WMcD

It is certainly not height. But it good that they are in earshot for the direct sound from the mid and the tweeter standpoint. The bass effect is what needs discussion. There is a recognized progression of conditions (of space) in which the speaker is sitting. A floor, or wall, or ceiling are equivalent. All just walls or boundaries. They trap sound pressure. 1) Full space. The speaker is hanging in the air. 2) Half space. The speaker is sitting on a plane, like a floor in a big room. Here is it radiating into only half the space of 1). 3) Quarter space. The speaker is sitting at a floor wall intersection. 4) One-eighth space. The speaker is sitting in a corner. Think about this. If you have an apartment room with a corner, there are eight other rooms sharing the point of intersection. Four on that floor, and four in the form of a ceiling below. 5) A pipe in front of the diaphragm of about the same size, or maybe smaller. A basic bass diaphargm in a closed box will move out and in at the face. A question is how much air this will pump. The more pumping effect it has, the better the bass output. How much it can pump depends on the space it pumping into. (This is horribly simplified, but enough for discussion.) You probably have an intuitive appreciation that pumping into a pipe is more effective than pumping into free space. All other conditions are in the middle range of efficency. You probably can appreciate that 5) is best. 4) is not as good, but if you visualize the corner, it is a bit like a megaphone with a broad conical structure, and as big as your room. The other conditions go downhill but not without merit. The above five conditions, particularly 2) through 4) assume the speaker is close to the boundary wall. In a real room you are mixing conditions. The speaker might be close to a corner, but a few feet away from it. It might be near a wall floor intersection, but not too close, and the third surface is not too far away. So, in short, moving the speaker location around the room, you can get to 4) in a corner, or almost 2) in the middle of the floor. So, you say, how close is "close"? Let's assume that "close" begins at 1/2 wavelenght, and gets better, the closer. Unfortunately this is wave mechanics. You have to start thinking in terms of wavelength to appreciate things. Very close is easier to achieve at 50 Hz than 100 Hz. At 100 Hz, a full wavelength is 10 feet. Therefore "close" is 5 feet. Therefore, it is not difficult to get some little increased efficency in any room because it is diffucult to get more than 5 feet from a boundary. Huhh, but go to 50 Hz and the full wave is 20 feet. Now what is "close" has become half the distance of what it was for 100 Hz. The math may be a bit hard to follow. The bottom line is that looking at a 50 Hz wave, 5 feet from a boundary is now 1/4 wavelength rather than 1/2 wavelenght. The condition 5) above is interesting. If there is a pipe in front of the diaphragm, it is going to move a lot of air in and out of the pipe. On the other hand, the column of air in the pipe doesn't do us much good. There is a lot of trapped air moving back and forth in a confined space. Perhaps we could expand the pipe along its length in a gentle way. One approach is to let the area of the pipe increase every "x" distance. With this doubling of area, it will get large at the big end, and radiate into the room. A complicated "exponential" equation describes this function of area. This is what an exponential horn is. The expanding pipe is what you have in the midrange of your Heresy. There is also a similar set up in the bass horns of LaScala, Belle, and K-Horn. You can appreciate, also, that the corner can form a part of the horn. Putting even a direct radiating bass box in a corner gives it a bit of a horn, or megaphone, in front of it. So there is a better pumping. I'm counting on a bit of intuitive thought here without going into difficult subjects like radiation resistance. Consider that humans have cupped their hands in front of their mouth to form a horn, or megaphone, to increase efficency of a shout by confining the area of air in front of our mouth and throat. Same thing with speaker placement in rooms. One final question might be whether corner placement in a room affects the midrange and treble efficency. Shouldn't there be some "gain" as in the bass? Nope, it is already there. The boundary effects turn on at about 1 or 1/2 wavelengh. At 1000 Hz, a wavelength is 1 foot. Therefore, given the size of the speaker box, its midrange radiator is already sitting in its own half space. "Didn't have time to make it short" Gil This message has been edited by William F. Gil McDermott on 08-10-2001 at 10:30 PM

