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Chris A

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  1. There is a reason why the Khorn needs wider placement than a Jubilee: time misalignment of drivers. Khorns need to be farther away from the listener in order for their image to coalesce better into a whole because of their time misalignment between the tweeter and midrange, and the midrange to bass bin. Of course, you could also time-align (tri-amp) a Khorn and dramatically reduce the minimum listening distance. The only remaining issue is the vertical separation of tweeter/midrange/bass bin horn mouths, and the horizontal null between the horn mouths of the bass bin at higher frequencies (nearer the Khorn's 400 Hz crossover frequency) due to dual mouth diffraction of the bass bin. The Jub bass bin was specifically designed to minimize the distance between the bass bin horn mouths to minimize this issue--as documented by Roy and PWK in their 1999 JAES article on the subject. I've not moved my Jubs to a wider stance in-room, but note that I moved my listening position a little closer to the front wall (i.e., the minimum listening distance of the Jubs is much closer than stock Khorns), thus increasing the horizontal separation angle between them. I moved from about a 10 feet listening distance (3 m) to about 8 feet (2.4 m) a change in horizontal separation angle of ~48 degrees to about ~77 degrees. This was a good trade in my listening room. The sense of envelopment (LEV) apparent source width (ASW) increased substantially. You may have issues moving closer to the Jubs due to the room modes, e.g., being half way or a third of the way between the front and rear walls. The other thing that helped the Jubs was shortening down the K-402s (and the phase/group delay measurements confirmed what my ears heard). Chris
  2. I don't use DATS often, mostly just to check consistency of impedance measurements between drivers, etc. The fully horn-loaded loudspeakers with which I'm into DIY aren't that sensitive to box parameters, but bass reflex is more sensitive to box size...hence the size of the Cornwall box. BTW: yesterday I plotted the group delay of the K-402-MEH, Jubilee and the Cornwall (1979 model, no correction/EQ) to see the rise in group delay due to the reflex ports. The Cornwall port resonance frequency looks to be about 35 Hz, while the woofer resonance seems to be about 52 Hz in the box. Note the scale (i.e., zoomed out on the vertical axis group delay). Group delay values above one half to one period (i.e., 1/2*frequency to 1/frequency) at the frequency of interest are typically audible. The smaller the relative group delay, the cleaner the sound and with an increase in perceived bass response: Chris
  3. If you're looking for impedance measurements, etc. I find that DATS (available from Parts Express) works well. I don't use it often, but when I do, it's a snap and it produces good data. Below is the impedance of a TAD TD-4002 driver on a K-402 horn: Here is the measurement for a Crites 15" cast frame woofer and showing the data for the T/S parameters:
  4. Room EQ Wizard (REW) works for me. It does all that you've mentioned, plus a lot more. Here's a link to a thread where many of the different plots/measurement types are shown:-- here and here. You can also look at Omnimic if you want to buy everything as a package. Personally, I'd buy the calibrated USB microphone at miniDSP (UMIK-1). There are other packages available that you can pay for: ARTA, Acourate, etc. For me, I don't see any advantages of these tools over REW. Chris
  5. See the following thread for an even nicer solution: Chris
  6. I'm listening to a CD (demastered by myself 4 years ago) of the Los Angeles Guitar Quartet (Delos 3132) with John Eargle, recording engineer: I don't remember the sound quality being what it is right now--extremely rich guitar harmonics with a very pleasant engaging presentation, and sparklingly clear, much like a DVD-A or SACD recording without any further mastering applied. The only thing that changed from last year is the quasi-linear phase Jubilees from reworking the crossover filters in the Xilica. The listening is so subjectively inviting that I really can't tear myself away to listen to other Christmas music selections--of which this CD is only part of that genre (the Nutcracker selections). I continue to be amazed in unpredictable ways with these flat-phase, full-range directivity loudspeakers (relative to the configuration before 1 May of this year)--in a listening room that has only been treated at the very front of the room for early reflections. This includes nine 2'x2'x1" Auralex Sonofiber squares on each side of the room, arranged adjacent to the mouth exits of the K-402s and Jubilee bass bins (and ~1.5 panels placed across the Jubilee bass bin cabinet front panels). The Jubilees are crossed nominally at 550 Hz. There is also one double thickness Owens-Corning 703 panel bass trap on top of each horn-loaded sub directly behind each Jubilee, that are positioned across the front room corners to form a closed-end cavity to trap lower frequencies, particularly in the 100-200 Hz band. Chris
