LARRY

ALK, How well would the GPA/Altec 902 driver compare with these drivers?? Larry

ALK, Thanks for the reply. At least I have a reference point. Larry

In a large room approximately 7000 cubic feet, what whould be the voltage needed for normal listening levels (65-80 db)? Thanks, Larry

There has been a lot of discussion on the crossover frequency for the mid range horn (300 hz, etc.) in a three way horn system, but very little on the tweeter crossover frequency. What would be the 'ideal' crossover frequency for the tweeter in a three way horn system? There are drivers available that have useable frequency response on the low end to approximately 800 hz and respond to 18000 hz and above. There are horns, waveguides, etc. that also cover this frequency range. For optimum reproduction should a crossover frequency in the 1000 hz, 3000 hz, 5000 hz ? or some higher frequency be chosen? The Khorn, Lascala, and Belle have a limitation due to their cabinet structure, but the Jubilee, Jamboree and others have no limitation, so this would allow for large high frequency horns that could crossover at lower frequencies. This forum has may knowledgeable people and I would appreciate discussion of what frequency is 'ideal'. Thanks, Larry

Coytee, Check out the 1/2 height J2 at Soniphase.com. This is a design by Dana Moore that you will find interesting and may help in your quest. Larry

Islander, Dana Moore designed the Jamboree and is located in Washington, Below is the name of his company and email address. Soniphase.com,,......email@soniphase.com Larry

Mystery solved! Thanks to all of you for the input. The Klipsch E/V woofer is 16 Ohms (11,2 ohm on meter) and compared to the Type C (just happen to have two of them), the taps are the same 5,2,1 and 0 for the negative input. The Type 4 is the same as a Type C, but with an inductor to limit the midrange, The K55V's are the push button type and I guess the inductor was to 'tame' the 9000 Hz peak. Thanks, Larry

Malcolm, Thanks for the reply. The autotransformer has the same tap layout as the T2A, so I would assume it is a T2A. The extra inductor is approximately the value on a 5000 Hz limit to the midrange horn. The horns in the cabinets are K1000's (1000 Hz). It would appear they are not original as the crossover refers to a 700 Hz crossover of the midrange. I am going to assume that it is a early Type E with an extra inductor to limit the midrange.. all negative terminals are tied together with a ground wire. I will try reversing the ground to positive on the mid and HF terminals to correct to 'like a Type E2. Thanks, Larry

I was unable to take a picture that would show the details of the crossover. I will try for a better picture at a later time. However, I drew the following sketch. The green lines are the Inductors, the red lines are the capacitors and the brown line is from the 2.5 MH inductor to the 1.0 MFD capacitor. As you can see, I have no artistic ability! It does not appear to be a Type E. Larry

John, I will remove the crossover and take a picture and post. I am trying to verify the crossover points, in that it has two large inductors with one of the inductor leads going to the positive side of the squaker. Capacitors are 1 and 2 ohm. I will try to take the picture asap. Larry

I need to find information on a type '4' crossover. I purchased a very old pair of Hersey speakers (no markings, but size is correct) with type 4 crossovers, K55v and K77 horns and Electrovoice woofers with Klipsch decals. The crossovers are similar to tye Type 4RB, but have two inductors and the layout is a little different. Any help would be appreciated. Larry

Bonder, I am also more of a reader than responder.. others are usually more knowledgeable! I am using the GPA 902-8 on either a Tractrix and Altec 511b horns, and my tests with True RTA software and Behringer mic/mixer, etc. have given different results. The 902's are excellent from about 550 hz to 17000 hz where they fall off until about 19000 cycles where they return on both horn lense. I am using ALK 600 hz steep slope crossovers in two way systems (left, right and center chanel-all folded horns). This protects the 902 driver. IMHO 600 hz is the low end of the 902. In reading others input on the GPA 902/Altec 511B combo, my sense was that there was no problem on the top end and that a two way system is as good or better than a three way system. I have pair of Klipsch Belles and Khorns, and the top end is very good, but the GPA 902/Altec 511B or Tractrix is noticeably better. The Klipsch K55V would be a good bet for the 500 Hz crossover, as it is a true 400 Hz driver. Good luck. Larry

Greg, If the edgebanding is still available, I could use 3 pieces approximately 6 Inches in length. I have a set of oiled walnut Belles that need a little touch up. Thank you, Larry Larry Redelfs 6730 N Langley Avenue Clovis, California 93619

The center channel and the right and left front speakers are O.K.! In general the 'experts' agree that a 22 guage wire at 8 ohms is fine to 12 feet. Your speakers will be probably be greater than 8 ohms over most if not all of the frequency range, so 13 feet will be fine. The rear channels may present a problem. Fournately they are not as critical as the front stage. IMHO the main problem will be that they will require more amp power to drive them. Listen to your system and if the rear channels blend (you really do not want to hear them, just sense that they are there), then enjoy your system. Hope this helps give you closure. Larry

