Jim E

Your Belles are looking great Tom. Keep the pics coming. Will your set have the stock horns and drivers?

John, The American website lists the driver. As to it's availability, I don't know. Try http://www.bcspeakersusa.com/downloads/component_downloads.htm Thanks, Jim

John, Thanks for your reply. There are numerous choices in the 6"~8" drivers. I have attached a pdf file on the PL21 driver. I will most likely build up several baffles and test each one. I still need to build the basic cabinet though. I seem to have come down with pneumonia last week and it will be at least several weeks before I can even consider getting around sawdust. Jim 8pl21.pdf

John, I have attached this pdf file for the Belle baffle insert. No modification is needed to the original cabinet if my supplied measurements are correct. What's your opinion? Jim Klipsch Belle Mod upper baffle.pdf

Peter, I would advise using an additional LaScala for the center channel. The overall heigth would require removing and modding the top section for placement above the screen but you would still benefit a greater return. It is generally agreed that use of the same speakers for all the front channels is your best bet. There are tonal changes between other the other models that would worry me more than just the reduced spl levels. The addition of a sub would be helpful as well. Good luck, Jim

Al, I agree, don't modify an original permanantly. Your mods look good and like you said, it can always be put back to the original design in short order. My situation is much easier, I can make a small change here and there with little concern other than minor esthetics. Gotta love that DIY approach. Would you consider sharing your plot of the bass bin by email? I swear to keep it and any information contained private if you could. It would help in the planning stage of my DIY Belles. I do understand if you can't, I have created several Altec cad drawings that might raise a few eyebrows in the legal dept. As some may know, Altec went through enormous changes during the seventies buyouts and mergers right up to the eventual demise in the mid-nineties. Many of the original designs for consumer models were trashed or stored and lost. So as a collector, I decided to re-create hand drawn plan sheets in cad to emulate the drawing style used during the period of manufacturing. I have shared plans on these with others in pdf format but with stipulations to avoid any possibility of violating any conceptual or intelectual rights or properties of others. I did try numerous time to contact all the "possible" owners of the rights but even they would not respond. Jim

---------------- On 11/11/2004 4:01:10 PM John Warren wrote: ---------------- On 11/11/2004 3:22:31 PM Jim E wrote: I have also considered the use of 8" coaxial drivers. Eminance manufactures one that would just fit. >>I took a peek a the Eminence site and found the 8CX which, has a very low sensitivity ranging from 92-93 dB/W/m, too low to match the DIY Belle bass unit (~104dB/W/m). To use this driver you would have to bi-amp with a rather considerable 10+dB of gain. When you are looking at potential drivers, you might wish to consider the dedicated midrange units. They have high Fs values which, along with large motors, will result in high sensitivity numbers. Pairs (or quads) per channel are usually needed to get the mid output to match the LF output without resorting to additional amps. jw ---------------- ---------------- John, I am looking at several mid-bass drivers that look promising. The B&C 8 PE21, B&C 8 PL21 and the Eminance LA 6cbmr line array driver. The response curve on the B&C PEV-13 looks to be slightly less desirable. The 8" B&C's as well as the Eminance drivers have rateings in the 98~99 dB zone. Used in pairs, these drivers should be a close match. I am tending towards the 8 PL21 or the LA 6cbmr. The sealed rear housing on the Eminance driver requires no rear volume, where the B&C will require approx. a 0.92 sq. ft sealed enclosure. The downside is the LA 6cbmr will not work below 500 Hz. This may not be a problem though. Al K. is crossing his Belle setup at 700 Hz. One of these "options" in combination with the JBL 2404 looks to be a better setup. I have dumped the coaxial driver idea for now. When using dual mid drivers have you found any noticable lobeing problems? Jim