Bob G. I may remain a home builder, but I could bite the bullet. In the sceme of things, I'd get serious about contemplating an HT system by Klipsch if the horn loading got down to the area of 500 Hz. Maybe a single, modern, horn could do this. There is a trend that Heresy, Forte, and other three way systems are much appreciated. I'll chalk that up to the coverage of lower freq by the horns, rather than simply a midrange horn. Also, it seems to me that the 80 Hz cross over to a sub is just about what the market expects in HT. This presents some odd constrants. Make a set of matched L,C,R and surrounds with horn loading down to 500 Hz and a direct radiator, etc, down to 80 Hz. A sub does the rest. I can't speak to price right now. I'd pay a premium for an integrated system. I know the R&D would not make it cheap. Gil

Eq, I buy a lot of stuff at the HD at Central and Forest. Yeah, there is one up north on Central which may be closer to you. They say (in the signs) they don't do precision cuts. But on the right day, with the right people, they might cut down a piece of MDF or ply to your size on a radial saw. (On a busy day, you get no help. On an off day, a retired craftsman will take over the project entirely.) There are racks of fir trim, some trim saws and sometimes a miter box in the aisles. It is not impossible that you could get all the cutting done in the store. Again, if you're a "handy man" with the tools at home, you'll construct in the garage. None the less, much of the cutting could be done at the HD if you need to. The rest of the project is glue and small nails. Maybe some paint. Gil This message has been edited by William F. Gil McDermott on 08-09-2001 at 11:45 PM

A little nagging voice in my head goes off. It seems odd that this is a reoccuring failure if you're not pushing the volume. Something to be considered. Gil

Both the above are good advice I'd agree with wholeheartedly. BTW, you'll find the unit comes apart when you back out the four screws. You should not do this yourself unless you have soldering skills. You should mark the orientation of all parts with a dot of nail polish and keep notes on placement of spacers, etc. Gil

It is a good guess that the voice coil is open, rather than shorted. The best, if not only solution is a new driver ordered from Klipsch. The general wisdom is that bigger amps are better than smaller amps because bigger amps can't as easily be driven to clipping. Clipping is usually a hazard to tweeters. Playing the woofer loud with lots of bass can be a hazard in its own right. However, I wouldn't buy a new, smaller amp for this reason. Regards, Gil

Not having Cornwalls, I shouldn't speak out. However, from the description there is no easy way put put spikes on the bottom of the speaker because the riser is hollow inside, for lack of a better description. (I have built speakers with such a riser. As you point out, they can be unstable.) I was to be faced with this problem, I'd build a spiked platform to put under the speakers. Let me suggest you cut some plywood 3/4 inch larger than the footprint of the riser. Then place 1/4 inch, 1/4 round, or square, molding at the edge to create a recess for the riser to fit in. This is just so the speaker doesn't slip off. You get the idea. The extra 1/4 inch all around is to give some clearance and allow for errors. Alternately, you might just cut the plywood 1/4 inch larger and put some 1 inch tall trim around the outer edges to cover the plywood plys. I don't know the level of your woodworking skill, but this is not too difficult. Then put the spikes of the bottom of this base. That way you haven't altered the speaker, and you get the benefits, whatever they may be, of the spikes. if you don't like the effect, the base board can go in the junk bin. Regards, Gil

Tom, There seems to be text on the sticker with the up arrows. Can you tell us, or show us, what it says. My guess is that the lowboy orientation (is that correct?) puts the tweeter at the top. Thanks, Gil

Thinking about this some more. Heritage series, stock, have a relatively high impedance in the midrange, going up to 30 ohms or so. I think with the direct radiator bass units, Cornwall and Heresy, continue that in the tweeter to some extent. Therefore, perhaps the losses caused by, say 4 ohms is going to cause more loss to the bass in those. On the other hand, Harris has Al K's constant impedance crossovers. So there wouldn't be quite the same effect as with the stock. This is just thinking. Real sound pressure measurements might give us something else, naturally. Gil

I've gotten used to saying that experimentation is always a good thing. Dogma is bad. Corner placement has been advocated by PWK . . . but. . . I dunno. There is some evidence piling which really argues for alternatives. 1) I observe (just by looking around as the great philospher Berra says) that many people find a good position to be "looking down the horns". I.e., aim the midrange and treble straight at you. 2) Another consistent comment comes from the derived center channel posts. Getting them too far apart creates a hole in the middle; the only solution for which is a center channel. The International Telecommunication Union and Dolby both seem to favor moving the speakers only 30 degrees each, off center for HT. This may be a bit off point in that they are using a center, and we may have an issue of making the sound stage too much bigger than the viewing screen. In any event, widely spaced corner placement may be just too much in many applications. 3) There was an issue of boomy bass with Heresys near wall ceiling intersections. A cure was tilting them so as to, again, get the mid and tweeter aimed to the listening position. My guess here is that there is a lesson. Too weak mids from being off axis might be interpreted at too much bass. Obviously an unbalance is open for interpretation either way. 4) The whole matter of "smearing" of the signal through cable design leave me antagonistic. Yet Klipsch is paying a lot of attention to room refections of the mids these days. So pulling them away from the walls makes sense. In any event. I sure it is well worth fooling around. No one can know everything about someone else's system, room, speakers. Regards, Gil

