse. With multiple listening positions the situation is different. The other caveat is the ability to interpret the measurements and constrain the filtering appropriately (this issue would have to be addressed to some extent regardless). 

     

    There are many successful implementations of single listening point filtering with psychoacoustic criteria , such as Acourate. It has been used successfully with Cornscala-type speakers. I would like to try it with my Klipschorns, but the PC-based audio interface is a barrier for me. 

  2. Can anyone comment  to what extent the Volti horns widen the sweet spot versus the K400? And how far back from the horn are you? A single seat sweet spot  is my main problem with the Klipschorns. It seems like it is a fundamental limitation of listening too close (15' to the baffle in my case) for exponential horns. I have read that there is some improvement with pure tractrix like Volti.  I have had some success listening off-axis and rebalancing, or using a center channel, but I would like a better solution.  It is more of a problem of a large shift in the sound towards the closer speaker and not a shift in the timbre.

  3. If you use weather stripping or double up on pipe insulation in the notched area is the seal good enough to not see a flashlight beam directed through the notches?

     

    Most implementations of pipe insulation on the tail pieces that I have seen follow the edge , and do not double up at the notches . Hence the notched area is not really sealed, assuming no baseboard trim or molding. Naively, I would guess this significantly affects the seal and possibly the output, assuming proper output requires a good seal.  Yet it is popular to use the pipe insulation this way.  Any thoughts or data on this? I have a crude measurement rig but I am not very confident using it.

  4. 29 minutes ago, djk said:

    Just a reminder.

     

    If you're willing to mount the tweeter on top on a block, then push it back to be aligned with the mid, you only need a simple 2 in 4 out crossover.

     

    If you have a tube amp with a 16Ω tap you only need a single high quality cap to connect the tweeter (to the 16Ω tap), and you hook the mid to the 8Ω tap.

     

    No autoformer needed, the transformer is doing that function now.

    How does this work? It seems like the mid and tweeter are both off the same channel, so only a HPF can be used. Then you are stuck with a 1st order tweeter filter, and you can't adjust the gain, change the crossover point, perform any equalization or linearization, or do anything but correct time delay without rolling in passive components. 

  5. I agree with the better fidelity of most of the albums in the list to the extent that I am familiar with it.

     

    However, I noticed that CSNY Deja Vu is on the list. I love the music but have found at least some of the tracks to be very heavy on mid bass,  even boomy, and also to have extremely wide channel separation (the latter is really a separate issue). Can you post the unmastering EQ or otherwise comment on it, for this album? 

  6. If I recall, there are noise level and spectral studies on the miniDSP, along with discussion of the role of digital input and gain structure on various forums, including miniDSP's own. Some of the results suggest different performance amongst the different implementations (2x4 versus 4x10 for e.g.).  I will look them up and we can have a discussion, but this is probably not the right thread. I don't own miniDSP so it isn't my solution, but I thought we were both just speculating - maybe not a good idea that.

     

    Not sure I understand your comment about AES/EBU output. I would use S/PDIF or perhaps HDMI from my digital player, the latter supports multichannel.

  7. On October 27, 2016 at 4:44 AM, Chris A said:

    If you're not experiencing noisy performance of miniDSP, consider yourself lucky.

     

    If you search this forum's pages on the use of miniDSP active crossovers by members owning high efficiency horn-loaded loudspeakers, you will see many instances where their use was abandoned.  The only fix in those instances where noise is an issue seems to be external battery power for the miniDSP. If it's their $100-$200 lower price that's more important--and the risk is worth it--then some folks might be able to use miniDSP. 

     

    However, I know that the other crossovers I listed will work without risk.  It's that quality thing (in this case: power supply) yet again.  Most people on this forum are paying far more for their passive crossover from third parties, and their passive networks cannot be reused if anything changes on the loudspeaker (like horns or drivers) without significant modification and testing.

     

    Active crossovers are meant to be used again and again with different loudspeakers for the life of their owners without physical modification, other than changing a few screen settings.