Thank you Al, I like the Altec horns and 802-8G/902-8A/902-8B drivers. These models with the Tangerene phase plugs and aluminum diaphragms seem to work very well. In my current setup the 902-8A/811B combo has almost perfect (+/-2dB) rolloff for theatre application (per SMPTE ISO-2969 curve). I took measurements with an Ivie PC-40 RTA and calibrated Ivie 1/2" capsule mic at five feet in room (both on axis and 20 degrees off axis). The crossover region is set at 1,180 Hz. For a two-way system it sounds excellent. I could add a tweeter but I'm not looking for flat response to 20 kHz. The low bass extension is -3 dB at 26 Hz and virtually flat to the crossover point. I didn't mean to confuse with the "W-Horn" statement. I was refering to the folded lower bass bin section of the Belle by itself. Is there a proper term for the bass bin section of the Belle's and LaScalas? I am still a little green with the Klipsch terminology. Baffles are "motorboards", the LF compression chamber is considered "the doghouse" etc. I hope to learn the Klipsch nominclature so I can avoid confusion. There are alot of sharp guys on this Forum. I'm sure they will help in this area. I checked out your Belle home system online and took a better look at your mods. A very clean conversion Al. Good work all the way around. Even the cabinet screws in the photos look like the correct type for counter/cabinetry work. I appreciate your skill and craftsmanship. This craftsmanship is missing with nearly all consumer and commercial cabinets these days. I know cost is a large primary consideration doing business these days. This is why I prefer DIY. If all the drawing data I have is correct, the 811B should fit with only an 1/8"~3/16" extension on the heigth opening of the upper cabinet. The extra space could be had by reducing the center divider heigth with little visual impact and no additional overall height change. The real beauty here is the way Klipsch designed the upper baffle or "motorboard". Several versions could be made to fit with what appears to be only four attaching screws from the backside. A simple arrangement that makes it perfect for expermentation. It makes me wonder if this was an intensional design thought in the original Klipsch build of the Belle? I really like the look of the Belle cabinet so maintaining the dimensions and original character are important to me. Thank you again for your quick reply and linked information Al. Very helpful. Jim

Al, I have been to your website. You have a lot of great info there. Your mods on the Belles are very interesting. I read that the Altec 811B/JBL driver combo is being crossed over at 700 Hz. Do you have any graphs on the w-horn section of the Belle? The upper limit of the bass section should roll off somewhere (I would think) below the abilities of the 811B. Have you used the 902-8A/8B Altec driver? I have found these to be rather smooth and pleasant compared to the JBL drivers. Just curious on your take. I will be constructing a pair of Belles for myself soon and I'm getting my "ducks" all in a row. From what I have researched, the top end on the Belles can be improved upon quite a bit. I already have a set of JBL 2404 tweets just waiting on the shelf. I am currently running all SS with DSP speaker management on my DIY Altec Model 19's. Like all things audio I suppose I'm still on the quest. My current setup is quite good but I'm ready for a change. I'd like to setup a pair of the K-Horns but my current abode has too many windows in all the wrong places so the Belles look like the next best set. Thanks in advance, Jim

Thank you very much. Exactly the info I need. I will see how these dimensions lineup. If everything goes well I can layout the components used during that production period. I believe there have been several tweeter changes over the years but the data on these is somewhat hard to find. Thank you, Jim

Thanks John, I did notice the numbers on those. I can tri-amp without any additional hardware however, as you point out the numbers are a little far off and if I decide to just go with passive crossovers, I would want the option to do so. This would also make the mod within reason for other DIY folks. Thank you, Jim

Thank you John. I actually have a mint pair of the JBL 2404's on the shelf. I agree they are fine tweets. I added a comment to my previous post. I will look at the driver you mentioned. I have also considered the use of 8" coaxial drivers. Eminance manufactures one that would just fit. The max opening on the Belle is 8 3/8". There are a few others. I am familiar with Altecs larger coaxials but have no experiance with these other companies products. Thank you again, Jim