I would say it is fairly even handed. At least he takes issue with close minded people. It is interesting that "looking straight down the horns" is being brought up as a cure for some disappointments. We've seen this on the forum regarding Heresy surrond applications. And this seems to be the factory recommendation for Reference series mains too. Gil

Call 1800KLIPSCH. They should be able to help you. However, make sure it is the woofer, that screws are snug, etc. Gil

There are often questions about the insides of a KHorn. Attached are drawings from the patent. Figure 5 was evidently a prototype, not applicable to our discussion. Regarding the other drawings: the modern version has some different details. For example, this shows a 12 inch driver rather than the present 15 inch. Also, there is a narrower 3 x 13 inch slot in front of the present driver. The treble unit is not shown. But, on the whole these drawings are good illustrations. You can make out the split path. First proceed up and down from the driver, then toward the back where the paths join at the tail board. Then there are two paths along the side. Here the structural wall of the room corner forms one of the boundaries. The cross sectional area along the path doubles ever 16 inches. I've used up 5 of my 6 upload spaces recently. So, I'll have to weed things in the future. Therefore, if you want it, save it on your computer. Naturally you can get the whole patent off of www.uspto.gov. Regards, Gil This message has been edited by William F. Gil McDermott on 08-05-2001 at 10:00 PM

I got mine from Hope, long time ago. In those days they'd give you a collection of papers by PWK and others, plus a collection of DFH for 10 bucks. DFH was an occasionally published flyer. I think it was discontinued several decades ago. All you can do is phone Trey Cannon and see what he says about availability. Gil

Attached is a Dope From Hope on the Bridged Center Channel Loudspeaker. Note two schematics for making a mixer. I note the use of volume controls. Regards, Gil

Reading Tom's response, you'd think we're coming from the opposite ends of the earth. Not so. I'm in his camp overall. It is my opinion that horns are great and have inherent advantages over direct radiators. Starting from ground zero in a construction project is tough. If you can pick up some of the old, classical systems, they may serve you very well, as Tom says. Duplicating a KLF is gonna be difficult without factory components. I think Tom is just saying that there are other alternatives to making a KLF clone. I don't doubt for a second that you'll like them. My guess is that Tom would agree with that building a massive, refrigerator, sized speaker is not the best way to go. Gil