  7. Uhhh...I wouldn't do that. The only time to move the microphone away from 1m distance (in-room) is when trying to dial in a subwoofer, and even then you're probably going to get better results if you leave the microphone distance at 1 m and live with the pressure zone/nearfield issues. The critical distance of the room (a not-damped room) at the crossover frequency with the K-402 and MWM-type bin (high directivity index for both of these horns at ~400-500 Hz) is probably on the order of 2-3 m, so you're going to be measuring diffuse reflections in-room if you try to measure farther away than 1m using something like continuous pink noise. The only way to measure farther back and avoid overwhelming reflections in-room is to use upsweeps ("chirps")--like the room correction software applications use. Chris
  8. There is no "threshold" for low volume level with the Jubilees like your Bowers & Wilkins 800s. If you heard the Jubilees before, you should be able to answer your own question here. I believe that the root problem is the low efficiency midrange and tweeter drivers used in the direct radiating designs. Since the equal loudness contours show a significant loss of aural acuity at low frequencies relative to midrange and lower treble frequencies, lower frequencies are typically not the issue because the human hearing system expects to lose the ability to hear very low frequencies at very low SPL: The issue becomes midrange and tweeter drivers that are designed for high power input and high power dissipation because of their low efficiency, then the problems of stiction and thresholding at very low SPL apparently becomes an issue with these drivers from B&W. There are no equivalent issues with the higher efficiency horn-loaded drivers from Klipsch and other third parties. Yes there is degradation: severe polar lobing for home hi-fi use due to the addition of another horn aperture for the tweeter (not at all related to "crossover complexity"), and the vertical offset of that tweeter horn-driver by many wavelengths, which causes lobing and self-cancellations. If you want a three-way, then use a BMS 4592ND dual diaphragm compression driver, which avoids the issues of dual horn apertures and vertical offsets. The three-way design (KPT-Jubilee/535-B) is meant for commercial cinema application where the power output must be spread over three drivers instead of two for the extreme SPL/power output requirements. The commercial cinema loudspeakers also have a much greater minimum listening distance than does home hi-fi loudspeakers. The K-691 driver is a good driver that does extremely well for its price class. It's also not terribly difficult to identify it when playing recordings with lots of cymbals, particularly ride cymbals--like small bebop combo. The breakup frequency is 13.8 kHz on the K-402 horn--the frequency that it goes into significant non-pistonic modes. This driver does very well for a lot of Jubilee owners, especially those that are budget conscious. If you're here asking questions about better 2" for the two-way (home hi-fi version) Jubilee compression drivers, then you're not a "typical Jubilee customer". In the late 2000s, Klipsch offered special drivers (TAD TD-4002s) for very special customers, i.e., a very large cinema house that buys many auditoriums worth of loudspeakers on a yearly basis. Since that time, the TAD TD-4002 has gone out of production (and so has the K-69-A), so the settings published for the two-way home Jubilee from that era are no longer viable for new Jubilees owners with the K-691 driver. No one that I know is buying new EV Dx38 DSP crossovers, rather they would likely consider Xilica or perhaps the EV DC-One, or even the very inexpensive miniDSP 2 x 4 HD--with a bit higher noise quiescently and common mode noise than the other DSP crossovers. If you are thinking about more expensive, higher performing 2" compression drivers, I can offer you my services to help dial them in, but note that (to my knowledge) Klipsch does not support these type of drivers. Many original Jubilee owners from the 2000s (including myself) upgraded to TAD TD-4002s before they went out of availability. Now, there is a small set of drivers from different manufacturers that have two-way Jubilee settings for them. This is due to the work of third parties and one non-profit member of this forum ("yours truly"). [BTW: The TAD TD-4002 is not a "MF" driver--rather it is a "full range compression driver".] However, the K-691 driver has published settings from Roy (i.e., Klipsch) that will work for Xilica DSP crossovers (found on this forum and from at least one Klipsch dealer: MetropolisLakeOutfitters). This is the current baseline for "stock" Jubilees, unless settings for the EV DSP crossovers has also been published (you can talk to Cory or Roy for that information). This is not true: the last time I checked, MetropolisLakeOutfitters will sell you Jubilees and a Xilica crossover with settings preloaded for the K-691--Roy's settings. I'm not sure what else matters. The extra amplifiers that you mention is, in my experience, not much of an issue in practice because most audio enthusiasts that I know that would be in the market for Jubilees already own amplifiers, one of which that can easily do the duty for the bass bins (assuming horizontal bi-amping). If however you are only considering vertical bi-amping, then you will need matched amplifiers, one for powering the left channel loudspeaker, and one for the right (assuming a stereo setup, not multichannel). I just did (above). I recommend using the supplied K-691s and a Xilica crossover, preloaded with Roy's settings for the K-691. Then let your ears be the judge. Many owners stop there and listen to them in that configuration for the duration. If you are then dissatisfied, then unlike any other Klipsch loudspeaker that I'm aware of, you have options to upgrade your compression drivers for the price of the drivers themselves (direct from a dealer). This is a benefit of owning Jubilees...definitely not a burden... Chris