John, I am new to this Forum. Over the last few weeks I have read many of the posts pertaining to the Heritage Models and modifications that have been done to them with great interest. I found your website to be very interesting. Your thoughts and modifications using cone transducers on the K-Horns mirrors my opinion on the subject. As I have been in theatre installation for many years, I have been a proponent in the use of horn systems on the stage end. After installing several screening rooms with the newer JBL 4632-T systems last year, I was stunned by the midrange accuracy. As the folding of low frequency horns restricts the lower midrange to 300 to 600 Hz. (estimated) few horn/driver combinations can overlap this critical crossover point without excessive size. Your mod on the K-Horn is quite nice and the conversion to the JBL tweet is text book right down to the polarity swap. Anyway...here are my questions: 1) Have you tried the Beyma CP-25 and if so, do they work as a possible replacement to the JBL? 2) I am building a set of Belle's (DIY). I am considering direct radiators for the mid. The JBL 4632's use 6.5" drivers (in wave guides). What would you advise for use in this application? There is only 8 3/8" of height to work in. A coaxial type is one possibility. 3) Are there any time alignment used in your modifications to the K-Horn? Thank you, and once again good work. Jim

---------------- On 11/8/2004 3:15:45 PM swells wrote: I also started toying with the idea of scaling down my plans and stuffing the guts out of my heresy in to; 1. see if I can build the cabinet. 2. Give me something to work for a couple of months without spending $1,000 on drivers. 3. see how the heresy would sound aa a fully loaded horn. 4. be able to scale the cabinets to fit my room. I started scaling my khorn drawing last night, but I am wondering how much to scale the plans to make them suitable for the k-22. or how much performance would be effect by scaling. ---------------- Since you are using cad, try a re-scale of the drawing to 80% of the original. That should get you very close. As the K-horn uses the joining walls as part of the design... Perhaps someone on the Klipsch Forum could calculate an expected curve if given the new horn measurements and your listening room info.

That's a hell of a long drive, not to mention the trip across the border. Exhausting to say the least. I don't know if I would trust shipping Khorns. Packing them alone could be several hundred dollars. I would use a furnture moving company like United Van Lines. Here in California United has a specialty division that moves electronics and trade show exibits. I would suspect there are companies that do this type of work in your area. From looking at the few plans available on the web, building a set of K-horns would be difficult even with a setup jig. I would guess many of the angled parts would have to be hand fit on the fly during construction. Personally, I like the challenge of DIY and enjoy building cabinets as a hobby. I might try to DIY a set of Klipschorns someday.

What is the mounting hole location (bolt circle) on these drivers?

Very clean work. The detail is excellent. I had to do a double take on the pictures. Were there other mods internally or is the design straight up across the board. What scaling was used to size your cabinets? JE

Thank you Jim, Congrats on the new Belles. What year are they and how do they sound? Maybe you could post a picture or two. I'm interested in any dimensions you can supply on the horns and drivers in the Belle. Ideally, I would like to generate accurate drawings for the horn and driver assemblies with mounting hole sizes and locations. Photos of the inside would help as well. It seems that the Belle's have had several different drivers and perhaps horn changes over the years. It would be helpfull to know what those changes were. I am also looking for someone to verify the dimensions shown in the latest pdf file I posted a few days ago. Any details that could be added are also appreciated. Thanks, Jim

Good luck

LaScala's were not constructed to fly as far as I know. There may be industrial versions that are but generally LaScalas have no internal braceing for this. The cabinets are constructed with glued butt joints and nails. Your best bet would be to install a fitted shelf built heavy enough to carry the weight. I would add a safety strap or cable just to be sure. If one of these puppies fell on you it would earn you a quick trip on a gurney to the EM ward or worse.

