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Marvel

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Everything posted by Marvel

  1. Dave, Check out the Sonoma DSD recorder. Up to 32 tracks at 2.8Mhz sample rate. http://www.superaudiocenter.com/Products.htm Oh yeah, runs on a pc (WinXP), and the 8 track kits costs $19.5K. I would love to have one of these systems. Bruce
  2. The 1202 is a few years earlier model with a different woofer. The 1234 uses the same woofer (421) as the 1233 but has the 511B horn. I don't need them at all. Would be easier to move around than the Yamaha cabinets I have in my barn though. EDIT: I take that back. The 1233 and the Yamaha cabinets are each right at 112 pounds. No wonder the pawn shop hasn't sold them. Most guys don't want to be moving things that heavy. Bruce
  3. Of course, music players only read at 1x, and most argue that the "data' is read more accurately at 1x. Probably the best to date is the DSD format 2.8Mhz sample rate, that has now been done as a multitrack recorder. Those who have used the system say that it literally sounds no different than the source. But... that isn't CD is it? Bruce
  4. Well, I love eggnog, but then I like buttermilk on occasion. Had some wassail at church caroling party once. It was too stout for my tastes even. Michael, some hot cider with cinnamon is good. Bruce
  5. You wouldn't widen the slot for the K33 or K43. They are about a 4 ohm speaker. I believe you would use the wider slot for an 8 ohm. Bruce
  6. Uh... do you mean the 3x13 inch slot? That is what feeds the horn.
  7. This has been posted a few times, but attached is a pdf of driwings made by Jim Easley. Unfortunatley, they are in English measurements. However, these are very accurate, and may help you out. Bruce LaScala11.pdf
  8. Dr. Who, You are obviously not reading the posted links. Below is very old copy from Dennis that I have posted before. I believe we are talking good repsonse down to about 31Hz. ================ The taper rate of a LaScala is 100hz,The mouth area is good for 125hz. Below this it is a big woofer in a small sealed box.If we plug the T/S parameters for the K33E into a box program we will see that the Qtc=.85, the Fc=82.5hz, and the F3=70.9hz. If we close in the back of the high frequency cabinet and open the woofer rear chamber up into this volume and fill with fiberglass we now have Qtc=.577, Fc=58.2hz, F3=73.6hz . Bessel=Qtc.577=D2 gives the best transient response and the least group delay of all the sealed boxes.At 30hz the Qtc=.577 has 4.5dB more output than the Qtc=.85 . Compared with sealed enclosures,the transient performance of the best vented enclosure is worse than the best sealed box enclosure.Since we have made great gains in performance some may elect to stop here.But please read on.The next step is to port it. The K33E is not the optimum woofer for this but it works pretty good. With the box size optimized for a D2 we can port the stock woofer to an SC4.The transient response of an SC4 while not as good as an SBB4(more on this later)is better than the more common QB3. Unequalized the F3=49hz and has 3dB more output at 30hz than the D2. The response curves are parallel with the D2 the only difference being the Fc being a half octave lower with the SC4 and the output being 3dB higher from 30~70hz. The output of the SC4 does not drop lower than the D2 until you go below 17hz. Again this may be a stopping point for some. But by adding a simple two pole high pass filter ahead of the power amp we can now have a C6 with a -3dB point of 31hz. Since this is the Fb of the system there is no increase in cone excursion or distortion. The filter consists of a cap, an inductor and a pot. The pot allows adjustment at Fb of +/- 3dB. This is similar to being able to change the Qtc of a sealed box from .5~1.0. If you think about it we have the choice between a D2,SC4,and a C6 in the same box by plugging the port and/or bypassing the eq. If you have a SET amp or simply want to get the most out of the LaScala you will want to upgrade the woofer to something with a lower Qts. The Klipsch K43E does the trick, as do the EV DL15W and the JBL 2205. The EV and JBL drivers require some minor network changes. The lower Qts drivers allow for an SBB4 alignment which has the best transient response of the vented alignments. With no eq they have 3dB more output at 30hz than the stock woofer. With eq we have a maximally flat B6 and the F3 of the system is 27~28hz. If using a solid state amp with the low Qts woofers a small resistor must be added in series with the driver to have the same Rg as the SET does. This mod can be backed out of a stock LaScala with no externally visible changes if you don't like it. No one has ever gone back to stock after hearing this mod. Paul Klipsch was violently opposed to the venting of horn speakers bassed on his experience with venting the K-horn. In retrospect it is easy to see why. The 12" Jensen field coil woofer he was using had an Fs of 60hz and a quick calculation of the vent area vs the Vb based on the photographs of this experiment looks like an Fb of ~80hz. I am sure this sounded horrible. Paul Wilbur Klipsch is a giant in audio.If I appear to see farther than PWK it is only because I am standing on his shoulders. None of the stock Eminence Delta, Kappa ,etc series drivers will work. The K43Es that I have measured has Fs=31hz and Qts=.25,the TS parameters that Klipsch hands out are bogus. The EV DL15W has an Fs=30 and Qts=.23 and the JBL 2205 has an Fs=30 and Qts=.21. After taking into consideration the dc resistance of the woofer inductor and the output impedance of the amplifier the optimum Qts for the vented LaScala would be .312 with a Vas of 10.5 cu ft and an Fs of 30hz. I'm looking for a total net volume of about 4.8 cu ft. I figure the stock back volume is about 2.25 cu ft. Call it an internal height of about 9" (22.5 X 22.5 X 8.70 = 4404 cu in = 2.55 cu ft). Two 4" ID by 10" long ports displace about .15 cu ft so 10" outside is close enough.