All is not lost! The lenght of the wire as well as the guage has a bearing on the end result. What are the lengths of the runs to the rear/side speakers and the front left and right? With this information then the problems, if they even exist, can be addressed. Larry

Well, it appears that the Belle is a speaker that has not been modified! Since this is the case, I am not going to modify it either, however I am going to use a depth of 22 3/4 inches rather than 18 3/4 inches. The expansion will be continue for the 4 inch difference, plus two braces inside the back chamber to make the sides and top and bottom more rigid. The net extra cuboc inches will be approximate to the Lascala back chamber. Since I have just learned how to use TrueRta, (finally), I will report results compared to a stock Belle. Thanks for[] all input and replies. Larry

seti, I agree, quality not quantity. My thouhgt is not more but lower bass. If a larger back chamber would help, then since they will be built, why not. The Belle is also one of my favorites, that is why I will keep my set in the den (could not ever let them depart). Thanks for the reply. Larry

Daddy Dee, Thanks for the reply. I will stay with the Belle bass bin if there is not an advantage to changing the back chamber volume. The Belle and Lascal have different volumes even as though they have the same cutoff, etc. My thoughts are as long as I am able to make a change and improve the low frequency response, then take advantage of it. I agree with you, the Belle bass bin is a proven design, however sometimes there are compromises for manufacturing purposes. Any extra bass would be appreciated![] Larry

I need some advise, etc. from those who know about horns. The build will be an exact copy of the Belle Bass Bin, with the possible exception of the back chamber volume. The system will be two way with a GPA 902 driver mated to an Altec 511B horn and use an ALK steep slope 600 Cycle crossover and a BEC cast frame woofer. The center channel will be used with left and right Jamboree horns, which are two way GPA 902/Altec 511B/ALK steep slope/Bec Cast woofers. If my calculations are correct, the Lascala back chamber volume is approximately 4120 cu in and the stock Belle is approximately 3900 cu in, while the Klipschorn is approximately 4800 cu in. The Belle clone will have to be 23 inches deep to accomodate the above driver and horn. This depth would allow a larger back chamber volume. In order to keep the 8 inch front center, the initial expansion could be modified as per the Lacala which keeps the initial expansion for about 7 inches before the actual expansion begins. If this is not feasible, then an extended Belle clone will be built with no modification to the back chamber. I have a set of 'real' Belles and a set of Altec 19s. The Altec is not better than a Belle, but has a presence (sound stage) that is clearly evident. Probably a combination of the two way and a larger horn. I set the Belle up with the GPA/Altec combo, and it sounds better than the Altec 19! I apologize for being so 'wordy', but wanted to make sure that it is understood that the Belle with no other modifications (no ports, etc.) is the criteria. As soon as I learn how to use TrueRta, I will be able to give feedback on the above horns. Thanks for advise! Larry

Wrinkles, sounds like a very good price on the Crowns. What is the price on the 402 and driver per pair. Thanks, Larry

Tom, The Speakerlab bass horn, if it has the 39 inch throat and was made in the 1970's, is a carbon copy of the Real Khorn. I would suggest that you replace the crossover with a Klipsch type A..you can easily make this from plans available on the forum. The midrange horn is also a carbon copy of the Khorn and if it has an Atlas K55v driver that would be the same driver as Klipsch used (and still uses!). If you replace the EV horn tweeters with BEC tweeters, (available on the Klipsch forum from BEC then you will have a system that is technically an exact clone, a very inexpensive Khorn. Cosmetics can be changed by some cabinet work to look like the Khorn. I have a pair of these horns that I purchased new in 1972.. the cabinets were changed to look like the Klipschorn. If you have the 4 Ohm woofers and the above changes/upgrades, you have a Klipschorn clone! Make sure to replace the crossovers, as they are really 'garbage'. Enjoy the speakers. Larry

Speakerlab had two versions of the 15 inch woofer. One was the W1508S which was the 8 ohm and the other was the W1504S which was a 4 ohm version. Both speakers had the large square magnet. The 4 ohm version actually is a little better than the K33E at the lower frequencies in the Khorn. Hope this info helps. Larry

GotHover, Very nice cabinets and interesting project. Note the Heresy has an internal volume of less than 1.9 Cubic feet, not allowing for the woofer displacement. Even though a 12 inch woofer is about 20 % less than a 15 inch woofer, the actual surface area is only about 60 % of a 15 inch woofer. I know very little about horn theory and am only pointing this out so that those who 'know' can comment. I am interested, as I would like to scale down a Belle for my center channel. Please keep us advised of your progress. Larry

Placing the crossover on the bottom, places the woofer magnet very close. I think that this would create a problem?? Larry

Speakerfritz, Thanks for the input. The Jamboree, along with the special 'steep slope' xover designed by ALK for 2 of the 4 ohm K33 woofers in parallel is my starting point. I have a pair of Klipsch Belles which allows me to compare the Jamboree to the Belle. It is necessary to increase the volume on the Belle by 2 Db to balance out the systems. That is the reason that I am interested in a higher output for the Midrange driver and the tweeter. Larry