Dear Klewless (are you a sail person?) There is a long appreciation of derived center channel from two channel recording. There is also a long appreciation of discrete center channel where there are three recording, storage, transmission channels. Consider that if you make a two channel recording with two spaced mikes in front of an orchestra, each channel is going to have common, in phase, information coming from the center location of the orchestra. An alternate way of doing this is to have a third center mike, recording in a third channel. But perhaps most of that information is already in the L and R. That information can be exploited. Also, in the old days, two channel was a major step from single channel mono recording. Three channel recording was not impossible, just another layer of complexity and could only be done on tape. The stereo LP was a breakthrough. It was a mechanical technique of modulating each edge of the record groove. It wasn't going to be possible to get another, third, channel without a lot of cranky multiplexing tricks. E.g. Quad. Derived center channel playback is also called "phantom channel". Phantom because it was not a discrete recored channel. By using a few resistors as a voltage adder, it was possible to add L + R from a pre amp output and send it to another amp. Then feed the amp to a center channel speaker. A type of analog processor which we find something similar to in our HT receivers. Question 1. Doesn't this resistor based processor lead to bleed thought of L channel into R, and vice versa. Answer 1. No. For technical reasons I will not go into, this doesn't happen in a well designed system. The center derived channel is L plus R, but there is not significant cross talk induced into the L and R. Dolby steering systems try to ascertain what is truly common and bump up the gain. Question 2. Assuming two channel recording, doesn't this mean that a musical instrument which is hard left (or right), now gets into the derived center channel when it should not. This is a type of bleed into the mike acoustic pick up at the mike itself. Isn't it best to keep things hard left and hard right? Answer 2. Yes, a bit. However, the musical instrument which located in the center of the orchestra makes a contribution to both left and right channel mike pick ups and the recording of it in the two channels is in phase. With good mike placement, the center located musical instrument makes a bigger contribution to L and R than the off center musical instrument. This is why we hear a central image with two channel stereo, when things are working perfectly. (You have to contempate this for a while. The sound stage can be better with medium spaced mikes because the central stuff is not ignored.) The problem is that two channel stereo has variables. The recording theater is not the same size as the listening room. The mike placement is not the same as the speaker placement. In the listening room we may wish to place the speakers apart as much as possible to get left and right stereo effects (in a way, avoiding cross talk in what we hear). However, then the center illusion doesn't work quite as well. It creates the "hole" in the center. But the use of a third center channel speaker solves many issues. The L plus R can be added and fed to it. This makes a tremendous difference. Now the information about what is center in the recording room really gets to a center located speaker in the listening room. Some of these issues remain with pop recording where it is not a matter of just putting two mikes in front of a classical orchestra. A singer may be mixed center, which means that the mix down from a multichannel master tape is fed in phase to L and to R. Of course this also happens with movies. Actor's voices are mixed center. Derived center channel helps here again. Three discrete recording channels, and three speakers probably work best, but phantom channel can work very well. Certainly better that two channel. This is by no means a new art. It is just re- discovered by every generation. PWK's writings implies that he reintroduced it to listeners at Bell Labs, even though Bell Labs did the intitial reseach which he relied upon in the first place. Coals to Newcastle. Question 3. Why hasn't this caught on in past. Answer 3. The cost of equipment in the past is something. Now, HT receivers should do it with ease. Also, it can take some fiddling with the "gain" of the center channel depending on the recording, itself. PWK suggests center playback should be -6 dB. I find it varies. A fixed setting can put too much level into the center on one recording and the side channel suffer; too much is center. Other times the center channel gain has to be bumped up to fill the hole. I'd be pleased to send you (or any one else) PWK's and Bell Labs publications if you give me your postal address. Also, check out the Wendy Carlos site on the web. Long post. I didn't have time to make it short. I worry sometimes. Am I too pedantic? I sure don't want to offend. Gil

Yeah, I'm in agreement with STC. I heard Lady Marmalade, Moulin Rouge soundtrack on the headphones at Virgin. A next buy. Gotta see the movie. I'm in the same camp with Ray on the Organ Symphony. Wonderful. I'm a bit jaded that any modern musician can exploit the effect, but it adds little to their craft. On the other hand, the masters were bass freaks too, taking advantage of large organs. They do it well. Gil This message has been edited by William F. Gil McDermott on 08-02-2001 at 11:04 PM

I'll give a couple of observations. Water damage to a finish often shows up as a white image in the finish. One woodworker magazine reported good results from the author's wife's remedy. Put on some Vaseline overnight and in the morning wipe it off. The gifted author was contemplating a more complicated approach. There could be a scientific reason why the Vaseline works. The Vaseline has some emulsifying agent allowing water and oil to mix (maybe), and draws the moisture out of the finish because of its own emulsifier. Other wipe on finishes and cleaning products may have the same effect in the right circumstances because they also have emulsifiers too. Strictly my speculation. The ring pattern shown in the picture looks like it could have been caused by simple water condestate from a beverage glass. Maybe. Maybe. However, the blackening argues a bit against damage to the finish alone, and maybe not simply H20. I'm not aware of any lacquer, varnish, or shellac turning black from simply water. It may be that the contamination got down to the wood. Lacquer finishes are thin. Oak is vulnerable to stain from iron, a major component of steel. The iron interacts with the tanin in the wood. Stains on unstained oak floors are notoriously diffucult to remedy. It might be that the beverage container was a steel bottomed soft drink or beer can (not common these days, but more common in the history of the Forte) or even some sort of metal vase. If so, the mark may well be in the wood itself. This is going to open up a problem of how far down it goes in the veneer and whether it can be removed by sanding. It could have penetrated through the entire, thin, layer of veneer. Forte's have a great reputation. No matter what the cosmetic problem, you're gonna be very happy. Try the cleaning with a furniture product as suggested. However, this might a matter that the wood is irreprarably stained. Gil This message has been edited by William F. Gil McDermott on 08-02-2001 at 10:44 PM