---------------- On 11/7/2004 10:56:05 AM jheis wrote: Jim: The B&K Ref. 50 pre-amp has XLR outputs (along with RCA's) and the B&K ST125.2 amps have XLR inputs (along with RCA's). I stopped by "Good Guys" the other day to pick up a digital coax cable and they had four "open box" Monster Cable Z200IX XLR cables marked down to $65 so I bought them (sounds like rolling your own is considerably cheaper). I figure if the equipment is designed for XLR, I might as well optimize what I've got. The Ref. 50 has two sets of balanced inputs for CD & DVD, but none of my line sources have balanced outputs. So, the only place I'm using the XLR balanced cables is from the pre-amp to the front and surround amps. My rear & center channel amps do not have XLR inputs, so I'm using Monster Cable RCA interconnects. I have a partial hearing loss in my right ear, so I doubt that I can actually distinquish incremental changes. So, as long as it sounds good, I'm happy. James ---------------- James, Then I would use the balanced connections from the pre-amp to the amp inputs. I am not a fan of these high end cable manufacturers. While most the cables are good to be sure, I have never been able to justify the cost of these so called "premium esoteric cables". I have not been able to measure (much less hear) a difference. A well built cable does not have to cost an arm and a leg.

---------------- On 11/5/2004 1:53:06 AM jheis wrote: I recently bought a B&K Ref 50 pre-amp/processor and a pair of B&K ST125.2 amps which have "XLR balanced inputs/outputs" What, if any, is the difference between these cables and good quality RCA cables. I've always considered "esoteric cables" to be a rip-off. Is XLR "more of the same" or are they worth the extra bucks? I'm asking because I don't know. James ---------------- XLR is a great way to connect equipment if you have balanced line components. If you can solder, custom length cables are a snap. Belden, Canaire and Mogami make excellent cable for this application for well under two dollars per foot. I use Neutric XLR connectors which run three to four bucks each. If you compare that to the cost of "good quality" RCA's the cost is reasonable. As far as XLR's being "esoteric" I would have to say no, they are not. In pro use XLR connections are the standard. One thing to keep in mind though, most balanced equipment is setup to function best (lowest noise) at either 0 dB or +4 dB at 50% modulation. This level is significantly higher that consumer unbalanced equipment. Also, connecting unbalanced audio to balanced can be difficult. Are unbalanced connections available for the inputs on the pre-amp for your line sources?

Thank you Jim. I'll wait for the measurements. From the photos it looks like Tom is nearly finished with the cabinets. Can't wait to see the finished set. I've seen Al's mods on the web. Nice work. How does the setup sound on the Belle with the 811B? I am also curious if the Altec 902 driver has been tried with any success. In the pics Al has a JBL coupled to the 811B horn and a Beyma HF.

You could try Marglass from your local marine shop. Marglass is a fiberglass filled patching material that sets up much like bondo. Mix as directed and apply it to the area of damage. This is tuff stuff and will stick to almost anything except oil. Once it cures, you can sand it out level and replace the veneer in either a spot patch or the entire panel. Many craftsmen hand cut the veneer directly on the area with a razor or veneer saw. Trick here is overlap the veneer on the cabinet and cut the veneer and the original veneer beyond the damaged area in a pattern that will blend the patch into the existing veneer. When you lift the new veneer, just use a sharp chisle to remove the old veneer from the cabinet to where your cut line is. Glue the patch on the cutout and press it down flat for an hour. Use minimal amounts of glue and avoid glue in the splice edges. The glue will show through stains and finishes. When cutting veneer, use multiple passes with the razor to avoid "tearing" the grain. Keep the cuts at 90 degrees from the surface.

OK...Here is the latest revision of my Belle file. I am still looking for the measurements on the squaker and tweeter so I can plug in the position of the openings and hole locations. If any of the dimensions are incorrect, please let me know. I have generated a cut list with layouts to optimise making these with three 4 by 8 sheets of 3/4" ply and one sheet of 1/2". If anyone is interested in the cutlist, let me know. I noticed that if the top of the upper cabinet on the Belle is raised 1/8" an Altec 811B horn fits perfectly when mounted to a 3/8" baffle board (motorboard?). I've seen several comments on using the 811's (and 511's) on the Klipsch Forum (Belles and Khorns). Is this conversion considered an improvement over the stock assemblies? Belle Klipsch2.pdf