garyrc

That really sounds like something to really see. Guess there was no recorders then.?. I don't know if anyone recorded it. A very young James Gabbert, a true audiophile, was there that night, and if anyone could have made a good recording, it would have been him. He then owned his first in a series of FM radio stations and television channels, which I think was KPEN. He may, or may not, have been instrumental in making the Multiplex version of FM radio happen --- he certainly pushed it, and he broadcasted an early music program in Multiplex, which got my friends and I to pool our equipment for that night. The music was the score to the film Exodus. Stereo Lps had been out for about 3 years by then, so it was time for FM to go stereo without having to get two competing stations to cooperate and each broadcast one channel (which some did from time to time). Walt Disney had tried one 3 channel broadcast, with AM for the far left channel, TV for the center, and FM for the right. Gabbert may have even been a sponsor of that last George Wright concert. If anyone has contact with him, he might be able to say if the concert was recorded.Even good microphones then tended to roll off quite a bit before they got down to 16 Hz, and 1/4" tape also rolled off some -- When I finally got a Crown 15 ips, I was surprised (duh!) to find that the bass rolled off more at 15 ips than it did at 7 1/2 ips, but 15 was preferred for high frequency response. George Wright had recorded several Lps by then, some of them stereo, and some in the Fox theater, but none of them had much truly deep bass extension in the vinyl format, perhaps due to the space requirements of deep, loud bass on vinyl. If he made some commercial 7 1/2 ips tapes, they might have gone down smoothly to about 20, and might have retrievable bass at 16.I just tried the Stereophile 20 and 25 Hz tracks (they don't go to 16), and they seem to be real tones with a characteristic pitch that is heard -- rather than just felt, although one can really feel them. Oddly, my wife, who has far superior high frequency hearing, doesn't hear deep bass as well as I do, perhaps due to a smaller ear canal??? Later, I'll ask her to listen and tell me if she hears, or just feels, those frequencies.

The 16 Hz theater organ pipe at the old Fox theater in San Francisco (torn down c1962 by idiots) had a clearly audible fundamental tone that seemed (rightly) to be about an octave below the 32 Hz pipe. Talk about shaking .... the pipe was mounted toward the ceiling, horizontally, because it was so long that there wasn't a space to mount it properly in a vertical orientation. There was a fairly transparent fish net suspended under the pipe to catch the plaster that often fell when the pipe sounded. Needless to say, they played this pipe rarely. One time they did was at the final George Wright organ concert at the Fox. It ended with him playing a rollicking version of San Francisco, as the magnificent, ornate fire curtain (which most of us had never seen until that moment), swept with spotlights, came down, and the organ console sank dramatically into the pit, with the 16 Hz pipe sounding periodically, and providing the strong underpinning for the final chord. There were no dry eyes.

John, Wow, I don't know. Could it be as simple as the 92 dB sensitivity of the subs being so far below that of the La Scalas that you would have to pump many times the power into them for them to seem equal to the La Scalas dynamically, during those famous movie surges? I know you probably have the subs and all other speakers set up for equal SPL from the listening position with test noise signals, but movies really push the envelope with dynamic bass SPL. La Scalas are rated by various writers anywhere from 98 dB to 105 dB, probably dependent on the "space" they are in -- I think 1/8 th produced the 105). With everything fairly near a corner (since you say the 92 dB includes some room gain) there is a 13 dB maximum difference, or ~~~ 20X the power needed??? If your subs are "clip proof," as some powered subs are, maybe they are just plateauing away when they run out of amp power. 50 watts into a La Scala (perfectly plausible according to PWK's chart, with 63 watts producing 115 dB in 3,000 cu. ft.) might conceivably require 1,000 watts into the subs to match ..... I doubt it but it's conceivable. The other annoyance is that some movie DVDs -- unlike the sound stripes of the movies themselves --- have compressed dynamic range. Who knows why? Most brand new movies are O.K. --- maybe they know the youth audience wants big bass, and full dynamics. Maybe the people who assemble the master from original visual, music and sound elements (when this is done) don't check a print of the best format original to see how the filmmakers mastered it, especially when transferring older, highly dynamic films, but they need to check the new ones as well. Examples of DVDs with compressed dynamic range, compared to the movies themselves, in well equipped San Francisco theaters are: Amadeus The Last Waltz and almost any other Rock movie, until recently. Phantom of the Opera (the musical version) ET Alien -- the "thing" that does you-know-what was so loud in the theater that I had fingernail marks in my arm (from my future wife) for days after. I'm surprised it didn't peel the paint off the theater walls ... Superman Ben-Hur (If you set it so the music is loud enough, the dialog is much too loud ... if you set it so the dialog is at a plausible conversational level, even some of it is lacking in dynamics ... the two times Mesala shouts are much too soft --- and the big bass effects are way below the theater levels, unless you ride the volume control) And almost any musical that was recorded and presented in magnetic stereo.

