Jim E

---------------- On 12/24/2004 12:28:08 PM ooteedee wrote: According to the factory design blueprints: Part #3 is called a "splitter". If you don't want to call it a "splitter", what would you prefer it be called? An acoustic diverter? Long wave re-director? A tri-sided chamber support? And if you don't want to call it a "wedge", what would you prefer it be called? Triangular shaped beam? An extended half pyramid? A bisected square rod? ---------------- It has been refered to as the "Prizm". Question on the "factory blueprints" you mentioned. I don't recall ever seeing a factory blueprint on the LaScalas. Would you post the drawing here? Jim

I'm located in Rancho Cucamonga about 45 miles due east of LA. Work in Hollywood for Deluxe Laboratories.

Swells, Yes, very nice work. Some of those angles must have been really tough to cut. I am curious as to what machinery and tools you used in the construction. Jim

---------------- On 12/18/2004 9:10:06 AM silver bullet wrote: Thanks for the reply, Jim. Actually, Al tells me that the Klipsch (Electro-Voice) driver is not bad. I probably will use the original driver with an adapter which will fit it to the 811s. Mick ---------------- Mick, Al K. is a wise man and you are welcome. Here is a drawing of the 811B in a Belle top cabinet. Please ignore the back cover and 902 driver. As you can see, adding the 3/16" clearance makes it a tight fit. You could extend the top 1/4" if you are uncomfortable with this. Using 3/8" material for the mounting board allows enough front clearance to locate a new grille with the cloth in the stock position 3/8" from the front edge. The squigley arrows indicate veneer grain direction.

Mick, Although I have not done this modification, the 811B horn only requires 3/16" of additional clearance to fit within the top section of the Belle. You will need to make a new mounting board and grille. The Belle grille is also the mounting board for the stock Mid/High frequency drivers. The new mounting board for the horn should be no more than 3/8" thick material or it (the horn) will extend past the front edge if you are front mounting the horn. You could use a router to cut two 3/8" wide channels in the upper cabinet and slide in the new baffle board but that would be a permanent modification and would show slightly on the outside edges. A better method would to either make new sides for the cabinet or place a couple of wood or plastic (black trim?) strips between the top and sides to extend the interior height of the box. I think the top of the cabinet is held on with screws through the corner blocks. I don't know this for a fact, perhaps someone else could explain how the top section is held together. In any case (my opinion) it would be better not to make permanent mods to the cabinet. What driver are you going to use on the Altec? I would suggest the Altec 902-8A or 8B with aluminum diaphragms. Diaphragms are available in 16 ohm versions as well. Please post your results if possible when it's finished and good luck.

DM, Thank you for the info. Here is a quick drawing of the basic mods I am considering. The "blue hatched" areas indicate the modifications. Jim

---------------- On 12/8/2004 8:40:31 PM jlossint wrote: Well Marvel, My intentions were only to clarify where that particular drawing is comming from. Wether it is used or not is not the question. That model uses a 12" driver and not a 15" like the "Belle" does. So the difference is obvius. Also there are errors in the given dimensions in that particular picture. ---------------- Peter, Which drawing are you refering to? There were several in this thread. Jim

Tom, The Belle looks great! Congratulations, and thank you for sharing the journey throughout the project. I'm looking forward to your comments on how it sounds. Jim

Larry and DM, Thank you. This is exactly the type of info needed. I read Larry's post on the K-Horns. Excellent post and very well written. It is interesting that just changing the spacing of the woofer mounting to the motorboard affected the performance. It looks like I will have to construct a re-configurable cabinet and run some tests. Are there any area's on the Belle design you guys feel could be optimized beside the splitter and LF aperture? Thaks again, Jim

---------------- On 12/5/2004 7:15:56 AM djk wrote: "So the question still stands science be damned (with all due respect). Has anyone actually done modifications to the splitter or "prizm" and/or added reflectors?" Yes, I have. It is a waste of time. Both Gil and I explained why. The mass corner of the K33 is the limit on HF response. If you use a high Q low pass filter at 400hz like the newer models that will boost the output at the crossover point. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4,237,340.WKU.&OS=PN/4,237,340&RS=PN/4,237,340 Basically add 100µF~125µF across the woofer terminals. Klipsch used film caps, not electrolytics. ---------------- DJK, I hear what you and Gil are saying. Since you have tried the modifications what was the end result? You stated "It was a waste of time". What qualifies this statement? Please understand, I respect your opinion and appreciate the information on the subject. I am not challenging anyone, just looking for an honest unbiased answer. Like many of the Forum Members, I am on the same quest for better audio and I'm sure it will go on 'till I lose my hearing or kick the bucket. The interest in Klipsch "Heritage" speakers is kind of new to me. I have been a "horn" addict for thirty years though. As you fellows have been involved with Klipsch speakers so long, your information is of great value. I have gained a lot of information on this site over the last few months. There is much passion here. The K33 woofer should be capable of response out to at least 1 kHz. as a direct radiator. The foldings of the bass bin will limit (rolloff) the upper end. I will not be using passive crossovers as I prefer active DSP based electronics.