  9. Before we get into "crusading" on the subject of Jubilees and before answering the above questions, I just want to say that it's okay to ask the sort of questions posed above, but with the understanding that these Jubilee customizations are for those that are seeking to squeeze the last ~5% of performance out of them. The changes discussed below are meant for those "maximizers" that want that extra 5% up front and are willing to pay the difference in order to avoid the perhaps 12 years of tinkering that it took me. Please don't think of these changes as either necessary or even commonly performed, because some of these tweaks are relatively rare among Jubilee owners. So it should be understood that stock Jubilees will blow away any loudspeaker that mere mortals have heard, i.e., the common rank-and-file home hi-fi enthusiast. No arguments there. Chris
  10. I presently have one K-402-MEH (the prototype that's currently performing as my center). If I can get more MEHs made by then it's possible that I might be able to bring a pair (but don't hold your breath). Chris
  11. It's been suggested that I mention that I'm currently planning on providing a tutorial on REW and using a DSP crossover for flattening in-room response of SPL and phase. The exact date/time/place while there is TBD. I'm planning on bringing a Yamaha SP2060 or EV Dx38, amplifiers, a laptop for running REW, a calibrated microphone, preamp, floor absorption, etc. for the demo. If there is any interest, I could also run through how I currently demaster music files using Audacity (freeware). If there are any specific topics that you''d specifically want to be covered in either of these subject areas or other subjects, you can discuss it here or by PM. Chris
  12. The common theme of the K-400, K-550, K-600, and K-700 midrange horns is that they don't have the same off-axis coverage vs. frequency as other more recently designed horns. Sounds like you'd probably be wanting to change the midrange horn out any way that you go. You've chosen an Elliptrac horn, but the same sort of upgrade is also apparent with the K-510, and to a greater extent, the K-402 horn. The issue of flattening the phase response to improve stereo imaging, listening involvement, perceived bass response, etc., that I've talked about are related to the crossover design. Unfortunately, higher order filters are more of a problem, not less. Older Klipsch Heritage crossovers use first order filters, which produces the lowest phase growth from high frequencies to low frequencies. The best sounding loudspeakers,in my experience, not only keep the phase as flat as possible, but also the drivers are time aligned to each other, unlike the K-77 tweeter to the K-400/K-500/K-500/K-700 midrange drivers, and the same midrange horns time aligned to the bass bins--particularly the horn-loaded bass bins. This is where DSP crossovers can make a big difference because they can time align all three drivers/horns in the fully horn-loaded Heritage series (Khorns, La Scalas, Belles) via digital delay of the higher frequency channels relative to the lower frequency channels. While you can correct the tweeter/midrange misalignment by moving the tweeter backwards on top of the top hats, the midrange/bass bin misalignment remains because of the distance the midrange horn/driver has to move backward to correct this lower frequency time misalignment (due to the longer wavelengths involved). And it turns out that the midrange/horn-loaded bass bin alignment has a great deal to do with this improved sound of the loudspeaker, i.e., below 1000 Hz. Have you looked at putting double-thickness Owens-Corning 703 bass traps across one or more corners or wall-floor/wall-ceiling? (They can be hidden from view oftentimes.) This will absolutely control the 100-200 Hz reverberation time in-room which is responsible for boominess. Standard absorption panels will lack effectiveness at these frequencies, which will allow you to completely control the boominess. Chris
  13. You're describing the case where you're trying to increase the direct/reflected ratio of the loudspeakers in the room. This is typical of loudspeakers having full-range directivity--like Belles, La Scalas, Khorns, Jubs, and MEHs. The downside is that by pulling the loudspeakers away from the walls, you're also killing off bass response. Probably adding midrange/treble absorption and moving the Belles back toward their prior locations nearer the walls is a better solution that doesn't kill bass response. The comment about standing up to get better imaging, etc. more than likely has to do with your floor covering and/or your couch needs more damping due to reflections around the listening position. Same comment about adding a little absorption--like a fuzzy comforter/blanket/quilt on the couch and/or thicker absorption on the floor--applies to this situation. This is probably your midrange horn performing better at off-axis angles--just like the newer horns from Klipsch (i.e., K-510, K-402, etc.). This is a good sign. This is more than likely the phase growth of the Belles vs. the La Scalas (at least, it's been my experience that this is the symptom). This is where measurement in-room is the only way to tell what's occurring. You can add more absorption all around the room to the most acoustically reflective objects/boundaries, but this issue won't change or go away until you flatten the phase response more. Chris
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