Do Klipsch systems used in commercial movie theaters use horn loaded subwoofers? In the "best" klipsch equipped theaters, what subs are used? As I've said before, strictly IMO: To get my movie bass to match the levels in the best theaters, I have to set the sub to a higher level than I would ever use for music listening. When playing music CDs or hybrids, there is often a "room rumble" that is annoying and causes me to turn down the sub, or turn it off. The sub (Klipsch RSW15) is not nearly as "clean" in the bass as our Klipshorns, which don't have as deep a reach. The best bass response in today's best theaters seems to excel only below about 40 Hz, and seems to go down to well below 20 Hz. The best 70 mm presentations of the late 50's and the '60s, in the best theaters (often those originally set up by Mike Todd), virtually all with horn loaded bass, seemed to have more dynamic bass -- above about 40 Hz -- than modern THX or other theaters. Even though they had very attenuated output below about 40 Hz, conccrete floors would shake, and quite a wind would hit the audience during heavy bass passages (example, the thunderstorm and earthquake sound in the 70 mm prints of Ben-Hur). When THX started, their literature contained a justification for moving away from completely horn loaded bass, on the grounds that horns had higher THD, and were thus not preferred. They did not seem to measure Frequency Modulation distortion, which PWK always thought was more irritating, and kept bass from sounding as clean.

So the question might be "compared to what?" Wasn't there an old Jazz song with that refrain? Les McCann? In the '70s, when most of my friends backed speakers up to the wall, but did not put them in a corner, PWK said something like put a speaker -- any speaker -- on the floor, in a corner, and it will be like making a 25 watt amplifier into a 100 watt amplifier. That would be +6 dB. I don't know what he was comparing it to, but the article was about direct/reflecting speakers like the Bose 901 or the JBL Aquarius series, so he might have been comparing the SPL in the corner to that of a speaker out in the middle of a room.....?

I guess if something bad is happening above 20K that causes anomalies below 20K, & it actually gets all the way to the tweeters, then what's happening up there is important below. For example I've heard that a distorted resonant peak above 20K in some phono cartridges and some tweeters, might cause anomalies below. And microphones?? But I imagine that something has to get through to excite the resonance, to "ring the bell." Microphones, if they have this problem, certainly get battered with a lot of sound, with the instruments' overtones themselves (think of cymbal crashes, and the uppermost violin tones) probably rolling off to 0 way above 20K. Phono cartridges may receive some stimulation above 20K with direct-to-disk Lps. Tweeters, at the end of the chain, would be expected to get the least eliciting stimulation above 20K, but what was it we heard about stray high frequencies on early SACDs??Another question: If there happens to be distorted sound above 20K in the recording, or let's say, caused by the phono cartridge, do you want to HEAR it (if you are a teenager, and can)?