Thank you Gil. All excellent answers. I do agree that achieving any fine control in this design would be a fruitless endeavor. What I'm looking for (hopefully) is to improve the upper cutoff of the low frequency bin. Even a modest upward tilt in level above 3oo~400 Hz. would help. I am in the planning stages of building a pair of Belles from scratch so modifications are no problem. The external dimensions will remain stock because they look great just as designed. Stock cabinets from the factory would be nearly impossible to modify. So the question still stands science be damned (with all due respect). Has anyone actually done modifications to the splitter or "prizm" and/or added reflectors?

Taylor, If you like the look of the spanish ceder go for it. If you plan to apply a finish using petroleum based products (oil stains, lacquer etc.) it would be wise to stay away from contact cement. Use the iron on pva glue method and be carefull that both the veneer and cabinet surfaces are flat and very clean. Most paper backed veneers are only 10 mils thick so anything on the glue surfaces will telegraph through to the finished face.

From what I have gathered, the splitter located in the rear of the Belle and LaScala cabinets facing the LF driver is about 13" in height by approximately 2 1/4" wide. The angle on the splitter face is 45 degrees centered on the woofer vertically. I believe the purpose of the splitter is to direct the sound out from the center of the cabinet to the outside of the folded horn. It would also help prevent reflected sound from re-entering the LF slot and improve high frequency output to some degree. Question is, what determines the correct depth (thickness) of the splitter? As it comes from the factory, it is around 1/3 of the distance from the motorboard and rear panel. It occured to me if the splitter was formed closer to the driver it would improve overall performance. It would also make sense if the cabinets were angled on the interior rear corners reflecting the sound from the motorboard/ramp assembly to the front of the cabinet. Given the frequency plots I have seen, the low/mid crossover point and the problem of small compression horns loading down to 400 Hz. I would think improvement in this area would be of benefit. As this is a 44 year old design, has anyone experimented with this?

For comparison, here is an edge shot of Baltic Birch.

---------------- On 12/3/2004 3:34:15 PM Dylanl wrote: Silly question then. Is the Lowes Home Depot MDF up to snuff for speaker cabinets? What are the gauges or what is this sheet judged on? ---------------- The material at Home Depot and Lowes will work fine but veneering four by eight sheets is really difficult and it is very time consuming veneering lots of smaller parts. This is why I suggest using A1/B2 panels. If you have the time and ability to veneer each part (both sides required to prevent warpage) then plain mdf is fine. I have used bare mdf on projects that required more exotic veneers. Pre-veneered mdf is not available in every wood type. Red oak, walnut, cherry, ash and several others are though. Georgia Pacific makes some of the best in this material. It really takes a lot of labor out of the job. Just for those who are not aware, Baltic Birch usually is only available in 5' by 5' sheets. Here is another great material for cabinet building. Appleply is a hardwood multi-layer plywood that can be had in 4' by 8' sheets. This is an edge view of the material. Has anyone here used this material?

Brett, The LaScala's have the same bass response as the Belle's according to all the literature I've seen as well as the posts on this forum. The "ported" LaScala looks like an interesting project, but I've only seen a few posts on them. Taking these posts into mind it would appear the same modification could be made to the Belles. Perhaps the original poster could comment on this. As to the use of MDF Vs. Plywood...they each have their uses and both MDF and plywoods come in different grades. I have seen what Home Depot and Lowes offer and I can assure you what they sell is not what you want. Neither outlet sells a decent grade of plywood much less high grade appleply,birch or marine ply. Cabinet grade MDF with A1/A2 veneer facings work very well in constructing bass reflex and sealed cabinets. Ply as used on the Klipschorn, Belle and LaScala is very appropriate because of the manufacturing process Klipsch employs. I recall reading on this forum that Klipsch does use some MDF in the later Heritage cabinets. Just my opinion.