     

    Chris

    Is this true about miniDSP? I get a different impression from this and other forums, specifically that the noise is mitigated by  a digital input  and/or appropriate gain structure. I personally would not use an analog input to a digital crossover, especially an analog preamp which is intended for volume control. It's also essential to have some way of attenuating the output, such as trims on the amplifier. Lacking this  approach, the miniDSP with its lower cost analog circuitry would be at a disadvantage.  

    • Like 1
  8.  

     

     

    B&C DE250

     

     

    This is what I would recommend for a tweeter or a BMS 4550 on a QSC waveguide from Parts Express. It's in my avatar and looks like a "mini me" K-402.

     

     

    that QSC horn sure looks fine (baby K-402~ :P ) but I've compared B&C DE500 combined to that horn with a CP-25. DE500 is very similar to DE250 but with a Neo magnet. CP-25 sounded more open and detailed. DE500 behind a Seos 12 horn was more sweet to ear than QSC. also better controlled dispersion pattern. after all, the best tweet I've ever heard so far is Fostex Fostex T500. this small tweeter sounds badly good! never heard anything better in term of micro detail and tonal accuracy. sure this opinion is subjective.

     

    Not having heard them side by side, I would probably agree with you, but the Seos Option was not on the table at my time of purchase. Besides when you throw prices in the equation, the price/performance ration isn't there with the other options you suggest, especially the Fostex, The best horn system I've ever heard was the Sadurni and it used a $1,000 Fostex. When I hear Nora Jones "Come Away With Me" on those horns at Axpona, it was an emotional experience. Best imaging and "live cymbals" sound I've ever heard.

     

    Any thoughts on the DE10 versus the DE250 with either the QSC or Seos when sensitivity is not an issue (active set up)?  Is there some throat angle issue?  I kind of like the idea of mylar, along with the Community M200. 

  9. I had to build up the gasket on the old style Community M200 to mount to a flat surface (Volti  horn). Took several gaskets stacked actually. New style M200 doesn't have that issue.

     

    Any suggestions on tweeters to use with the M200 other than Beyma CP25 and JBL 2404 with say LR 24 dB cross at 4.0 kHz? I have the Eminence APT 200 which I don't like. Maybe something like QSC PL-000446GP or Denovo SEOS-12 with B&C DE250 or DE10?

     
    • Like 1
  10. Signal convolution is hardly "revolutionary". Their particular processing algorithm may be proprietary and their hardware may have some very handy features, but that's no excuse to tout this technology as something amazing or worth your first born child, IMO.

    My impression is that it is the measurement process and the transfer function identification which is novel. Also, they don't use deconvolution (inverse filtering) since the problem is ill-posed, but rather least squares and in some cases model-based methods for estimation. I have not heard it, but am intrigued by their claims. I will say that if I put on a set of headphones and aside from tactile feedback could not distinguish the sound from the speakers, then I would consider that revolutionary. Haven't heard it, would certainly like to.

  11. Curious whether you noticed any improvement by cutting the
    additional piece of wood and sealing vertically all the way to the
    floor as you have done. Most of the pipe insulation seal jobs I have
    seen (mine included) simply follow the tailpiece to the floor. Since I
    dont have baseboard, this does leave a gap.

  12. I am thinking about a sub for a chorus II/academy front (RS3
    rears) system which will be used 75%/25% for music/HT. My room is about
    3000 ft^2. I would like something which integrates well with the chorus
    II especially it's tight mid bass down to maybe 40-50 Hz. From some
    reading, it seems like the new epik valor or the av123 MFW-15 might
    work. Is anyone using one of these new subs with chorus (or forte or
    heritage) and could comment on how they integrate for music? Other
    suggestions are also welcome of course. Thanks

  13. Hi, can anyone offer experience on UPS shipping of Heresies (as

    opposed to larger speakers)? I mean what is peoples experience

    regarding damage. There are a lot of them on ebay now. Also, what

    happens if they show up in bad shape, is the procedure to recover

    expenses feasible, or do you just take your chances and live with

    the result? I recognize that local pickup is great, and there may be

    some possibility of this, but the availability of different models in

    different conditions across the US is attractive. Thanks

  14. Considering a center channel between two Khorns spaced about 17'.
    Due to projection screen only have about 30" max height below screen
    for center channel speaker. Mostly will be used for 3 channel stereo,
    but will serve double duty as HT center channel.