One of the urban legends of c1959 involved the Pentagon evaluating using the JBL 075 tweeter (the one that looked like an orange juice squeezer) as a weapon. It was said that they put a high frequency, high intensity signal through it, but all they managed to do was to destroy some vegetable material (or, in the more elaborate version, cut grass). I think if you disabled the midrange in a three way system, and left the tweeter on, cymbal crashes wouldn't have much impact ,,,, lots of shimmer, even loud sounding shimmer, but I think the real punch happens below 4K.

So you have people in your house that go around pulling on speaker wire and knocking your equipment around? Anything can happen when chasing a banned cat out of the music room -- hopefully before she sharpens her claws on a speaker, bats a pulsing subwoofer, runs over the power amps, or hangs by the cables!

rplace: "It is never too loud If it's too loud, you are too old." An interesting formulation, but ..... all my life, starting when I was about 14 with my first High Fidelity system (the stereo Lp came out about 2 years later), I was told "Turn it down!" .... by parents, older relatives, and all those old people in general. My peers and I found that our parents would not believe how loud our orchestra got during Pictures at an Exposition until we invited them to a concert and they could hear for themselves. Old people! The exact same thing happened when we dragged them to the gloriously loud, clean & authoritative 6 channel magnetic stereo 70 mm Todd-AO version of Around the World in 80 Days (1956) -- they broke out in somewhat immature giggles, because they knew we were right. They never experienced the old Fillmore auditorium's rock bands of the late 60's, but they would have been horrified. It figures that the oldest person there probably was Allen Ginsberg, in his 40s, and sometimes naked. So I thought I understood the age factor, until I became an old geezer. My hearing is still good (despite the Fillmore). Some 50 years have gone by since the first instance listed above, and I have been repeatedly shocked when my music loving daughter (in her early '20s) and her friends ask me to "Turn it down!" Go figure.

colterphoto1: " What evidence? Let's see and hear the "evidence." " Yes, indeed, and how was the evidence collected? As Dr. Who may have suggested, we may see a lot of "correlation but not causation" error in our conclusions. Even when restricting ourselves to the same speakers (all with the same supertweeters capable of going far above 20K), and using filters to cut off response just above 20K, in one condition, and with the kind of procedures discussed below, we still wouldn't know if something about the damn filters was causing the difference. Of course, we could build in "type of filter" as yet another analyzable independent variable in our multivariate analysis, but what if they all have artifacts? To try to answer the 20K question, and many other questions in audio, I would like to see double blind experiments set up, even though some of the "Golden Ears" are allergic to research of this type. In the case of the "above 20K" question, we might ask three or more questions: Does content (if any) above 20K Hz make a difference to groups of participants who are randomly assigned to "cut off above 20K" v.s. "no cut off" listening groups? This could be a "between by within" experiment with each individual hearing a collection of music twice, but half (randomly determined) hearing the cut-off version first, with the others hearing the full range version first. They would need to use rating scales already shown to be sensitive to audio quality differences. They could rate on several response measures, such as preference, realism, musicality, what-have-you. Does content (if any) above 20K Hz make a difference to groups of "special people" -- musicians, audiophiles, people who earn their living playing or recording music -- who are randomly assigned to "cut off above 20K" v.s. "no cut off" listening groups? The experimental design would be the same as above. Does content (if any) above 20K Hz make a difference to a given individual -- YOU, for instance, when exposed to a series of "cut off above 20K" v.s. "no cut off" blind trials? Similar design. The often heard objections to A-B testing (e,g,, the brain is functioning differently when making immediate comparisons -- judging is different than relaxed but attentive listening) would still be a problem, but might be partly overcome by building in the variable of "type of auditioning," with levels of "immediate judgments " vs "end of prolonged listening session judgments." This might be done in the participants' homes over several days, but would be hard to set up, and full of problems, but in the "prolonged listening" condition the participant, blinded to whether the filter is on, could listen as usual for several sessions, then fill out a dated card on leaving the music room. The equipment would have to automatically record whether the filter was in "pass through" or "cut off" on that particular day.