Bob, Just curious. Could you go into a little more detail in how you did the measurements. What instruments, mics and/or pre-amps do you use? If a sound pressure meter was used was any weighting applied? What signal source source was used? Thamks, Jim

Al, I'm sure you are correct. The advantages of horn loaded compression drivers have been known for many years. I am sending you a private message. Jim

Al, Thank you for sharing your work. Few of us have the time much less the equipment to examine audio gear with your detail. Very interesting. If I am reading the charts correctly, the JBL driver appears to have some advantage over the KV55. Have you charted the JBL on the 500 horn as well? I am curious if you have you done a similar comparison with the Altec 902 driver? I know the 902's have limited usage below 500 Hz but it would be interesting none the less. From the article you posted, it is obvious that the 8" cone radiator compares unfavorably to the compression driver. Would it be fair to say a smaller cone driver with less moving mass and stronger magnet structure would exibit less distortion?

Can anyone provide the known history of driver and or horn changes Klipsch made to the LaScala and Belle over the years? From what I gather, several manufacturers have built components for Klipsch.

I agree with Picky. The Romex should not be a problem unless you are way too close to a radio broadcast tower. For surround application it should be fine. Stranded wire is a little easier to use on the input terminals. Just give it a shot, if something unusual crops up you can repull the runs with new cable.

---------------- On 11/17/2004 12:53:11 AM Tom Mobley wrote: Jim, The pics I have here (except for some on the first page) are 640 x 480 pixels, they run about 50K per. The camera has four qualities of resolution selectable, it's on the next to lowest. If I move it up one step the images grow to about 150K, don't look much different on screen. J., Thanks for your kind words. I hope to be able to produce work similar to jorjen's at some point, but I'm not near there yet. There's a lot of fine points around wood finishing that I'm just catching on to. Like how to do a lot of sanding on a piece without rounding off the corners and edges. Stuff like that. ---------------- Thank you Tom. I was in a moment of stupidity when I attached the image file. The picture once I got it to show on the post was huge. The 640 x 480 range does look much better. So thank you for the info. I will rescale the image size first thing in the future. I want to say you are right about all those little sanding details and such but wood has the advantage of character. No two jobs are exactly the same in custom cabinetry. From looking at your photos, you have created a really appealing cabinet and with out a ton of woodworking facilities. I am not partial to red toned woods and finishes but your work here has brought out that quality of character in the veneer. Veneering can be a very tough job. There are so many finishes and stains that can either enhance or destroy a project. I honestly think you have done a fine job here and appreciate you sharing the progress. You will have pride in this work for many years. Please know that I am not a carpenter but my Father inlaw is. I have learned a great deal from him on woods and veneers over the last dozen years. No smoke Tom. Nice job. I'm not being kind, just truthfull.

---------------- On 11/16/2004 7:53:28 PM Marvel wrote: Jim, Is that a Model 19 style cabinet you made? Looks very nice. There's a pawn shop near me with a pair of Altec 1233 PA speakers for sale. They've been there for months. They look mint, and if the drivers aren't blown would be nice just for the components. 811B horns with 808-8B drivers, 421-8LF woofers (not as great as some others). They want $600, and I've made a point of not being too interested when I go in there. If they are still there in a few months and I have the money I'll offer them a lot less and see if they'll bite, just to move them out. Tom, The cabinet is looking wonderfull. Picks never show quite how nice things do look. Marvel ---------------- Marvel, It is a Model 19 dupe. There are a few modifications in the cabinet construction from the original 19's. From the outside they are dimensionaly the same except there are no crossover cutouts as the system is bi-amped. The price on those 1233's is not too far off. If you can get the pair for between 4 and 5 hundred it would be a decent buy. The 821-8LF drivers were not used in VOT's or any of their consumer home gear as far as I know but they are nice drivers for guitar work (they sound a bit more brassy with some added punch). I am not sure of this but several of the musical instrument series speakers from Altec can be reconed to 416-8B specs. With the components you described, you have a good start for a project. Jim

What is considered the ideal picture sizing when posting images? Jim

I have seen several posts regarding use of the Belle's for center channel with K-Horn's. When you get the system setup, I would enjoy hearing your opinion on the combination. I am curious how the bass and mid-horn response between the Belle and K-Horn work together. Again, nice work. I really like the figure in the veneer. The finish compliments the grain. Tom, Here is a shot of one of my Altec DIY projects from about 3 years ago. I hope to build a set of Belles soon. It will be my first attempt with a full horn loaded system project. After seeing your Belle I gotta try it. I hope this picture linking thingy works. Oh...I know this is the Klipsch Forum so please don't flame me for the Altec stuff. I have no intent to offend anyone.