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Everything posted by PrestonTom

  1. Interesting perspectives from a speaker engineer & designer who had an illustrious career at JBL. The interview is lengthy and not always crisp, but there are insights about "horn sound", relations and interactions between dynamics, dispersion, and efficiency, and the difficulty of understanding what creates good imaging. -Enjoy
  2. I am going to disagree on this! With high sensitivity speakers, the overarching issue is whether there is any hiss, hum or buzzing in the background. Non-linearities causing distortion are another matter. Especially since the distortion is generally a function of overall level. If it is only putting out a few watts (and putting out plenty of sound) there will be very little distortion. That is the beauty of a high efficiency speaker. The down side is that any background noise from the amp will be quite audible. Over at DIYAudio, there is fairly sophisticated discussion about "just how many watts do you need". The thread was started by a sharp guy ("Pano"). You would be surprised about what a tiny amount of wattage is actually required.
  3. I believe this is the Type B schematic for your Cornwalls. Leave the inductor and autoformer alone, but the 4uf and 2 uf caps are your target. Check the Parts Express website to see what they have. When I have done this in the past I simply used the Solen Polyprop caps. IIRC, sometimes it is hard to find a 2uf substitute, so feel free to use the more commonly found 2.2uf cap. If you want to get fancy then a spend a few dollars more and bypass (wire in parallel) a second cap across the main cap. This bypass cap should be about 1 or 2% the value of the main cap (approximately or even a little less). I like to use a Dayton film / foil as the bypass cap also available at the same website. There are also other brands to choose from and there are also ways ways to spend even more money (the sky is the limit). When you refresh the caps, you will notice a bit more energy in the high frequencies. Some folks will offer very flowery language about the "new found" sound. Given the price, it is certainly worth doing. Good luck, -Tom
  4. Certainly, JEM is one vendor, but there are others also. Search the threads.
  5. Shakey, you may be beating a dead horse. By now those who have the knowledge and the willingness to help, have probably left the room (for this particular thread).
  6. I have no idea what was originally promised ....... But that seems like a long wait. Unless there is something I am missing, it obviously seems unacceptable. Is there another side to this story (and I don't mean excuses ....)? Good luck, -Tom
  7. You have been extraordinarily patient! At least you have been able to hear them ahead of time, so you know that it is worth the wait. Do you have their new home all prepped and ready to go with all the other components lined up?
  8. My comments may seem a bit abrupt but I am trying to be helpful. A key finding in the the studies of Toole etc is that a speaker system (key word: system) sounds best when the dispersion is somewhat comparable across the spectrum. (measured by beam width or Directivity Index -DI). Three features are 1) the dispersion will always be quite wide for the lowest octaves, 2) dispersion will generally be narrow at the highest octaves (in part mitigated by clever use of a phase plug or vanes at the horn throat), 3) deviations in the dispersion (as a function of frequency) should be gradual (especially at the woofer to tweeter transition). When most talk about a horn's dispersion they are typically emphasizing dispersion on the horizontal plane and ignoring dispersion in the vertical plane. However, Roy has been very careful to give weight to the vertical plane also. That is why he frequently uses the term "coverage angle" in order to emphasize of importance of paying attention to dispersion in both planes. The K-510 controls dispersion (coverage angle) in both planes at about 1600 Hz and up. It actually controls dispersion down to about 500Hz in the horizontal plane. Have you guys looked at the specs on the JBL horn? Key point is what is the intended crossover frequency? Further, what is the dispersion of the woofer in that spectral region and is it comparable for the tweeter horn (especially in the horizontal plane)? Does the tweeter horn have any abrupt changes in dispersion across the spectrum (ignore the extremes for now) or are the changes gradual? You will see that the K-510 horn is actually quite a horn for such a little guy. Examination of the JBL shows some anomalies (including "pinching"). Are they big enough to matter? Who knows since it depends on the choice of crossover. Additionally are the anomalies big enough to have a perceptual impact. I don't know. So all in all, the comparison may be more complicated than simply repeating the mantra that "bigger is better". It depends ....... The other nagging issue is that the JBL horn needs a driver that is 1.4 or 1.5 inch and the K-510 horn uses a 2 inch driver (don't bother with an adapter, simply get the right size to begin with). Crossing the smaller driver at a low frequency can lead to distortion (especially if it is crossed with a shallow filter and played loudly). Again this is a system design issue and it is not clear what your target crossover might be. IOW, choosing a crossover point is determined or constrained by a number of things. I am not being negative. I just wanted to point out some system design considerations. Good luck, -Tom
  9. I guess my opinion of the K-510 differs from yours. I like it! In in fact if you cross it a bit higher than 1000Hz, then it is in the same ballpark as the big K-402 (not as good, but in the same ballpark). Please remember it is hard to judge a system until it has been setup correctly. This needs to be done first with careful measurement (the fine tuning by ear comes much later). When the engineers at Klipsch and JBL design the product, the crossover and balancing network is gone through many times and possibly judged by various listening panels and revised (rinse and repeat). In your case, the K-510 is a CD horn (comparable dispersion on and off axis). As such it will need some high end boost. You are also swapping drivers along with swapping horns. The SPL output will change. That needs to be measured and the system design will need to incorporate those measured differences. If you are using a generic passive crossover, your chance of success is bleak. It can be hard to judge the output "by ear". These are "designed" systems. I would encourage you to get an inexpensive DSP crossover (it does not have to be a Xilica) and install some software (REW or Holmimpulse ) and work from there. IOW, this is not accomplished in an afternoon and it is not accomplished "by ear". It is much more complicated. In either case, good luck, -Tom