All that I wrote in my last post applies to all standard Khorns, but not to the 60 th Anniversary model, which has a sealed back. Elsewhere on the forum people have talked about sealing the backs of their older Khorns. Even with the 60th and its sealed back, one of the Klipsch engineers commented that the Khorn should be at least near a corner to exploit corner loading, Jubs also. I would think that the best for a sealed back Khorn would be in a corner, but toed as you like it.

I'm not sure what you mean, but you can only toe-in Khorns when they are snug in -- nearly sealed in with a rubber gasket -- and completely touching some kind of firm corner --- either an artificial corner that you turn, but keep sealed to the Khorn at all times, or a natural corner which would mean that the tweeter would be on the 45 degree line. In either case, you should probably sit pretty much on axis. When PWK introduced the idea of the artificial corner he said it would produce 90% of the performance, Klipsch has always said that you need 48" of uninterupped wall on both sides, measuring from the apex of the corner itself .... recently they have started to measure from the Khorn's side grills (but what part of the side grill?), and that specification may, or may not, be 25" .... I forget. In any case, you need that expanse on both sides, so any toe-in other than 45 degrees is not possible without movable artificial corners. One editorial review (in High Fidelity mag, I think) implied that Khorns work better with 5 feet of uninterrupted wall on bothe sides coming out from the corner. I have seen them (in an irresponsible dealership) with only a little wall space ,,, they sounded much worse than mine, which have corner walls extending 17 feet in one direction, and about 23 in the other!

"You know, a good audio connector has yet to be invented. Now that I'm retired maybe I can come up with one.............." Amen. While you are at it, please come up with Home Theater connectors better than those HDMI things! And get rid of RCA plugs! And let's put an end to wire nuts in lighting, etc. 90% serious!

Your overall room size is fine for K-horns. I have never heard a better all-around speaker (but I haven't heard the Klipsch Jubilee or the Palladium). A somewhat higher ceiling MIGHT be better, but you could consider putting a small Sonex foam pad with anechoic wedges (or other similar) at each of the two first reflection points on the ceiling. The point is to keep the tweeter sound from being returned to your ears (by reflection from the ceiling) too soon, since the primary tweeter sound is arriving before the midrange anyway (See the Heyser article c 1986). Don't put too much absorption in the room, though. Khorns like diffusion, and a good reverberant tail. Are the two corners you would use good and solid? I don't know if this would help much, but if someone lives on the other side of that particular wall, you MIGHT be able reduce the amount of bass hammering on that wall by using artificial corners that are moved out into the room a little bit. Make them out of 3/4 ply on both sides of 2 x 4s or 2 x 6s that are 16 " o.c., or, better, 8"o.c.. If you get plywood with hardwood veneer, they could be nicely stained to match the Khorns. Several forum members use them to allow the Khorns and artificial corners to be toed-in exactly right amount so that the person in the center chair is looking straight down the throats of the tweeters. Your current speakers may put out just as much (or more) bass as Khorns at certain frequencies, and many subwoofers certainly would. The advantage of the Khorn is not more, smoother, or more extended bass, but bass cleanliness, effortlessness. low distortion, and high enough efficiency to flap you pants legs from across the room on Fanfare for the Common Man. For some movies you may need a sub anyway. Just for ducks, you might want to look into your local sound ordinances. They may list a certain maximum dB level at the border of your property (in your case, on the other side of the your walls and out in the hall). If you do, be sure to get a printable copy that specifies the weighting. Staying within the legal limit won't keep the neighbors from calling the police, over and over again. One of the reasons we moved from an apartment into a house was to be able to play our music the way it was written. Some people have mental problems if they can even hear someone else's music. Others go with the flow. When we lived in Berkeley, CA, we put up with Knights in White Satin, on infinite repeat, at the wee hours of the morning, just about every night.. We finally found a vantage point that would allow us to look into the guy's window. There he was, dancing and leaping around in a white robe. A few months later it stopped. Perhaps the guys who came for him were wearing white, as well.