    Am somewhat
    confused about center channel height (for 3 channel stereo). Most
    suggest same height as tweeter/mids in mains. If so why are LaScala
    Belle Cornwall significantly shorter than Khorn which they were center
    channel for originally (like 15" shorter, although not sure of exactl
    tweeter/mid heights there)? Were they intended to be used on stands?

    The
    only thing that seems workable without replacing screen is a
    Heresy on a stand (10" stand maybe). Does anyone have experience
    using Heresy with riser or other angling either on floor or short stand
    as center channel for 3 channel stereo between Khorns?

    Thanks.

  15. Seller says that tweeter failed and Klipsch replaced tweeter and

    network. Unclear why they would replace with different parts

    in network, perhaps what Klipsch had available?.

    Also, how common is it for tweeters to blow in these things, does this

    mean it was being pushed too hard? I guess it isnt easy to determine

    the answers to these, but any input is appreciated.

  16. Thanks for the suggestions. Right now the visual aspect is secondary
    to the sound, although obviously I would like something that has some
    hiding capability. It does seem like a huge amount of work to do the
    whole ceiling in these couplers. I think I will experiment with
    buying/manufacturing a few of them, and mixing them with either the
    existing tiles or some standard but heavier more reflecting ones. I was
    also thinking about trying some of the fluorescent light grids which
    are plastic and have a narrower grid. There would not be as much
    diffusion from the grid but perhaps would still benefit from the
    effective increase in ceiling height and reflection off of the above
    floor and joists.

    I am still curious why the Khorn seems to require more ceiling
    height (or if they really do): room volume, room modes,?

    <>

  17. <>At this point I have an Apple Powerbook (with lossless encoding) to

    a Lavry DA10 Dac which also has a decent preamp and volume control

    network. Right now I use it to drive Wright 3.5 monoblocks or

    Charlize t-amp. I am also waiting on a tube preamp (actually a

    headphone amp with preamp capability Singlepower MPX3). So there are

    various combos and I am playing around with them and the Chorus II. I

    also have some CD player and other gear, but the above is what I use. I

    am pretty satisfied with it at the moment, although I might get one of

    the JM Merlin preamp if the Singlepower doesnt work out.

    The

    problem I have is the room seems so dead to me, not

    vibration or reflection or other serious issues at least that seem

    obvious to me. I could try removing some of the area carpet but the tile

    floor that they cover is cold. That is why I removed some of the

    ceiling tiles to experiment with, just a few along the reflected paths

    from the speakers to my sitting position. I was really surprised how it

    appeared to improve things. But I need something to replace them with.

    And maybe get further improvement. Since going from the Chorus II

    (which I would move upstairs to a family living room with HT where I

    currently have Kg4.5's) to Khorn is big step, I am trying to get a feel

    if others had this problem and a solution. Somehow my perceived

    deadness of the room really bothered me, I have heard of this complaint

    before with absorbing drop ceiling. I recognize there are two

    factors here : the ceiling height and the absorbing tiles.I wasnt sure

    how all of this affected the Khorn or why it needed the ceiling height

    maybe compared to other speakers.

    The

    diffraction gratings (which I would use as direct replacement for some

    of the drop ceiling tiles) are discussed in

    http://forums.klipsch.com/forums/permalink/795474/776905/ShowThread.aspx#776905.

    I would be willing I think to manufacture myself probably a whole

    ceiling of them to replace the drop ceiling if necessary as I am not

    worried about sound isolation and the claim seems to be that one cannot

    have too many (although their may be diminishing returns).

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