  10. I think you are being too kind. That guy was just confused and rambling.
  11. At that price, maybe the dealer could remove the badge without marring the finish.
  12. I may be becoming a grumpy old guy. I lived for many years with a previous version of Klipschorns (1982s). They sounded good and I enjoyed them. My guess, and it is only a guess, is that the sound from the new vs older versions is probably fairly similar (in spite of the marketing that "new" equals "improved"). The veneer looks nice, but other veneers also look nice and in neither case it will it affect the sound quality. Also, I am indifferent to the possible merits of the units being an "anniversary edition". So where does that leave us. A pair of (slightly used) Klipschorns for nearly $15K. That seems like a good deal of money and for what? I periodically see Klipschorns for sale in New England for far less money ($3K to $6K). I guess I am grumpy, but there are much better deals out there.
  13. Same here. I am using a MacBook (latest OS) and Chrome (most recent upgrade)
  14. It best not to think in term of distance, but rather in terms of angle. If the listening angle is between 45-60 deg you will be fine. If it is larger than about 75 deg, then you may need a center speaker to maintain a "stable center" image. These numbers are approximations and should not be worshipped.
  15. I would contact American Cinema Equipment again. My understanding is that the original Jubilee (in a three-way version, as shown above) and the "underground" Jubilee (two-way version which is more common for home users) are no longer manufactured (as of about late last Spring). My guess is that the price you were quoted two years ago, was for the three-way version (the two-way was about $1 -$1.5K less). I assume you live in the US. In my uneducated estimation, if the two-way version (the "underground" Jubilee) was still available (at close to last year's price) they would be enjoying brisk sales to the home market. Either way, good luck, -Tom
  16. It is potentially even more complicated. The document did not show any bass bin PEQs for the (underground) Jubilee. Originally, Roy did provide these for use with Electrovoice DX38 processor. Additionally not only is identifying which bass bin is being used, we need to know which processor is being used. For instance, loading the parameters for the EV DX38 into a miniDSP processor will require modification.
  17. The type of product that Shiva recommended is good. They are sometimes called Tibetan wood (or wax) sticks. It can make it look better but not perfect if you look closely. If you phone a local moving company you can ask them who they send out to make these kinds of repairs (they will be quite experienced and can do it in your home).
  18. The JBL 2446 (or 2445) will fit a Klipsch K-510 horn (2inc exit driver to a 2 inch throat horn). I previously used this combination.
  19. I think your tone of voice is unwarranted, but maybe this is what the internet has reduced us to (whoops, I ended the sentence on a preposition).
  20. I really have no idea where your information is coming from. In Spring 2021, another member and I separately contacted two vendors and were quoted the following prices for a pair of "underground" Jubilees (two-way, plain black and no DSP crossover). This was a month or two before the "underground " Jubilee was discontinued. The vendor in Kentucky stated a price of about $9K Spencer at American Cinema Equipment stated a price of $8.5 K (included free shipping). He had contacted Klipsch and the factory said they would be available with about a two-week turn around. I hope this sets the record straight and as such I am no longer interested.
  21. My understanding is that the vendor had the last two pair of the "underground" Jubilees before they were discontinued by Klipsch. Veneer was applied and the vendor took advantage of the scarcity of the product. Some would call this a smart business practice. Others might call this price gouging. My comment still stands that before the "underground" Jubilee was discontinued, they were one of the great values (performance divided by price). They were selling for the last several years for between $ 7K and 8.5 K. Over the last decade or so I have helped a number of people purchase Jubilees. I have some experience on this.
  22. No, this is incorrect by a factor of two. The originals (2 way version - now called the "underground" and sometimes called the "rogue") were $7-8k for a pair. They were a heck of a deal. If you got a veneer on the baffle there was a 10-15% up charge.
  23. At a price of $5,500, you are in the range of buying a used (underground-) Jubilee. Although the Klipschorn is a good sounding speaker, the Jubilee is better. --- Hands down better! Note: I have personally enjoyed and lived with both. They are no longer manufactured and they are somewhat hard to find on the used market. So it would take some diligence. The OP said these were for a living room, so below is an example of what Kudret did to make his Jubilees more living room friendly. There are other variations also, although his implementation is probably within the capabilities of many DIYers. This is meant as food for thought .... Good luck, -Tom
  24. That is an interesting thought and I have no way of predicting the future ....... However, I suspect there will be some who may replace theirs with the new version, but I don't think there will be a "flood". The original version gave very good performance at a relatively reasonable price. I don't know how many current owners will see the need to change. It will be interesting to watch. -Tom
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