O.K., some of this still is not consistently clear to me. In one of the Dope From Hope issues, PWK opined that one needs 115 dB at one's ears to simulate a full symphony orchestra's peaks. I have heard other estimates as high as 125 dB, plausible for rim shots and the like. In another Dope From Hope (January 1977, Keele, revised November 1980), Klipschorns, one of the most efficient speakers in the world (then rated at 104 dB / 8 Ohms / 2.83v / 1 m), in a 3,000 cu. ft, room, were said to emit the following SPLs. One Klipschorn only, in case a powerful instrument was positioned on the far right or left: 1W would produce 97 dB out in the room, presumably in the listening area (as opposed to @ 1 M, where we would get about 104 dB) 63 W would produce 115 dB and .... The W for 125 dB is off the chart, which ends at 375 W (@122.7 dB). I presume that even if "dynamic power" or "peak power" that is available for only an instant is what is needed to produce these extreme peaks, we would still need the power in watts specified in the chat, but only for that instant. Wouldn't that mean that for an ittybitty mini-micro-nanosecond we would need > 375 W for one of those 125 dB peaks, and my 150 W amp (really more like 120 W RMS @ , .707 x 171 W clipping point) would clip? Or is it implied that the peak is so brief that the peak would pass without clipping? And that the peak is so brief that the speakers won't blow either? Obviously, this brings me back to my original question of several posts ago. Since I can easily produce the 63 W needed to produce 115 dB, do the Klipsch charts really mean (as they seem to state) that my amp will pass very, very short peaks @ 10 dB higher (125 dB!!) without clipping? Is it that the strain on the power supply, etc., etc. is too brief to cause the amp to run out of steam and the waveform flatten?

Who knows what year EV went over to the new 5 watt continuous power handling diaphragm in the T 35 tweeter (with the copper beryllium flat wire leads), as opposed to the older 2 wt continuous model? Anyone have a dated brochure that mentions the 2 wt continuous? I'm pretty sure they had switched over by 1984. I'm interested in the power handling of the tweeters (1980) we took out of our old Klipschorns, and that of a set of T35s (1977) we are currently using on the TV in our bedroom (sound amazingly good!) Thanks

Don Richard, Hashimoto, DeanG and everyone else, O.K., if one good approach (Deans?) is to not overdrive amplifiers -- to avoid clipping in the first place (or have it happen a very small percentage of the time and for very short durations) -- then I'm not at all clear on how to predict the multiple of some measured figure --- say RMS power -- at which actual clipping will occur. There is a garble in my head, the field, or both. I am aware that this came up on the forum before, in 2006, but I don't think that Don Richard and Hashimoto were posting then, and I'm curious to know what they (and others) would make of the following: In the old days, before solid state became popular, it was often assumed that "peak power" was twice "rated power," and the better companies used the RMS figure as their "rated power." This rule of the thumb seemed to disappear in the 1960s. Was it well founded? Klipsch published an amplifier power rating table, called "Amplifier Power to Drive Klipsch Speakers," showing the SPLs various Klipsch speakers would produce in a 3,000 cubic foot room, with amps of various amplifier power ratings -- specified as continuous average at 8 Ohms." This table went out over Keele's name in 1977, then was revised very slightly and went out a few years later with no author listed. In BOTH versions it was stated that peaks 10 dB above the continuous average rating will pass without clipping. This was well into the Solid State era -- solid state became very popular in the mid '60s, although McIntosh hadn't thrown in the towel at that early time. Did they mean 10 dB above average for both Solid State and Tube amps? Have we ever heard this figure anywhere else? We often see "dynamic headroom at 8 Ohms" listed as about 3 dB. In various articles I have seen, Tube peak power is listed as 5 to 6.25 times that of Solid State peak power, for amps having the same power rating (RMS? Continouos Average @ 8 Ohms?), always with the admmission that there will be a great amount of distortion at this Tube peak power, but that it will be much more pleasent distortion than Solid State distortion. How does all this information fit together?

