Marvel

Uh... do you mean the 3x13 inch slot? That is what feeds the horn.

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

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.

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

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

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/

Thanks DD, My brain went out the window and I couldn't remember who it was.

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

Indeed! THe grounds department at the college where I work has a Kubota. Very nice piece of equipment.

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

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:

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.

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.

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

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

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

Yes you are correct My schematic shows the larger one as a 2.5mh and not 2.8. Which is really correct? Bruce

Jerohm, Here is a more readable drawing:

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

5 Altec/Iconic 15" woofers for each bass horn. Cool!

I found that my Heresys really opened up once I took them out of the boxes. They look much nicer too. Thinking I will eplace the caps in the crossovers one of these days, but I enjoy them anyway.

Lay a Khorn on its side and you're looking at almost the same size. The JBL 4350 is 48" wide x 35" high x 20" deep. I would love a set of these things.

If you have a digital multimeter, you can check the resistance on the diaphragms. If they are smoked, they would be open, or have an infinite resistance. They could have melted and shorted, making the value lower than what they should be. Klipsch has the parts about as cheap/low caost as anyone else. Bob Crites may have those (BEC on the forum) Bruce

John, I have rendered files of the exploded view with different wood 'applied', and different views. Mahogany, maple, walnut, white ash. Some just don't look as good as I would have thought. Maybe if I had played with the lighting more. I have wanted to do the actual drivers, but haven't learned the program well enough (Lightwave or 3D Studio would probably be better, but then I just don't spend much time with this. The only reason I have TrueSpace is because my son switched to Lightwave. The oldest likes 3D Studio better). If I did this for a living it would be a piece of cake, I'm sure. Bruce

Can you see why they are fanatics too? Notice the background of the last pic? He made cabs from scratch to be vertical for his HT setup. The inside of the cabinets shots are incredible. How about 260 pounds each! They aren't horns but who cares, once you hear them. They use the 2405 slot tweeter, a ring radiator similar to the 2404 'baby cheeks' model everyone here raves about. Except the 2405 has better high end and doesn't take up as much space on the front baffle.. Bruce