  9. Although it does look like there may be two different versions, one with the British transformer and one with an American transformer, with appropriate taps for each. Just have to get a good look at it. The schematic will be good to have anyway. Bruce
  10. Darn you Allan!!!! There's lots of great stuff on the Folkways site. As if I didn't have enough to spend money on. Bruce
  11. It may have a switch on it, to change the voltage. Attached is a schematic of the Leak Stereo 20. Plus, a link to the yahoo group for Leak equipment: http://groups.yahoo.com/group/hjleak/
  12. Thanks DD, My brain went out the window and I couldn't remember who it was.
  13. That would actually make the LS taller than the KHorn. The new KHorn is shown at 50.75 inches. The older LS are 35.5 inches. You would just have to try it. The good thing about raising them up is the tweeter and midrange being more at ear level, so your situation and seating may make a difference. Bruce
  14. Indeed! THe grounds department at the college where I work has a Kubota. Very nice piece of equipment.
  15. It may already be wired for 110-120, which would make it easier. If you knew the current rating, the easiest way would be to get a proper stepup transformer. Who was it that was moving back to Israel? I though he had a Leak, and could probably help out. Bruce
  16. Are those a specific JBL model or a custom system you built? Bruce ps I have my eye on a set of 1233 model Altecs at a local pawn shop. Mint condition, and they've been there a long time now. I'm just waiting till I have some cash and will make an offer to them to take them off their hands. The 1233 is a bit shorter that the ones mentioned earlier. Same drivers, so I would need to do some upgrades on them, unless I just use them for PA work, which is not often but does happen. The 1233 is the very top cab and the 1234 is in the bottom right:
  17. My wife is currently on a morphine based pain med, but also has a Percocet prescription for the breakthrough pain. Percosets also contain acetaminophen, which means it can be an issue with liver damage over a long period of time.
  18. You can also try the Lansing Heritage site and get on their forums. They won't slam you too much. http://www.lansingheritage.org/ They have sectons for JBL and Altec.
  19. DD, I was thinking (I could look on the klipsch site of course) that the Tangent 400 used the same drivers as the Heresy, but is taller and has ports, aka, the Heresy on steroids idea. Lower bass. Be easier to copy that than to try and calculate a bigger Heresy box. Bruce
  20. Well, I've been using Sennheiser headphones since 1972 and they are very good. Just because they have marketing like that doesn't mean they are bad. Bruce
  21. So... Bob, are you saying that any of these values are in the ballpark? Or should I look at my later model HII to see what they are? Bruce
  22. Yes you are correct My schematic shows the larger one as a 2.5mh and not 2.8. Which is really correct? Bruce
  23. If you want to know about subs, go to that section and ask. The EAR has a bunch, and I think he really likes the Sunfire. I sometimes have an old, small, Velodyne (8 inch) connected to my Heresys. At the volumes I listen at, it keeps up very well (it WAS free after all). Would like to have two subs to connect up. My son uses two JBLs with his Heresys and it is very nice indeed. Bruce
  24. 5 Altec/Iconic 15" woofers for each bass horn. Cool!
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