Did you say why you don't want to use subwoofer? A common complaint is that subs tend to sound imprecise and "floppy" compared to the best Klipsch bass. I got around that (most of the time) by cutting in my Klipsch RSW-15 sub at 40 Hz with the Klipschorns running full range (Khorns properly cornered stay pretty clean & tight even below the point that they begin to attenuate seriously, which is at about 35 Hz). The 40 Hz cut-in sounds far better than 80 or higher. Sometimes, for some music, I turn the sub way down so it just provides a hint of extenson to 20 Hz, and for other music & movies I run it flat, relative to the Khorns. You might get great results with a Cornwall and a sub of recent design ... I understand that the newer Klipsch top-of-the-line subs are "faster." Be sure to check to make sure that any candidate will match or exceed the sensitivity / efficiency of whatever front speakers you consider.

"... in the end I preferred the huge drawbacks of the Sony. " Hornylicious, Your complaint is utterly fascinating. I'm wondering if the true dynamics, authority and almost dangerous sounding power and energy that are often NOT captured in our recordings (due to inadequacies in micing or the media and equipment) are somehow compensated for by certain kinds of (probably nameless) distortion. Take that distortion away, and the music is flatter, less complex, less cortically arousing. I have noticed that some "high end" audiophile equipment sounds bland, compared to the upper middle occupied by our beloved Klipshorns ......... But you have to feed them with something exciting. Perhaps the subtle distortion (not necessarily IM, Harmonic, TIM, or any of the forms we measure) in your older, cheaper CD player simulated the uncaptured cues we would get in loud & live music. Here, per\haps, is another side of the same coin. In comparing the same recordings on my old vinyl stereo Lps (with a variety of older Ortophon cartridges) and on CD, I found that, in addition to the usual differences (the vinyl seems warmer anf\d more "there," but sometimes not quite as clear) I have noticed that there was a subtle and quite musical sense of strain, especially in the climaxes, on the vinyl that tends to be missing in the CD versions. I seem to like this strain. In playing in a live orchestra I have heard a similar (but not identical) sound when the French horns, cello and basses are playing at the top of their loudness range. I have never heard this in a digital recording, but, again, the sense of strain that I attribute to the phono cartridge/ record/cutter system puts back some excitement. It certainly makes the music sound more complex. Complexity is one of Berlyne's arousal increasing variables.

Thanks LarryC, BEC, and greg!

LarryC, By pipe insulation, I assume you mean the curved (nearly cylindrical) insulation meant to go around pipes?? I'm considering trying this, after removing the "rubber runner" (sheet rubber meant to go under rugs) that I put on just the tail piece only (at Klipsch's recommendation) in 1982. I would be replacing the rubber runner only to make the thickness of the new, pipe insulation gasket the same on the tail piece as the pipe insulation that would then be placed on the horizontally oriented "home plate" top of the bass bin. I'm not sure how you put it on. Did you slice the pipe insulation along its length to make it less than 360 degrees, more like 90 degrees, then glue it on, so it would stay in place until it was squeezed against the wall? "I changed mine temporarily, but didn't like it as much and changed back to AK-4's." What was it you liked better about the sound of the AK4s over the 5s? Thanks!