I'd think you're on the right track. Household dust will not be a problem. We've had reports from a buyer of used LaScalas. The open back cabinet allows collection of dust, pet dander, and the like. When he bought them, they needed a good cleaning, after year of neglect. I've dealt with Speaker Lab K's and my own home built. They get dusty inside. Without being flip. This may invite a good natured debate of whether it is better to have an open system which accumulates household dust and is easy to clean, versus a closed system which accumulates less dust, but it not easy to clean. Gil

In short. It seems like you have a good connection. Banana plugs are probably not going to improve it. With them, you've typically got a screw down connection to the banana male, and another connection of the banana to the, errr, female banana. (No, no, don't be a wise guy. The United Fruit Company will object.) Seriously, I think there is some concensus above. Banana plug are great if you're switching things around. If you are not switching things, and you have a good screw on connection, there might be little justification to mess with it. Gil

IMHO, the Quintets or HT in a box is not going to keep you happy for long. You'll probably have to replace everything in the short run when you get the bug. As suggested, you could look at a low end Klipsch set up in the R series or the like. If you can find a 5.1 matched Klipsch system (bigger than Quintets) new, or used, you will have a very good start. One thing to consider is whether you'd be able to build up a compatable system over time. It is important to get matched center and mains. A three speaker system might keep you happy for a long time. Even VHS HI FI tapes through a decent stereo system is a startling improvement over the sound from a TV speaker. An HT receiver with a center channel is a next, impressive, step up. Subs have fewer matching issues, and might be the next purchase. You could put that off a year. I certainly wouldn't say the surrounds are not an important issue, including matching. But they probably are nearer the lesser end of purchase priority if you have to build slowly. IMHO. Gil

I really keep an open mind these days. If someone says a tweek fixes a problem, who am I to say differently. I'm not there and haven't tried it. However, it seems odd from an engineering point of view that this is an a.c. issue. You'd expect the same problem in all channels, if the shrill voice goes to them. Which, admittedly, may not be the case. Ground loops normally cause an a.c. low frequency buzz. Let me suggest that you try one of your other speakers, temporarially, in the center channel. That might rule in or rule out the speaker. Also, try playing the shrill track in mono through the side, main channels. Alternatively, do you hear it on headphones. As pointed out, it might be that the mix is bad. It could be that there is a problem with the center channel amp, or the center channel speaker. I'd try a methodology to investigate those first, or at least as part of the overall program. Audio review magazines find flaws with the mix down to consumer video from time to time. Maybe chain saw / hooker movies don't get the attention they deserve. I say that a bit sarcastically. In my heart, if you pay the money, you deserve a good mix. But it doesn't always work out that way. One additional problem might be that there is a lot of mid bass information mixed in. Make sure center is to small. Even so. In drama scenes, it not uncommon to have enough other signal present to challenge a good speaker. Just take a closer listen is all I'm saying here. Gil This message has been edited by William F. Gil McDermott on 08-02-2001 at 08:53 PM

Speaker building is not mechanically difficult if you have the ability to build the box and you can get the components you need. Calculation of bass box size and vent design is not impossible for the hobbyist, if you're good at math and physics. However, designing good cross overs is exceptionally difficult. The only truly accurate way to do is requires a lot of test equipment, knowledge, and re-testing. I'm not aware of any kits similar to the KLF series. The only thing close was some building block kits from EV, now unavailable for decades. They weren't too far off from a Cornwall. If you want to give a try, using JBL or anything else, it can be a lifelong hobby. Some of lifelong aspect is that it may take a lifetime to come up to speed on the complex interactions of the individual speaker components. I'm not trying to discourage you by any means. However, used speakers of your favorite design are a better alternative for most people. Gil

There are sometimes questions about product identification. Recently about Heresy designer models. But we have others too. I'm posting an old flyer from Klipsch which will be of assistance. Perhaps someone with info on the consumer price index will compute what present prices could be. Gil PS and Edit. Sorry for bad spelling in the title. Now corrected. Should we petition the Webmaster for some upload space for old literature? I could scan some Dope From Hope. Others could make contributions. This message has been edited by William F. Gil McDermott on 08-02-2001 at 09:55 PM