RE: IMAX sound, thinness, harshness, & lack of bass impact. Upper midrange loudness and impact without bass impact makes the sound seem inappropriately loud and thin, rather than fittingly and excitingly loud, IMO. Even though most of today's cinemas have improved response from 40 Hz down to below 20 Hz, in many cases they -- perhaps especially IMAX theaters -- don't have the overwhelming impact that the typical 70 mm theater sound system used to have between about 40 Hz and about 300 Hz. The IMAX theaters I have been to on the West coast (LA, San Francisco, Seattle) all presented a before-the-movie demo in which they bragged about the sound, among other aspects of the process. They turned on the lights behind the screen so the audience could see the speakers ... there were no "wings" -- big baffle boards like the ones Altec was famous for installing -- next to the speakers. The baffle boards installed in most or all 70 mm, &/or Cinerama theaters that were equipped in the 1950s and '60s helped reinforce bass response, and IMO, impact. The cabinets in the IMAX were small (looked like JBLs), and just hanging out there in space. True, the wall wasn't very far behind them, but the speakers were not anywhere near flush mounted either! Flush mounting can add as much as 5 or 6 dB at 40 Hz, which is an appreciable, even dramatic, amount, and the huge stud reinforced plywood "wings" in some theaters simulate flush mounting. I understand that the nowadays the subs are thought to do the job, but I can't see how they can move as much air above 40Hz as a big horn coupled to a big baffle board. In those days, an alternative set up with JBL speakers installed by Ampex for 70 mm Todd-AO, was to have the speaker cabinets themselves extend solidly far to the sides, the middle part being a bass horn, and the outer part serving as a baffle and reflex chamber... even some of these had additional baffle boards to the side, if there was available space between these oversize cabinets (in those days 70 mm had 5 channels behind a huge curved screen, plus surround in the theater). We have all learned to be suspicious of "improvements" like digital over analog, and solid state over tubes ... there are both advantages and disadvantages to these changes, and some valuable characteristics are lost. I think the movie industry may have made a mistake in relying on the now available subwoofers to do the job -- above 40 Hz -- that big horns with baffle augmentation used to do. The clean, effortless, sheer and utter impact of the sound in the old 70 mm theaters -- at least some of the time -- is hard to simulate today. Here are examples of when this impact was and was not present. The thunderstorm and earth tremors during the crucifixion scene in Ben-Hur shook the concrete floor, created gusts of wind in the theater, and to my ears these effects were much louder than anything I've heard in IMAX, yet undistorted (there is distortion on the DVD, and it's dynamically compressed to boot -- hope they do better on the Blu-ray). The ramming of one galley ship into another earlier in the same movie, with wood splintering, caused many in the audience to sway away from the impact, and the bass and lower midrange sounded "fast," as audiophiles say. The musical score sometimes got extraordinarily loud, but was always rich and clean. On the other hand, Lawrence of Arabia, as great as that movie was, had comparatively little impactive sound, so 70 mm in a theater equipped for that medium was not a guarantee of impactive sound. The Altec variety of the wings I am talking about are clearly visible in the thread on theater sound CONVERGENCE either started, or was the main contributor to, about a year ago.

Thanks, Roger. What is the shelf life of caps before they are ever charged up or used at all?

Two related questions: 1) What is the horizontal wall seal on the newer Klipschorns, and where does it go exactly? I use a vertical seal on the tailboard, but I'm in the dark about a horizontal one. 2) On the Klipschcorner.com Klipschorn Timeline they say that the AK-5 network was "... introduced to compensate for the improvement in low frequency response resulting from the addition of a horizontal wall seal..." I opted not to convert my AK4s to AK5s (by clipping a wire in the network) because I was told the AK5 cut back the tweeter "to let you hear a little more midrange," and I didn't want to lose any treble, and I didn't want the midrange any higher (relative to the treble). But from what K.Corner seems to be saying, it is conceivable that the AK5 actually turns up the tweeter a bit, to compensate for "Improved" low frequency response (perhaps a further lessening of the dips that bad seals encourage). A slight increase in the tweeter level might be attractive. Does anyone know the details of how the change from AK4 to AK5 affected he response? Thanks

Do caps in a crossover network go bad (get resistive, dry out, change value, whatever) faster when the speaker is being used, or when it is in storage? Does use or disuse affect them at all?